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Sample records for bear ursus arctos

  1. Management of brown bears (Ursus arctos) in Europe.

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    Klenzendorf, Sybille A.

    1997-01-01

    Management of Brown Bears (Ursus arctos) in Europe. Sybille A. Klenzendorf (Abstract) Successful conservation of brown bears (Ursus arctos) in Europe is associated with public acceptance of damages caused by bears. Recent increases in sheep depredation and beehive damage in central Austria resulted in the deaths of two bears there. Since bear numbers are low in most European populations, alternatives to the elimination of problem bears associated with dam...

  2. First report of Taenia arctos (Cestoda: Taeniidae) from grizzly (Ursus arctos horribilis) and black bears (Ursus americanus) in North America.

    Science.gov (United States)

    Catalano, Stefano; Lejeune, Manigandan; Verocai, Guilherme G; Duignan, Pádraig J

    2014-04-01

    The cestode Taenia arctos was found at necropsy in the small intestine of a grizzly (Ursus arctos horribilis) and a black bear (Ursus americanus) from Kananaskis Country in southwestern Alberta, Canada. The autolysis of the tapeworm specimens precluded detailed morphological characterization of the parasites but molecular analysis based on mitochondrial DNA cytochrome c oxidase subunit 1 gene confirmed their identity as T. arctos. This is the first report of T. arctos from definitive hosts in North America. Its detection in Canadian grizzly and black bears further supports the Holarctic distribution of this tapeworm species and its specificity for ursids as final hosts. Previously, T. arctos was unambiguously described at its adult stage in brown bears (Ursus arctos arctos) from Finland, and as larval stages in Eurasian elk (Alces alces) from Finland and moose (Alces americanus) from Alaska, USA. Given the morphological similarity between T. arctos and other Taenia species, the present study underlines the potential for misidentification of tapeworm taxa in previous parasitological reports from bears and moose across North America. The biogeographical history of both definitive and intermediate hosts in the Holarctic suggests an ancient interaction between U. arctos, Alces spp., and T. arctos, and a relatively recent host-switching event in U. americanus. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  3. Genetic relationships of extant brown bears (Ursus arctos) and polar bears (Ursus maritimus).

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    Cronin, Matthew A; MacNeil, Michael D

    2012-01-01

    Polar bears (Ursus maritimus) and brown bears (Ursus arctos) are closely related species for which extensive mitochondrial and nuclear phylogenetic comparisons have been made. We used previously published genotype data for 8 microsatellite DNA loci from 930 brown bears in 19 populations and 473 polar bears in 16 populations to compare the population genetic relationships of extant populations of the species. Genetic distances (Nei standard distance = 1.157), the proportion of private alleles (52% of alleles are not shared by the species), and Bayesian cluster analysis are consistent with morphological and life-history characteristics that distinguish polar bears and brown bears as different species with little or no gene flow among extant populations.

  4. EVALUATION OF CARDIOLOGIC FUNCTIONS IN CAPTIVE EURASIAN BROWN BEARS (URSUS ARCTOS ARCTOS) IN TURKEY.

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    Cihan, Huseyin; Yilmaz, Zeki; Aytug, Nilufer

    2016-03-01

    The aim of this study was to evaluate the cardiac functions in healthy Eurasian brown bears (Ursus arctos arctos) living in a seminatural area during their active season. Twelve clinically healthy brown bears were selected based on their normal physical examination, hematologic, and serum biochemistry results. These bears were divided into two groups based on age; subadult (bears. Notching of QRS complexes and peaked T wave were also observed in both groups. Left ventricular diameter at systole and diastole in adult bears was wider (P bears. Subadult bears had reduced aortic diameter compared to adult bears (P bears.

  5. Questioning current practice in brown bear, Ursus arctos, conservation in Europe that undervalues taxonomy

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    Gippoliti, S.

    2016-07-01

    The present paper highlights problems associated with the currently–accepted taxonomy of brown bear, Ursus arctos, and their consequences for conservation at the European level. The enormous morphological variability within Ursus arctos is not acknowledged in current taxonomy and conservation practice. Seven major clades are recognized in Ursus arctos by molecular researchers, and although Western Europe maintains most of the populations belonging to the relict Clade 1 brown bear lineage, no reference to this is made in current conservation policy. Furthermore, the tiny population of Apennine brown bears, characterized by unique skull morphology, is not even recognized as a distinct ESU (evolutionari significant unit) by current European legislation, nor is it included in the IUCN Red List. This may have serious consequences as brown bear conservation in Western Europe has been mainly based on restocking and reintroduction programs. (Author)

  6. Gastric dilatation and volvulus in brown bear (Ursus arctos)

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    Marinković, Darko; Özvegy, Jòzsef; Aničić, Milan; Vučićević, Ivana; Nešić, Slađan; Kukolj, Vladimir

    2016-01-01

    Gastric dilatation and volvulus is a life-threatening condition characterized by rapid accumulation of food and gases that cause displacement and distension of the stomach. The large and giant, deep-chested breeds of dogs are at higher risk for developing the gastric dilatation and volvulus. Uncommonly, it can also develop in cats, but it is also described in free-range polar bears. A case of gastric dilatation and volvulus in a brown bear (Ursus arctos) is described in this paper. This case ...

  7. Grizzly bears (Ursus arctos horribilis) and black bears (Ursus americanus) prevent trabecular bone loss during disuse (hibernation).

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    McGee-Lawrence, Meghan E; Wojda, Samantha J; Barlow, Lindsay N; Drummer, Thomas D; Castillo, Alesha B; Kennedy, Oran; Condon, Keith W; Auger, Janene; Black, Hal L; Nelson, O Lynne; Robbins, Charles T; Donahue, Seth W

    2009-12-01

    Disuse typically causes an imbalance in bone formation and bone resorption, leading to losses of cortical and trabecular bone. In contrast, bears maintain balanced intracortical remodeling and prevent cortical bone loss during disuse (hibernation). Trabecular bone, however, is more detrimentally affected than cortical bone in other animal models of disuse. Here we investigated the effects of hibernation on bone remodeling, architectural properties, and mineral density of grizzly bear (Ursus arctos horribilis) and black bear (Ursus americanus) trabecular bone in several skeletal locations. There were no differences in bone volume fraction or tissue mineral density between hibernating and active bears or between pre- and post-hibernation bears in the ilium, distal femur, or calcaneus. Though indices of cellular activity level (mineral apposition rate, osteoid thickness) decreased, trabecular bone resorption and formation indices remained balanced in hibernating grizzly bears. These data suggest that bears prevent bone loss during disuse by maintaining a balance between bone formation and bone resorption, which consequently preserves bone structure and strength. Further investigation of bone metabolism in hibernating bears may lead to the translation of mechanisms preventing disuse-induced bone loss in bears into novel treatments for osteoporosis.

  8. MEDULLOBLASTOMA IN A GRIZZLY BEAR (URSUS ARCTOS HORRIBLIS).

    Science.gov (United States)

    Mitchell, Jeffrey W; Thomovsky, Stephanie A; Chen, Annie V; Layton, Arthur W; Haldorson, Gary; Tucker, Russell L; Roberts, Gregory

    2015-09-01

    A 3-yr-old female spayed grizzly bear (Ursus arctos horribilis) was evaluated for seizure activity along with lethargy, inappetence, dull mentation, and aggressive behavior. Magnetic resonance (MR) examination of the brain revealed a contrast-enhanced right cerebellar mass with multifocal smaller nodules located in the left cerebellum, thalamus, hippocampus, and cerebrum with resultant obstructive hydrocephalus. Cerebrospinal fluid analysis revealed mild mononuclear pleocytosis, with differentials including inflammatory versus neoplastic processes. Blood and cerebrospinal fluid were also submitted for polymerase chain reaction and agar gel immunodiffusion to rule out infectious causes of meningitis/encephalitis. While awaiting these results, the bear was placed on steroid and antibiotic therapy. Over the next week, the bear deteriorated; she died 1 wk after MR. A complete postmortem examination, including immunohistochemisty, revealed the cerebellar mass to be a medulloblastoma. This is the only case report, to the authors' knowledge, describing a medulloblastoma in a grizzly bear.

  9. One of the last wild brown bears (Ursus arctos) in the Netherlands (Noordwijk)

    NARCIS (Netherlands)

    van der Plicht, Johannes; Kuijper, Wim J.; Verheijen, Ivo K.A.; Ramcharan, André; Kolfschoten, T. van

    2016-01-01

    Early in 2016, bones of a left front leg of a brown bear (Ursus arctos) were found in the dunes between Noordwijk and Zandvoort (Amsterdamse Waterleidingduinen - Amsterdam Water Supply Dunes). The stratigraphical composition of the find horizon was identified as the old surface (palaeosoil) of the

  10. Chewing lice Trichodectes pinguis pinguis in Scandinavian brown bears (Ursus arctos

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    Núria Fandos Esteruelas

    2016-08-01

    Full Text Available In April 2014 and 2015, we noted localized alopecia (neck, forelimbs, and chest and hyperpigmentation on two adult brown bears (Ursus arctos captured in central-south Sweden for ecological studies under the Scandinavian Brown Bear Research Project. In spring 2015, a brown bear was shot because of human-wildlife conflict in the same region. This bear also had extensive alopecia and hyperpigmentation. Ectoparasites were collected from the affected skin areas in all three individuals and preserved in ethanol for identification. Based on morphological characteristics, the lice were identified as Trichodectes spp. and Trichodectes pinguis pinguis. To our knowledge, these are the first reported cases of chewing lice in free-ranging brown bears in Scandinavia.

  11. Acquired arteriovenous fistula in a grizzly bear (Ursus arctos horribilis).

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    Tuttle, Allison D; MacLean, Robert A; Linder, Keith; Cullen, John M; Wolfe, Barbara A; Loomis, Michael

    2009-03-01

    A captive adult male grizzly bear (Ursus arctos horribilis) was evaluated due to multifocal wounds of the skin and subcutaneous tissues sustained as a result of trauma from another grizzly bear. On presentation, one lesion that was located in the perineal region seemed to be a deep puncture with purple tissue protruding from it. This perineal wound did not heal in the same manner or rate as did the other wounds. Twenty-five days after initial detection, substantial active hemorrhage from the lesion occurred and necessitated anesthesia for examination of the bear. The entire lesion was surgically excised, which later proved curative. An acquired arteriovenous fistula was diagnosed via histopathology. Arteriovenous fistulas can develop after traumatic injury and should be considered as a potential complication in bears with nonhealing wounds.

  12. Spinal spondylosis and acute intervertebral disc prolapse in a European brown bear (Ursus arctos arctos : clinical communication

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    W.M. Wagner

    2005-06-01

    Full Text Available A 22-year-old male European brown bear (Ursus arctos arctos was presented to the Onderstepoort Veterinary Academic Hospital after an acute onset of hind limb paralysis 4 days earlier. Previous radiographs revealed marked degenerative joint disease of the stifles, tarsi and digits. The clinical findings were consistent with acute disc prolapse. Lateral radiographs of the entire vertebral column were made as well as ventrodorsal pelvic radiographs. The latter were within normal limits. The vertebral column revealed multiple lesions consistent with chronic and acute disc herniations. Lateral compression of the caudal lumbar nerve roots could not be ruled out. Owing to multiple significant findings of the vertebral column and the poor prognosis for full recovery after surgery, the bear was euthanased. The diagnosis of an acute disc prolapse and multiple chronic disc herniations was confirmed on necropsy.

  13. Application of brown bear (Ursus arctos) records for retrospective assessment of mercury.

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    Solgi, Eisa; Ghasempouri, Seyed Mahmoud

    2015-01-01

    Because mercury (Hg) is released into the atmosphere, wildlife living in habitats located far from point sources of metal may still be at risk. Mercury accumulation, previously considered a risk for aquatic ecosystems, is also found in many wildlife terrestrial species. The aim of the present study was to examine total Hg concentrations in the brown bear (Ursus arctos) by measurement of metal in hair from museum collections in Iran. Another objective of this investigation was to characterize the risk of Hg exposure in bears in several parts of Iran. Brown bear (Ursus arctos) hair samples (n = 35) were collected from 14 provinces in Iran for analysis of Hg contamination, performed using an advanced mercury analyzer (model Leco 254 AMA, USA) according to ASTM standard D-6722. Total Hg levels in Iranian bears from all areas ranged from 115.81 to 505.82 μg/kg, with a mean of 193.39 ng/g. Mercury concentrations in brown bear hair from different provinces in Iran were as follows in descending order: Khorasan Razavi > Esfahan > Khozestan > Yazd > Lorestan > Charmahalva Bakhtiari > Bushehr > Mazandaran > Markazi > Tehran > Ardebil > Gilan > East Azerbaijan. The highest content of Hg was found in the south (206.62 ± 31.95 ng/g), whereas the lowest levels were detected in the west (167.71 ± 32.97 ng/g). Overall total Hg content in bear hair was below harmful levels for this species. A decreasing trend was noted in the period 1986-2006, which may be mainly due to reduction of global Hg emissions. Data suggest that food habits and habitat are two important factors that influence Hg accumulation in bears.

  14. Disseminated pleomorphic myofibrosarcoma in a grizzly bear (Ursus arctos horribilis).

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    Mete, A; Woods, L; Famini, D; Anderson, M

    2012-01-01

    The pathological and diagnostic features of a widely disseminated pleomorphic high-grade myofibroblastic sarcoma are described in a 23-year-old male brown bear (Ursus arctos horribilis). Firm, solid, white to tan neoplastic nodules, often with cavitated or soft grey-red necrotic centres, were observed throughout most internal organs, subcutaneous tissues and skeletal muscles on gross examination. Microscopically, the tumour consisted of pleomorphic spindle cells forming interlacing fascicles with a focal storiform pattern with large numbers of bizarre polygonal multinucleate cells, frequently within a collagenous stroma. Immunohistochemistry, Masson's trichrome stain and transmission electron microscopy designated the myofibroblast as the cell of origin. This is the first case of a high-grade myofibrosarcoma in a grizzly bear. Published by Elsevier Ltd.

  15. Helminths of brown bears (Ursus arctos) in the Kola Peninsula.

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    Bugmyrin, S V; Tirronen, K F; Panchenko, D V; Kopatz, A; Hagen, S B; Eiken, H G; Kuznetsova, A S

    2017-06-01

    We present data on the species composition of helminths in brown bears (Ursus arctos) from the Murmansk Region, Russia. The absence of any information about helminths of brown bear in the region necessitated the conduct of these studies. Samples were collected in 2014 and 2015 in the southern part of the Kola Peninsula from the White Sea coastal habitats. Annually, in the study area, 1-3 bears are legally hunted and biological samples for examination are very difficult to obtain. Therefore, we used fecal samples. We studied 93 feces and identified parasite eggs identified in 43 of them by morphometric criteria. The surveys revealed eggs of the following helminths: Dicrocoelium sp., Diphyllobothrium sp., Anoplocephalidae, Capillariidae, Baylisascaris sp., Strongylida 1, and Strongylida 2. These results represent the first reconnaissance stage, which allowed characterizing the taxonomic diversity and prevalence of parasites of brown bears of the Kola Peninsula.

  16. First case of Trichodectes pinguis (Phthiraptera: Ischnocera: Trichodectidae) on a Bear (Ursus arctos) in Turkey.

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    Dik, Bilal; Orunç Kılınç, Özlem

    2015-12-01

    This study was conducted to provide morphological characters of Trichodectes pinguis Burmeister, 1838 that was found on a European brown bear (Ursus arctos Linnaeus) that was found injured in the Van province, eastern Turkey. Three lice specimens were collected from the bear, and they were identified as T. pinguis. The morphological characteristics of this species were provided in this study. T. pinguis was reported for the first time in Turkey.

  17. Role of brown bears (Ursus arctos) in the flow of marine nitrogen into a terrestrial ecosystem.

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    Grant V. Hilderbrand; Thomas A. Hanley; Charles T. Robbins; Charles C. Schwartz

    1999-01-01

    We quantified the amount, spatial distribution, and importance of salmon (Oncorhynchus spp.)-derived nitrogen (N) by brown bears (Ursus arctos) on the Kenai Peninsula, Alaska. We tested and confirmed the hypothesis that the stable isotope signature (δ15N) of N in foliage of white spruce (

  18. Exertional myopathy in a grizzly bear (Ursus arctos) captured by leghold snare.

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    Cattet, Marc; Stenhouse, Gordon; Bollinger, Trent

    2008-10-01

    We diagnosed exertional myopathy (EM) in a grizzly bear (Ursus arctos) that died approximately 10 days after capture by leghold snare in west-central Alberta, Canada, in June 2003. The diagnosis was based on history, post-capture movement data, gross necropsy, histopathology, and serum enzyme levels. We were unable to determine whether EM was the primary cause of death because autolysis precluded accurate evaluation of all tissues. Nevertheless, comparison of serum aspartate aminotransferase and creatine kinase concentrations and survival between the affected bear and other grizzly bears captured by leghold snare in the same research project suggests EM also occurred in other bears, but that it is not generally a cause of mortality. We propose, however, occurrence of nonfatal EM in grizzly bears after capture by leghold snare has potential implications for use of this capture method, including negative effects on wildlife welfare and research data.

  19. Winter blood values of selected parameters in a group of non-hibernating captive brown bears (Ursus arctos).

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    Sergiel, A; Bednarski, M; Maślak, R; Piasecki, T; Huber, D

    2015-01-01

    Bears undergo some significant changes reflected in blood values during winter season. The most significant are reduced urea and increased creatinine, by some authors considered to be physiological indicators of hibernation. Studied group of six captive brown bears (Ursus arctos) showed decreased activity in winter but were accepting food and walked outdoors. Blood parameters assessed in February 2011 revealed mean values of leucocytes and neutrophils as significantly lower, and creatinine significantly increased compared to captive and free living bears sampled during other seasons when bears are active.

  20. Platelet function in brown bear (Ursus arctos compared to man

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    Särndahl Eva

    2010-06-01

    Full Text Available Abstract Background Information on hemostasis and platelet function in brown bear (Ursus arctos is of importance for understanding the physiological, protective changes during hibernation. Objective The study objective was to document platelet activity values in brown bears shortly after leaving the den and compare them to platelet function in healthy humans. Methods Blood was drawn from immobilized wild brown bears 7-10 days after leaving the den in mid April. Blood samples from healthy human adults before and after clopidogrel and acetylsalicylic acid administration served as control. We analyzed blood samples by standard blood testing and platelet aggregation was quantified after stimulation with various agonists using multiple electrode aggregometry within 3 hours of sampling. Results Blood samples were collected from 6 bears (3 females between 1 and 16 years old and from 10 healthy humans. Results of adenosine diphosphate, aspirin, and thrombin receptor activating peptide tests in bears were all half or less of those in humans. Platelet and white blood cell counts did not differ between species but brown bears had more and smaller red blood cells compared with humans. Conclusion Using three different tests, we conclude that platelet function is lower in brown bears compared to humans. Our findings represent the first descriptive study on platelet function in brown bears and may contribute to explain how bears can endure denning without obvious thrombus building. However, the possibility that our findings reflect test-dependent and not true biological variations in platelet reactivity needs further studies.

  1. Allelic diversity of the MHC class II DRB genes in brown bears (Ursus arctos) and a comparison of DRB sequences within the family Ursidae.

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    Goda, N; Mano, T; Kosintsev, P; Vorobiev, A; Masuda, R

    2010-11-01

    The allelic diversity of the DRB locus in major histocompatibility complex (MHC) genes was analyzed in the brown bear (Ursus arctos) from the Hokkaido Island of Japan, Siberia, and Kodiak of Alaska. Nineteen alleles of the DRB exon 2 were identified from a total of 38 individuals of U. arctos and were highly polymorphic. Comparisons of non-synonymous and synonymous substitutions in the antigen-binding sites of deduced amino acid sequences indicated evidence for balancing selection on the bear DRB locus. The phylogenetic analysis of the DRB alleles among three genera (Ursus, Tremarctos, and Ailuropoda) in the family Ursidae revealed that DRB allelic lineages were not separated according to species. This strongly shows trans-species persistence of DRB alleles within the Ursidae. © 2010 John Wiley & Sons A/S.

  2. De novo SNP discovery in the Scandinavian brown bear (Ursus arctos.

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    Anita J Norman

    Full Text Available Information about relatedness between individuals in wild populations is advantageous when studying evolutionary, behavioural and ecological processes. Genomic data can be used to determine relatedness between individuals either when no prior knowledge exists or to confirm suspected relatedness. Here we present a set of 96 SNPs suitable for inferring relatedness for brown bears (Ursus arctos within Scandinavia. We sequenced reduced representation libraries from nine individuals throughout the geographic range. With consensus reads containing putative SNPs, we applied strict filtering criteria with the aim of finding only high-quality, highly-informative SNPs. We tested 150 putative SNPs of which 96% were validated on a panel of 68 individuals. Ninety-six of the validated SNPs with the highest minor allele frequency were selected. The final SNP panel includes four mitochondrial markers, two monomorphic Y-chromosome sex-determination markers, three X-chromosome SNPs and 87 autosomal SNPs. From our validation sample panel, we identified two previously known parent-offspring dyads with reasonable accuracy. This panel of SNPs is a promising tool for inferring relatedness in the brown bear population in Scandinavia.

  3. Immobilization of grizzly bears (Ursus arctos) with dexmedetomidine, tiletamine, and zolazepam.

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    Teisberg, Justin E; Farley, Sean D; Nelson, O Lynne; Hilderbrand, Grant V; Madel, Michael J; Owen, Patricia A; Erlenbach, Joy A; Robbins, Charles T

    2014-01-01

    Safe and effective immobilization of grizzly bears (Ursus arctos) is essential for research and management. Fast induction of anesthesia, maintenance of healthy vital rates, and predictable recoveries are priorities. From September 2010 to May 2012, we investigated these attributes in captive and wild grizzly bears anesthetized with a combination of a reversible α2 agonist (dexmedetomidine [dexM], the dextrorotatory enantiomer of medetomidine) and a nonreversible N-methyl-d-aspartate (NMDA) agonist and tranquilizer (tiletamine and zolazepam [TZ], respectively). A smaller-than-expected dose of the combination (1.23 mg tiletamine, 1.23 mg zolazepam, and 6.04 µg dexmedetomidine per kg bear) produced reliable, fast ataxia (3.7 ± 0.5 min, x̄±SE) and workable anesthesia (8.1 ± 0.6 min) in captive adult grizzly bears. For wild bears darted from a helicopter, a dose of 2.06 mg tiletamine, 2.06 mg zolazepam, and 10.1 µg dexmedetomidine/kg produced ataxia in 2.5 ± 0.3 min and anesthesia in 5.5 ± 1.0 min. Contrary to published accounts of bear anesthesia with medetomidine, tiletamine, and zolazepam, this combination did not cause hypoxemia or hypoventilation, although mild bradycardia (bears during the active season. With captive bears, effective dose rates during hibernation were approximately half those during the active season. The time to first signs of recovery after the initial injection of dexMTZ was influenced by heart rate (Pgrizzly bears, especially during helicopter capture operations.

  4. Major decline in marine and terrestrial animal consumption by brown bears (Ursus arctos).

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    Matsubayashi, Jun; Morimoto, Junko O; Tayasu, Ichiro; Mano, Tsutomu; Nakajima, Miyuki; Takahashi, Osamu; Kobayashi, Kyoko; Nakamura, Futoshi

    2015-03-17

    Human activities have had the strongest impacts on natural ecosystems since the last glacial period, including the alteration of interspecific relationships such as food webs. In this paper, we present a historical record of major alterations of trophic structure by revealing millennium-scale dietary shifts of brown bears (Ursus arctos) on the Hokkaido islands, Japan, using carbon, nitrogen, and sulfur stable isotope analysis. Dietary analysis of brown bears revealed that salmon consumption by bears in the eastern region of Hokkaido significantly decreased from 19% to 8%. In addition, consumption of terrestrial animals decreased from 56% to 5% in western region, and 64% to 8% in eastern region. These dietary shifts are likely to have occurred in the last approximately 100-200 years, which coincides with the beginning of modernisation in this region. Our results suggest that human activities have caused an alteration in the trophic structure of brown bears in the Hokkaido islands. This alteration includes a major decline in the marine-terrestrial linkage in eastern region, and a loss of indirect-interactions between bears and wolves, because the interactions potentially enhanced deer predation by brown bears.

  5. Grizzly bear (Ursus arctos horribilis) locomotion: gaits and ground reaction forces.

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    Shine, Catherine L; Penberthy, Skylar; Robbins, Charles T; Nelson, O Lynne; McGowan, Craig P

    2015-10-01

    Locomotion of plantigrade generalists has been relatively little studied compared with more specialised postures even though plantigrady is ancestral among quadrupeds. Bears (Ursidae) are a representative family for plantigrade carnivorans, they have the majority of the morphological characteristics identified for plantigrade species, and they have the full range of generalist behaviours. This study compared the locomotion of adult grizzly bears (Ursus arctos horribilis Linnaeus 1758), including stride parameters, gaits and analysis of three-dimensional ground reaction forces, with that of previously studied quadrupeds. At slow to moderate speeds, grizzly bears use walks, running walks and canters. Vertical ground reaction forces demonstrated the typical M-shaped curve for walks; however, this was significantly more pronounced in the hindlimb. The rate of force development was also significantly higher for the hindlimbs than for the forelimbs at all speeds. Mediolateral forces were significantly higher than would be expected for a large erect mammal, almost to the extent of a sprawling crocodilian. There may be morphological or energetic explanations for the use of the running walk rather than the trot. The high medial forces (produced from a lateral push by the animal) could be caused by frontal plane movement of the carpus and elbow by bears. Overall, while grizzly bears share some similarities with large cursorial species, their locomotor kinetics have unique characteristics. Additional studies are needed to determine whether these characters are a feature of all bears or plantigrade species. © 2015. Published by The Company of Biologists Ltd.

  6. Molecular phylogeny and SNP variation of polar bears (Ursus maritimus), brown bears (U. arctos), and black bears (U. americanus) derived from genome sequences.

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    Cronin, Matthew A; Rincon, Gonzalo; Meredith, Robert W; MacNeil, Michael D; Islas-Trejo, Alma; Cánovas, Angela; Medrano, Juan F

    2014-01-01

    We assessed the relationships of polar bears (Ursus maritimus), brown bears (U. arctos), and black bears (U. americanus) with high throughput genomic sequencing data with an average coverage of 25× for each species. A total of 1.4 billion 100-bp paired-end reads were assembled using the polar bear and annotated giant panda (Ailuropoda melanoleuca) genome sequences as references. We identified 13.8 million single nucleotide polymorphisms (SNP) in the 3 species aligned to the polar bear genome. These data indicate that polar bears and brown bears share more SNP with each other than either does with black bears. Concatenation and coalescence-based analysis of consensus sequences of approximately 1 million base pairs of ultraconserved elements in the nuclear genome resulted in a phylogeny with black bears as the sister group to brown and polar bears, and all brown bears are in a separate clade from polar bears. Genotypes for 162 SNP loci of 336 bears from Alaska and Montana showed that the species are genetically differentiated and there is geographic population structure of brown and black bears but not polar bears.

  7. Persistent or not persistent? Polychlorinated biphenyls are readily depurated by grizzly bears (Ursus arctos horribilis).

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    Christensen, Jennie R; Letcher, Robert J; Ross, Peter S

    2009-10-01

    Major pharmacokinetic processes influencing polychlorinated biphenyl (PCB) accumulation in mammals include uptake, biotransformation, respiration, and excretion. We characterized some of the factors underlying PCB accumulation/loss by evaluating PCB concentrations and patterns in pre- and posthibernation grizzly bears (Ursus arctos horribilis) and their prey. The PCB congeners with vicinal meta- and para-chlorine unsubstituted hydrogen positions consistently showed loss both before and during hibernation, supporting the idea of a dominant role for biotransformation. Retention of all other studied congeners relative to that of PCB 194 varied widely (from bears do not eat or excrete. We estimate that grizzly bears retain less than 10% of total PCBs taken up from their diet. Our results suggest that for grizzly bears, depuration of PCBs via biotransformation is important (explaining approximately 40% of loss), but that nonbiotransformation processes, such as excretion, may be more important (explaining approximately 60% of loss). These findings, together with the approximately 91% loss of the persistent PCB 153 congener relative to PCB 194 in grizzly bears, raise important questions about how one defines persistence of PCBs in wildlife and may have bearing on the interpretation of food-web biomagnification studies.

  8. Physiological evidence for a human-induced landscape of fear in brown bears (Ursus arctos).

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    Støen, Ole-Gunnar; Ordiz, Andres; Evans, Alina L; Laske, Timothy G; Kindberg, Jonas; Fröbert, Ole; Swenson, Jon E; Arnemo, Jon M

    2015-12-01

    Human persecution is a major cause of mortality for large carnivores. Consequently, large carnivores avoid humans, but may use human-dominated landscapes by being nocturnal and elusive. Behavioral studies indicate that certain ecological systems are "landscapes of fear", driven by antipredator behavior. Because behavior and physiology are closely interrelated, physiological assessments may provide insight into the behavioral response of large carnivores to human activity. To elucidate changes in brown bears' (Ursus arctos) behavior associated with human activity, we evaluated stress as changes in heart rate (HR) and heart rate variability (HRV) in 12 GPS-collared, free-ranging bears, 7 males and 5 females, 3-11 years old, using cardiac-monitoring devices. We applied generalized linear regression models with HR and HRV as response variables and chest activity, time of day, season, distance traveled, and distance to human settlements from GPS positions recorded every 30 min as potential explanatory variables. Bears exhibited lower HRV, an indication of stress, when they were close to human settlements and especially during the berry season, when humans were more often in the forest, picking berries and hunting. Our findings provide evidence of a human-induced landscape of fear in this hunted population of brown bears. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  9. Cardiac function adaptations in hibernating grizzly bears (Ursus arctos horribilis).

    Science.gov (United States)

    Nelson, O Lynne; Robbins, Charles T

    2010-03-01

    Research on the cardiovascular physiology of hibernating mammals may provide insight into evolutionary adaptations; however, anesthesia used to handle wild animals may affect the cardiovascular parameters of interest. To overcome these potential biases, we investigated the functional cardiac phenotype of the hibernating grizzly bear (Ursus arctos horribilis) during the active, transitional and hibernating phases over a 4 year period in conscious rather than anesthetized bears. The bears were captive born and serially studied from the age of 5 months to 4 years. Heart rate was significantly different from active (82.6 +/- 7.7 beats/min) to hibernating states (17.8 +/- 2.8 beats/min). There was no difference from the active to the hibernating state in diastolic and stroke volume parameters or in left atrial area. Left ventricular volume:mass was significantly increased during hibernation indicating decreased ventricular mass. Ejection fraction of the left ventricle was not different between active and hibernating states. In contrast, total left atrial emptying fraction was significantly reduced during hibernation (17.8 +/- 2.8%) as compared to the active state (40.8 +/- 1.9%). Reduced atrial chamber function was also supported by reduced atrial contraction blood flow velocities and atrial contraction ejection fraction during hibernation; 7.1 +/- 2.8% as compared to 20.7 +/- 3% during the active state. Changes in the diastolic cardiac filling cycle, especially atrial chamber contribution to ventricular filling, appear to be the most prominent macroscopic functional change during hibernation. Thus, we propose that these changes in atrial chamber function constitute a major adaptation during hibernation which allows the myocardium to conserve energy, avoid chamber dilation and remain healthy during a period of extremely low heart rates. These findings will aid in rational approaches to identifying underlying molecular mechanisms.

  10. Genetic characterization of Kenai brown bears (Ursus arctos): Microsatellite and mitochondrial DNA control region variation in brown bears of the Kenai Peninsula, south central Alaska

    Science.gov (United States)

    Jackson, J.V.; Talbot, S.L.; Farley, S.

    2008-01-01

    We collected data from 20 biparentally inherited microsatellite loci, and nucleotide sequence from the maternally inherited mitochondrial DNA (mtDNA) control region, to determine levels of genetic variation of the brown bears (Ursus arctos L., 1758) of the Kenai Peninsula, south central Alaska. Nuclear genetic variation was similar to that observed in other Alaskan peninsular populations. We detected no significant inbreeding and found no evidence of population substructuring on the Kenai Peninsula. We observed a genetic signature of a bottleneck under the infinite alleles model (IAM), but not under the stepwise mutation model (SMM) or the two-phase model (TPM) of microsatellite mutation. Kenai brown bears have lower levels of mtDNA haplotypic diversity relative to most other brown bear populations in Alaska. ?? 2008 NRC.

  11. Analysis of seminal plasma from brown bear (Ursus arctos during the breeding season: Its relationship with testosterone levels.

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    L Anel-López

    Full Text Available Seminal plasma (SP plays an important role in the motility, viability and maintenance of the fertilizing capacity of mammalian spermatozoa. This study is the first on brown bear (Ursus arctos SP components, and has two main objectives: 1 to define the SP composition in bear ejaculate and 2 to identify variations in SP composition in relation to high and low levels of testosterone in serum during the breeding season. Forty-eight sperm samples from 30 sexually mature male brown bears (Ursus arctos were obtained by electroejaculation, and their serum testosterone levels were assessed to sort the animals into 2 groups (high and low testosterone levels, threshold 5 ng/dl. The biochemical and protein compositions of the SP samples were assessed, and sperm motility was analyzed. We found that lactate dehydrogenase was significantly higher in the low-serum-testosterone samples, while concentrations of lipase and Mg+ values were significantly higher in the high-serum-testosterone samples. In contrast, sperm motility did not significantly differ (P>0.05 between the testosterone level groups (total motility: 74.42.8% in the high-level group vs. 77.1±4.7% in the low-level group. A reference digital model was constructed since there is no information for this wild species. To do this, all gel images were added in a binary multidimensional image and thirty-three spots were identified as the most-repeated spots. An analysis of these proteins was done by qualitative equivalency (isoelectric point and molecular weight with published data for a bull. SP protein composition was compared between bears with high and low serum testosterone, and three proteins (binder of sperm and two enzymes not identified in the reference bull showed significant (P<0.05 quantitative differences. We conclude that male bears with high or low serum testosterone levels differs only in some properties of their SP, differences in enzyme LDIP2, energy source LACT2, one protein (similar to

  12. Oxygen supplementation in anesthetized brown bears (Ursus arctos)-how low can you go?

    Science.gov (United States)

    Fahlman, Åsa; Arnemo, Jon M; Pringle, John; Nyman, Görel

    2014-07-01

    Hypoxemia is anticipated during wildlife anesthesia and thus should be prevented. We evaluated the efficacy of low flow rates of supplemental oxygen for improvement of arterial oxygenation in anesthetized brown bears (Ursus arctos). The study included 32 free-ranging brown bears (yearlings, subadults, and adults; body mass 12-250 kg) that were darted with medetomidine-zolazepam-tiletamine (MZT) from a helicopter in Sweden. During anesthesia, oxygen was administered intranasally from portable oxygen cylinders at different flow rates (0.5-3 L/min). Arterial blood samples were collected before (pre-O2), during, and after oxygen therapy and immediately processed with a portable analyzer. Rectal temperature, respiratory rate, heart rate, and pulse oximetry-derived hemoglobin oxygen saturation were recorded. Intranasal oxygen supplementation at the evaluated flow rates significantly increased the partial pressure of arterial oxygen (PaO2) from pre-O2 values of 9.1 ± 1.3 (6.3-10.9) kPa to 20.4 ± 6.8 (11.1-38.7) kPa during oxygen therapy. When oxygen therapy was discontinued, the PaO2 decreased to values not significantly different from the pre-O2 values. In relation to the body mass of the bears, the following oxygen flow rates are recommended: 0.5 L/min to bears bears 51-100 kg, 2 L/min to bears 101-200 kg, and 3 L/min to bears 201-250 kg. In conclusion, low flow rates of intranasal oxygen were sufficient to improve arterial oxygenation in brown bears anesthetized with MZT. Because hypoxemia quickly recurred when oxygen was discontinued, oxygen supplementation should be provided continuously throughout anesthesia.

  13. Prioritizing Sites for Protection and Restoration for Grizzly Bears (Ursus arctos) in Southwestern Alberta, Canada.

    Science.gov (United States)

    Braid, Andrew C R; Nielsen, Scott E

    2015-01-01

    As the influence of human activities on natural systems continues to expand, there is a growing need to prioritize not only pristine sites for protection, but also degraded sites for restoration. We present an approach for simultaneously prioritizing sites for protection and restoration that considers landscape patterns for a threatened population of grizzly bears (Ursus arctos) in southwestern Alberta, Canada. We considered tradeoffs between bottom-up (food resource supply) and top-down (mortality risk from roads) factors affecting seasonal habitat quality for bears. Simulated annealing was used to prioritize source-like sites (high habitat productivity, low mortality risk) for protection, as well as sink-like sites (high habitat productivity, high mortality risk) for restoration. Priority source-like habitats identified key conservation areas where future developments should be limited, whereas priority sink-like habitats identified key areas for mitigating road-related mortality risk with access management. Systematic conservation planning methods can be used to complement traditional habitat-based methods for individual focal species by identifying habitats where conservation actions (both protection and restoration) have the highest potential utility.

  14. Prioritizing Sites for Protection and Restoration for Grizzly Bears (Ursus arctos in Southwestern Alberta, Canada.

    Directory of Open Access Journals (Sweden)

    Andrew C R Braid

    Full Text Available As the influence of human activities on natural systems continues to expand, there is a growing need to prioritize not only pristine sites for protection, but also degraded sites for restoration. We present an approach for simultaneously prioritizing sites for protection and restoration that considers landscape patterns for a threatened population of grizzly bears (Ursus arctos in southwestern Alberta, Canada. We considered tradeoffs between bottom-up (food resource supply and top-down (mortality risk from roads factors affecting seasonal habitat quality for bears. Simulated annealing was used to prioritize source-like sites (high habitat productivity, low mortality risk for protection, as well as sink-like sites (high habitat productivity, high mortality risk for restoration. Priority source-like habitats identified key conservation areas where future developments should be limited, whereas priority sink-like habitats identified key areas for mitigating road-related mortality risk with access management. Systematic conservation planning methods can be used to complement traditional habitat-based methods for individual focal species by identifying habitats where conservation actions (both protection and restoration have the highest potential utility.

  15. Molecular phylogeography of the brown bear (Ursus arctos) in Northeastern Asia based on analyses of complete mitochondrial DNA sequences.

    Science.gov (United States)

    Hirata, Daisuke; Mano, Tsutomu; Abramov, Alexei V; Baryshnikov, Gennady F; Kosintsev, Pavel A; Vorobiev, Alexandr A; Raichev, Evgeny G; Tsunoda, Hiroshi; Kaneko, Yayoi; Murata, Koichi; Fukui, Daisuke; Masuda, Ryuichi

    2013-07-01

    To further elucidate the migration history of the brown bears (Ursus arctos) on Hokkaido Island, Japan, we analyzed the complete mitochondrial DNA (mtDNA) sequences of 35 brown bears from Hokkaido, the southern Kuril Islands (Etorofu and Kunashiri), Sakhalin Island, and the Eurasian Continent (continental Russia, Bulgaria, and Tibet), and those of four polar bears. Based on these sequences, we reconstructed the maternal phylogeny of the brown bear and estimated divergence times to investigate the timing of brown bear migrations, especially in northeastern Eurasia. Our gene tree showed the mtDNA haplotypes of all 73 brown and polar bears to be divided into eight divergent lineages. The brown bear on Hokkaido was divided into three lineages (central, eastern, and southern). The Sakhalin brown bear grouped with eastern European and western Alaskan brown bears. Etorofu and Kunashiri brown bears were closely related to eastern Hokkaido brown bears and could have diverged from the eastern Hokkaido lineage after formation of the channel between Hokkaido and the southern Kuril Islands. Tibetan brown bears diverged early in the eastern lineage. Southern Hokkaido brown bears were closely related to North American brown bears.

  16. Assessment of Brown Bear\\'s (Ursus arctos syriacus Winter Habitat Using Geographically Weighted Regression and Generalized Linear Model in South of Iran

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    A. A. Zarei

    2016-03-01

    Full Text Available Winter dens are one of the important components of brown bear's (Ursus arctos syriacus habitat, affecting their reproduction and survival. Therefore identification of factors affecting the habitat selection and suitable denning areas in the conservation of our largest carnivore is necessary. We used Geographically Weighted Logistic Regression (GWLR and Generalized Linear Model (GLM for modeling suitability of denning habitat in Kouhkhom region in Fars province. In the present research, 20 dens (presence locations and 20 caves where signs of bear were not found (absence locations were used as dependent variables and six environmental factors were used for each location as independent variables. The results of GLM showed that variables of distance to settlements, altitude, and distance to water were the most important parameters affecting suitability of the brown bear's denning habitat. The results of GWLR showed the significant local variations in the relationship between occurrence of brown bear dens and the variable of distance to settlements. Based on the results of both models, suitable habitats for denning of the species are impassable areas in the mountains and inaccessible for humans.

  17. The food habits of the Himalayan Brown Bear Ursus arctos (Mammalia: Carnivora: Ursidae in Kugti Wildlife Sanctuary, Himachal Pradesh, India

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    Bipan C. Rathore

    2014-12-01

    Full Text Available We documented the food habits of the Himalayan Brown Bear Ursus arctos in Kugti Wildlife Sanctuary, Himachal Pradesh, India, between 2002 and 2004 using scat analysis (n=222, direct observation (n=57, and feeding sign observations (n=57.  We concluded that Himalayan Brown Bears lead a predominantly herbivorous life style as plant matter occurred more frequently in scats (79% than animal matter (21%.  During summer, monsoon and fall, the frequency occurrence of plant matter was 72.2%, 77% and 91% respectively.  During early summer, brown bears foraged primarily on green vegetation such as Rumex nepalensis followed by Chaerophyllum reflexum.  Based on direct feeding observations, brown bears were observed to be feeding on 29 species of plants including agricultural crops and one fungi, Morchella esculenta.  The overuse by livestock, decline in local herbs and excessive extraction of high altitudinal medicinal plants in this habitat may pose a threat to the fragmented brown bear population. 

  18. Role of brown bears (Ursus arctos) in the flow of marine nitrogen into a terrestrial ecosystem.

    Science.gov (United States)

    Hilderbrand, G V; Hanley, Thomas A; Robbins, Charles T; Schwartz, C C

    1999-12-01

    We quantified the amount, spatial distribution, and importance of salmon (Oncorhynchus spp.)-derived nitrogen (N) by brown bears (Ursus arctos) on the Kenai Peninsula, Alaska. We tested and confirmed the hypothesis that the stable isotope signature (δ 15 N) of N in foliage of white spruce (Picea glauca) was inversely proportional to the distance from salmon-spawning streams (r=-0.99 and Pbrown bears, relative to their distance from a stream, were highly correlated with δ 15 N depletion of foliage across the same gradient (r=-0.98 and -0.96 and Pbrown bears were 37.2±2.9 kg/year per bear (range 23.1-56.3), of which 96% (35.7±2.7 kg/year per bear) was excreted in urine, 3% (1.1±0.1 kg/year per bear) was excreted in feces, and bear) was retained in the body. On an area basis, salmon-N redistribution rates were as high as 5.1±0.7 mg/m 2 per year per bear within 500 m of the stream but dropped off greatly with increasing distance. We estimated that 15.5-17.8% of the total N in spruce foliage within 500 m of the stream was derived from salmon. Of that, bears had distributed 83-84%. Thus, brown bears can be an important vector of salmon-derived N into riparian ecosystems, but their effects are highly variable spatially and a function of bear density.

  19. Capture, anesthesia, and disturbance of free-ranging brown bears (Ursus arctos) during hibernation.

    Science.gov (United States)

    Evans, Alina L; Sahlén, Veronica; Støen, Ole-Gunnar; Fahlman, Åsa; Brunberg, Sven; Madslien, Knut; Fröbert, Ole; Swenson, Jon E; Arnemo, Jon M

    2012-01-01

    We conducted thirteen immobilizations of previously collared hibernating two- to four-year-old brown bears (Ursus arctos) weighing 21-66 kg in central Sweden in winter 2010 and 2011 for comparative physiology research. Here we report, for the first time, an effective protocol for the capture and anesthesia of free-ranging brown bears during hibernation and an assessment of the disturbance the captures caused. Bears were darted in anthill, soil, or uprooted tree dens on eleven occasions, but two bears in rock dens fled and were darted outside the den. We used medetomidine at 0.02-0.06 mg/kg and zolazepam-tiletamine at 0.9-2.8 mg/kg for anesthesia. In addition, ketamine at 1.5 mg/kg was hand-injected intramuscularly in four bears and in six it was included in the dart at 1.1-3.0 mg/kg. Once anesthetized, bears were removed from the dens. In nine bears, arterial blood samples were analyzed immediately with a portable blood gas analyzer. We corrected hypoxemia in seven bears (PaO(2) 57-74 mmHg) with supplemental oxygen. We placed the bears back into the dens and antagonized the effect of medetomidine with atipamezole. Capturing bears in the den significantly increased the risk of den abandonment. One of twelve collared bears that were captured remained at the original den until spring, and eleven, left their dens (mean ± standard deviation) 3.2±3.6 (range 0.5-10.5) days after capture. They used 1.9±0.9 intermediate resting sites, during 6.2±7.8 days before entering a new permanent den. The eleven new permanent dens were located 730±589 m from the original dens. We documented that it was feasible and safe to capture hibernating brown bears, although they behaved differently than black bears. When doing so, researchers should use 25% of the doses used for helicopter darting during the active period and should consider increased energetic costs associated with den abandonment.

  20. Capture, anesthesia, and disturbance of free-ranging brown bears (Ursus arctos during hibernation.

    Directory of Open Access Journals (Sweden)

    Alina L Evans

    Full Text Available We conducted thirteen immobilizations of previously collared hibernating two- to four-year-old brown bears (Ursus arctos weighing 21-66 kg in central Sweden in winter 2010 and 2011 for comparative physiology research. Here we report, for the first time, an effective protocol for the capture and anesthesia of free-ranging brown bears during hibernation and an assessment of the disturbance the captures caused. Bears were darted in anthill, soil, or uprooted tree dens on eleven occasions, but two bears in rock dens fled and were darted outside the den. We used medetomidine at 0.02-0.06 mg/kg and zolazepam-tiletamine at 0.9-2.8 mg/kg for anesthesia. In addition, ketamine at 1.5 mg/kg was hand-injected intramuscularly in four bears and in six it was included in the dart at 1.1-3.0 mg/kg. Once anesthetized, bears were removed from the dens. In nine bears, arterial blood samples were analyzed immediately with a portable blood gas analyzer. We corrected hypoxemia in seven bears (PaO(2 57-74 mmHg with supplemental oxygen. We placed the bears back into the dens and antagonized the effect of medetomidine with atipamezole. Capturing bears in the den significantly increased the risk of den abandonment. One of twelve collared bears that were captured remained at the original den until spring, and eleven, left their dens (mean ± standard deviation 3.2±3.6 (range 0.5-10.5 days after capture. They used 1.9±0.9 intermediate resting sites, during 6.2±7.8 days before entering a new permanent den. The eleven new permanent dens were located 730±589 m from the original dens. We documented that it was feasible and safe to capture hibernating brown bears, although they behaved differently than black bears. When doing so, researchers should use 25% of the doses used for helicopter darting during the active period and should consider increased energetic costs associated with den abandonment.

  1. Metabolic changes in summer active and anuric hibernating free-ranging brown bears (Ursus arctos.

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    Peter Stenvinkel

    Full Text Available The brown bear (Ursus arctos hibernates for 5 to 6 months each winter and during this time ingests no food or water and remains anuric and inactive. Despite these extreme conditions, bears do not develop azotemia and preserve their muscle and bone strength. To date most renal studies have been limited to small numbers of bears, often in captive environments. Sixteen free-ranging bears were darted and had blood drawn both during hibernation in winter and summer. Samples were collected for measurement of creatinine and urea, markers of inflammation, the calcium-phosphate axis, and nutritional parameters including amino acids. In winter the bear serum creatinine increased 2.5 fold despite a 2-fold decrease in urea, indicating a remarkable ability to recycle urea nitrogen during hibernation. During hibernation serum calcium remained constant despite a decrease in serum phosphate and a rise in FGF23 levels. Despite prolonged inactivity and reduced renal function, inflammation does not ensue and bears seem to have enhanced antioxidant defense mechanisms during hibernation. Nutrition parameters showed high fat stores, preserved amino acids and mild hyperglycemia during hibernation. While total, essential, non-essential and branched chain amino acids concentrations do not change during hibernation anorexia, changes in individual amino acids ornithine, citrulline and arginine indicate an active, although reduced urea cycle and nitrogen recycling to proteins. Serum uric acid and serum fructose levels were elevated in summer and changes between seasons were positively correlated. Further studies to understand how bears can prevent the development of uremia despite minimal renal function during hibernation could provide new therapeutic avenues for the treatment of human kidney disease.

  2. Metabolic Changes in Summer Active and Anuric Hibernating Free-Ranging Brown Bears (Ursus arctos)

    Science.gov (United States)

    Stenvinkel, Peter; Fröbert, Ole; Anderstam, Björn; Palm, Fredrik; Eriksson, Monica; Bragfors-Helin, Ann-Christin; Qureshi, Abdul Rashid; Larsson, Tobias; Friebe, Andrea; Zedrosser, Andreas; Josefsson, Johan; Svensson, My; Sahdo, Berolla; Bankir, Lise; Johnson, Richard J.

    2013-01-01

    The brown bear (Ursus arctos) hibernates for 5 to 6 months each winter and during this time ingests no food or water and remains anuric and inactive. Despite these extreme conditions, bears do not develop azotemia and preserve their muscle and bone strength. To date most renal studies have been limited to small numbers of bears, often in captive environments. Sixteen free-ranging bears were darted and had blood drawn both during hibernation in winter and summer. Samples were collected for measurement of creatinine and urea, markers of inflammation, the calcium-phosphate axis, and nutritional parameters including amino acids. In winter the bear serum creatinine increased 2.5 fold despite a 2-fold decrease in urea, indicating a remarkable ability to recycle urea nitrogen during hibernation. During hibernation serum calcium remained constant despite a decrease in serum phosphate and a rise in FGF23 levels. Despite prolonged inactivity and reduced renal function, inflammation does not ensue and bears seem to have enhanced antioxidant defense mechanisms during hibernation. Nutrition parameters showed high fat stores, preserved amino acids and mild hyperglycemia during hibernation. While total, essential, non-essential and branched chain amino acids concentrations do not change during hibernation anorexia, changes in individual amino acids ornithine, citrulline and arginine indicate an active, although reduced urea cycle and nitrogen recycling to proteins. Serum uric acid and serum fructose levels were elevated in summer and changes between seasons were positively correlated. Further studies to understand how bears can prevent the development of uremia despite minimal renal function during hibernation could provide new therapeutic avenues for the treatment of human kidney disease. PMID:24039826

  3. Behaviour of solitary adult Scandinavian brown bears (Ursus arctos when approached by humans on foot.

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    Gro Kvelprud Moen

    Full Text Available Successful management has brought the Scandinavian brown bear (Ursus arctos L. back from the brink of extinction, but as the population grows and expands the probability of bear-human encounters increases. More people express concerns about spending time in the forest, because of the possibility of encountering bears, and acceptance for the bear is decreasing. In this context, reliable information about the bear's normal behaviour during bear-human encounters is important. Here we describe the behaviour of brown bears when encountering humans on foot. During 2006-2009, we approached 30 adult (21 females, 9 males GPS-collared bears 169 times during midday, using 1-minute positioning before, during and after the approach. Observer movements were registered with a handheld GPS. The approaches started 869±348 m from the bears, with the wind towards the bear when passing it at approximately 50 m. The bears were detected in 15% of the approaches, and none of the bears displayed any aggressive behaviour. Most bears (80% left the initial site during the approach, going away from the observers, whereas some remained at the initial site after being approached (20%. Young bears left more often than older bears, possibly due to differences in experience, but the difference between ages decreased during the berry season compared to the pre-berry season. The flight initiation distance was longer for active bears (115±94 m than passive bears (69±47 m, and was further affected by horizontal vegetation cover and the bear's age. Our findings show that bears try to avoid confrontations with humans on foot, and support the conclusions of earlier studies that the Scandinavian brown bear is normally not aggressive during encounters with humans.

  4. LEUKOCYTE COPING CAPACITY AS A TOOL TO ASSESS CAPTURE- AND HANDLING-INDUCED STRESS IN SCANDINAVIAN BROWN BEARS (URSUS ARCTOS).

    Science.gov (United States)

    Esteruelas, Núria Fandos; Huber, Nikolaus; Evans, Alina L; Zedrosser, Andreas; Cattet, Marc; Palomares, Francisco; Angel, Martine; Swenson, Jon E; Arnemo, Jon M

    2016-04-01

    Brown bears (Ursus arctos) are often captured and handled for research and management purposes. Although the techniques used are potentially stressful for the animals and might have detrimental and long-lasting consequences, it is difficult to assess their physiological impact. Here we report the use of the leukocyte coping capacity (LCC) technique to quantify the acute stress of capture and handling in brown bears in Scandinavia. In April and May 2012 and 2013, we collected venous blood samples and recorded a range of physiological variables to evaluate the effects of capture and the added impact of surgical implantation or removal of transmitters and sensors. We studied 24 brown bears, including 19 that had abdominal surgery. We found 1) LCC values following capture were lower in solitary bears than in bears in family groups suggesting capture caused relatively more stress in solitary bears, 2) ability to cope with handling stress was better (greater LCC values) in bears with good body condition, and 3) LCC values did not appear to be influenced by surgery. Although further evaluation of this technique is required, our preliminary results support the use of the LCC technique as a quantitative measure of stress.

  5. Effect of season and high ambient temperature on activity levels and patterns of grizzly bears (Ursus arctos).

    Science.gov (United States)

    McLellan, Michelle L; McLellan, Bruce N

    2015-01-01

    Understanding factors that influence daily and annual activity patterns of a species provides insights to challenges facing individuals, particularly when climate shifts, and thus is important in conservation. Using GPS collars with dual-axis motion sensors that recorded the number of switches every 5 minutes we tested the hypotheses: 1. Grizzly bears (Ursus arctos) increase daily activity levels and active bout lengths when they forage on berries, the major high-energy food in this ecosystem, and 2. Grizzly bears become less active and more nocturnal when ambient temperature exceeds 20°C. We found support for hypothesis 1 with both male and female bears being active from 0.7 to 2.8 h longer in the berry season than in other seasons. Our prediction under hypothesis 2 was not supported. When bears foraged on berries on a dry, open mountainside, there was no relationship between daily maximum temperature (which varied from 20.4 to 40.1°C) and the total amount of time bears were active, and no difference in activity levels during day or night between warm (20.4-27.3°C) and hot (27.9-40.1°C) days. Our results highlight the strong influence that food acquisition has on activity levels and patterns of grizzly bears and is a challenge to the heat dissipation limitation theory.

  6. Effect of season and high ambient temperature on activity levels and patterns of grizzly bears (Ursus arctos.

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    Michelle L McLellan

    Full Text Available Understanding factors that influence daily and annual activity patterns of a species provides insights to challenges facing individuals, particularly when climate shifts, and thus is important in conservation. Using GPS collars with dual-axis motion sensors that recorded the number of switches every 5 minutes we tested the hypotheses: 1. Grizzly bears (Ursus arctos increase daily activity levels and active bout lengths when they forage on berries, the major high-energy food in this ecosystem, and 2. Grizzly bears become less active and more nocturnal when ambient temperature exceeds 20°C. We found support for hypothesis 1 with both male and female bears being active from 0.7 to 2.8 h longer in the berry season than in other seasons. Our prediction under hypothesis 2 was not supported. When bears foraged on berries on a dry, open mountainside, there was no relationship between daily maximum temperature (which varied from 20.4 to 40.1°C and the total amount of time bears were active, and no difference in activity levels during day or night between warm (20.4-27.3°C and hot (27.9-40.1°C days. Our results highlight the strong influence that food acquisition has on activity levels and patterns of grizzly bears and is a challenge to the heat dissipation limitation theory.

  7. [New data on the phylogeography and genetic diversity of the brown bear Ursus arctos Linnaeus, 1758 of northeastern Eurasia (mtDNA control region polymorphism analysis)].

    Science.gov (United States)

    Salomashkina, V V; Kholodova, M V; Tiuten'kov, O Iu; Moskvitina, N S; Erokhin, N G

    2014-01-01

    An analysis of polymorphism of the fragment of the control region of mitochondrial DNA of 53 tissue samples of the brown bear Ursus arctos from several regions of the eastern part of Russia was carried out. It was found that most of the described haplotypes belong to cluster 3a, the most common in Eurasia, and do not form regionally specific haplogroups. However, among the bears from Western and Eastern Siberia, as well as the island of Kunashir, three haplotypes were identified, which are close to the haplogroup typical of Eastern Hokkaido bears. The assumption was made of the existence in Siberia and the Far East of one or more Pleistocene refugia.

  8. A Double-Blinded, Randomized Comparison of Medetomidine-Tiletamine-Zolazepam and Dexmedetomidine-Tiletamine-Zolazepam Anesthesia in Free-Ranging Brown Bears (Ursus Arctos).

    Science.gov (United States)

    Fandos Esteruelas, Núria; Cattet, Marc; Zedrosser, Andreas; Stenhouse, Gordon B; Küker, Susanne; Evans, Alina L; Arnemo, Jon M

    2017-01-01

    We compared anesthetic features, blood parameters, and physiological responses to either medetomidine-tiletamine-zolazepam or dexmedetomidine-tiletamine-zolazepam using a double-blinded, randomized experimental design during 40 anesthetic events of free-ranging brown bears (Ursus arctos) either captured by helicopter in Sweden or by culvert trap in Canada. Induction was smooth and predictable with both anesthetic protocols. Induction time, the need for supplemental drugs to sustain anesthesia, and capture-related stress were analyzed using generalized linear models, but anesthetic protocol did not differentially affect these variables. Arterial blood gases and acid-base status, and physiological responses were examined using linear mixed models. We documented acidemia (pH of arterial blood bears could not be attributed to the anesthetic protocol. Heart rate increased with increasing rectal temperature (p bears captured by helicopter in Sweden than in bears captured by culvert trap in Canada (p bears. Both drug combinations appeared to be safe and reliable for the anesthesia of free-ranging brown bears captured by helicopter or by culvert trap.

  9. Fatal snake bite in a brown bear (Ursus arctos L.: A case report

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    Romel Velev

    2015-03-01

    Full Text Available Poisoning from snake venom in animals is an emergency which requires immediate attention or otherwise, the delayed and inadequate treatment leads to untoward consequences and death. The present paper describes a case of venomous snakebite in a brown bear cub (Ursus arctos L. and its therapeutic management. The brown bear cub of which was found alone on the slopes of a mountain in the southwest part of the country was presented to the peripheral veterinary practice in Ohrid with a history of dullness, disorientation and excessive swelling around the left forepaw. It was diagnosed for snakebite based on the history and physical examination. The hematological parameters showed reduced values of hemoglobin, packed cell volume and increased total leukocyte count. The biochemical values showed elevated levels of alanine aminotransferase and creatinine. After immobilization of the animal, the treatment was conducted with fluids, corticosteroid and broad spectrum antibiotic with careful monitoring. Despite the treatment which was initiated immediately, it was only partially effective, and the animal died one hour after the beginning of its course. Poisonous snakes are common in the mountainous part of Macedonia and, just like humans, wild bears especially their cubs are susceptible to the deadly venom of some species. The severity of the reaction to snake venom and prognosis in animals depends on a number of factors: on the type and species of snake, on how much venom was injected, on the location of the bite, on the age, health and body weight of the animal and crucially, the time interval between the snakebite and the application of the treatment.

  10. Positive Reinforcement Training for Blood Collection in Grizzly Bears (Ursus arctos horribilis) Results in Undetectable Elevations in Serum Cortisol Levels: A Preliminary Investigation.

    Science.gov (United States)

    Joyce-Zuniga, Nicole M; Newberry, Ruth C; Robbins, Charles T; Ware, Jasmine V; Jansen, Heiko T; Nelson, O Lynne

    2016-01-01

    Training nonhuman animals in captivity for participation in routine husbandry procedures is believed to produce a lower stress environment compared with undergoing a general anesthetic event for the same procedure. This hypothesis rests largely on anecdotal evidence that the captive subjects appear more relaxed with the trained event. Blood markers of physiological stress responses were evaluated in 4 captive grizzly bears (Ursus arctos horribilis) who were clicker-trained for blood collection versus 4 bears who were chemically immobilized for blood collection. Serum cortisol and immunoglobulin A (IgA) and plasma β-endorphin were measured as indicators of responses to stress. Plasma β-endorphin was not different between the groups. Serum IgA was undetectable in all bears. Serum cortisol was undetectable in all trained bears, whereas chemically immobilized bears had marked cortisol elevations (p bears with extensive recent immobilization experience. These findings support the use of positive reinforcement training for routine health procedures to minimize anxiety.

  11. An Evolutionarily Young Polar Bear (Ursus maritimus) Endogenous Retrovirus Identified from Next Generation Sequence Data.

    Science.gov (United States)

    Tsangaras, Kyriakos; Mayer, Jens; Alquezar-Planas, David E; Greenwood, Alex D

    2015-11-24

    Transcriptome analysis of polar bear (Ursus maritimus) tissues identified sequences with similarity to Porcine Endogenous Retroviruses (PERV). Based on these sequences, four proviral copies and 15 solo long terminal repeats (LTRs) of a newly described endogenous retrovirus were characterized from the polar bear draft genome sequence. Closely related sequences were identified by PCR analysis of brown bear (Ursus arctos) and black bear (Ursus americanus) but were absent in non-Ursinae bear species. The virus was therefore designated UrsusERV. Two distinct groups of LTRs were observed including a recombinant ERV that contained one LTR belonging to each group indicating that genomic invasions by at least two UrsusERV variants have recently occurred. Age estimates based on proviral LTR divergence and conservation of integration sites among ursids suggest the viral group is only a few million years old. The youngest provirus was polar bear specific, had intact open reading frames (ORFs) and could potentially encode functional proteins. Phylogenetic analyses of UrsusERV consensus protein sequences suggest that it is part of a pig, gibbon and koala retrovirus clade. The young age estimates and lineage specificity of the virus suggests UrsusERV is a recent cross species transmission from an unknown reservoir and places the viral group among the youngest of ERVs identified in mammals.

  12. An Evolutionarily Young Polar Bear (Ursus maritimus) Endogenous Retrovirus Identified from Next Generation Sequence Data

    Science.gov (United States)

    Tsangaras, Kyriakos; Mayer, Jens; Alquezar-Planas, David E.; Greenwood, Alex D.

    2015-01-01

    Transcriptome analysis of polar bear (Ursus maritimus) tissues identified sequences with similarity to Porcine Endogenous Retroviruses (PERV). Based on these sequences, four proviral copies and 15 solo long terminal repeats (LTRs) of a newly described endogenous retrovirus were characterized from the polar bear draft genome sequence. Closely related sequences were identified by PCR analysis of brown bear (Ursus arctos) and black bear (Ursus americanus) but were absent in non-Ursinae bear species. The virus was therefore designated UrsusERV. Two distinct groups of LTRs were observed including a recombinant ERV that contained one LTR belonging to each group indicating that genomic invasions by at least two UrsusERV variants have recently occurred. Age estimates based on proviral LTR divergence and conservation of integration sites among ursids suggest the viral group is only a few million years old. The youngest provirus was polar bear specific, had intact open reading frames (ORFs) and could potentially encode functional proteins. Phylogenetic analyses of UrsusERV consensus protein sequences suggest that it is part of a pig, gibbon and koala retrovirus clade. The young age estimates and lineage specificity of the virus suggests UrsusERV is a recent cross species transmission from an unknown reservoir and places the viral group among the youngest of ERVs identified in mammals. PMID:26610552

  13. Impacts of Human Recreation on Brown Bears (Ursus arctos): A Review and New Management Tool.

    Science.gov (United States)

    Fortin, Jennifer K; Rode, Karyn D; Hilderbrand, Grant V; Wilder, James; Farley, Sean; Jorgensen, Carole; Marcot, Bruce G

    2016-01-01

    Increased popularity of recreational activities in natural areas has led to the need to better understand their impacts on wildlife. The majority of research conducted to date has focused on behavioral effects from individual recreations, thus there is a limited understanding of the potential for population-level or cumulative effects. Brown bears (Ursus arctos) are the focus of a growing wildlife viewing industry and are found in habitats frequented by recreationists. Managers face difficult decisions in balancing recreational opportunities with habitat protection for wildlife. Here, we integrate results from empirical studies with expert knowledge to better understand the potential population-level effects of recreational activities on brown bears. We conducted a literature review and Delphi survey of brown bear experts to better understand the frequencies and types of recreations occurring in bear habitats and their potential effects, and to identify management solutions and research needs. We then developed a Bayesian network model that allows managers to estimate the potential effects of recreational management decisions in bear habitats. A higher proportion of individual brown bears in coastal habitats were exposed to recreation, including photography and bear-viewing than bears in interior habitats where camping and hiking were more common. Our results suggest that the primary mechanism by which recreation may impact brown bears is through temporal and spatial displacement with associated increases in energetic costs and declines in nutritional intake. Killings in defense of life and property were found to be minimally associated with recreation in Alaska, but are important considerations in population management. Regulating recreation to occur predictably in space and time and limiting recreation in habitats with concentrated food resources reduces impacts on food intake and may thereby, reduce impacts on reproduction and survival. Our results suggest that

  14. Impacts of Human Recreation on Brown Bears (Ursus arctos: A Review and New Management Tool.

    Directory of Open Access Journals (Sweden)

    Jennifer K Fortin

    Full Text Available Increased popularity of recreational activities in natural areas has led to the need to better understand their impacts on wildlife. The majority of research conducted to date has focused on behavioral effects from individual recreations, thus there is a limited understanding of the potential for population-level or cumulative effects. Brown bears (Ursus arctos are the focus of a growing wildlife viewing industry and are found in habitats frequented by recreationists. Managers face difficult decisions in balancing recreational opportunities with habitat protection for wildlife. Here, we integrate results from empirical studies with expert knowledge to better understand the potential population-level effects of recreational activities on brown bears. We conducted a literature review and Delphi survey of brown bear experts to better understand the frequencies and types of recreations occurring in bear habitats and their potential effects, and to identify management solutions and research needs. We then developed a Bayesian network model that allows managers to estimate the potential effects of recreational management decisions in bear habitats. A higher proportion of individual brown bears in coastal habitats were exposed to recreation, including photography and bear-viewing than bears in interior habitats where camping and hiking were more common. Our results suggest that the primary mechanism by which recreation may impact brown bears is through temporal and spatial displacement with associated increases in energetic costs and declines in nutritional intake. Killings in defense of life and property were found to be minimally associated with recreation in Alaska, but are important considerations in population management. Regulating recreation to occur predictably in space and time and limiting recreation in habitats with concentrated food resources reduces impacts on food intake and may thereby, reduce impacts on reproduction and survival. Our

  15. Activity patterns of brown bears (Ursus arctos on the Deosai Plateau, northern Pakistan

    Directory of Open Access Journals (Sweden)

    M. A. Nawaz

    2004-09-01

    Full Text Available Ondersoek is ingestel na die daaglikse aktiwiteite van Himalaja-bruinbere (Ursus arctos in die Deosai Nasionale Park, noordelike Pakistan, oor ’n tydperk van vier jaar (1993 – 1995 en 1999. Bere spandeer die grootste gedeelte van die dag aan voeding, gevolg deur beweging. Rus en ander aktiwiteite gekombineerd vorm ’n wesentlike gedeelte van die daaglikse program. Geen betekenisvolle verskil in die daaglikse tydsbegroting kon tussen manlike en vroulike individue aangetoon word nie, maar onvolwassenes beweeg beduidend meer rond as beide volwassenes of jong beertjies en eenjariges. Afwykende aktiwiteitspatrone wat gedurende die somer van 1999 opgemerk is, kan aan menslike versteuring wat deur die Kargil-oorlog tussen Indië en Pakistan teweeggebring is, toegeskryf word.

  16. An Evolutionarily Young Polar Bear (Ursus maritimus Endogenous Retrovirus Identified from Next Generation Sequence Data

    Directory of Open Access Journals (Sweden)

    Kyriakos Tsangaras

    2015-11-01

    Full Text Available Transcriptome analysis of polar bear (Ursus maritimus tissues identified sequences with similarity to Porcine Endogenous Retroviruses (PERV. Based on these sequences, four proviral copies and 15 solo long terminal repeats (LTRs of a newly described endogenous retrovirus were characterized from the polar bear draft genome sequence. Closely related sequences were identified by PCR analysis of brown bear (Ursus arctos and black bear (Ursus americanus but were absent in non-Ursinae bear species. The virus was therefore designated UrsusERV. Two distinct groups of LTRs were observed including a recombinant ERV that contained one LTR belonging to each group indicating that genomic invasions by at least two UrsusERV variants have recently occurred. Age estimates based on proviral LTR divergence and conservation of integration sites among ursids suggest the viral group is only a few million years old. The youngest provirus was polar bear specific, had intact open reading frames (ORFs and could potentially encode functional proteins. Phylogenetic analyses of UrsusERV consensus protein sequences suggest that it is part of a pig, gibbon and koala retrovirus clade. The young age estimates and lineage specificity of the virus suggests UrsusERV is a recent cross species transmission from an unknown reservoir and places the viral group among the youngest of ERVs identified in mammals.

  17. Brown bear (Ursus arctos attacks resulting in human casualties in Scandinavia 1977-2016; management implications and recommendations.

    Directory of Open Access Journals (Sweden)

    Ole-Gunnar Støen

    Full Text Available Human persecution and habitat loss have endangered large carnivore populations worldwide, but some are recovering, exacerbating old conflicts. Carnivores can injure and kill people; the most dramatic form of wildlife-human conflict. In Scandinavia, the brown bear (Ursus arctos population increased from ~500 bears in 1977 to ~3300 in 2008, with an increase in injuries, fatalities, and public fear of bear attacks. We reviewed media coverage and interviewed victims to explore how bear population trends, hunter education, and other factors may have influenced the number of injuries and fatalities in Scandinavia from 1977 to 2016. We found 42 incidents with 42 injuries and 2 fatalities; 42 were adult men, one was an adult woman conducting forestry work, and one was a boy skiing off-piste. Thirty-three adult men were hunting bears, moose, or small game, often with a hunting dog, and 26 had shot at the bear at 8±11 m before injury. Eleven nonhunters were conducting forestry work, inspecting a hunting area, picking berries, tending livestock, hiking, harassing a denned bear, and one person was killed outside his house at night. Eight of the 11 incidents of nonhunters involved female bears with cubs; three of these family groups were in dens and two were on carcasses. The annual number of hunters injured/killed was mostly influenced by the increase in the bear population size. The pattern was similar regarding injuries/fatalities to other outdoor users, but the relation with the bear population size was weaker than for hunters, and the null model was equally supported. Bear physiology at denning may make encounters with bears more risky in the fall, when bears show prehibernation behavior. Awareness and education efforts, especially among hunters, seem important to ensure human safety. Recreationists and forestry workers should avoid dense vegetation or make noise to warn bears of their presence.

  18. Pronounced expression of the lipolytic inhibitor G0/G1 Switch Gene 2 (G0S2) in adipose tissue from brown bears (Ursus arctos) prior to hibernation

    DEFF Research Database (Denmark)

    Jessen, Niels; Nielsen, Thomas S; Vendelbo, Mikkel H

    2016-01-01

    Prior to hibernation, the brown bear (Ursus arctos) exhibits unparalleled weight gain. Unlike humans, weight gain in bears is associated with lower levels of circulating free fatty acids (FFA) and increased insulin sensitivity. Understanding how free-ranging brown bears suppress lipolysis when...... gaining weight may therefore provide novel insight toward the development of human therapies. Blood and subcutaneous adipose tissue were collected from immobilized free-ranging brown bears (fitted with GPS-collars) during hibernation in winter and from the same bears during the active period in summer...... in Dalarna, Sweden. The expression of lipid droplet-associated proteins in adipose tissue was examined under the hypothesis that bears suppress lipolysis during summer while gaining weight by increased expression of negative regulators of lipolysis. Adipose triglyceride lipase (ATGL) expression did...

  19. Genetic and demographic recovery of an isolated population of brown bear Ursus arctos L., 1758

    Directory of Open Access Journals (Sweden)

    Elena G. Gonzalez

    2016-04-01

    Full Text Available The brown bear Ursus arctos L., 1758 population of the Cantabrian Mountains (northwestern Spain became isolated from other bear populations in Europe about 500 years ago and has declined due to hunting and habitat degradation. At the beginning of the 20th century, the Cantabrian population split into eastern and western subpopulations, and genetic exchange between them ceased. In the early 1990s, total population size was estimated to be < 100 bears. Subsequently, reduction in human-caused mortality has brought about an increase in numbers, mainly in the western subpopulation, likely promoting male-mediated migration and gene flow from the western nucleus to the eastern. To evaluate the possible genetic recovery of the small and genetically depauperate eastern subpopulation, in 2013 and 2014 we genotyped hair and faeces samples (116 from the eastern subpopulation and 36 from the western for 18 microsatellite markers. Data from the annual count of females with cubs of the year (COY during the past twenty-six years was used to analyze demographic changes. The number of females with COY fell to a minimum of seven in the western and three in eastern subpopulations in the biennium 1993–1994 and reached a respective maximum of 54 and 10 individuals in 2013–2014. We also observed increased bear dispersal and gene flow, mainly from the western to the eastern subpopulation. Of the 26 unique genotypes detected in the eastern subpopulation, 14 (54% presented an admixture composition, and seven (27% were determined to be migrants from the western subpopulation. Hence, the two separated and clearly structured subpopulations identified in the past currently show some degree of genetic admixture. This research shows the partial demographic recovery and a change in genetic composition due to migration process in a population of bears that has been isolated for several centuries.

  20. Development and application of an antibody-based protein microarray to assess physiological stress in grizzly bears (Ursus arctos).

    Science.gov (United States)

    Carlson, Ruth I; Cattet, Marc R L; Sarauer, Bryan L; Nielsen, Scott E; Boulanger, John; Stenhouse, Gordon B; Janz, David M

    2016-01-01

    A novel antibody-based protein microarray was developed that simultaneously determines expression of 31 stress-associated proteins in skin samples collected from free-ranging grizzly bears (Ursus arctos) in Alberta, Canada. The microarray determines proteins belonging to four broad functional categories associated with stress physiology: hypothalamic-pituitary-adrenal axis proteins, apoptosis/cell cycle proteins, cellular stress/proteotoxicity proteins and oxidative stress/inflammation proteins. Small skin samples (50-100 mg) were collected from captured bears using biopsy punches. Proteins were isolated and labelled with fluorescent dyes, with labelled protein homogenates loaded onto microarrays to hybridize with antibodies. Relative protein expression was determined by comparison with a pooled standard skin sample. The assay was sensitive, requiring 80 µg of protein per sample to be run in triplicate on the microarray. Intra-array and inter-array coefficients of variation for individual proteins were generally bears. This suggests that remotely delivered biopsy darts could be used in future sampling. Using generalized linear mixed models, certain proteins within each functional category demonstrated altered expression with respect to differences in year, season, geographical sampling location within Alberta and bear biological parameters, suggesting that these general variables may influence expression of specific proteins in the microarray. Our goal is to apply the protein microarray as a conservation physiology tool that can detect, evaluate and monitor physiological stress in grizzly bears and other species at risk over time in response to environmental change.

  1. EFFECT OF ACTIVE COOLING AND α-2 ADRENOCEPTOR ANTAGONISM ON CORE TEMPERATURE IN ANESTHETIZED BROWN BEARS (URSUS ARCTOS).

    Science.gov (United States)

    Ozeki, Larissa Mourad; Caulkett, Nigel; Stenhouse, Gordon; Arnemo, Jon M; Fahlman, Åsa

    2015-06-01

    Hyperthermia is a common complication during anesthesia of bears, and it can be life threatening. The objective of this study was to evaluate the effectiveness of active cooling on core body temperature for treatment of hyperthermia in anesthetized brown bears (Ursus arctos). In addition, body temperature after reversal with atipamezole was also evaluated. Twenty-five adult and subadult brown bears were captured with a combination of zolazepam-tiletamine and xylazine or medetomidine. A core temperature capsule was inserted into the bears' stomach or 15 cm into their rectum or a combination of both. In six bears with gastric temperatures≥40.0°C, an active cooling protocol was performed, and the temperature change over 30 min was analyzed. The cooling protocol consisted of enemas with 2 L of water at approximately 5°C/100 kg of body weight every 10 min, 1 L of intravenous fluids at ambient temperature, water or snow on the paws or the inguinal area, intranasal oxygen supplementation, and removing the bear from direct sunlight or providing shade. Nine bears with body temperature>39.0°C that were not cooled served as control for the treated animals. Their body temperatures were recorded for 30 min, prior to administration of reversal. At the end of the anesthetic procedure, all bears received an intramuscular dose of atipamezole. In 10 bears, deep rectal temperature change over 30 min after administration of atipamezole was evaluated. The active cooling protocol used in hyperthermic bears significantly decreased their body temperatures within 10 min, and it produced a significantly greater decrease in their temperature than that recorded in the control group.

  2. The impacts of human recreation on brown bears (Ursus arctos): A review and new management tool

    Science.gov (United States)

    Fortin-noreus, Jennifer; Rode, Karyn D.; Hilderbrand, Grant V; Wilder, James; Farley, Sean; Jorgensen, Carole; Marcot, Bruce G.

    2016-01-01

    Increased popularity of recreational activities in natural areas has led to the need to better understand their impacts on wildlife. The majority of research conducted to date has focused on behavioral effects from individual recreations, thus there is a limited understanding of the potential for population-level or cumulative effects. Brown bears (Ursus arctos) are the focus of a growing wildlife viewing industry and are found in habitats frequented by recreationists. Managers face difficult decisions in balancing recreational opportunities with habitat protection for wildlife. Here, we integrate results from empirical studies with expert knowledge to better understand the potential population-level effects of recreational activities on brown bears. We conducted a literature review and Delphi survey of brown bear experts to better understand the frequencies and types of recreations occurring in bear habitats and their potential effects, and to identify management solutions and research needs. We then developed a Bayesian network model that allows managers to estimate the potential effects of recreational management decisions in bear habitats. A higher proportion of individual brown bears in coastal habitats were exposed to recreation, including photography and bear-viewing than bears in interior habitats where camping and hiking were more common. Our results suggest that the primary mechanism by which recreation may impact brown bears is through temporal and spatial displacement with associated increases in energetic costs and declines in nutritional intake. Killings in defense of life and property were found to be minimally associated with recreation in Alaska, but are important considerations in population management. Regulating recreation to occur predictably in space and time and limiting recreation in habitats with concentrated food resources reduces impacts on food intake and may thereby, reduce impacts on reproduction and survival. Our results suggest that

  3. Impacts of rural development on Yellowstone wildlife: linking grizzly bear Ursus arctos demographics with projected residential growth

    Science.gov (United States)

    Schwartz, Charles C.; Gude, Patricia H.; Landenburger, Lisa; Haroldson, Mark A.; Podruzny, Shannon

    2012-01-01

    Exurban development is consuming wildlife habitat within the Greater Yellowstone Ecosystem with potential consequences to the long-term conservation of grizzly bears Ursus arctos. We assessed the impacts of alternative future land-use scenarios by linking an existing regression-based simulation model predicting rural development with a spatially explicit model that predicted bear survival. Using demographic criteria that predict population trajectory, we portioned habitats into either source or sink, and projected the loss of source habitat associated with four different build out (new home construction) scenarios through 2020. Under boom growth, we predicted that 12 km2 of source habitat were converted to sink habitat within the Grizzly Bear Recovery Zone (RZ), 189 km2 were converted within the current distribution of grizzly bears outside of the RZ, and 289 km2 were converted in the area outside the RZ identified as suitable grizzly bear habitat. Our findings showed that extremely low densities of residential development created sink habitats. We suggest that tools, such as those outlined in this article, in addition to zoning and subdivision regulation may prove more practical, and the most effective means of retaining large areas of undeveloped land and conserving grizzly bear source habitat will likely require a landscape-scale approach. We recommend a focus on land conservation efforts that retain open space (easements, purchases and trades) coupled with the implementation of ‘bear community programmes’ on an ecosystem wide basis in an effort to minimize human-bear conflicts, minimize management-related bear mortalities associated with preventable conflicts and to safeguard human communities. Our approach has application to other species and areas, and it has illustrated how spatially explicit demographic models can be combined with models predicting land-use change to help focus conservation priorities.

  4. Molecular evidence of the multiple genotype infection of a wild Hokkaido brown bear (Ursus arctos yesoensis) by Babesia sp. UR1.

    Science.gov (United States)

    Jinnai, Michio; Kawabuchi-Kurata, Takako; Tsuji, Masayoshi; Nakajima, Rui; Hirata, Haruyuki; Fujisawa, Kohei; Shiraki, Hiromi; Asakawa, Mitsuhiko; Nasuno, Toyohiko; Ishihara, Chiaki

    2010-10-11

    A frozen-stored blood clot of a wild brown bear cub Ursus arctos yesoensis that had been captured in Hokkaido, Japan was examined for piroplasma infection using polymerase chain reaction (PCR). Two 18S ribosomal RNA gene (SSU rDNA) sequences were generated. One 1565-bp sequence showed the highest similarity with B. gibsoni (95.9% identity) but, phylogenetically, was found to belong to a distinct lineage. The other sequence (1709-bp) could not be definitively assigned to a described taxon, sharing only limited homology to the closest named species (90.1% identity with C. felis). In order to enhance information obtained from the SSU rDNA sequence, further detection and sequence analysis of the CCTeta gene sequence were done revealing the simultaneous presence of three closely related genotypes (all in a monophyletic lineage) within a single bear host. This finding suggested the possibility that a new Babesia species (Babesia sp. UR1) might have been maintained in nature in wild brown bears. While the parasite's biology is yet unknown, to our knowledge, this is, excepting the single case documentation in 1910 of a hemoparasite in a bear at Russian zoo, the first reported case of piroplasms inhabiting a bear species. Copyright 2010 Elsevier B.V. All rights reserved.

  5. Interthalamic hematoma secondary to cerebrovascular atherosclerosis in an aged grizzly bear (Ursus arctos horribilis) with primary cardiac schwannoma.

    Science.gov (United States)

    Miller, Andrew David; McDonough, Sean

    2008-12-01

    A 38-year-old intact female Grizzly bear (Ursus arctos horribilis) was evaluated for progressive seizure activity, pale mucous membranes, deficient pupillary light and menace responses, and irregular shallow respiration. Because of poor response to treatment, the animal was euthanized. Gross examination revealed abundant hemorrhage in both lateral ventricles; a large, encapsulated mass within the rostral interthalamic region; and a well-demarcated, round white mass in the apex of the right ventricle. Histologic examination of the interthalamic mass revealed a resolving hematoma composed of stratified layers of fibrin and white blood cells that was surrounded by a thick fibrous capsule. Most meningeal and intraparenchymal blood vessels had multifocal degeneration, fragmentation, and fraying of the internal elastic lamina with prominent intimal proliferations and plaques. The plaques were formed by small numbers of lipid-laden macrophages (foam cells) that were intermixed with occasional lymphocytes and plasma cells. The cardiac mass was composed of pallisading and interlacing spindle cells with parallel nuclei and abundant, pale eosinophilic cytoplasm consistent with a schwannoma.

  6. Behavioural differences between single scandinavian brown bears (Ursus arctos) and females with dependent young when experimentally approached by humans.

    Science.gov (United States)

    Sahlén, Veronica; Ordiz, Andrés; Swenson, Jon E; Støen, Ole Gunnar

    2015-01-01

    Carnivore-human encounters that result in human injury present a conservation and management challenge and it is therefore important to understand under what conditions such incidents occur. Females with cubs are often involved when humans are injured by brown bears Ursus arctos. In Scandinavia, this is particularly true for unarmed recreational forest users. Our aim was to document behavioural differences between single bears and females with cubs in order to develop recommendations to minimize the risk of injuries to recreational forest users. We documented the reactions of GPS-collared females with cubs and single brown bears to experimental approaches by humans to 50 m from the bear on 42 and 108 occasions, respectively. The majority of females with cubs (95%) and single bears (89%) left when approached. Bears that left were passed at shorter distances and were in more open areas than those that stayed. Both groups had similar flight initiation distances, which were longer for bears that were active at the time of the disturbance. Females with cubs selected more open habitat than single bears, also for the new site they selected following disturbance. Females with cubs, particularly active females with cubs of the year, moved greater distances and spent more time active following the approach. Females with cubs and single bears were seen or heard in 26% and 14% of the approaches, respectively. None of the bears displayed any aggressive behaviour during the approaches. Females with cubs selected more open habitat, perhaps predisposing them to encountering people that are not involved in hunting activities, which might be the primary explanation why females with cubs are most frequently involved when unarmed people are injured by bears in Scandinavia. To mitigate injury risks, one must consider factors that bring bears closer to human activity in the first place.

  7. Low cardiac output as physiological phenomenon in hibernating, free-ranging Scandinavian brown bears (Ursus arctos) - an observational study.

    Science.gov (United States)

    Jørgensen, Peter Godsk; Arnemo, Jon; Swenson, Jon E; Jensen, Jan S; Galatius, Søren; Frøbert, Ole

    2014-09-16

    Despite 5-7 months of physical inactivity during hibernation, brown bears (Ursus arctos) are able to cope with physiological conditions that would be detrimental to humans. During hibernation, the tissue metabolic demands fall to 25% of the active state. Our objective was to assess cardiac function associated with metabolic depression in the hibernating vs. active states in free-ranging Scandinavian brown bears. We performed echocardiography on seven free-ranging brown bears in Dalarna, Sweden, anesthetized with medetomidine-zolazepam-tiletamine-ketamine during winter hibernation in February 2013 and with medetomidine-zolazepam-tiletamine during active state in June 2013. We measured cardiac output noninvasively using estimates of hemodynamics obtained by pulsed wave Doppler echocardiography and 2D imaging. Comparisons were made using paired T-tests. During hibernation, all hemodynamic indices were significantly decreased (hibernating vs. active state): mean heart rate was 26.0 (standard deviation (SD): 5.6) beats per min vs. 75.0 (SD: 17.1) per min (P=0.002), mean stroke volume 32.3 (SD: 5.2) ml vs. 47.1 (SD: 7.9) ml (P=0.008), mean cardiac output 0.86 (SD: 0.31) l/min vs. 3.54 (SD: 1.04) l/min (P=0.003), and mean cardiac index 0.63 (SD: 0.21) l/min/kg vs. 2.45 (SD: 0.52) l/min/ m2 (Pbears during hibernation, despite the absence of atrial arrhythmias and valvular disease. Free-ranging brown bears demonstrate hemodynamics comparable to humans during active state, whereas during hibernation, we documented extremely low-flow hemodynamics. Understanding these physiological changes in bears may help to gain insight into the mechanisms of cardiogenic shock and heart failure in humans.

  8. Dietary plasticity in a nutrient-rich system does not influence brown bear (Ursus arctos) body condition or denning

    Science.gov (United States)

    Mangipane, Lindsey S.; Belant, Jerrold L.; Lafferty, Diana J. R.; Gustine, David D.; Hiller, Tim L.; Colvin, Michael E.; Mangipane, Buck A.; Hilderbrand, Grant V.

    2018-01-01

    Behavioral differences within a population can allow use of a greater range of resources among individuals. The brown bear (Ursus arctos) is a generalist omnivore that occupies diverse habitats and displays considerable plasticity in food use. We evaluated whether brown bear foraging that resulted in deviations from a proposed optimal diet influenced body condition and, in turn, denning duration in Lake Clark National Park and Preserve, Alaska. To assess assimilated diet, we used sectioned guard hair samples (n = 23) collected in autumn to determine stable carbon and nitrogen isotope ratios. To index proportional contributions of meat and vegetation to assimilated diets, we compared the carbon (δ13C) and nitrogen (δ15N) values of hair samples with the values identified for major food categories. We then compared percentage body fat and body mass in relation to the proportion of assimilated meat in the diet using linear models. We also examined the influence of autumn percentage body fat and mass on denning duration. Percentage body fat was not influenced by the proportion of assimilated meat in the diet. Additionally, percentage body fat and body mass did not influence denning duration. However, body mass of bears assimilating proportionately more meat was greater than bears assimilating less meat. Our results provide support for previous findings that larger bears consume higher amounts of protein to maintain their body size and therefore forage further from the proposed optimal diet. Additionally, our results demonstrate that individuals can achieve similar biological outcomes (e.g., percentage body fat) despite variable foraging strategies, suggesting that individuals within generalist populations may confer an adaptive advantage through behavioral plasticity.

  9. Spatial analysis of factors influencing long-term stress in the grizzly bear (Ursus arctos) population of Alberta, Canada.

    Science.gov (United States)

    Bourbonnais, Mathieu L; Nelson, Trisalyn A; Cattet, Marc R L; Darimont, Chris T; Stenhouse, Gordon B

    2013-01-01

    Non-invasive measures for assessing long-term stress in free ranging mammals are an increasingly important approach for understanding physiological responses to landscape conditions. Using a spatially and temporally expansive dataset of hair cortisol concentrations (HCC) generated from a threatened grizzly bear (Ursus arctos) population in Alberta, Canada, we quantified how variables representing habitat conditions and anthropogenic disturbance impact long-term stress in grizzly bears. We characterized spatial variability in male and female HCC point data using kernel density estimation and quantified variable influence on spatial patterns of male and female HCC stress surfaces using random forests. Separate models were developed for regions inside and outside of parks and protected areas to account for substantial differences in anthropogenic activity and disturbance within the study area. Variance explained in the random forest models ranged from 55.34% to 74.96% for males and 58.15% to 68.46% for females. Predicted HCC levels were higher for females compared to males. Generally, high spatially continuous female HCC levels were associated with parks and protected areas while low-to-moderate levels were associated with increased anthropogenic disturbance. In contrast, male HCC levels were low in parks and protected areas and low-to-moderate in areas with increased anthropogenic disturbance. Spatial variability in gender-specific HCC levels reveal that the type and intensity of external stressors are not uniform across the landscape and that male and female grizzly bears may be exposed to, or perceive, potential stressors differently. We suggest observed spatial patterns of long-term stress may be the result of the availability and distribution of foods related to disturbance features, potential sexual segregation in available habitat selection, and may not be influenced by sources of mortality which represent acute traumas. In this wildlife system and others

  10. Decrease in the red cell cofactor 2,3-diphosphoglycerate increases hemoglobin oxygen affinity in the hibernating brown bear Ursus arctos.

    Science.gov (United States)

    Revsbech, Inge G; Malte, Hans; Fröbert, Ole; Evans, Alina; Blanc, Stéphane; Josefsson, Johan; Fago, Angela

    2013-01-01

    During winter hibernation, brown bears (Ursus arctos) reduce basal O(2) consumption rate to ∼25% compared with the active state, while body temperature decreases moderately (to ∼30°C), suggesting a temperature-independent component in their metabolic depression. To establish whether changes in O(2) consumption during hibernation correlate with changes in blood O(2) affinity, we took blood samples from the same six individuals of hibernating and nonhibernating free-ranging brown bears during winter and summer, respectively. A single hemoglobin (Hb) component was detected in all samples, indicating no switch in Hb synthesis. O(2) binding curves measured on red blood cell lysates at 30°C and 37°C showed a less temperature-sensitive O(2) affinity than in other vertebrates. Furthermore, hemolysates from hibernating bears consistently showed lower cooperativity and higher O(2) affinity than their summer counterparts, regardless of the temperature. We found that this increase in O(2) affinity was associated with a significant decrease in the red cell Hb-cofactor 2,3-diphosphoglycerate (DPG) during hibernation to approximately half of the summer value. Experiments performed on purified Hb, to which DPG had been added to match summer and winter levels, confirmed that the low DPG content was the cause of the left shift in the Hb-O(2) equilibrium curve during hibernation. Levels of plasma lactate indicated that glycolysis is not upregulated during hibernation and that metabolism is essentially aerobic. Calculations show that the increase in Hb-O(2) affinity and decrease in cooperativity resulting from decreased red cell DPG may be crucial in maintaining a fairly constant tissue oxygen tension during hibernation in vivo.

  11. Planning the Brown Bear Ursus arctos reintroduction in the Adamello Brenta Natural Park. A tool to establish a metapopulation in the Central-Eastern Alps

    Directory of Open Access Journals (Sweden)

    Andrea Mustoni

    2003-10-01

    Full Text Available Abstract In the 17th century, brown bears (Ursus arctos were still abundant and widely distributed over the entire alpine area of northern Italy and even in large, dense forests of the prealps and the Po plain. The start of the decline coincided with increasing deforestation for farming at the end of the 18th century and, in the 19th century, increased access to previously remote wilderness areas of the prealpine and alpine mountains, where direct persecution by farmers and hunters caused the extinction of local bear populations. The last remnant population that occupied the Adamello-Brenta Alps was considered biologically extinct since 1989 (only three, non-reproducing bears. Here we present an analysis of the reintroduction process as the most suitable tool for brown bear recovery in the Italian Alps, taking into account both the benefits of reinstating a viable population and the risks that the coexistence between man and bear could cause. The reintroduction process is discussed aiming at an evaluation of its contribution to the global future efforts for brown bear conservation in the alpine region. A GIS-based habitat suitability analysis was implemented to test for good-quality bear habitat in a vast mountainous area around the Adamello-Brenta Natural Park (6500 km², the release site of bears. The model was based on presence/absence data, gathered over the last 20 years, and habitat parameters in 25 ha cells in the core-area of the remnant bear population (645 km² study area. Other parameters of human disturbance and livestock densities, were considered at the scale of the municipality. Bears positively selected deciduous forest but seemed to avoid areas with intensive pasture activity, mainly of horses and sheep, despite the latter being a potential prey. Habitats containing large amounts of bare rock, farmland and urbanised areas were avoided. There were no significant

  12. Spatial analysis of factors influencing long-term stress in the grizzly bear (Ursus arctos population of Alberta, Canada.

    Directory of Open Access Journals (Sweden)

    Mathieu L Bourbonnais

    Full Text Available Non-invasive measures for assessing long-term stress in free ranging mammals are an increasingly important approach for understanding physiological responses to landscape conditions. Using a spatially and temporally expansive dataset of hair cortisol concentrations (HCC generated from a threatened grizzly bear (Ursus arctos population in Alberta, Canada, we quantified how variables representing habitat conditions and anthropogenic disturbance impact long-term stress in grizzly bears. We characterized spatial variability in male and female HCC point data using kernel density estimation and quantified variable influence on spatial patterns of male and female HCC stress surfaces using random forests. Separate models were developed for regions inside and outside of parks and protected areas to account for substantial differences in anthropogenic activity and disturbance within the study area. Variance explained in the random forest models ranged from 55.34% to 74.96% for males and 58.15% to 68.46% for females. Predicted HCC levels were higher for females compared to males. Generally, high spatially continuous female HCC levels were associated with parks and protected areas while low-to-moderate levels were associated with increased anthropogenic disturbance. In contrast, male HCC levels were low in parks and protected areas and low-to-moderate in areas with increased anthropogenic disturbance. Spatial variability in gender-specific HCC levels reveal that the type and intensity of external stressors are not uniform across the landscape and that male and female grizzly bears may be exposed to, or perceive, potential stressors differently. We suggest observed spatial patterns of long-term stress may be the result of the availability and distribution of foods related to disturbance features, potential sexual segregation in available habitat selection, and may not be influenced by sources of mortality which represent acute traumas. In this wildlife

  13. Assessing bear-human conflicts in the Yukon Territory

    OpenAIRE

    Lukie, Raechel Dawn

    2010-01-01

    Managing conflicts between bears and humans is vital for human safety and for the conservation of bears. This study investigated black bear (Ursus americanus) and grizzly bear (Ursus arctos) interactions with humans in 18 major communities of the Yukon Territory. I used an information theoretic approach to generate predictive models of the relative potential of bear-human interaction for the 9 conservation officer management regions in the Yukon Territory. I independently modeled interactions...

  14. Pronounced expression of the lipolytic inhibitor G0/G1 Switch Gene 2 (G0S2) in adipose tissue from brown bears (Ursus arctos) prior to hibernation.

    Science.gov (United States)

    Jessen, Niels; Nielsen, Thomas S; Vendelbo, Mikkel H; Viggers, Rikke; Støen, Ole-Gunnar; Evans, Alina; Frøbert, Ole

    2016-04-01

    Prior to hibernation, the brown bear (Ursus arctos) exhibits unparalleled weight gain. Unlike humans, weight gain in bears is associated with lower levels of circulating free fatty acids (FFA) and increased insulin sensitivity. Understanding how free-ranging brown bears suppress lipolysis when gaining weight may therefore provide novel insight toward the development of human therapies. Blood and subcutaneous adipose tissue were collected from immobilized free-ranging brown bears (fitted with GPS-collars) during hibernation in winter and from the same bears during the active period in summer in Dalarna, Sweden. The expression of lipid droplet-associated proteins in adipose tissue was examined under the hypothesis that bears suppress lipolysis during summer while gaining weight by increased expression of negative regulators of lipolysis. Adipose triglyceride lipase (ATGL) expression did not differ between seasons, but in contrast, the expression of ATGL coactivator Comparative gene identification-58 (CGI-58) was lower in summer. In addition, the expression of the negative regulators of lipolysis, G0S2 and cell-death inducing DNA fragmentation factor-a-like effector (CIDE)C markedly increased during summer. Free-ranging brown bears display potent upregulation of inhibitors of lipolysis in adipose tissue during summer. This is a potential mechanism for increased insulin sensitivity during weight gain and G0S2 may serve as a target to modulate insulin sensitivity. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

  15. Seasonal and individual variation in the use of rail-associated food attractants by grizzly bears (Ursus arctos) in a national park.

    Science.gov (United States)

    Murray, Maureen H; Fassina, Sarah; Hopkins, John B; Whittington, Jesse; St Clair, Colleen C

    2017-01-01

    Similar to vehicles on roadways, trains frequently kill wildlife via collisions along railways. Despite the prevalence of this mortality worldwide, little is known about the relative importance of wildlife attractants associated with railways, including spilled agricultural products, enhanced vegetation, invertebrates, and carcasses of rail-killed ungulates. We assessed the relative importance of several railway attractants to a provincially-threatened population of grizzly bears (Ursus arctos) in Banff and Yoho National Parks, Canada, for which rail-caused mortality has increased in recent decades without known cause. We examined the relationship between the use of the railway and diet by fitting 21 grizzly bears with GPS collars in 2011-2013 and measuring the stable isotope values (δ15N, δ34S) derived from their hair. We also examined the importance of rail-associated foods to grizzly bears by analyzing 230 grizzly bear scats collected from May through October in 2012-2014, some of which could be attributed to GPS-collared bears. Among the 21 collared bears, 17 used the rail rarely (bears (which included the three smallest bears and the largest bear in our sample) used the rail frequently (>20% of their monitored days). We found no significant relationships between δ15N and δ34S values measured from the hair of grizzlies and their frequency of rail use. Instead, δ15N increased with body mass, especially for male bears, suggesting large males consumed more animal protein during hair growth. All four bears that used the railway frequently produced scats containing grain. Almost half the scats (43%) collected within 150 m of the railway contained grain compared to only 7% of scats found >150 m from the railway. Scats deposited near the rail were also more likely to contain grain in the fall (85% of scats) compared to summer (14%) and spring (17%), and those containing grain were more diverse in their contents (6.8 ± 2.2 species vs. 4.9 ± 1.6, P bears in the

  16. Trace and macro elements in the femoral bone as indicators of long-term environmental exposure to toxic metals in European brown bear (Ursus arctos) from Croatia.

    Science.gov (United States)

    Lazarus, Maja; Orct, Tatjana; Reljić, Slaven; Sedak, Marija; Bilandžić, Nina; Jurasović, Jasna; Huber, Đuro

    2018-05-21

    We explored the long-term accumulation of aluminium, strontium, cadmium and lead in the compact and trabecular bone of the femoral epiphysis, metaphysis and diaphysis in 41 brown bears (Ursus arctos) from Croatia. Also, we assessed their influence on macro and trace elements (sodium, magnesium, phosphorus, potassium, calcium, manganese, iron, cobalt, copper, zinc and barium) in bears' bone. There were no sex differences in element levels in general, while age was associated with bone length and levels of all elements, except for cadmium. Elements had different levels depending on the part of the bone sampled. More pronounced differences were observed between the compact and trabecular regions, with higher levels of majority of elements found in compact bone. Moderate to high associations (Spearman coefficient, r S  = 0.59-0.97) were confirmed between calcium and potassium, magnesium, phosphorus, manganese, cobalt, zinc, strontium and lead. Lead levels in the bone were below those known to cause adverse health effects, but in 4 of 41 animals they exceeded baseline levels for domestic animals. The femoral bone of the brown bear reflected the accumulative nature of lead and strontium well, as it did the impairment of bone-forming essential element levels associated with these two elements. However, the distribution pattern of elements along the bone was not uniform, so additional care should be taken when choosing on the part of the bone sampled.

  17. Dietary ecology of the extinct cave bear: Evidence of omnivory as inferred from dental microwear textures

    Directory of Open Access Journals (Sweden)

    D. Brent Jones

    2016-12-01

    Full Text Available The diet of the extinct European cave bear, Ursus spelaeus, has widely been debated. Diverging from the extant brown bear (Ursus arctos approximately 1.2 million years ago, the cave bear is one of the most ubiquitous fossil bears occurring in Europe during the middle and Late Pleistocene. Early morphological studies suggested that the cave bear was likely specialized on processing tough and/or abrasive foods, while later two-dimensional low-magnification microwear studies suggested that they were omnivorous and may have consumed more bone than U. arctos. Here, we used dental microwear texture analysis (DMTA to further interpret the diet of the cave bear. Microscopic wear features were assessed and compared to modern ursids, including the cave bears’ closest living relative, U. arctos. Results suggest that U. spelaeus consumed a diet with a diversity of textural properties, similar to most other bears and only distinguishable from the hyper-carnivorous polar bear (Ursus maritimus. Further, only U. maritimus can be distinguished from all bear species here examined (i.e., the giant panda bear, Ailuropoda melanoleuca; sun-bear, Ursus malayanus; spectacled bear, Tremarctos ornatus; American black bear, Ursus americanus; and U. arctos, with significantly greater area-scale fractal complexity (Asfc of microwear surfaces. The DMTA of A. melanoleuca also has significantly lower Asfc than T. ornatus and U. americanus, consistent with observed dietary behavior. As modern bears vary their diets seasonally and across their range, it may be difficult to characterize the dietary ecology of extinct bears using dental microwear alone. Nevertheless, DMTA here demonstrates that U. spelaeus had a diet distinct from the hyper-carnivorous U. maritimus and instead likely consumed food with textural properties most similar to other herbivorous/omnivorous bears. Lastly, the European cave bear and North American giant short-faced bear (Arctodus simus may have had

  18. Public Perceptions of Bears and Management Interventions in Japan

    OpenAIRE

    Sakurai, Ryo; Jacobson, Susan K.

    2011-01-01

    Conservation of bears is a challenge globally. In Japan, Asiatic black bears (Ursus thibetanus) and brown bears (Ursus arctos) are considered a nuisance because of agricultural and property damage and personal human danger due to occasional human casualties. Reduction of human–bear conflicts in Japan would improve long-term conservation of bears and reduce risks to human health and safety. To understand Japanese perceptions of and experience with bears, we analyzed results of 5 public surveys...

  19. Yellowstone grizzly bear investigations: Annual report of the Interagency Grizzly Bear Study Team, 2001

    Science.gov (United States)

    Schwartz, Charles C.; Haroldson, Mark A.

    2001-01-01

    The contents of this Annual Report summarize results of monitoring and research from the 2001 field season. The report also contains a summary of nuisance grizzly bear (Ursus arctos horribilis) management actions.

  20. Yellowstone grizzly bear investigations: Annual report of the Interagency Grizzly Bear Study Team, 2006

    Science.gov (United States)

    Schwartz, Charles C.; Haroldson, Mark A.; West, Karrie K.

    2007-01-01

    The contents of this Annual Report summarize results of monitoring and research from the 2006 field season. The report also contains a summary of nuisance grizzly bear (Ursus arctos horribilis) management actions.

  1. Seasonal and individual variation in the use of rail-associated food attractants by grizzly bears (Ursus arctos in a national park.

    Directory of Open Access Journals (Sweden)

    Maureen H Murray

    Full Text Available Similar to vehicles on roadways, trains frequently kill wildlife via collisions along railways. Despite the prevalence of this mortality worldwide, little is known about the relative importance of wildlife attractants associated with railways, including spilled agricultural products, enhanced vegetation, invertebrates, and carcasses of rail-killed ungulates. We assessed the relative importance of several railway attractants to a provincially-threatened population of grizzly bears (Ursus arctos in Banff and Yoho National Parks, Canada, for which rail-caused mortality has increased in recent decades without known cause. We examined the relationship between the use of the railway and diet by fitting 21 grizzly bears with GPS collars in 2011-2013 and measuring the stable isotope values (δ15N, δ34S derived from their hair. We also examined the importance of rail-associated foods to grizzly bears by analyzing 230 grizzly bear scats collected from May through October in 2012-2014, some of which could be attributed to GPS-collared bears. Among the 21 collared bears, 17 used the rail rarely (20% of their monitored days. We found no significant relationships between δ15N and δ34S values measured from the hair of grizzlies and their frequency of rail use. Instead, δ15N increased with body mass, especially for male bears, suggesting large males consumed more animal protein during hair growth. All four bears that used the railway frequently produced scats containing grain. Almost half the scats (43% collected within 150 m of the railway contained grain compared to only 7% of scats found >150 m from the railway. Scats deposited near the rail were also more likely to contain grain in the fall (85% of scats compared to summer (14% and spring (17%, and those containing grain were more diverse in their contents (6.8 ± 2.2 species vs. 4.9 ± 1.6, P < 0.001. Lastly, scats collected near the rail were more likely to contain ungulate hair and ant remains

  2. Removal of Lipid from Serum Increases Coherence between Brucellosis Rapid Agglutination Test and Enzyme-linked Immunosorbent Assay in Bears in Alaska, USA.

    Science.gov (United States)

    Godfroid, Jacques; Beckmen, Kimberlee; Helena Nymo, Ingebjørg

    2016-10-01

    In cases of chronic Brucella spp. infection, results of the rose bengal plate test (RBPT) and indirect enzyme-linked immunosorbent assay (ELISA) should be coherent, as reported in controlled conditions in the literature. We compared RBPT and ELISA results in 58 Alaska grizzly bears ( Ursus arctos horribilis), eight Kodiak brown bears ( Ursus arctos middendorffi), and six Alaska Peninsula brown bears ( Ursus arctos gyas). Of the 72 bears tested, 42 (58%) were ELISA positive and 53 (73%) were RBPT positive. However, the coherence between the tests was only fair (K=0.37, SE=0.11), suggesting that either the serologic results were not compatible with Brucella spp. infection or that there was a technical problem with the tests. To address a potential technical problem, we performed a 30-min chloroform/centrifugation cleanup. Following cleanup, the ELISA identified 43 positives (59%) and the RBPT identified 47 (65%), and the coherence between the tests was much improved (K=0.80, SE=0.07). We recommend cleaning wildlife sera with a high lipid content before performing RBPT and performing RBPT and ELISA in parallel to assess coherence. Our results suggest that Alaskan brown bears have been exposed to Brucella spp.

  3. Dietary ecology of the extinct cave bear: Evidence of omnivory as inferred from dental microwear textures

    OpenAIRE

    D. Brent Jones; Larisa R.G. DeSantis

    2016-01-01

    The diet of the extinct European cave bear, Ursus spelaeus, has widely been debated. Diverging from the extant brown bear (Ursus arctos) approximately 1.2 million years ago, the cave bear is one of the most ubiquitous fossil bears occurring in Europe during the middle and Late Pleistocene. Early morphological studies suggested that the cave bear was likely specialized on processing tough and/or abrasive foods, while later two-dimensional low-magnification microwear studies suggested that they...

  4. 75 FR 14496 - Endangered and Threatened Wildlife and Plants; Reinstatement of Protections for the Grizzly Bear...

    Science.gov (United States)

    2010-03-26

    ... of Protections for the Grizzly Bear in the Greater Yellowstone Ecosystem in Compliance With Court... grizzly bear (Ursus arctos horribilis) in the Greater Yellowstone Area (GYA) and surrounding area. This rule corrects the grizzly bear listing to reinstate the listing of grizzly bears in the GYA. This final...

  5. Growth trajectories in the cave bear and its extant relatives: an examination of ontogenetic patterns in phylogeny.

    Science.gov (United States)

    Fuchs, Manuela; Geiger, Madeleine; Stange, Madlen; Sánchez-Villagra, Marcelo R

    2015-11-02

    The study of postnatal ontogeny can provide insights into evolution by offering an understanding of how growth trajectories have evolved resulting in adult morphological disparity. The Ursus lineage is a good subject for studying cranial and mandibular shape and size variation in relation to postnatal ontogeny and phylogeny because it is at the same time not diverse but the species exhibit different feeding ecologies. Cranial and mandibular shapes of Ursus arctos (brown bear), U. maritimus (polar bear), U. americanus (American black bear), and the extinct U. spelaeus (cave bear) were examined, using a three-dimensional geometric morphometric approach. Additionally, ontogenetic series of crania and mandibles of U. arctos and U. spelaeus ranging from newborns to senile age were sampled. The distribution of specimens in morphospace allowed to distinguish species and age classes and the ontogenetic trajectories U. arctos and U. spelaeus were found to be more similar than expected by chance. Cranial shape changes during ontogeny are largely size related whereas the evolution of cranial shape disparity in this clade appears to be more influenced by dietary adaptation than by size and phylogeny. The different feeding ecologies are reflected in different cranial and mandibular shapes among species. The cranial and mandibular shape disparity in the Ursus lineage appears to be more influenced by adaptation to diet than by size or phylogeny. In contrast, the cranial and mandibular shape changes during postnatal ontogeny in U. arctos and U. spelaeus are probably largely size related. The patterns of morphospace occupation of the cranium and the mandible in adults and through ontogeny are different.

  6. Studying boat-based bear viewing: Methodological challenges and solutions

    Science.gov (United States)

    Sarah Elmeligi

    2007-01-01

    Wildlife viewing, a growing industry throughout North America, holds much potential for increased revenue and public awareness regarding species conservation. In Alaska and British Columbia, grizzly bear (Ursus arctos) viewing is becoming more popular, attracting tourists from around the world. Viewing is typically done from a land-based observation...

  7. USE OF SULFUR AND NITROGEN STABLE ISOTOPES TO DETERMINE THE IMPORTANCE OF WHITEBARK PINE NUTS TO YELLOWSTONE GRIZZLY BEARS

    Science.gov (United States)

    Whitebark pine (Pinus albicaulis) is a masting species that produces relatively large, fat and protein-rich nuts that are consumed by grizzly bears (Ursus arctos horribilis). Trees produce abundant nut crops in some years and poor crops in other years. Grizzly bear survival in ...

  8. Ancient hybridization and an Irish origin for the modern polar bear matriline

    DEFF Research Database (Denmark)

    Edwards, Ceiridwen J.; Suchard, Marc A.; Lemey, Philippe

    2011-01-01

    Polar bears (Ursus maritimus) are among those species most susceptible to the rapidly changing arctic climate, and their survival is of global concern. Despite this, little is known about polar bear species history. Future conservation strategies would significantly benefit from an understanding...... of basic evolutionary information, such as the timing and conditions of their initial divergence from brown bears (U. arctos) or their response to previous environmental change....

  9. Trichinella surveillance in black bears (Ursus americanus) from Oregon, USA.

    Science.gov (United States)

    Mortenson, J A; Kent, M L; Fowler, D R; Chomel, B B; Immell, D A

    2014-01-01

    We used serology and muscle digestion to test black bears (Ursus americanus) from western Oregon, USA, for Trichinella. Results indicate black bears in Oregon are not part of a sylvatic cycle for Trichinella, and risk of human exposure to Trichinella larvae from eating black bear meat from Oregon appears low.

  10. New challenges for grizzly bear management in Yellowstone National Park

    Science.gov (United States)

    van Manen, Frank T.; Gunther, Kerry A.

    2016-01-01

    A key factor contributing to the success of grizzly bear Ursus arctos conservation in the Greater Yellowstone Ecosystem has been the existence of a large protected area, Yellowstone National Park. We provide an overview of recovery efforts, how demographic parameters changed as the population increased, and how the bear management program in Yellowstone National Park has evolved to address new management challenges over time. Finally, using the management experiences in Yellowstone National Park, we present comparisons and perspectives regarding brown bear management in Shiretoko National Park.

  11. Influence of whitebark pine decline on fall habitat use and movements of grizzly bears in the Greater Yellowstone Ecosystem

    OpenAIRE

    Costello, Cecily M; van Manen, Frank T; Haroldson, Mark A; Ebinger, Michael R; Cain, Steven L; Gunther, Kerry A; Bjornlie, Daniel D

    2014-01-01

    When abundant, seeds of the high-elevation whitebark pine (WBP; Pinus albicaulis) are an important fall food for grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem. Rates of bear mortality and bear/human conflicts have been inversely associated with WBP productivity. Recently, mountain pine beetles (Dendroctonus ponderosae) have killed many cone-producing WBP trees. We used fall (15 August–30 September) Global Positioning System locations from 89 bear years to investigate tempo...

  12. The importance of meat, particularly salmon, to body size, population productivity, and conservation of North American brown bears.

    Science.gov (United States)

    G.V. Hilderbrand; C.C. Schwartz; C.T. Robbins; M.E. Hanley Jacoby; S.M. Arthur; C. Servheen

    1999-01-01

    We hypothesized that the relative availability of meat, indicated by contribution to the diet, would be positively related to body size and population productivity of North American brown, or grizzly, bears (Ursus arctos). Dietary contributions of plant matter and meat derived from both terrestrial and marine sources were quantified by stable-...

  13. Perspectives on grizzly bear management in Banff National Park and the Bow River Watershed, Alberta: A Q methodology study

    OpenAIRE

    Chamberlain, Emily Carter

    2006-01-01

    Conserving populations of large carnivores such as grizzly bears (Ursus arctos) requires not only biophysical research, but also an understanding of the values and beliefs of the people involved with and affected by carnivore management. I used Q methodology to examine views of stakeholders concerning grizzly bear management in the Banff-Bow Valley region of Alberta, Canada. In recent years, decision-making about bears in this region has been characterized by acrimonious disputes over scienti...

  14. Diet and Co-ecology of Pleistocene Short-Faced Bears and Brown Bears in Eastern Beringia

    Science.gov (United States)

    Matheus, Paul E.

    1995-11-01

    Carbon and nitrogen stable isotope analysis of fossil bone collagen reveals that Pleistocene short-faced bears ( Arctodus simus) of Beringia were highly carnivorous, while contemporaneous brown bears ( Ursus arctos) had highly variable diets that included varying amounts of terrestrial vegetation, salmon, and small amounts of terrestrial meat. A reconsideration of the short-faced bear's highly derived morphology indicates that they foraged as scavengers of widely dispersed large mammal carcasses and were simultaneously designed both for highly efficient locomotion and for intimidating other large carnivores. This allowed Arctodus to forage economically over a large home range and seek out, procure, and defend carcasses from other large carnivores. The isotope data and this reconstruction of Arctodus' foraging behavior refute the hypothesis that competition from brown bears was a significant factor in the extinction of short-faced bears.

  15. Trichinella and polar bears: a limited risk for humans.

    Science.gov (United States)

    Dupouy-Camet, J; Bourée, P; Yera, H

    2017-07-01

    In this review, we identified 63 cases reported since World War II of human trichinellosis linked to the consumption of parasitized polar bear (Ursus maritimus) meat. This low number contrasts to the numerous cases of human trichinellosis related to consumption of the meat of black (U. americanus) or brown bears (U. arctos). The prevalence of Trichinella infection is high in bears, but larval muscular burden is usually lower in polar bears compared to other bear species. Polar bears, therefore, seem to play a limited role in the transmission of trichinellosis to humans, as native residents living in the Arctic traditionally consume well-cooked bear meat, and travellers and foreign hunters have only limited access to this protected species due to the declining polar bear population.

  16. Genomic Evidence of Widespread Admixture from Polar Bears into Brown Bears during the Last Ice Age.

    Science.gov (United States)

    Cahill, James A; Heintzman, Peter D; Harris, Kelley; Teasdale, Matthew D; Kapp, Joshua; Soares, Andre E R; Stirling, Ian; Bradley, Daniel; Edwards, Ceiridwen J; Graim, Kiley; Kisleika, Aliaksandr A; Malev, Alexander V; Monaghan, Nigel; Green, Richard E; Shapiro, Beth

    2018-05-01

    Recent genomic analyses have provided substantial evidence for past periods of gene flow from polar bears (Ursus maritimus) into Alaskan brown bears (Ursus arctos), with some analyses suggesting a link between climate change and genomic introgression. However, because it has mainly been possible to sample bears from the present day, the timing, frequency, and evolutionary significance of this admixture remains unknown. Here, we analyze genomic DNA from three additional and geographically distinct brown bear populations, including two that lived temporally close to the peak of the last ice age. We find evidence of admixture in all three populations, suggesting that admixture between these species has been common in their recent evolutionary history. In addition, analyses of ten fossil bears from the now-extinct Irish population indicate that admixture peaked during the last ice age, whereas brown bear and polar bear ranges overlapped. Following this peak, the proportion of polar bear ancestry in Irish brown bears declined rapidly until their extinction. Our results support a model in which ice age climate change created geographically widespread conditions conducive to admixture between polar bears and brown bears, as is again occurring today. We postulate that this model will be informative for many admixing species pairs impacted by climate change. Our results highlight the power of paleogenomics to reveal patterns of evolutionary change that are otherwise masked in contemporary data.

  17. Prevalence of Anaplasma phagocytophilum in North Carolina Eastern Black Bears ( Ursus americanus ).

    Science.gov (United States)

    Westmoreland, Lori S H; Stoskopf, Michael K; Maggi, Ricardo G

    2016-10-01

    We detected Anaplasma phagocytophilum by DNA amplification in whole blood from free-ranging, hunter-killed American black bears ( Ursus americanus ) from the east coast of North Carolina, US. Molecular prevalence for Anaplasma phagocytophilum was 3% from 68 black bears. No DNA of other Anaplasma or Ehrlichia spp. was identified.

  18. Circumpolar contaminant concentrations in polar bears (Ursus maritimus) and potential population-level effects

    NARCIS (Netherlands)

    Nuijten, R.J.M.; Hendriks, A.J.; Jenssen, B.M.; Schipper, A.M.

    2016-01-01

    Abstract Polar bears (Ursus maritimus) currently receive much attention in the context of global climate change. However, there are other stressors that might threaten the viability of polar bear populations as well, such as exposure to anthropogenic pollutants. Lipophilic organic compounds

  19. Prevalence of Trichinella spp. in black bears, grizzly bears, and wolves in the Dehcho Region, Northwest Territories, Canada, including the first report of T. nativa in a grizzly bear from Canada.

    Science.gov (United States)

    Larter, Nicholas C; Forbes, Lorry B; Elkin, Brett T; Allaire, Danny G

    2011-07-01

    Samples of muscle from 120 black bears (Ursus americanus), 11 grizzly bears (Ursus arctos), and 27 wolves (Canis lupus) collected in the Dehcho Region of the Northwest Territories from 2001 to 2010 were examined for the presence of Trichinella spp. larvae using a pepsin-HCl digestion assay. Trichinella spp. larvae were found in eight of 11 (73%) grizzly bears, 14 of 27 (52%) wolves, and seven of 120 (5.8%) black bears. The average age of positive grizzly bears, black bears, and wolves was 13.5, 9.9, and approximately 4 yr, respectively. Larvae from 11 wolves, six black bears, and seven grizzly bears were genotyped. Six wolves were infected with T. nativa and five with Trichinella T6, four black bears were infected with T. nativa and two with Trichinella T6, and all seven grizzly bears were infected with Trichinella T6 and one of them had a coinfection with T. nativa. This is the first report of T. nativa in a grizzly bear from Canada. Bears have been linked to trichinellosis outbreaks in humans in Canada, and black bears are a subsistence food source for residents of the Dehcho region. In order to assess food safety risk it is important to monitor the prevalence of Trichinella spp. in both species of bear and their cohabiting mammalian food sources.

  20. Quantitative Characteristics of Brown Bear (Ursus arctos L. Feeding on Umbelliferae Plants

    Directory of Open Access Journals (Sweden)

    S.S. Ogurtsov

    2015-03-01

    Full Text Available The natural feeding preferences of brown bear for Umbelliferae plants have been considered. The general quantitative characteristics of feeding on forbs have been revealed for bears inhabiting the Central Forest State Nature Biosphere Reserve (Tver region. Umbelliferae plants dominate in the diet of brown bears during late spring and early summer. Angelica sylvestris, Chaerophyllum aromaticum, Aegopodium podagraria, and Heracleum sibiricum are most frequently consumed by bears in the nature reserve. Feeding on A. sylvestris is directly associated with the overall abundance of this plant species and varies depending on its phenological stages. The preference is given to widely distributed age-size forb groups with the thickest stems. The maximum share of consumed plants has been observed in small forest herblands and overgrown fields adjacent to the forest cover. In all the biotopes, bears are attracted to herb sites with the highest abundance of consumed plants. Ch. aromaticum and H. sibiricum are distributed more locally and, therefore, less common in the diet of bears.

  1. Steroid hormone profile in female polar bears (Ursus maritimus)

    DEFF Research Database (Denmark)

    Gustavson, Lisa; Jenssen, Bjørn Munro; Bytingsvik, Jenny

    2015-01-01

    The polar bear is an iconic Arctic species, threatened by anthropogenic impacts such as pollution and climate change. Successful reproduction of polar bears depends on a functioning steroid hormone system, which is susceptible to effects of persistent organic pollutants. The present study...... is the first study to report circulating concentrations of nine steroid hormones (i.e., estrogens, androgens and progestagens) in female polar bears (Ursus maritimus). The aim of the study was to investigate the effects of age, condition, location and reproductive status on steroid profile in female polar...... bears. Levels of pregnenolone (PRE), progesterone, androstenedione (AN), dehydroepiandrosterone (DHEA), testosterone, dihydrotestosterone, estrone (E1), 17α-estradiol (αE2) and 17β-estradiol (βE2) were quantified in blood (serum) of free-living female polar bears (n = 15) from Svalbard, Norway, by gas...

  2. Geographic pattern of serum antibody prevalence for Brucella spp. in caribou, grizzly bears, and wolves from Alaska, 1975-1998.

    Science.gov (United States)

    Zarnke, Randall L; Ver Hoef, Jay M; DeLong, Robert A

    2006-07-01

    Blood samples were collected from 2,635 caribou (Rangifer tarandus), 1,238 grizzly bears (Ursus arctos), and 930 wolves (Canis lupus) from throughout mainland Alaska during 1975-98. Sera were tested for evidence of exposure to Brucella spp. Serum antibody prevalences were highest in the northwestern region of the state. In any specific area, antibody prevalences for caribou and wolves were of a similar magnitude, whereas antibody prevalence for bears in these same areas were two to three times higher.

  3. Effects of sex, age, body mass, and capturing method on hematologic values of brown bears in Croatia.

    Science.gov (United States)

    Kusak, Josip; Rafaj, Renata Barić; Zvorc, Zdravko; Huber, Djuro; Forsek, Jadranka; Bedrica, Ljiljana; Mrljak, Vladimir

    2005-10-01

    Effects of various intrinsic and extrinsic factors on 17 hematologic values from 56 brown bears (Ursus arctos) sampled in Croatia from 1981 to 2005 were evaluated. Differences between female and male bears were detected for number of erythrocytes, sedimentation rate after 30 min, and number of leukocytes and segmented neutrophils. Significant differences between free-living vs. captive and snared vs. not snared bears were detected for the same three parameters: leukocytes, segmented neutrophils, and eosinophils. It was concluded that the physical exertion of bears snared by leg, rather than their free-living status, influenced differences of results among these groups. The obtained mean values are useful reference values for the species.

  4. The role of Pleistocene glaciations in shaping the evolution of polar and brown bears. Evidence from a critical review of mitochondrial and nuclear genome analyses.

    Science.gov (United States)

    Hassanin, Alexandre

    2015-07-01

    In this report, I review recent molecular studies dealing with the origin and evolution of polar bears (Ursus maritimus), with special emphasis on their relationships with brown bears (U. arctos). On the basis of mitochondrial and nuclear data, different hypotheses have been proposed, including rapid morphological differentiation of U. maritimus, genetic introgression from U. arctos into U. maritimus, or inversely from U. maritimus into U. arctos, involving either male- or female-mediated gene flow. In the light of available molecular and eco-ethological data, I suggest, firstly, that all divergences among major clades of large bears can be linked to glacial periods, secondly, that polar bears diverged from brown bears before 530 thousand years ago (ka), during one of the three glacial marine isotope stages (MIS) 14, 15.2 or 16, and, thirdly, that genetic introgression had occurred from female polar bears into brown bear populations during at least two glacial periods, at 340 ± 10 ka (MIS 10) in western Europe, and at 155 ± 5 ka (MIS 6) on the ABC islands of southeastern Alaska, and probably also in Beringia and Ireland based on ancient DNA sequences. Copyright © 2015 Académie des sciences. Published by Elsevier SAS. All rights reserved.

  5. Omental torsion in a captive polar bear (Ursus maritimus).

    Science.gov (United States)

    Mendez-Angulo, Jose L; Funes, Francisco J; Trent, Ava M; Willette, Michelle; Woodhouse, Kerry; Renier, Anna C

    2014-03-01

    This is the first case report of an omental torsion in a polar bear (Ursus maritimus). A captive, 23-yr-old, 250-kg, intact female polar bear presented to the University of Minnesota Veterinary Medical Center with a 2-day history of lethargy, depression, and vomiting. Abdominal ultrasound identified large amounts of hyperechoic free peritoneal fluid. Ultrasound-guided abdominocentesis was performed and yielded thick serosanguinous fluid compatible with a hemoabdomen. An exploratory laparotomy revealed a large amount of malodorous, serosanguineous fluid and multiple necrotic blood clots associated with a torsion of the greater omentum and rupture of a branch of the omental artery. A partial omentectomy was performed to remove the necrotic tissue and the abdomen was copiously lavaged. The polar bear recovered successfully and is reported to be clinically well 6 mo later. This condition should be considered as a differential in bears with clinical signs of intestinal obstruction and hemoabdomen.

  6. Salvaging urospermic ejaculates from brown bear (Ursus arctos).

    Science.gov (United States)

    Gomes-Alves, S; Alvarez, M; Nicolas, M; Martínez-Rodríguez, C; Borragán, S; Chamorro, C A; Anel, L; de Paz, P

    2014-11-30

    The objective of this study was to reverse the osmotic stress of sperm in urine contaminated bear ejaculates that were obtained by electroejaculation using pre-freezing washing or density gradient centrifugation isolation. In Experiment 1, ejaculates were divided into six aliquots, five were diluted in each washing extender: 200, 300, 400, 500 and 700 mOsm/kg (prepared from a Tes-Tris-Fructose base, adding water or fructose as corresponds), at a 1:2 ratio (raw semen: washing solution, v/v); and the other aliquot was handled without washing (Control group). Samples were centrifuged at 600 × g for 6 min prior to freezing. In Experiment 2, ejaculates were divided into two aliquots: one was diluted 1:1 with TCG (Tris-Citric acid-Glucose) and centrifuged at 600 × g for 6 min (Centrifugation Control; C-Control); the other was treated with PureSperm density gradient column. After treatments, samples were cryopreserved. Sperm motility, viability (SYBR-14/propidium iodide (PI)) and acrosomal status (peanut agglutinin-fluorescein isothiocyanate (PNA-FITC)/PI) were analyzed before and after freezing. Ejaculates with an initial osmolality of less than 120 mOsm/kg treated with pre-freezing washing, and the Control sample had greater pre-freezing sperm motility than the raw ejaculate, but sperm viability was not different among these groups. The samples washed with 700 mOsm/kg solutions had the least pre-freezing viability. In the post-thawing evaluation, pre-freezing washing treatments did not provide any improvement in comparison with the Control sample, and treatment with 700 mOsm/kg extender had deleterious effects in all urospermic samples. PureSperm density gradient centrifugation applied to urospermic raw semen was suitable for improving sperm motility and viability of pre-freezing samples and the selected spermatozoa had greater freezing capacity. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. The Gut Microbiota Modulates Energy Metabolism in the Hibernating Brown Bear Ursus arctos.

    Science.gov (United States)

    Sommer, Felix; Ståhlman, Marcus; Ilkayeva, Olga; Arnemo, Jon M; Kindberg, Jonas; Josefsson, Johan; Newgard, Christopher B; Fröbert, Ole; Bäckhed, Fredrik

    2016-02-23

    Hibernation is an adaptation that helps many animals to conserve energy during food shortage in winter. Brown bears double their fat depots during summer and use these stored lipids during hibernation. Although bears seasonally become obese, they remain metabolically healthy. We analyzed the microbiota of free-ranging brown bears during their active phase and hibernation. Compared to the active phase, hibernation microbiota had reduced diversity, reduced levels of Firmicutes and Actinobacteria, and increased levels of Bacteroidetes. Several metabolites involved in lipid metabolism, including triglycerides, cholesterol, and bile acids, were also affected by hibernation. Transplantation of the bear microbiota from summer and winter to germ-free mice transferred some of the seasonal metabolic features and demonstrated that the summer microbiota promoted adiposity without impairing glucose tolerance, suggesting that seasonal variation in the microbiota may contribute to host energy metabolism in the hibernating brown bear. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  8. Respect for Grizzly Bears: an Aboriginal Approach for Co-existence and Resilience

    Directory of Open Access Journals (Sweden)

    Douglas A. Clark

    2009-06-01

    Full Text Available Aboriginal peoples' respect for grizzly bear (Ursus arctos is widely acknowledged, but rarely explored, in wildlife management discourse in northern Canada. Practices of respect expressed toward bears were observed and grouped into four categories: terminology, stories, reciprocity, and ritual. In the southwest Yukon, practices in all four categories form a coherent qualitative resource management system that may enhance the resilience of the bear-human system as a whole. This system also demonstrates the possibility of a previously unrecognized human role in maintaining productive riparian ecosystems and salmon runs, potentially providing a range of valued social-ecological outcomes. Practices of respect hold promise for new strategies to manage bear-human interactions, but such successful systems may be irreducibly small scale and place based.

  9. Detection of Dirofilaria immitis in a brown bear (Ursus arctos in Greece

    Directory of Open Access Journals (Sweden)

    Papadopoulos E.

    2017-09-01

    Full Text Available Dirofilaria immitis (canine heartworm is a filarial nematode found in the pulmonary circulation and the heart of susceptible hosts. It represents an important zoonotic vector-borne disease of domestic dogs and several wildlife species. Herein we report for the first time, the finding of Dirofilaria immitis worms in a brown bear killed in a vehicle collision in Northern Greece. The worms were morphologically identified; molecular examination, based on the analysis of the mitochondrial genes 12S (433 bp and CO1 (610 bp, verified the identification by demonstrating 100% similarity to D. immitis specimens deposited in GenBank. Brown bears in Greece occupy habitats that are shared with the potential wild and domestic hosts and the vectors of D. immitis and thus may be particularly susceptible to this parasite. This report contributes to the knowledge of dirofilariosis spread in Europe and on the epidemiological threats that may affect the survival of the endangered brown bear in Greece.

  10. Immobilization of Wyoming bears using carfentanil and xylazine.

    Science.gov (United States)

    Kreeger, Terry J; Bjornlie, Dan; Thompson, Dan; Clapp, Justin; Clark, Colby; Hansen, Cole; Huizenga, Matt; Lockwood, Sam

    2013-07-01

    Seven grizzly (Ursus arctos; four male, three female) and three black (Ursus americanus; two male, one female) bears caught in culvert traps or leg snares were immobilized in northwestern Wyoming with carfentanil and xylazine at doses, respectively, of 0.011 ± 0.001 and 0.12 ± 0.01 mg/kg for grizzly bears and 0.014 ± 0.002 and 0.15 ± 0.04 mg/kg for black bears. These drugs were antagonized with 1 mg/kg naltrexone and 2 mg/kg tolazoline. Induction and recovery times, respectively, were 4.3 ± 0.5 and 7.1 ± 0.8 min for grizzly bears and 5.2 ± 0.4 and 9.1 ± 2.2 min for black bears. Inductions were smooth and uneventful. Recoveries were characterized initially by increased respiration followed by raising of the head, which quickly led to a full recovery, with the bears recognizing and avoiding humans and moving away, maneuvering around obstacles. All bears experienced respiratory depression, which did not significantly improve with supplemental oxygen on the basis of pulse oximetry (P=0.56). Rectal temperatures were normothermic. Carfentanil-xylazine immobilization of bears provided significant advantages over other drug regimens, including small drug volumes, predictable inductions, quick and complete recoveries, and lower costs. On the basis of these data, both grizzly and black bears can be immobilized effectively with 0.01 mg/kg carfentanil and 0.1 mg/kg xylazine.

  11. PREVALENCE OF ANTIBODIES AGAINST TOXOPLASMA GONDII IN POLAR BEARS (URSUS MARITIMUS) FROM SVALBARD AND EAST GREENLAND

    Science.gov (United States)

    Serum samples from 419 polar bears (Ursus maritimus) from Svalbard and the Barents Sea (collected 1990 - 2000) and 108 polar bears from East Greenland (collected 1999 - 2004) were assayed for antibodies against Toxoplasma gondii using the modified agglutination test (MAT). Antibody prevalences were ...

  12. Could brown bears (Ursus arctos) have survived in Ireland during the Last Glacial Maximum?

    Science.gov (United States)

    Leonard, Saoirse A; Risley, Claire L; Turvey, Samuel T

    2013-08-23

    Brown bears are recorded from Ireland during both the Late Pleistocene and early-mid Holocene. Although most of the Irish landmass was covered by an ice sheet during the Last Glacial Maximum (LGM), Irish brown bears are known to have hybridized with polar bears during the Late Pleistocene, and it is suggested that the Irish brown bear population did not become extinct but instead persisted in situ through the LGM in a southwestern ice-free refugium. We use historical population modelling to demonstrate that brown bears are highly unlikely to have survived through the LGM in Ireland under any combination of life-history parameters shown by living bear populations, but instead would have rapidly become extinct following advance of the British-Irish ice sheet, and probably recolonized Ireland during the end-Pleistocene Woodgrange Interstadial from a closely related nearby source population. The time available for brown bear-polar bear hybridization was therefore restricted to narrow periods at the beginning or end of the LGM. Brown bears would have been extremely vulnerable to extinction in Quaternary habitat refugia and required areas substantially larger than southwestern Ireland to survive adverse glacial conditions.

  13. Temporal, spatial, and environmental influences on the demographics of grizzly bears in the Greater Yellowstone Ecosystem

    Science.gov (United States)

    Schwartz, Charles C.; Haroldson, Mark A.; White, Gary C.; Harris, Richard B.; Cherry, Steve; Keating, Kim A.; Moody, Dave; Servheen, Christopher

    2006-01-01

    During the past 2 decades, the grizzly bear (Ursus arctos) population in the Greater Yellowstone Ecosystem (GYE) has increased in numbers and expanded in range. Understanding temporal, environmental, and spatial variables responsible for this change is useful in evaluating what likely influenced grizzly bear demographics in the GYE and where future management efforts might benefit conservation and management. We used recent data from radio-marked bears to estimate reproduction (1983–2002) and survival (1983–2001); these we combined into models to evaluate demographic vigor (lambda [λ]). We explored the influence of an array of individual, temporal, and spatial covariates on demographic vigor.

  14. Is Bone Mineral Composition Disrupted by Organochlorines in East Greenland Polar Bears (Ursus maritimus)?

    DEFF Research Database (Denmark)

    Sonne, C.; Dietz, R.; Born, E. W.

    2004-01-01

    We analyzed bone mineral density (BMD) in skulls of polar bears (Ursus maritimus) (n = 139) from East Greenland sampled during 1892-2002. Our primary goal was to detect possible changes in bone mineral content (osteopenia) due to elevated exposure to organochlorine [polychlorinated biphenyls (PCBs.......04) and SigmaCHL (p polar...... bears may have been caused by organochlorine exposure. Udgivelsesdato: 2004-Dec...

  15. HYDROCEPHALUS IN THREE JUVENILE NORTH AMERICAN BLACK BEARS (URSUS AMERICANUS).

    Science.gov (United States)

    Ferguson, Sylvia H; Novak, Janelle; Hecht, Silke; Craig, Linden E

    2016-06-01

    Hydrocephalus has been reported in a variety of species, including the North American black bear ( Ursus americanus ). This report describes three cases of hydrocephalus in this species from wild bears aged 3-4 mo considered retrospectively from necropsy records of one institution. Clinical signs included cortical blindness and ataxia. Primary gross findings were doming of the skull, gyri compression and flattening, and lateral ventricle dilation. Two cases had severe bilateral ventricular dilation with loss of the septum pellucidum; atrophy of the surrounding corpus callosum; and bilateral periventricular tears involving the caudate nuclei, internal capsule, and adjacent cerebrum. Histologically, the cases with periventricular tearing had severe axonal loss and degeneration, malacia, hemorrhage, and variable periventricular astrocytosis. All cases were likely congenital, given the bears' age and lack of an apparent acquired obstruction.

  16. Seroprevalence of Toxoplasma gondii in American Black Bears ( Ursus americanus ) of the Central Appalachians, USA.

    Science.gov (United States)

    Cox, John J; Murphy, Sean M; Augustine, Ben C; Guthrie, Joseph M; Hast, John T; Maehr, Sutton C; McDermott, Joseph

    2017-07-01

    We assessed Toxoplasma gondii seroprevalence in 53 free-ranging American black bears ( Ursus americanus ) in the Central Appalachian Mountains, US. Seroprevalence was 62% with no difference between males and females or between juvenile and adult bears. Wildlife agencies should consider warnings in hunter education programs to reduce the chances for human infection from this source.

  17. Transthyretin-Binding Activity of Contaminants in Blood from Polar Bear (Ursus maritimus) Cubs

    NARCIS (Netherlands)

    Bytingsvik, J.; Simon, E.; Leonards, P.E.G.; Lamoree, M.H.; Lie, E.; Aars, J.; Derocher, A. E.; Wiig, O.; Jenssen, B.M.; Hamers, T.

    2013-01-01

    We determined the transthyretin (TTR)-binding activity of blood-accumulating contaminants in blood plasma samples of approximately 4-months-old polar bear (Ursus maritimus) cubs from Svalbard sampled in 1998 and 2008. The TTR-binding activity was measured as thyroxine (T4)-like equivalents (T4-EQ

  18. Could brown bears (Ursus arctos) have survived in Ireland during the Last Glacial Maximum?

    OpenAIRE

    Leonard, Saoirse A.; Risley, Claire L.; Turvey, Samuel T.

    2013-01-01

    Brown bears are recorded from Ireland during both the Late Pleistocene and early?mid Holocene. Although most of the Irish landmass was covered by an ice sheet during the Last Glacial Maximum (LGM), Irish brown bears are known to have hybridized with polar bears during the Late Pleistocene, and it is suggested that the Irish brown bear population did not become extinct but instead persisted in situ through the LGM in a southwestern ice-free refugium. We use historical population modelling to d...

  19. Can polar bears use terrestrial foods to offset lost ice-based hunting opportunities?

    Science.gov (United States)

    Rode, Karyn D.; Robbins, Charles T.; Nelson, Lynne; Amstrup, Steven C.

    2015-01-01

    Increased land use by polar bears (Ursus maritimus) due to climate-change-induced reduction of their sea-ice habitat illustrates the impact of climate change on species distributions and the difficulty of conserving a large, highly specialized carnivore in the face of this global threat. Some authors have suggested that terrestrial food consumption by polar bears will help them withstand sea-ice loss as they are forced to spend increasing amounts of time on land. Here, we evaluate the nutritional needs of polar bears as well as the physiological and environmental constraints that shape their use of terrestrial ecosystems. Only small numbers of polar bears have been documented consuming terrestrial foods even in modest quantities. Over much of the polar bear's range, limited terrestrial food availability supports only low densities of much smaller, resident brown bears (Ursus arctos), which use low-quality resources more efficiently and may compete with polar bears in these areas. Where consumption of terrestrial foods has been documented, polar bear body condition and survival rates have declined even as land use has increased. Thus far, observed consumption of terrestrial food by polar bears has been insufficient to offset lost ice-based hunting opportunities but can have ecological consequences for other species. Warming-induced loss of sea ice remains the primary threat faced by polar bears.

  20. Tetranucleotide microsatellite loci from the black bear (Ursus americanus)

    Science.gov (United States)

    Sanderlin, J.S.; Faircloth, B.C.; Shamblin, B.; Conroy, M.J.

    2009-01-01

    We describe primers and polymerase chain reaction conditions to amplify 21 tetranucleotide microsatellite DNA loci in black bears (Ursus americanus). We tested primers using individuals from two populations, one each in Georgia and Florida. Among individuals from Georgia (n = 29), primer pairs yielded an average of 2.9 alleles (range, one to four) and an average observed heterozygosity (HO) of 0.50 (range, 0.00 to 0.79). Among individuals from Florida (n = 19), primer pairs yielded an average of 5.7 alleles (range, one to 14) and an HO of 0.55 (range, 0.00 to 1.00). A comparison of previously developed markers with individuals from Georgia suggests that bear populations in Georgia and Florida have reduced allelic diversity relative to other populations. ?? 2008 The Authors.

  1. Acquired umbilical hernias in four captive polar bears (Ursus maritimus).

    Science.gov (United States)

    Velguth, Karen E; Rochat, Mark C; Langan, Jennifer N; Backues, Kay

    2009-12-01

    Umbilical hernias are a common occurrence in domestic animals and humans but have not been well documented in polar bears. Surgical reduction and herniorrhaphies were performed to correct acquired hernias in the region of the umbilicus in four adult captive polar bears (Ursus maritimus) housed in North American zoos. Two of the four bears were clinically unaffected by their hernias prior to surgery. One bear showed signs of severe discomfort following acute enlargement of the hernia. In another bear, re-herniation led to acute abdominal pain due to gastric entrapment and strangulation. The hernias in three bears were surgically repaired by debridement of the hernia ring and direct apposition of the abdominal wall, while the large defect in the most severely affected bear was closed using polypropylene mesh to prevent excessive tension. The cases in this series demonstrate that while small hernias may remain clinically inconsequential for long periods of time, enlargement or recurrence of the defect can lead to incarceration and acute abdominal crisis. Umbilical herniation has not been reported in free-ranging polar bears, and it is suspected that factors such as body condition, limited exercise, or enclosure design potentially contribute to the development of umbilical hernias in captive polar bears.

  2. Population viability and connectivity of the Louisiana black bear (Ursus americanus luteolus)

    Science.gov (United States)

    Laufenberg, Jared S.; Clark, Joseph D.

    2014-01-01

    In 1992, the U.S. Fish and Wildlife Service (USFWS) granted Ursus americanus luteolus (Louisiana black bear) threatened status under the U.S. Endangered Species Act of 1973, listing loss and fragmentation of habitat as the primary threats. A study was developed by the U.S. Geological Survey in cooperation with the University of Tennessee, the Louisiana Department of Wildlife and Fisheries, and the USFWS to estimate demographic rates and genetic structure of Louisiana black bear populations; evaluate relations between environmental and anthropogenic factors and demographic, genetic, and movement characteristics of Louisiana black bear populations; and develop data-driven stochastic population projection models to assess long-term persistence of individual subpopulations and the overall black bear population in Louisiana.

  3. Trichinella Surveillance in Black Bears ( Ursus americanus ) from the Dehcho Region, Northwest Territories, Canada, 2002-15.

    Science.gov (United States)

    Larter, Nicholas C; Elkin, Brett T; Forbes, Lorry B; Wagner, Brent; Allaire, Danny G

    2017-04-01

    We used muscle digestion to test black bears ( Ursus americanus ) from the southwestern Northwest Territories, Canada, for Trichinella. Results showed a prevalence of 4.1%. Some bears had infection intensities of more than one larva per gram of muscle tissue; this level in meat is considered to pose a human consumption safety risk.

  4. Consumption of seeds of southwestern white pine (Pinus strobiformis) by Black Bear (Ursus americanus)

    Science.gov (United States)

    Mattson, David J.; Arundel, Terry A.

    2013-01-01

    We report a discovery of black bears (Ursus americanus) consuming seeds of southwestern white pine (Pinus strobiformis) on north slopes of the San Francisco Peaks near Flagstaff, Arizona, in high-elevation, mixed-species conifer forest. In one instance, a bear had obtained seeds from cones excavated from a larder horde made by a red squirrel (Tamiasciurus hudsonicus). Consumption of seeds of southwestern white pine by bears had not been previously documented. This discovery adds to the number of species of pine used by bears for food as well as the geographic range within which the behavior occurs.

  5. Grizzly bear use of army cutworm moths in the Yellowstone Ecosystem

    Science.gov (United States)

    French, Steven P.; French, Marilynn G.; Knight, Richard R.

    1994-01-01

    The ecology of alpine aggregations of army cutworm moths (Euxoa auxiliaris) and the feeding behavior of grizzly bears (Ursus arctos horribilis) at these areas were studied in the Yellowstone ecosystem from 1988 to 1991. Army cutworm moths migrate to mountain regions each summer to feed at night on the nectar of alpine and subalpine flowers, and during the day they seek shelter under various rock formations. Grizzly bears were observed feeding almost exclusively on moths up to 3 months each summer at the 10 moth-aggregation areas we identified. Fifty-one different grizzly bears were observed feeding at 4 of these areas during a single day in August 1991. Army cutworm moths are a preferred source of nutrition for many grizzly bears in the Yellowstone ecosystem and represent a high quality food that is available during hyperphagia.

  6. Is bone mineral composition disrupted by organochlorines in east Greenland polar bears (Ursus maritimus)?

    DEFF Research Database (Denmark)

    Sonne, Christian; Dietz, Rune; Born, Erik W

    2004-01-01

    We analyzed bone mineral density (BMD) in skulls of polar bears (Ursus maritimus) (n = 139) from East Greenland sampled during 1892-2002. Our primary goal was to detect possible changes in bone mineral content (osteopenia) due to elevated exposure to organochlorine [polychlorinated biphenyls (PCBs...

  7. Foot-and-mouth disease in Asiatic black bears (Ursus thibetanus).

    Science.gov (United States)

    Officer, Kirsty; Lan, Nguyen Thi; Wicker, Leanne; Hoa, Nguyen Thi; Weegenaar, Annemarie; Robinson, Jill; Ryoji, Yamaguchi; Loukopoulos, Panayiotis

    2014-09-01

    Foot-and-mouth disease (FMD) is a highly contagious, debilitating, and globally significant viral disease typically affecting cloven-hoofed hosts. The diagnosis of FMD in bears in Vietnam is described. The current study describes a confirmed case of FMD in a bear species, and the clinical signs compatible with FMD in a Malayan sun bear. Thirteen Asiatic black bears (Ursus thibetanus) and 1 Malayan sun bear (Helarctos malayanus) were apparently affected. In August 2011, an adult bear became lethargic, and developed footpad vesicles. Over 15 days, 14 out of 17 bears developed similar signs; the remaining 3 co-housed bears and another 57 resident bears did not. All affected bears developed vesicles on all footpads, and most were lethargic for 24-48 hr. Nasal and oral lesions were noted in 6 and 3 cases, respectively. Within 1 month, all looked normal. Foot-and-mouth disease virus (FMDV) was detected by reverse transcription polymerase chain reaction, classified as serotype O, and isolated by virus isolation techniques. Phylogenetic analysis demonstrated clustering of 3 bear isolates, in a branch distinct from other FMDV type O isolates. The outbreak likely occurred due to indirect contact with livestock, and was facilitated by the high density of captive bears. It showed that Asiatic black bears are capable of contracting FMDV and developing clinical disease, and that the virus spreads easily between bears in close contact. © 2014 The Author(s).

  8. Hemotropic mycoplasma infection in wild black bears (Ursus thibetanus japonicus).

    Science.gov (United States)

    Iso, Takehiro; Suzuki, Jin; Sasaoka, Fumina; Sashida, Hinako; Watanabe, Yusaku; Fujihara, Masatoshi; Nagai, Kazuya; Harasawa, Ryô

    2013-04-12

    This is the first report on Mycoplasma infection in wild bears. We report a novel hemotropic Mycoplasma (also called hemoplasma) detected in a free-ranging black bear (Ursus thibetanus japonicus) in Japan. We then used real-time PCR to look for hemoplasma DNA in blood samples collected from 15 bears and found that eight (53%) were positive. Among these eight PCR samples, seven showed a melting temperature of around 85.5°C, while the remaining one showed a single peak at 82.26°C. Almost the entire region of the 16S rRNA gene as well as the 16S-23S rRNA intergenic transcribed spacer (ITS) region from the sample that showed a melting temperature of 82.26°C was successfully amplified by means of end-point PCR. The nucleotide sequences of the 16S rRNA gene and the ITS region were then determined and compared with those of authentic Mycoplasma species. Our examinations revealed the presence of a novel hemoplasma in Japanese black bears. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. A novel endogenous betaretrovirus group characterized from polar bears (Ursus maritimus) and giant pandas (Ailuropoda melanoleuca)

    OpenAIRE

    Mayer, Jens; Tsangaras, Kyriakos; Heeger, Felix; Ávila-Arcos, Maria; Stenglein, Mark D.; Chen, Wei; Sun, Wei; Mazzoni, Camila; Osterrieder, Nikolaus; Greenwood, Alex D.

    2013-01-01

    Transcriptome analysis of polar bears (Ursus maritimus) yielded sequences with highest similarity to the human endogenous retrovirus group HERV-K(HML-2). Further analysis of the polar bear draft genome identified an endogenous betaretrovirus group comprising 26 proviral copies and 231 solo LTRs. Molecular dating indicates the group originated before the divergence of bears from a common ancestor but is not present in all carnivores. Closely related sequences were identified in the giant panda...

  10. Active fans and grizzly bears: Reducing risks for wilderness campers

    Science.gov (United States)

    Sakals, M. E.; Wilford, D. J.; Wellwood, D. W.; MacDougall, S. A.

    2010-03-01

    Active geomorphic fans experience debris flows, debris floods and/or floods (hydrogeomorphic processes) that can be hazards to humans. Grizzly bears ( Ursus arctos) can also be a hazard to humans. This paper presents the results of a cross-disciplinary study that analyzed both hydrogeomorphic and grizzly bear hazards to wilderness campers on geomorphic fans along a popular hiking trail in Kluane National Park and Reserve in southwestern Yukon Territory, Canada. Based on the results, a method is proposed to reduce the risks to campers associated with camping on fans. The method includes both landscape and site scales and is based on easily understood and readily available information regarding weather, vegetation, stream bank conditions, and bear ecology and behaviour. Educating wilderness campers and providing a method of decision-making to reduce risk supports Parks Canada's public safety program; a program based on the principle of user self-sufficiency. Reducing grizzly bear-human conflicts complements the efforts of Parks Canada to ensure a healthy grizzly bear population.

  11. Admixture and gene flow from Russia in the recovering Northern European brown bear (Ursus arctos).

    Science.gov (United States)

    Kopatz, Alexander; Eiken, Hans Geir; Aspi, Jouni; Kojola, Ilpo; Tobiassen, Camilla; Tirronen, Konstantin F; Danilov, Pjotr I; Hagen, Snorre B

    2014-01-01

    Large carnivores were persecuted to near extinction during the last centuries, but have now recovered in some countries. It has been proposed earlier that the recovery of the Northern European brown bear is supported by migration from Russia. We tested this hypothesis by obtaining for the first time continuous sampling of the whole Finnish bear population, which is located centrally between the Russian and Scandinavian bear populations. The Finnish population is assumed to experience high gene flow from Russian Karelia. If so, no or a low degree of genetic differentiation between Finnish and Russian bears could be expected. We have genotyped bears extensively from all over Finland using 12 validated microsatellite markers and compared their genetic composition to bears from Russian Karelia, Sweden, and Norway. Our fine masked investigation identified two overlapping genetic clusters structured by isolation-by-distance in Finland (pairwise FST = 0.025). One cluster included Russian bears, and migration analyses showed a high number of migrants from Russia into Finland, providing evidence of eastern gene flow as an important driver during recovery. In comparison, both clusters excluded bears from Sweden and Norway, and we found no migrants from Finland in either country, indicating that eastern gene flow was probably not important for the population recovery in Scandinavia. Our analyses on different spatial scales suggest a continuous bear population in Finland and Russian Karelia, separated from Scandinavia.

  12. Grizzly bear density in Glacier National Park, Montana

    Science.gov (United States)

    Kendall, K.C.; Stetz, J.B.; Roon, David A.; Waits, L.P.; Boulanger, J.B.; Paetkau, David

    2008-01-01

    We present the first rigorous estimate of grizzly bear (Ursus arctos) population density and distribution in and around Glacier National Park (GNP), Montana, USA. We used genetic analysis to identify individual bears from hair samples collected via 2 concurrent sampling methods: 1) systematically distributed, baited, barbed-wire hair traps and 2) unbaited bear rub trees found along trails. We used Huggins closed mixture models in Program MARK to estimate total population size and developed a method to account for heterogeneity caused by unequal access to rub trees. We corrected our estimate for lack of geographic closure using a new method that utilizes information from radiocollared bears and the distribution of bears captured with DNA sampling. Adjusted for closure, the average number of grizzly bears in our study area was 240.7 (95% CI = 202–303) in 1998 and 240.6 (95% CI = 205–304) in 2000. Average grizzly bear density was 30 bears/1,000 km2, with 2.4 times more bears detected per hair trap inside than outside GNP. We provide baseline information important for managing one of the few remaining populations of grizzlies in the contiguous United States.

  13. Enlarged clitoris in wild polar bears (Ursus maritimus) can be misdiagnosed as pseudohermaphroditism

    DEFF Research Database (Denmark)

    Sonne, C.; Leifsson, Páll Skuli; Dietz, R.

    2005-01-01

    A 23-year-old female polar bear (Ursus maritimus) killed in an Inuit hunt in East Greenland on July 9, 1999 had a significantly enlarged clitoris resembling, in size, form and colour, those of previously reported 'pseudohermaphroditic' polar bears from Svalbard. It has been suggested that an enzyme...... and internal reproductive organs of the present were similar to a reference group of 23 normal adult female polar bears from East Greenland collected in 1999-2002. The aberrant bear was a female genotype, and macroscopic examination of her internal reproductive organs indicated that she was reproductively....... It is hence possible that the previously reported adult female polar bear pseudohermaphrodites from Svalbard are in fact misdiagnoses. Therefore, future studies examining pseudohermaphroditism in wildlife should consider that certain occurrences are natural events, e.g., enlarged clitoris in the present East...

  14. MHC class II DQB diversity in the Japanese black bear, Ursus thibetanus japonicus

    Science.gov (United States)

    2012-01-01

    Background The major histocompatibility complex (MHC) genes are one of the most important genetic systems in the vertebrate immune response. The diversity of MHC genes may directly influence the survival of individuals against infectious disease. However, there has been no investigation of MHC diversity in the Asiatic black bear (Ursus thibetanus). Here, we analyzed 270-bp nucleotide sequences of the entire exon 2 region of the MHC DQB gene by using 188 samples from the Japanese black bear (Ursus thibetanus japonicus) from 12 local populations. Results Among 185 of 188 samples, we identified 44 MHC variants that encoded 31 different amino acid sequences (allotypes) and one putative pseudogene. The phylogenetic analysis suggests that MHC variants detected from the Japanese black bear are derived from the DQB locus. One of the 31 DQB allotypes, Urth-DQB*01, was found to be common to all local populations. Moreover, this allotype was shared between the black bear on the Asian continent and the Japanese black bear, suggesting that Urth-DQB*01 might have been maintained in the ancestral black bear population for at least 300,000 years. Our findings, from calculating the ratio of non-synonymous to synonymous substitutions, indicate that balancing selection has maintained genetic variation of peptide-binding residues at the DQB locus of the Japanese black bear. From examination of genotype frequencies among local populations, we observed a considerably lower level of observed heterozygosity than expected. Conclusions The low level of observed heterozygosity suggests that genetic drift reduced DQB diversity in the Japanese black bear due to a bottleneck event at the population or species level. The decline of DQB diversity might have been accelerated by the loss of rare variants that have been maintained by negative frequency-dependent selection. Nevertheless, DQB diversity of the black bear appears to be relatively high compared with some other endangered mammalian

  15. MHC class II DQB diversity in the Japanese black bear, Ursus thibetanus japonicus

    Directory of Open Access Journals (Sweden)

    Yasukochi Yoshiki

    2012-11-01

    Full Text Available Abstract Background The major histocompatibility complex (MHC genes are one of the most important genetic systems in the vertebrate immune response. The diversity of MHC genes may directly influence the survival of individuals against infectious disease. However, there has been no investigation of MHC diversity in the Asiatic black bear (Ursus thibetanus. Here, we analyzed 270-bp nucleotide sequences of the entire exon 2 region of the MHC DQB gene by using 188 samples from the Japanese black bear (Ursus thibetanus japonicus from 12 local populations. Results Among 185 of 188 samples, we identified 44 MHC variants that encoded 31 different amino acid sequences (allotypes and one putative pseudogene. The phylogenetic analysis suggests that MHC variants detected from the Japanese black bear are derived from the DQB locus. One of the 31 DQB allotypes, Urth-DQB*01, was found to be common to all local populations. Moreover, this allotype was shared between the black bear on the Asian continent and the Japanese black bear, suggesting that Urth-DQB*01 might have been maintained in the ancestral black bear population for at least 300,000 years. Our findings, from calculating the ratio of non-synonymous to synonymous substitutions, indicate that balancing selection has maintained genetic variation of peptide-binding residues at the DQB locus of the Japanese black bear. From examination of genotype frequencies among local populations, we observed a considerably lower level of observed heterozygosity than expected. Conclusions The low level of observed heterozygosity suggests that genetic drift reduced DQB diversity in the Japanese black bear due to a bottleneck event at the population or species level. The decline of DQB diversity might have been accelerated by the loss of rare variants that have been maintained by negative frequency-dependent selection. Nevertheless, DQB diversity of the black bear appears to be relatively high compared with some other

  16. MHC class II DQB diversity in the Japanese black bear, Ursus thibetanus japonicus.

    Science.gov (United States)

    Yasukochi, Yoshiki; Kurosaki, Toshifumi; Yoneda, Masaaki; Koike, Hiroko; Satta, Yoko

    2012-11-29

    The major histocompatibility complex (MHC) genes are one of the most important genetic systems in the vertebrate immune response. The diversity of MHC genes may directly influence the survival of individuals against infectious disease. However, there has been no investigation of MHC diversity in the Asiatic black bear (Ursus thibetanus). Here, we analyzed 270-bp nucleotide sequences of the entire exon 2 region of the MHC DQB gene by using 188 samples from the Japanese black bear (Ursus thibetanus japonicus) from 12 local populations. Among 185 of 188 samples, we identified 44 MHC variants that encoded 31 different amino acid sequences (allotypes) and one putative pseudogene. The phylogenetic analysis suggests that MHC variants detected from the Japanese black bear are derived from the DQB locus. One of the 31 DQB allotypes, Urth-DQB*01, was found to be common to all local populations. Moreover, this allotype was shared between the black bear on the Asian continent and the Japanese black bear, suggesting that Urth-DQB*01 might have been maintained in the ancestral black bear population for at least 300,000 years. Our findings, from calculating the ratio of non-synonymous to synonymous substitutions, indicate that balancing selection has maintained genetic variation of peptide-binding residues at the DQB locus of the Japanese black bear. From examination of genotype frequencies among local populations, we observed a considerably lower level of observed heterozygosity than expected. The low level of observed heterozygosity suggests that genetic drift reduced DQB diversity in the Japanese black bear due to a bottleneck event at the population or species level. The decline of DQB diversity might have been accelerated by the loss of rare variants that have been maintained by negative frequency-dependent selection. Nevertheless, DQB diversity of the black bear appears to be relatively high compared with some other endangered mammalian species. This result suggests that

  17. Predatory behavior of grizzly bears feeding on elk calves in Yellowstone National Park

    Science.gov (United States)

    French, Steven P.; French, Marilynn G.

    1990-01-01

    Grizzly bears (Ursus arctos horribilis) were observed preying on elk calves (Cervus elaphus) on 60 occasions in Yellowstone National Park, with 29 confirmed kills. Some bears were deliberate predators and effectively preyed on elk calves for short periods each spring, killing up to 1 calf daily. Primary hunting techniques were searching and chasing although some bears used a variety of techniques during a single hunt. They hunted both day and night and preyed on calves in the open and in the woods. Excess killing occurred when circumstances permitted. One bear caught 5 calves in a 15-minute interval. Elk used a variety of antipredator defenses and occasionally attacked predacious bears. The current level of this feeding behavior appears to be greater than previously reported. This is probably related to the increased availability of calves providing a greater opportunity for learning, and the adaptation of a more predatory behavior by some grizzly bears in Yellowstone.

  18. Diet and Macronutrient Optimization in Wild Ursids: A Comparison of Grizzly Bears with Sympatric and Allopatric Black Bears.

    Science.gov (United States)

    Costello, Cecily M; Cain, Steven L; Pils, Shannon; Frattaroli, Leslie; Haroldson, Mark A; van Manen, Frank T

    2016-01-01

    When fed ad libitum, ursids can maximize mass gain by selecting mixed diets wherein protein provides 17 ± 4% of digestible energy, relative to carbohydrates or lipids. In the wild, this ability is likely constrained by seasonal food availability, limits of intake rate as body size increases, and competition. By visiting locations of 37 individuals during 274 bear-days, we documented foods consumed by grizzly (Ursus arctos) and black bears (Ursus americanus) in Grand Teton National Park during 2004-2006. Based on published nutritional data, we estimated foods and macronutrients as percentages of daily energy intake. Using principal components and cluster analyses, we identified 14 daily diet types. Only 4 diets, accounting for 21% of days, provided protein levels within the optimal range. Nine diets (75% of days) led to over-consumption of protein, and 1 diet (3% of days) led to under-consumption. Highest protein levels were associated with animal matter (i.e., insects, vertebrates), which accounted for 46-47% of daily energy for both species. As predicted: 1) daily diets dominated by high-energy vertebrates were positively associated with grizzly bears and mean percent protein intake was positively associated with body mass; 2) diets dominated by low-protein fruits were positively associated with smaller-bodied black bears; and 3) mean protein was highest during spring, when high-energy plant foods were scarce, however it was also higher than optimal during summer and fall. Contrary to our prediction: 4) allopatric black bears did not exhibit food selection for high-energy foods similar to grizzly bears. Although optimal gain of body mass was typically constrained, bears usually opted for the energetically superior trade-off of consuming high-energy, high-protein foods. Given protein digestion efficiency similar to obligate carnivores, this choice likely supported mass gain, consistent with studies showing monthly increases in percent body fat among bears in this

  19. Identification of functional corridors with movement characteristics of brown bears on the Kenai Peninsula, Alaska

    Science.gov (United States)

    Graves, T.A.; Farley, S.; Goldstein, M.I.; Servheen, C.

    2007-01-01

    We identified primary habitat and functional corridors across a landscape using Global Positioning System (GPS) collar locations of brown bears (Ursus arctos). After deriving density, speed, and angular deviation of movement, we classified landscape function for a group of animals with a cluster analysis. We described areas with high amounts of sinuous movement as primary habitat patches and areas with high amounts of very directional, fast movement as highly functional bear corridors. The time between bear locations and scale of analysis influenced the number and size of corridors identified. Bear locations should be collected at intervals ???6 h to correctly identify travel corridors. Our corridor identification technique will help managers move beyond the theoretical discussion of corridors and linkage zones to active management of landscape features that will preserve connectivity. ?? 2007 Springer Science+Business Media, Inc.

  20. Spatial memory in captive American black bears (Ursus americanus).

    Science.gov (United States)

    Zamisch, Valeria; Vonk, Jennifer

    2012-11-01

    The spatial memory and foraging strategies of four adult captive-born American black bears (Ursus americanus) were explored in four experiments using a simulated foraging task. In the first three experiments, each session consisted of two phases separated by a delay: During the exploration phase, subjects foraged among a set of baited and unbaited sites. During the delay, the same locations were rebaited and subjects were released again and allowed to search the sites (search phase). In Experiments 1a and 1b, different sites were baited each day and the interval between exploration and search was short (4 hr or 15 min). Subjects were not accurate at recovering the food items in either experiment. In Experiment 2, an "informed forager" paradigm was used in which one subject was given privileged knowledge about the location of the food during the exploration phase and was later released with an "uninformed" competitor during the search phase. The bears did not achieve above-chance recovery accuracy even in the presence of a competitor. In Experiment 3, the same two of four sites were continually baited and the bears were released simultaneously over a period of 20 days, with each baiting separated by 2 or 3 days. As a group, the bears' foraging accuracy with repeated baiting and longer intervals approached greater than chance accuracy. Results suggest some limitations on bears' use of spatial memory in captive environments, but reveal the potential for use of spatial memory over longer delays.

  1. The Gut Microbiota Modulates Energy Metabolism in the Hibernating Brown Bear Ursus arctos

    DEFF Research Database (Denmark)

    Sommer, Felix; Ståhlman, Marcus; Ilkayeva, Olga

    2016-01-01

    the microbiota of free-ranging brown bears during their active phase and hibernation. Compared to the active phase, hibernation microbiota had reduced diversity, reduced levels of Firmicutes and Actinobacteria, and increased levels of Bacteroidetes. Several metabolites involved in lipid metabolism, including...

  2. Caching behaviour by red squirrels may contribute to food conditioning of grizzly bears

    Directory of Open Access Journals (Sweden)

    Julia Elizabeth Put

    2017-08-01

    Full Text Available We describe an interspecific relationship wherein grizzly bears (Ursus arctos horribilis appear to seek out and consume agricultural seeds concentrated in the middens of red squirrels (Tamiasciurus hudsonicus, which had collected and cached spilled grain from a railway. We studied this interaction by estimating squirrel density, midden density and contents, and bear activity along paired transects that were near (within 50 m or far (200 m from the railway. Relative to far ones, near transects had 2.4 times more squirrel sightings, but similar numbers of squirrel middens. Among 15 middens in which agricultural products were found, 14 were near the rail and 4 subsequently exhibited evidence of bear digging. Remote cameras confirmed the presence of squirrels on the rail and bears excavating middens. We speculate that obtaining grain from squirrel middens encourages bears to seek grain on the railway, potentially contributing to their rising risk of collisions with trains.

  3. Acute Chagas' cardiopathy in a polar bear (Ursus maritimus in Guadalajara, Mexico

    Directory of Open Access Journals (Sweden)

    J. Jaime-Andrade G.

    1997-08-01

    Full Text Available We report a 24 year old female polar bear (Ursus maritimus who contracted Chagas' infection at the Guadalajara Zoo, in Jalisco, México, and died of acute Chagas' carditis 15 days later. The histopathological findings are described, as well as the presence of triatomines (Triatoma longipennis Usinger infected with Trypanosoma cruzi collected within 5 meters from the place where the animal lived in the city of Guadalajara.Relatamos o caso de uma ursa polar (Ursus maritimus de 24 anos de idade, que contraiu a infecção chagásica no Zoológico de Guadalajara, em Jalisco, no México, e morreu de cardite chagásica aguda 15 dias após o início da sintomatologia. Os achados histopatológicos são descritos, bem como a presença de triatomíneos (Triatoma longipennis Usinger infectados por Trypanosoma cruzi coletados a 5 metros do local onde o animal vivia, na cidade de Guadalajara.

  4. Bears and pipeline construction in Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Follmann, E.H.; Hechtel, J.L. (Univ. of Alaska Fairbanks, AK (USA))

    1990-06-01

    Serious problems were encountered with bears during construction of the 1274-km trans-Alaska oil pipeline between Prudhoe Bay and Valdez. This multi-billion-dollar project traversed both black bear (Ursus americanus Pallas) and grizzly bear (U. arctos L.) habitat throughtout its entire length. Plans for dealing with anticipated problems with bears were often inadequate. Most (71%) problems occurred north of the Yukon River in a previously roadless wilderness where inadequate refuse disposal and widespread animal feeding created dangerous situations. Of the 192 officially reported bear problems associated with the Trans-Alaska Pipeline System (TAPS) (1971-1979), about 65% involved the presence of bears in camps or dumps, 13% the feeding of bears on garbage or handouts, 10% property damage or economic loss, 7% bears under and in buildings, and only 5% charges by bears. Remarkably, no bear-related injuries were reported, suggesting that bears became accustomed to people and did not regard them as a threat. Following construction of the TAPS there have been proposals for pipelines to transport natural gas from Prudhoe Bay to southern and Pacific-rim markets. Based on past experience, some animal control measures were developed during the planning phase for the authorized gas pipeline route in Alaska. Fences installed around 100-person survey camps were found to be effective in deterring bears in two traditionally troublesome areas. 16 refs., 7 figs., 1 tab.

  5. Seasonal food habits of brown bear (Ursus arctos syriacus Linnaeus, 1758 in Cenral Alborz Protected Area

    Directory of Open Access Journals (Sweden)

    Bagher Nezami Balouchi

    2014-11-01

    Full Text Available Mountains of Central Alborz Protected Area hold a big population of brown bear, the largest varnivore species in Iran. Understanding food habits is crucial to understanding the ecology of the species. Diet influences many ecological and life-history traits, such as spatial distribution, social and foraging behavior, body mass and reproduction. Therefore, during Jun 2006 to May 2007 we had a comprehensive study on brown bear food habits, as the largest omnivorous of the country in Central Alborz Protected Area. Our investigation showed that plant materials composed the main proportion of food items of the brown bears in the spring until mid-summer. Insects, especially ants were predominantly eaten in the first half of summer. As approaching to hibernation period in late autumn, fruits played the main role of bear food items having high fat content. We never witnessed bear attack on wild herbivores. Furthermore, we never found remains of wild herbivores except a few livestock remains in brown bear scats during our survey period. Accordingly, we concluded that brown bears were almost herbivorous in the Central Alborz Protected Area. We never found any bear scats or fresh signs in three consecutive years, between first of December until mid of March. Also, no direct sighting of brown bear was reported to us by local people and game keepers within the mentioned period. Accordingly, it can be concluded that the brown bears hibernate for a period of 3-3.5 months in winter in the Central Alborz Protected Area.

  6. Individual effects of seasonal changes, visitor density, and concurrent bear behavior on stereotypical behaviors in captive polar bears (Ursus maritimus).

    Science.gov (United States)

    Kelly, Krista R; Harrison, Michelle L; Size, Daniele D; MacDonald, Suzanne E

    2015-01-01

    Stereotypical behaviors in captive polar bears (Ursus maritimus) can be detrimental to their welfare. These behaviors can be reduced through enrichment programs but are often not completely eliminated, so identifying potential triggers is important. The present study investigated the influences of seasonal changes, visitor density, and concurrent bear activity on stereotypical behaviors exhibited by 3 captive polar bears at the Toronto Zoo. All bears exhibited these behaviors; however, individual differences were found in duration and form. The male exhibited less stereotypical behavior during spring, and the females exhibited less stereotypical behavior during winter. An increase in visitor density was associated with more stereotypical behavior in 1 female but less stereotypical behavior in the other 2 bears. All bears engaged in more stereotypical behaviors when the other bears were inactive, and 1 female engaged in more stereotypical behaviors when the other bears were out of sight. Further, when conspecifics were active, all bears engaged in less stereotypical behaviors. Given the variability among individual bears, future enrichment programs must be tailored to the needs of individuals to maximize efficacy.

  7. Effect of colloid (Androcoll-Bear, Percoll, and PureSperm) selection on the freezability of brown bear (Ursus arctos) sperm.

    Science.gov (United States)

    Álvarez-Rodríguez, M; Álvarez, M; Anel-López, L; López-Urueña, E; Manrique, P; Borragán, S; Morrell, J M; de Paz, P; Anel, L

    2016-04-01

    The development of a species-specific conservation protocol that involves artificial insemination with frozen semen needs to validate an effective methodology for freezing semen. Colloid centrifugation has been suggested and widely applied as an effective tool for selecting animal spermatozoa for artificial breeding. The objective of the present study was to compare different methods of centrifugation, single layer using Androcoll-Bear and Percoll and double layer using PureSperm 100 (in two different discontinuous gradients 40%-80% and 45%-90%), for the selection of fresh brown bear sperm samples. In the before freezing group, all selected samples showed a higher progressive motility and viability (except Percoll for motility 43.0 ± 5.3 [P Bear in number of damaged acrosomes, different relative to the control (control, 5.3 ± 0.6; PureSperm 80, 2.0 ± 0.3; Androcoll, 2.1 ± 0.9 [P Bear constitutes a useful tool for handling of brown bear ejaculates owing to its simple handling and procedure with a reliable sperm selection and freezability. This colloid yielded an improvement in several sperm parameters in brown bear frozen-thawed semen; the selected spermatozoa of fresh samples with this colloid showed a better resistance to freezing compared with the control sample not only for motility but also for viability. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Biochemical Content of Cambium of Abies nephrolepis Eaten by Bears on the Far East of Russia

    Directory of Open Access Journals (Sweden)

    I. V. Seryodkin

    2017-01-01

    Full Text Available The peculiarity of bears behavior of stripping of bark is typical for all species. We have described the damage to trees, by Asiatic black bear (Ursus thibetanus and brown bear (U. arctos in Primorsky Krai and by brown bears on the Sakhalin Island during 1998–2015. In this study, we studied the damaged bark of the tree only in cases where it was clear that part of the cambium was eaten by bears. Cambium of species Abies nephrolepis is the most preferred for bear consumption in Primorsky Krai. We distinguished very large seasonal fluctuations in the amount of its consumption. The greatest interest of bears in this kind of food is in the summer time. We have analyzed the composition of the cambium of A. nephrolepis. These results suggest that the important purpose of the use of this kind of food is to restore and maintain the normal functioning of the intestines.

  9. Environmental Impact Analysis Process. Draft Environmental Impact Statement Proposed Alaskan Radar System Over-the-Horizon Backscatter Radar Program

    Science.gov (United States)

    1986-08-01

    Mustela vison wolverine Gulo Kulo river otter Lutra canadensis lynx Lynx canadensis moose Alces alces caribou Rangifer tarandus Dall’s sheep Ovic dalli...tissue respiratory chain function at a power density of 5 mW/cm2 . It is unlikely that such effects would be detectable at the power densities at ground...Vulves vulpes black bear Ursus americanus grizzly bear Ursus arctos marten Martes americana ermine Mustela erminea least weasel Mustela nivalis mink

  10. A retrospective study of end-stage renal disease in captive polar bears (Ursus maritimus).

    Science.gov (United States)

    LaDouceur, Elise E B; Davis, Barbara; Tseng, Flo

    2014-03-01

    This retrospective study summarizes 11 cases of end-stage renal disease (ESRD) in captive polar bears (Ursus maritimus) from eight zoologic institutions across the United States and Canada. Ten bears were female, one was male, and the mean age at the time of death was 24 yr old. The most common clinical signs were lethargy, inappetence, and polyuria-polydipsia. Biochemical findings included azotemia, anemia, hyperphosphatemia, and isosthenuria. Histologic examination commonly showed glomerulonephropathies and interstitial fibrosis. Based on submissions to a private diagnostic institution over a 16-yr period, ESRD was the most commonly diagnosed cause of death or euthanasia in captive polar bears in the United States, with an estimated prevalence of over 20%. Further research is needed to discern the etiology of this apparently common disease of captive polar bears.

  11. Arterial supply and venous drainage of the brain of the black bear (Ursus americanus). II.Intracranial microvasculature

    NARCIS (Netherlands)

    Anderson, B.G.; Anderson, W.D.; Seguin, R.J.

    1989-01-01

    A morphological study of the intracranial microvasculature of the Black bear (Ursus americanus) using vascular casts was undertaken. The object was to provide basic information regarding structural modifications of the microvasculature that might provide insight into the ability to cope with low

  12. Denning of grizzly bears in the Yellowstone National Park area

    Science.gov (United States)

    Judd, Steven L.; Knight, Richard R.; Blanchard, Bonnie M.

    1986-01-01

    Radiotelemetry was used to locate 101 grizzly bear (Ursus arctos) dens from 1975 to 1980; 35 dens were examined on the ground. Pregnant females denned in late October, and most other bears denned by mid-November. Duration of denning average 113, 132, and 170 days for males, females, and females with new cubs, respectively. Males emerged from mid-February to late March, followed by single females and females with yearlings and 2-year-olds. Females with new cubs emerged from early mid-April. Den sites were associated with moderate tree cover (26%-75% canopy cover) on 30°-60° slopes. Dens occurred on all aspects, although northerly exposures were most common. Grizzly bears usually dug new dens but occasionally used natural cavities or a den from a previous year. Males usually dug larger dens than females with young. Eight excavated and 2 natural dens of the 35 examined dens were used for more than 1 year.

  13. Bet-hedging applications for conservation

    Indian Academy of Sciences (India)

    Unknown

    Bet hedging; Bitterroot wilderness; environmental correlation; grizzly bear; least tern; Sterna antillarum; Ursus arctos horribilis ... market, a hedging investor can reduce the risk of devas- ..... populations were approximated by three methods:.

  14. Isolation and characterization of new genetic types of toxoplasma gondii and prevalence of trichinella murrelli from black bear (Ursus americanus)

    Science.gov (United States)

    Black bears (Ursus americanus) are hosts for two important zoonotic parasites, Toxoplasma gondii and Trichinella spp. and bears are hunted for human consumption in the USA. Little is known of the genetic diversity of T. gondii circulating in wildlife. In the present study, antibodies to T. gondii we...

  15. Genomic analysis of expressed sequence tags in American black bear Ursus americanus

    Science.gov (United States)

    2010-01-01

    Background Species of the bear family (Ursidae) are important organisms for research in molecular evolution, comparative physiology and conservation biology, but relatively little genetic sequence information is available for this group. Here we report the development and analyses of the first large scale Expressed Sequence Tag (EST) resource for the American black bear (Ursus americanus). Results Comprehensive analyses of molecular functions, alternative splicing, and tissue-specific expression of 38,757 black bear EST sequences were conducted using the dog genome as a reference. We identified 18 genes, involved in functions such as lipid catabolism, cell cycle, and vesicle-mediated transport, that are showing rapid evolution in the bear lineage Three genes, Phospholamban (PLN), cysteine glycine-rich protein 3 (CSRP3) and Troponin I type 3 (TNNI3), are related to heart contraction, and defects in these genes in humans lead to heart disease. Two genes, biphenyl hydrolase-like (BPHL) and CSRP3, contain positively selected sites in bear. Global analysis of evolution rates of hibernation-related genes in bear showed that they are largely conserved and slowly evolving genes, rather than novel and fast-evolving genes. Conclusion We provide a genomic resource for an important mammalian organism and our study sheds new light on the possible functions and evolution of bear genes. PMID:20338065

  16. Genomic analysis of expressed sequence tags in American black bear Ursus americanus.

    Science.gov (United States)

    Zhao, Sen; Shao, Chunxuan; Goropashnaya, Anna V; Stewart, Nathan C; Xu, Yichi; Tøien, Øivind; Barnes, Brian M; Fedorov, Vadim B; Yan, Jun

    2010-03-26

    Species of the bear family (Ursidae) are important organisms for research in molecular evolution, comparative physiology and conservation biology, but relatively little genetic sequence information is available for this group. Here we report the development and analyses of the first large scale Expressed Sequence Tag (EST) resource for the American black bear (Ursus americanus). Comprehensive analyses of molecular functions, alternative splicing, and tissue-specific expression of 38,757 black bear EST sequences were conducted using the dog genome as a reference. We identified 18 genes, involved in functions such as lipid catabolism, cell cycle, and vesicle-mediated transport, that are showing rapid evolution in the bear lineage Three genes, Phospholamban (PLN), cysteine glycine-rich protein 3 (CSRP3) and Troponin I type 3 (TNNI3), are related to heart contraction, and defects in these genes in humans lead to heart disease. Two genes, biphenyl hydrolase-like (BPHL) and CSRP3, contain positively selected sites in bear. Global analysis of evolution rates of hibernation-related genes in bear showed that they are largely conserved and slowly evolving genes, rather than novel and fast-evolving genes. We provide a genomic resource for an important mammalian organism and our study sheds new light on the possible functions and evolution of bear genes.

  17. Temporal Trends and Future Predictions of Mercury Concentrations in Northwest Greenland Polar Bear (Ursus maritimus) Hair

    DEFF Research Database (Denmark)

    Dietz, Rune; Born, E.W.; Riget, Frank Farsø

    2011-01-01

    -2008 concentrations ofHg in Northwest Greenland polar bear hair exceeded the general guideline values of 20-30 μg/g dry weight for terrestrial wildlife, whereas the neurochemical effect level of 5.4 μg Hg/g dry weight proposed for East Greenland polar bears was exceeded in 93.5% of the cases. These results call......Hair samples from 117 Northwest Greenland polar bears (Ursus maritimus) were taken during 1892-2008 and analyzed for total mercury (hereafterHg). The sample represented 28 independent years and the aim of the study was to analyze for temporal Hg trends. Mercury concentrations showed yearly...

  18. Haematological and biochemical reference intervals for free-ranging brown bears (Ursus arctos) in Sweden

    DEFF Research Database (Denmark)

    Græsli, Anne Randi; Fahlman, Åsa; Evans, Alina L.

    2014-01-01

    BackgroundEstablishment of haematological and biochemical reference intervals is important to assess health of animals on individual and population level. Reference intervals for 13 haematological and 34 biochemical variables were established based on 88 apparently healthy free-ranging brown bears...... and marking for ecological studies. For each of the variables, the reference interval was described based on the 95% confidence interval, and differences due to host characteristics sex and age were included if detected. To our knowledge, this is the first report of reference intervals for free-ranging brown...... and the differences due to host factors age and gender can be useful for evaluation of health status in free-ranging European brown bears....

  19. Evaluation of black bear (Ursus americanus) diet and consequences in its conservation in Sierra de Picachos, Nuevo León, Mexico

    OpenAIRE

    Juárez-Casillas, Luis Antonio; Varas, Cora

    2013-01-01

    Black bears (Ursus americanus) are considered endangered in Mexico. In northern Mexico, bears are considered responsible for preying on livestock, damaging private property, and crops; therefore they are killed to protect locals' livelihoods. There is a need to understand bears' ecological requirements in order to create conservation plans that include human-bear conflict resolution and that reduce the hunting of this endangered species. We studied the diet of black bears in the Sierra de Pic...

  20. Consumption choice by bears feeding on salmon.

    Science.gov (United States)

    Gende, S M; Quinn, T P; Willson, M F

    2001-05-01

    Consumption choice by brown (Ursus arctos) and black bears (U. americanus) feeding on salmon was recorded for over 20,000 bear-killed fish from 1994 to 1999 in Bristol Bay (sockeye salmon, Oncorhynchus nerka) and southeastern Alaska (pink, O. gorbuscha and chum salmon O. keta). These data revealed striking patterns of partial and selective consumption that varied with relative availability and attributes of the fish. As the availability of salmon decreased, bears consumed a larger proportion of each fish among both years and habitats. When availability was high (absolute number and density of salmon), bears consumed less biomass per captured fish, targeting energy-rich fish (those that had not spawned) or energy-rich body parts (eggs in females; brain in males). In contrast, individual fish were consumed to a much greater extent, regardless of sex or spawning status, in habitats or years of low salmon availability. The proportion of biomass consumed per fish was similar for males and females, when spawning status was statistically controlled, but bears targeted different body parts: the body flesh, brain and dorsal hump in males and the roe in females. Bears thus appeared to maximize energy intake by modifying the amount and body parts consumed, based on availability and attributes of spawning salmon.

  1. SURGICAL CORRECTION OF BILATERAL PATELLAR LUXATION IN AN AMERICAN BLACK BEAR CUB (URSUS AMERICANUS).

    Science.gov (United States)

    Bennett, Katarina R; Desmarchelier, Marion R; Bailey, Trina R

    2015-06-01

    A wild orphaned male American black bear cub ( Ursus americanus ) presented with hind limb gait abnormalities and was found to have bilateral grade 3 laterally luxating patellas. There were no other significant abnormalities detected on neurologic, radiographic, or hematologic examinations. The trochlear grooves were deepened with a chondroplasty, and the redundant soft tissues imbricated. There was a marked improvement in the bear's gait postoperatively, with an apparent full return to function. To the authors' knowledge, patellar luxation has not been reported in the Ursidae family, and the success in this case suggests that this technique may be used in large wild or captive carnivore cubs.

  2. Studies on endoparasites of the black bear (Ursus americanus) in the southeastern United States.

    Science.gov (United States)

    Crum, J M; Nettles, V F; Davidson, W R

    1978-04-01

    Examination of 53 black bears (Ursus americanus) from six states in the southeastern United States revealed at least 17 species of endoparasites, including Sarcocystis sp., Spirometra mansonoides (spargana), Macracanthorhynchus ingens, Ancylostoma caninum, Arthrocephalus lotoris, Baylisascaris transfuga, Capillaria aerophila, Capillaria putorii, Crenosoma sp., Cyathospirura sp., Dirofilaria immitis, Gnathostoma sp., Gongylonema pulchrum, microfilariae, Molineus barbatus, Physaloptera sp. and Strongyloides sp. Twelve of these represent new host records for black bear, and two are considered to be new species. Data are presented on prevalence, intensity and geographic distribution of each species. Pathologic effects were associated with infections of spargana of S. mansonoides and adults of C. aerophilia.

  3. Energy homeostasis regulatory peptides in hibernating grizzly bears.

    Science.gov (United States)

    Gardi, János; Nelson, O Lynne; Robbins, Charles T; Szentirmai, Eva; Kapás, Levente; Krueger, James M

    2011-05-15

    Grizzly bears (Ursus arctos horribilis) are inactive for up to 6 months during hibernation. They undergo profound seasonal changes in food intake, body mass, and energy expenditure. The circa-annual regulation of metabolism is poorly understood. In this study, we measured plasma ghrelin, leptin, obestatin, and neuropeptide-Y (NPY) levels, hormones known to be involved in the regulation of energy homeostasis, in ten grizzly bears. Blood samples were collected during the active summer period, early hibernation and late hibernation. Plasma levels of leptin, obestatin, and NPY did not change between the active and the hibernation periods. Plasma total ghrelin and desacyl-ghrelin concentrations significantly decreased during the inactive winter period compared to summer levels. The elevated ghrelin levels may help enhance body mass during pre-hibernation, while the low plasma ghrelin concentrations during hibernation season may contribute to the maintenance of hypophagia, low energy utilization and behavioral inactivity. Our results suggest that ghrelin plays a potential role in the regulation of metabolic changes and energy homeostasis during hibernation in grizzly bears. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Response of Yellowstone grizzly bears to changes in food resources: A synthesis. Final report to the Interagency Grizzly Bear Committee and Yellowstone Ecosystem Subcommittee

    Science.gov (United States)

    ,; van Manen, Frank T.; Costello, Cecily M.; Haroldson, Mark A.; Bjornlie, Daniel D.; Ebinger, Michael R.; Gunther, Kerry A.; Mahalovich, Mary Frances; Thompson, Daniel J.; Higgs, Megan D.; Irvine, Kathryn M.; Legg, Kristin; Tyers, Daniel B.; Landenburger, Lisa; Cain, Steven L.; Frey, Kevin L.; Aber, Bryan C.; Schwartz, Charles C.

    2013-01-01

    The Yellowstone grizzly bear (Ursus arctos) was listed as a threatened species in 1975 (Federal Register 40 FR:31734-31736). Since listing, recovery efforts have focused on increasing population size, improving habitat security, managing bear mortalities, and reducing bear-human conflicts. The Interagency Grizzly Bear Committee (IGBC; partnership of federal and state agencies responsible for grizzly bear recovery in the lower 48 states) and its Yellowstone Ecosystem Subcommitte (YES; federal, state, county, and tribal partners charged with recovery of grizzly bears in the Greater Yelowston Ecosystem [GYE]) tasked the Interagency Grizzly Bear Study Team to provide information and further research relevant to three concerns arising from the 9th Circuit Court of Appeals November 2011 decision: 1) the ability of grizzly bears as omnivores to find alternative foods to whitebark pine seeds; 2) literature to support their conclusions; and 3) the non-intuitive biological reality that impacts can occur to individuals without causing the overall population to decline. Specifically, the IGBC and YES requested a comprehensive synthesis of the current state of knowledge regarding whitebark pinbe decline and individual and population-level responses of grizzly bears to changing food resources in the GYE. This research was particularly relevant to grizzly bear conservation given changes in the population trajectory observed during the last decade.

  5. Haematological and biochemical reference intervals for free-ranging brown bears (Ursus arctos) in Sweden

    Science.gov (United States)

    2014-01-01

    Background Establishment of haematological and biochemical reference intervals is important to assess health of animals on individual and population level. Reference intervals for 13 haematological and 34 biochemical variables were established based on 88 apparently healthy free-ranging brown bears (39 males and 49 females) in Sweden. The animals were chemically immobilised by darting from a helicopter with a combination of medetomidine, tiletamine and zolazepam in April and May 2006–2012 in the county of Dalarna, Sweden. Venous blood samples were collected during anaesthesia for radio collaring and marking for ecological studies. For each of the variables, the reference interval was described based on the 95% confidence interval, and differences due to host characteristics sex and age were included if detected. To our knowledge, this is the first report of reference intervals for free-ranging brown bears in Sweden. Results The following variables were not affected by host characteristics: red blood cell, white blood cell, monocyte and platelet count, alanine transaminase, amylase, bilirubin, free fatty acids, glucose, calcium, chloride, potassium, and cortisol. Age differences were seen for the majority of the haematological variables, whereas sex influenced only mean corpuscular haemoglobin concentration, aspartate aminotransferase, lipase, lactate dehydrogenase, β-globulin, bile acids, triglycerides and sodium. Conclusions The biochemical and haematological reference intervals provided and the differences due to host factors age and gender can be useful for evaluation of health status in free-ranging European brown bears. PMID:25139149

  6. A novel endogenous betaretrovirus group characterized from polar bears (Ursus maritimus) and giant pandas (Ailuropoda melanoleuca)

    DEFF Research Database (Denmark)

    Mayer, Jens; Tsangaras, Kyriakos; Heeger, Felix

    2013-01-01

    . Molecular dating indicates the group originated before the divergence of bears from a common ancestor but is not present in all carnivores. Closely related sequences were identified in the giant panda (Ailuropoda melanoleuca) and characterized from its genome. We have designated the polar bear and giant...... panda sequences U. maritimus endogenous retrovirus (UmaERV) and A. melanoleuca endogenous retrovirus (AmeERV), respectively. Phylogenetic analysis demonstrated that the bear virus group is nested within the HERV-K supergroup among bovine and bat endogenous retroviruses suggesting a complex evolutionary......Transcriptome analysis of polar bears (Ursus maritimus) yielded sequences with highest similarity to the human endogenous retrovirus group HERV-K(HML-2). Further analysis of the polar bear draft genome identified an endogenous betaretrovirus group comprising 26 proviral copies and 231 solo LTRs...

  7. Diet and Macronutrient Optimization in Wild Ursids: A Comparison of Grizzly Bears with Sympatric and Allopatric Black Bears.

    Directory of Open Access Journals (Sweden)

    Cecily M Costello

    Full Text Available When fed ad libitum, ursids can maximize mass gain by selecting mixed diets wherein protein provides 17 ± 4% of digestible energy, relative to carbohydrates or lipids. In the wild, this ability is likely constrained by seasonal food availability, limits of intake rate as body size increases, and competition. By visiting locations of 37 individuals during 274 bear-days, we documented foods consumed by grizzly (Ursus arctos and black bears (Ursus americanus in Grand Teton National Park during 2004-2006. Based on published nutritional data, we estimated foods and macronutrients as percentages of daily energy intake. Using principal components and cluster analyses, we identified 14 daily diet types. Only 4 diets, accounting for 21% of days, provided protein levels within the optimal range. Nine diets (75% of days led to over-consumption of protein, and 1 diet (3% of days led to under-consumption. Highest protein levels were associated with animal matter (i.e., insects, vertebrates, which accounted for 46-47% of daily energy for both species. As predicted: 1 daily diets dominated by high-energy vertebrates were positively associated with grizzly bears and mean percent protein intake was positively associated with body mass; 2 diets dominated by low-protein fruits were positively associated with smaller-bodied black bears; and 3 mean protein was highest during spring, when high-energy plant foods were scarce, however it was also higher than optimal during summer and fall. Contrary to our prediction: 4 allopatric black bears did not exhibit food selection for high-energy foods similar to grizzly bears. Although optimal gain of body mass was typically constrained, bears usually opted for the energetically superior trade-off of consuming high-energy, high-protein foods. Given protein digestion efficiency similar to obligate carnivores, this choice likely supported mass gain, consistent with studies showing monthly increases in percent body fat among

  8. Diet and macronutrient optimization in wild ursids: A comparison of grizzly bears with sympatric and allopatric black bears

    Science.gov (United States)

    Costello, Cecily M.; Cain, Steven L.; Pils, Shannon R; Frattaroli, Leslie; Haroldson, Mark A.; van Manen, Frank T.

    2016-01-01

    When fed ad libitum, ursids can maximize mass gain by selecting mixed diets wherein protein provides 17 ± 4% of digestible energy, relative to carbohydrates or lipids. In the wild, this ability is likely constrained by seasonal food availability, limits of intake rate as body size increases, and competition. By visiting locations of 37 individuals during 274 bear-days, we documented foods consumed by grizzly (Ursus arctos) and black bears (Ursus americanus) in Grand Teton National Park during 2004–2006. Based on published nutritional data, we estimated foods and macronutrients as percentages of daily energy intake. Using principal components and cluster analyses, we identified 14 daily diet types. Only 4 diets, accounting for 21% of days, provided protein levels within the optimal range. Nine diets (75% of days) led to over-consumption of protein, and 1 diet (3% of days) led to under-consumption. Highest protein levels were associated with animal matter (i.e., insects, vertebrates), which accounted for 46–47% of daily energy for both species. As predicted: 1) daily diets dominated by high-energy vertebrates were positively associated with grizzly bears and mean percent protein intake was positively associated with body mass; 2) diets dominated by low-protein fruits were positively associated with smaller-bodied black bears; and 3) mean protein was highest during spring, when high-energy plant foods were scarce, however it was also higher than optimal during summer and fall. Contrary to our prediction: 4) allopatric black bears did not exhibit food selection for high-energy foods similar to grizzly bears. Although optimal gain of body mass was typically constrained, bears usually opted for the energetically superior trade-off of consuming high-energy, high-protein foods. Given protein digestion efficiency similar to obligate carnivores, this choice likely supported mass gain, consistent with studies showing monthly increases in percent body fat among bears in

  9. Physiological reactions to capture in hibernating brown bears.

    Science.gov (United States)

    Evans, Alina L; Singh, Navinder J; Fuchs, Boris; Blanc, Stéphane; Friebe, Andrea; Laske, Timothy G; Frobert, Ole; Swenson, Jon E; Arnemo, Jon M

    2016-01-01

    Human disturbance can affect animal life history and even population dynamics. However, the consequences of these disturbances are difficult to measure. This is especially true for hibernating animals, which are highly vulnerable to disturbance, because hibernation is a process of major physiological changes, involving conservation of energy during a resource-depleted time of year. During the winters of 2011-15, we captured 15 subadult brown bears ( Ursus arctos ) and recorded their body temperatures ( n  = 11) and heart rates ( n = 10) before, during and after capture using biologgers. We estimated the time for body temperature and heart rate to normalize after the capture event. We then evaluated the effect of the captures on the pattern and depth of hibernation and the day of den emergence by comparing the body temperature of captured bears with that of undisturbed subadult bears ( n  = 11). Both body temperature and heart rate increased during capture and returned to hibernation levels after 15-20 days. We showed that bears required 2-3 weeks to return to hibernation levels after winter captures, suggesting high metabolic costs during this period. There were also indications that the winter captures resulted in delayed den emergence.

  10. Grizzly bear-human conflicts in the Yellowstone Ecosystem, 1992-2000

    Science.gov (United States)

    Gunther, K.A.; Haroldson, M.A.; Cain, S.L.; Copeland, J.; Frey, K.; Schwartz, C.C.

    2004-01-01

    For many years, the primary strategy for managing grizzly bears (Ursus arctos) that came into conflict with humans in the Greater Yellowstone Ecosystem (GYE) was to capture and translocate the offending bears away from conflict sites. Translocation usually only temporarily alleviated the problems and most often did not result in long-term solutions. Wildlife managers needed to be able to predict the causes, types, locations, and trends of conflicts to more efficiently allocate resources for pro-active rather than reactive management actions. To address this need, we recorded all grizzly bear-human conflicts reported in the GYE during 1992-2000. We analyzed trends in conflicts over time (increasing or decreasing), geographic location on macro- (inside or outside of the designated Yellowstone Grizzly Bear Recovery Zone [YGBRZ]) and micro- (geographic location) scales, land ownership (public or private), and relationship to the seasonal availability of bear foods. We recorded 995 grizzly bear-human conflicts in the GYE. Fifty-three percent of the conflicts occurred outside and 47% inside the YGBRZ boundary. Fifty-nine percent of the conflicts occurred on public and 41% on private land. Incidents of bears damaging property and obtaining anthropogenic foods were inversely correlated to the abundance of naturally occurring bear foods. Livestock depredations occurred independent of the availability of bear foods. To further aid in prioritizing management strategies to reduce conflicts, we also analyzed conflicts in relation to subsequent human-caused grizzly bear mortality. There were 74 human-caused grizzly bear mortalities during the study, primarily from killing bears in defense of life and property (43%) and management removal of bears involved in bear-human conflicts (28%). Other sources of human-caused mortality included illegal kills, electrocution by downed power-lines, mistaken identification by American black bear (Ursus americanus) hunters, and vehicle strikes

  11. Arterial supply and venous drainage of the brain of the black bear (Ursus americanus). I.Gross anatomical distribution

    NARCIS (Netherlands)

    Anderson, W.D.; Anderson, B.G.; Seguin, R.J.

    1989-01-01

    A morphological study of the intracranial vessels of the Black bear (Ursus americanus) was undertaken. The object was to provide basic information related to the vascular pattern in these animals as compared with other carnivores and with the human. Vascular casts were prepared from 6 animals. The

  12. A Review of Infectious Agents in Polar Bears (Ursus maritimus) and Their Long-Term Ecological Relevance.

    Science.gov (United States)

    Fagre, Anna C; Patyk, Kelly A; Nol, Pauline; Atwood, Todd; Hueffer, Karsten; Duncan, Colleen

    2015-09-01

    Disease was a listing criterion for the polar bear (Ursus maritimus) as threatened under the Endangered Species Act in 2008; it is therefore important to evaluate the current state of knowledge and identify any information gaps pertaining to diseases in polar bears. We conducted a systematic literature review focused on infectious agents and associated health impacts identified in polar bears. Overall, the majority of reports in free-ranging bears concerned serosurveys or fecal examinations with little to no information on associated health effects. In contrast, most reports documenting illness or pathology referenced captive animals and diseases caused by etiologic agents not representative of exposure opportunities in wild bears. As such, most of the available infectious disease literature has limited utility as a basis for development of future health assessment and management plans. Given that ecological change is a considerable risk facing polar bear populations, future work should focus on cumulative effects of multiple stressors that could impact polar bear population dynamics.

  13. The presence of Ursus ex gr. minimus-thibetanus in the late villányian and its position among the Pliocene and Pleistocene black bears in Europe

    Czech Academy of Sciences Publication Activity Database

    Wagner, Jan; Čermák, Stanislav; Horáček, I.

    -, č. 4 (2011), s. 39-58 ISSN 1771-1150 R&D Projects: GA ČR GA205/09/0184 Institutional research plan: CEZ:AV0Z30130516 Keywords : Black bear * MN17 * Ursus aff. thibetanus * Villány 3 * Central Europe - Hungary * Ursus * Pleistocene * Pliocene Subject RIV: DB - Geology ; Mineralogy

  14. PCR-Based Detection of Trypanosoma evansi Infection in Semi-Captive Asiatic Black Bears (Ursus thibetanus

    Directory of Open Access Journals (Sweden)

    Maliha Shahid, Safia Janjua*, Fakhar-i-Abbas and Jan Schmidt Burbach1

    2013-11-01

    Full Text Available Clinical signs, viz lethargy, increased heart rate and reduced appetite, making trypanosomiasis a possible differential diagnosis, were found in five out of twenty semi-captive Asiatic black bears (Ursus thibetanus in a sanctuary, located in Kund, District Sawabi, KPK, Pakistan. Microscopic examination of blood samples of bears expressing clinical signs and symptoms revealed the presence of haemoflagellates, which was found to be trypanosomes. Subsequently, the PCR technique was exploited to screen for the presence of trypanosomal species in all bears’ blood samples. Blood samples from 20 individual bears were screened using three sets of primers specific to Trypanosoma evansi species. Three primer pairs used are equally effective in successful detection of the parasite. Two out of five, diseased bears died prior to any trypanosoma specific medication while the rest were given an administered dose of Melarsomine (Immiticide. The treated bears survived and were assured to be aparasitemic on post-treatment examination after six weeks.

  15. Size and density of East Greenland polar bear (Ursus maritimus) skulls

    DEFF Research Database (Denmark)

    Sonne, Christian; Bechshoft, Thea Ø.; Rigét, Frank F.

    2013-01-01

    density (BMD) in 87 East Greenland male polar bears (Ursus maritimus) sampled in the time period of 1892-2010. The purpose of the study was to investigate if these measures are potential candidates as indicators for stress associated with climate change and long-range transported toxic industrial...... of the limited sample size in period 2 and lower mean age in period 4. Therefore, precautions should be taken towards a final conclusion on BMD and CBL as bioindicators for climate oscillations and exposure to toxic environmental chemicals. It is recommended that the sampling and archiving of East Greenland...... chemicals. The analyses showed that both BMD and CBL in polar bears sampled in period 4 (1999-2010, n = 57) were significantly lower when compared with period 2 (1920-1936, n = 19) (both p

  16. High contributions of sea ice derived carbon in polar bear (Ursus maritimus) tissue.

    Science.gov (United States)

    Brown, Thomas A; Galicia, Melissa P; Thiemann, Gregory W; Belt, Simon T; Yurkowski, David J; Dyck, Markus G

    2018-01-01

    Polar bears (Ursus maritimus) rely upon Arctic sea ice as a physical habitat. Consequently, conservation assessments of polar bears identify the ongoing reduction in sea ice to represent a significant threat to their survival. However, the additional role of sea ice as a potential, indirect, source of energy to bears has been overlooked. Here we used the highly branched isoprenoid lipid biomarker-based index (H-Print) approach in combination with quantitative fatty acid signature analysis to show that sympagic (sea ice-associated), rather than pelagic, carbon contributions dominated the marine component of polar bear diet (72-100%; 99% CI, n = 55), irrespective of differences in diet composition. The lowest mean estimates of sympagic carbon were found in Baffin Bay bears, which were also exposed to the most rapidly increasing open water season. Therefore, our data illustrate that for future Arctic ecosystems that are likely to be characterised by reduced sea ice cover, polar bears will not only be impacted by a change in their physical habitat, but also potentially in the supply of energy to the ecosystems upon which they depend. This data represents the first quantifiable baseline that is critical for the assessment of likely ongoing changes in energy supply to Arctic predators as we move into an increasingly uncertain future for polar ecosystems.

  17. Contrasting activity patterns of sympatric and allopatric black and grizzly bears

    Science.gov (United States)

    Schwartz, C.C.; Cain, S.L.; Podruzny, S.; Cherry, S.; Frattaroli, L.

    2010-01-01

    The distribution of grizzly (Ursus arctos) and American black bears (U. americanus) overlaps in western North America. Few studies have detailed activity patterns where the species are sympatric and no studies contrasted patterns where populations are both sympatric and allopatric. We contrasted activity patterns for sympatric black and grizzly bears and for black bears allopatric to grizzly bears, how human influences altered patterns, and rates of grizzlyblack bear predation. Activity patterns differed between black bear populations, with those sympatric to grizzly bears more day-active. Activity patterns of black bears allopatric with grizzly bears were similar to those of female grizzly bears; both were crepuscular and day-active. Male grizzly bears were crepuscular and night-active. Both species were more night-active and less day-active when ???1 km from roads or developments. In our sympatric study area, 2 of 4 black bear mortalities were due to grizzly bear predation. Our results suggested patterns of activity that allowed for intra- and inter-species avoidance. National park management often results in convergence of locally high human densities in quality bear habitat. Our data provide additional understanding into how bears alter their activity patterns in response to other bears and humans and should help park managers minimize undesirable bearhuman encounters when considering needs for temporal and spatial management of humans and human developments in bear habitats. ?? 2010 The Wildlife Society.

  18. Consumption of pondweed rhizomes by Yellowstone grizzly bears

    Science.gov (United States)

    Mattson, D.J.; Podruzny, S.R.; Haroldson, M.A.

    2005-01-01

    Pondweeds (Potamogeton spp.) are common foods of waterfowl throughout the Northern Hemisphere. However, consumption of pondweeds by bears has been noted only once, in Russia. We documented consumption of pondweed rhizomes by grizzly bears (Ursus arctos) in the Yellowstone region, 1977-96, during investigations of telemetry locations obtained from 175 radiomarked bears. We documented pondweed excavations at 25 sites and detected pondweed rhizomes in 18 feces. We observed grizzly bears excavating and consuming pondweed on 2 occasions. All excavations occurred in wetlands that were inundated during and after snowmelt, but dry by late August or early September of most years. These wetlands were typified by the presence of inflated sedge (Carex vesicaria) and occurred almost exclusively on plateaus of Pliocene-Pleistocene detrital sediments or volcanic rhyolite flows. Bears excavated wetlands with pondweeds when they were free of standing water, most commonly during October and occasionally during spring prior to the onset of terminal snowmelt. Most excavations were about 4.5 cm deep, 40 cubic decimeter (dm3) in total volume, and targeted the thickened pondweed rhizomes. Starch content of rhizomes collected near grizzly bear excavations averaged 28% (12% SD; n = 6). These results add to the documented diversity of grizzly bear food habits and, because pondweed is distributed circumboreally, also raise the possibility that consumption of pondweed by grizzly bears has been overlooked in other regions.

  19. Distribution of grizzly bears in the Greater Yellowstone Ecosystem, 2004

    Science.gov (United States)

    Schwartz, C.C.; Haroldson, M.A.; Gunther, K.; Moody, D.

    2006-01-01

    The US Fish and Wildlife Service (USFWS) proposed delisting the Yellowstone grizzly bear (Ursus arctos horribilis) in November 2005. Part of that process required knowledge of the most current distribution of the species. Here, we update an earlier estimate of occupied range (1990–2000) with data through 2004. We used kernel estimators to develop distribution maps of occupied habitats based on initial sightings of unduplicated females (n = 481) with cubs of the year, locations of radiomarked bears (n = 170), and spatially unique locations of conflicts, confrontations, and mortalities (n = 1,075). Although each data set was constrained by potential sampling bias, together they provided insight into areas in the Greater Yellowstone Ecosystem (GYE) currently occupied by grizzly bears. The current distribution of 37,258 km2 (1990–2004) extends beyond the distribution map generated with data from 1990–2000 (34,416 km2 ). Range expansion is particularly evident in parts of the Caribou–Targhee National Forest in Idaho and north of Spanish Peaks on the Gallatin National Forest in Montana.

  20. Three decades (1983-2010) of contaminant trends in East Greenland polar bears (Ursus maritimus). Part 2

    DEFF Research Database (Denmark)

    Dietz, Rune; Rigét, Frank F; Sonne, Christian

    2013-01-01

    Legacy organochlorine contaminants were determined in adipose tissues from 294 polar bears (Ursus maritimus) sampled in East Greenland in 23 of the 28years between 1983 and 2010. Of 19 major legacy contaminants and congeners (ΣPCB, 4 PCB congeners (CB153, 180, 170/190), ΣDDT, p,p'-DDE, p,p' -DDD...... and p,p'-DDT, α- and β-hexachlorocyclohexane (HCH), HCB, octachlorostyrene, dieldrin, oxychlordane, cis- and trans-chlordane, cis- and trans-nonachlor, heptachlor epoxide and BB-153), 18 showed statistically significant average yearly declines of -4.4% (range: -2.0 to -10.8%/year) among subadult polar...... bears (i.e. females...

  1. Body and diet composition of sympatric black and grizzly bears in the Greater Yellowstone Ecosystem

    Science.gov (United States)

    Schwartz, Charles C.; Fortin, Jennifer K.; Teisberg, Justin E.; Haroldson, Mark A.; Servheen, Christopher; Robbins, Charles T.; van Manen, Frank T.

    2013-01-01

    The Greater Yellowstone Ecosystem (GYE) has experienced changes in the distribution and availability of grizzly bear (Ursus arctos) food resources in recent decades. The decline of ungulates, fish, and whitebark pine seeds (Pinus albicaulis) has prompted questions regarding their ability to adapt. We examined body composition and diet of grizzly bears using bioelectrical impedance and stable isotopes to determine if 1) we can detect a change in diet quality associated with the decline in either ungulates or whitebark pine, and 2) the combined decline in ungulates, fish, and pine seeds resulted in a change in grizzly bear carrying capacity in the GYE. We contrasted body fat and mass in grizzly bears with a potential competitor, the American black bear (Ursus americanus), to address these questions. Grizzly bears assimilated more meat into their diet and were in better body condition than black bears throughout the study period, indicating the decline in ungulate resources did not affect grizzly bears more than black bears. We also found no difference in autumn fat levels in grizzly bears in years of good or poor pine seed production, and stable isotope analyses revealed this was primarily a function of switching to meat resources during poor seed-producing years. This dietary plasticity was consistent over the course of our study. We did not detect an overall downward trend in either body mass or the fraction of meat assimilated into the diet by grizzly bears over the past decade, but we did detect a downward trend in percent body fat in adult female grizzly bears after 2006. Whether this decline is an artifact of small sample size or due to the population reaching the ecological carrying capacity of the Yellowstone ecosystem warrants further investigation.

  2. Factors influencing annual fecal testosterone metabolite profiles in captive male polar bears (Ursus maritimus).

    Science.gov (United States)

    Curry, E; Roth, T L; MacKinnon, K M; Stoops, M A

    2012-12-01

    The objectives of this study were to assess the effects of season, breeding activity, age and latitude on fecal testosterone metabolite concentrations in captive, adult male polar bears (Ursus maritimus). Fourteen polar bears from 13 North American zoos were monitored for 12-36 months, producing 25-year-long testosterone profiles. Results indicated that testosterone was significantly higher during the breeding season (early January through the end of May) compared with the non-breeding season with the highest concentrations excreted from early January through late March. Variations in excretion patterns were observed among individuals and also between years within an individual, with testosterone peaks closely associated with breeding activity. Results indicate that fecal testosterone concentrations are influenced by season, breeding activity and age, but not by latitude. This is the first report describing longitudinal fecal testosterone metabolite concentrations in individual adult male polar bears. © 2012 Blackwell Verlag GmbH.

  3. Black bear density in Glacier National Park, Montana

    Science.gov (United States)

    Stetz, Jeff B.; Kendall, Katherine C.; Macleod, Amy C.

    2013-01-01

    We report the first abundance and density estimates for American black bears (Ursus americanus) in Glacier National Park (NP),Montana, USA.We used data from 2 independent and concurrent noninvasive genetic sampling methods—hair traps and bear rubs—collected during 2004 to generate individual black bear encounter histories for use in closed population mark–recapture models. We improved the precision of our abundance estimate by using noninvasive genetic detection events to develop individual-level covariates of sampling effort within the full and one-half mean maximum distance moved (MMDM) from each bear’s estimated activity center to explain capture probability heterogeneity and inform our estimate of the effective sampling area.Models including the one-halfMMDMcovariate received overwhelming Akaike’s Information Criterion support suggesting that buffering our study area by this distance would be more appropriate than no buffer or the full MMDM buffer for estimating the effectively sampled area and thereby density. Our modelaveraged super-population abundance estimate was 603 (95% CI¼522–684) black bears for Glacier NP. Our black bear density estimate (11.4 bears/100 km2, 95% CI¼9.9–13.0) was consistent with published estimates for populations that are sympatric with grizzly bears (U. arctos) and without access to spawning salmonids. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

  4. Effects of exotic species on Yellowstone's grizzly bears

    Science.gov (United States)

    Reinhart, Daniel P.; Haroldson, Mark A.; Mattson, D.J.; Gunther, Kerry A.

    2001-01-01

    Humans have affected grizzly bears (Ursus arctos horribilis) by direct mortality, competition for space and resources, and introduction of exotic species. Exotic organisms that have affected grizzly bears in the Greater Yellowstone Area include common dandelion (Taraxacum officinale), nonnative clovers (Trifolium spp.), domesticated livestock, bovine brucellosis (Brucella abortus), lake trout (Salvelinus namaycush), and white pine blister rust (Cronartium ribicola). Some bears consume substantial amounts of dandelion and clover. However, these exotic foods provide little digested energy compared to higher-quality bear foods. Domestic livestock are of greater energetic value, but use of this food by bears often leads to conflicts with humans and subsequent increases in bear mortality. Lake trout, blister rust, and brucellosis diminish grizzly bears foods. Lake trout prey on native cutthroat trout (Oncorhynchus clarkii) in Yellowstone Lake; white pine blister rust has the potential to destroy native whitebark pine (Pinus albicaulis) stands; and management response to bovine brucellosis, a disease found in the Yellowstone bison (Bison bison) and elk (Cervus elaphus), could reduce populations of these 2 species. Exotic species will likely cause more harm than good for Yellowstone grizzly bears. Managers have few options to mitigate or contain the impacts of exotics on Yellowstone's grizzly bears. Moreover, their potential negative impacts have only begun to unfold. Exotic species may lead to the loss of substantial highquality grizzly bear foods, including much of the bison, trout, and pine seeds that Yellowstone grizzly bears currently depend upon.

  5. Recent observations of intraspecific predation and cannibalism among polar bears in the southern Beaufort Sea

    Science.gov (United States)

    Amstrup, Steven C.; Stirling, I.; Smith, T.S.; Perham, C.; Thiemann, G.W.

    2006-01-01

    Intraspecific killing has been reported among polar bears (Ursus maritimus), brown bears (U. arctos), and black bears (U. americanus). Although cannibalism is one motivation for such killings, the ecological factors mediating such events are poorly understood. Between 24 January and 10 April 2004, we confirmed three instances of intraspecific predation and cannibalism in the Beaufort Sea. One of these, the first of this type ever reported for polar bears, was a parturient female killed at her maternal den. The predating bear was hunting in a known maternal denning area and apparently discovered the den by scent. A second predation event involved an adult female and cub recently emerged from their den, and the third involved a yearling male. During 24 years of research on polar bears in the southern Beaufort Sea region of northern Alaska and 34 years in northwestern Canada, we have not seen other incidents of polar bears stalking, killing, and eating other polar bears. We hypothesize that nutritional stresses related to the longer ice-free seasons that have occurred in the Beaufort Sea in recent years may have led to the cannibalism incidents we observed in 2004. ?? Springer-Verlag 2006.

  6. Geographic structure and demographic history of Iranian brown bear (Ursus arctos based on mtDNA control region sequences

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Ashrafzadeh

    2015-12-01

    Full Text Available In recent years, the brown bear's range has declined and its populations in some areas have faced extinction. Therefore, to have a comprehensive picture of genetic diversity and geographic structure of populations is essential for effective conservation strategies. In this research, we sequenced a 271bp segment of mtDNA control region of seven Iranian brown bears, where a total dataset of 467 sequences (brown and polar bears were used in analyses. Overall, 113 different haplotypes and 77 polymorphic sites were identified within the segment. Based on phylogenetic analyses, Iranian brown bears were not nested in any other clades. The low values of Nm (range=0.014-0.187 and high values of Fst (range=0.728-0.972 among Iranian bears and others revealed a genetically significant differentiation. We aren't found any significant signal of demographic reduction in Iranian bears. The time to the most recent common ancestor of Iranian brown bears (Northern Iran was found to be around 19000 BP.

  7. Social network analysis of mating patterns in American black bears (Ursus americanus).

    Science.gov (United States)

    Moore, Jennifer A; Xu, Ran; Frank, Kenneth; Draheim, Hope; Scribner, Kim T

    2015-08-01

    Nonrandom mating can structure populations and has important implications for population-level processes. Investigating how and why mating deviates from random is important for understanding evolutionary processes as well as informing conservation and management. Prior to the implementation of parentage analyses, understanding mating patterns in solitary, elusive species like bears was virtually impossible. Here, we capitalize on a long-term genetic data set collected from black bears (Ursus americanus) (N = 2422) in the Northern Lower Peninsula (NLP) of Michigan, USA. We identified mated pairs using parentage analysis and applied logistic regression (selection) models that controlled for features of the social network, to quantify the effects of individual characteristics, and spatial and population demographic factors on mating dynamics. Logistic regression models revealed that black bear mating was associated with spatial proximity of mates, male age, the time a pair had coexisted, local population density and relatedness. Mated pairs were more likely to contain older males. On average, bears tended to mate with nearby individuals to whom they were related, which does not support the existence of kin recognition in black bears. Pairwise relatedness was especially high for mated pairs containing young males. Restricted dispersal and high male turnover from intensive harvest mortality of NLP black bears are probably the underlying factors associated with younger male bears mating more often with female relatives. Our findings illustrate how harvest has the potential to disrupt the social structure of game species, which warrants further attention for conservation and management. © 2015 John Wiley & Sons Ltd.

  8. Selection of microsites by grizzly bears to excavate biscuitroots (Lomatium cous)

    Science.gov (United States)

    Mattson, D.J.

    1997-01-01

    Roots of the biscuitroot (Lomatium cous) are a common food of grizzly bears (Ursus arctos horribilis) in drier parts of their southern range. I used random sampling and locations of radiomarked bears in the Yellowstone ecosystem to investigate the importance of mass and starch content of roots, digability of the site, and density of plants relative to selection of sites by grizzly bears to dig biscuitroots. Where biscuitroots were present, most differences between dug and undug sites were related to digability of the site and mass and starch content of roots. Grizzly bears more often dug in sites where average milligrams of starch per kilogram of pull per root (a??energy gain) was high. Density of biscuitroots was not related to selection of sites by grizzly bears. Mass of biscuitroot stems also provided relatively little information about mass of roots. Distribution of biscuitroots was associated with increased cover of rocks and exposure to wind, and with decreased slopes and cover of forbs. Digs by grizzly bears were associated with the presence of biscuitroots, proximity to edge of forest, and increased cover of rocks. Results were consistent with previously observed tendencies of grizzly bears to concentrate their feeding within 50-100 m of cover.

  9. In vitro assay shows that PCB metabolites completely saturate thyroid hormone transport capacity in blood of wild polar bears (Ursus maritimus)

    NARCIS (Netherlands)

    Gutleb, A.C.; Cenijn, P.H.; van Velzen, P.; Lie, E.; Ropstad, E.; Skaare, J.U.; Malmberg, T.; Bergman, A.; Gabrielsen, G. W.; Legler, J.

    2010-01-01

    Persistent chemicals accumulate in the arctic environment due to their chemical reactivity and physicochemical properties and polychlorinated biphenyls (PCBs) are the most concentrated pollutant class in polar bears (Ursus maritimus). Metabolism of PCB and polybrominated biphenyl ether (PBDE)

  10. High contributions of sea ice derived carbon in polar bear (Ursus maritimus tissue.

    Directory of Open Access Journals (Sweden)

    Thomas A Brown

    Full Text Available Polar bears (Ursus maritimus rely upon Arctic sea ice as a physical habitat. Consequently, conservation assessments of polar bears identify the ongoing reduction in sea ice to represent a significant threat to their survival. However, the additional role of sea ice as a potential, indirect, source of energy to bears has been overlooked. Here we used the highly branched isoprenoid lipid biomarker-based index (H-Print approach in combination with quantitative fatty acid signature analysis to show that sympagic (sea ice-associated, rather than pelagic, carbon contributions dominated the marine component of polar bear diet (72-100%; 99% CI, n = 55, irrespective of differences in diet composition. The lowest mean estimates of sympagic carbon were found in Baffin Bay bears, which were also exposed to the most rapidly increasing open water season. Therefore, our data illustrate that for future Arctic ecosystems that are likely to be characterised by reduced sea ice cover, polar bears will not only be impacted by a change in their physical habitat, but also potentially in the supply of energy to the ecosystems upon which they depend. This data represents the first quantifiable baseline that is critical for the assessment of likely ongoing changes in energy supply to Arctic predators as we move into an increasingly uncertain future for polar ecosystems.

  11. Assisted reproductive technology in bear (ursidae) conservation Ailuropoda Melanoleuca, Ursus Arctos and Usus Maritimus

    OpenAIRE

    Baldoví Sánchez, Isabel; Universitat Autònoma de Barcelona. Facultat de Veterinària

    2014-01-01

    Póster The Ursidae family is severely threatened having 6 of the 8 bear species in danger of extinction. Due to its reproductive physiology characteristics, ursids have a low reproduction rate which aggravates in captivity. It is because of this, that reproductive assisted technology has become a key element in the conservation of this species. The following study is the compendium of the obtained results in this field in three ursid species: giant panda (Auliropoda melanoleuca), brown bea...

  12. A novel endogenous betaretrovirus group characterized from polar bears (Ursus maritimus) and giant pandas (Ailuropoda melanoleuca).

    Science.gov (United States)

    Mayer, Jens; Tsangaras, Kyriakos; Heeger, Felix; Avila-Arcos, María; Stenglein, Mark D; Chen, Wei; Sun, Wei; Mazzoni, Camila J; Osterrieder, Nikolaus; Greenwood, Alex D

    2013-08-15

    Transcriptome analysis of polar bears (Ursus maritimus) yielded sequences with highest similarity to the human endogenous retrovirus group HERV-K(HML-2). Further analysis of the polar bear draft genome identified an endogenous betaretrovirus group comprising 26 proviral copies and 231 solo LTRs. Molecular dating indicates the group originated before the divergence of bears from a common ancestor but is not present in all carnivores. Closely related sequences were identified in the giant panda (Ailuropoda melanoleuca) and characterized from its genome. We have designated the polar bear and giant panda sequences U. maritimus endogenous retrovirus (UmaERV) and A. melanoleuca endogenous retrovirus (AmeERV), respectively. Phylogenetic analysis demonstrated that the bear virus group is nested within the HERV-K supergroup among bovine and bat endogenous retroviruses suggesting a complex evolutionary history within the HERV-K group. All individual remnants of proviral sequences contain numerous frameshifts and stop codons and thus, the virus is likely non-infectious. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Temporal monitoring of liver and kidney lesions in contaminated East Greenland polar bears (Ursus maritimus) during 1999-2010.

    Science.gov (United States)

    Sonne, Christian; Letcher, Robert J; Leifsson, Pall S; Rigét, Frank F; Bechshøft, Thea Ø; Bossi, Rossana; Asmund, Gert; Dietz, Rune

    2012-11-01

    Organohalogen contaminants bioaccumulate to high concentrations in tissues of polar bears (Ursus maritimus). The exposure levels are in the order to be toxic to inner organs like liver and kidney. We therefore investigated the temporal development of lesions in liver (n=115) and kidney (n=122) samples from East Greenland polar bears taken over the 12 year period from 1999 to 2010. Seven liver and seven kidney lesions were observed of which six were age-related. Controlling for this, the analyses showed that hepatic steatosis and renal cell infiltrations, glomerular sclerosis and tubular hyperplasia decreased over the investigated time period (all ppolar bears. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. The effects of hibernation and captivity on glucose metabolism and thyroid hormones in American black bear (Ursus americanus).

    Science.gov (United States)

    McCain, Stephanie; Ramsay, Ed; Kirk, Claudia

    2013-06-01

    American black bears (Ursus americanus) have been shown to become transiently insulin resistant and hypothyroid during winter, but no studies have investigated these changes in long-term captive bears or in bears which remain awake year-round. Wild, captive hibernating, and captive nonhibernating bears were evaluated at times corresponding to three of their major physiologic stages: fall (hyperphagic stage), winter (hibernation stage), and summer (normal activity stage). Combined insulin and glucose tolerance tests and thyroid hormone profiles were performed on all bears during each stage. All three groups of bears had evidence of insulin resistance during the winter, as compared to the summer or fall, based on glucose tolerance curves. Analysis of thyroid hormone concentration varied and distinct patterns or similarities were not apparent. While obesity in captive American black bears is multifactorial, the finding that, regardless of their ability to hibernate, captive bears retain similar physiology to their wild counterparts indicates that captive bears' complex physiologic changes need to be addressed in their management.

  15. Diet and morphology of extant and recently extinct northern bears

    Science.gov (United States)

    Mattson, David J.

    1998-01-01

    I examined the relationship of diets to skull morphology of extant northern bears and used this information to speculate on diets of the recently extinct cave (Ursus spelaeus) and short-faced (Arctodus simus) bears. Analyses relied upon published skull measurements and food habits of Asiatic (U. thibetanus) and American (U. americanus) black bears, polar bears (U. maritimus), various subspecies of brown bears (U. arctos), and the giant panda (Ailuropoda melanoleuca). Principal components analysis showed major trends in skull morphology related to size, crushing force, and snout shape. Giant pandas, short-faced bears, cave bears, and polar bears exhibited extreme features along these gradients. Diets of brown bears in colder, often non-forested environments were distinguished by large volumes of roots, foliage, and vertebrates, while diets of the 2 black bear species and brown bears occupying broadleaf forests contained greater volumes of mast and invertebrates and overlapped considerably. Fractions of fibrous foods in feces (foliage and roots) were strongly related to skull morphology (R2=0.97)">(R2=0.97). Based on this relationship, feces of cave and short-faced bears were predicted to consist almost wholly of foliage, roots, or both. I hypothesized that cave bears specialized in root grubbing. In contrast, based upon body proportions and features of the ursid digestive tract, I hypothesized that skull features associated with crushing force facilitated a carnivorous rather than herbivorous diet for short-faced bears.

  16. Conservation of brown bear in the Alps: space use and settlement behavior of reintroduced bears

    Science.gov (United States)

    Preatoni, Damiano; Mustoni, Andrea; Martinoli, Adriano; Carlini, Eugenio; Chiarenzi, Barbara; Chiozzini, Simonetta; Van Dongen, Stefan; Wauters, Luc A.; Tosi, Guido

    2005-11-01

    Large carnivores typically need large home ranges containing habitats patches of different quality. Consequently, their conservation requires habitat protection and management at the landscape scale. In some cases, reintroduction might be used to support remnant or restore extinct populations. This is the case for the brown bear ( Ursus arctos) in the Italian Alps. We monitored spacing behavior and settlement of reintroduced brown bears in Adamello-Brenta Natural Park, North-Italy, using radio-tracking. Habitat use, dispersion and survival were studied to evaluate the success of reintroduction and possible conflicts with man. All three males and five of seven females settled in the study area. Most bears roamed widely the first months after release, exploring the new habitat. Patterns of home range overlap between seasons and years revealed that home range use stabilized the year after first hibernation. Home ranges were larger in the mating season (May-July) than in spring or autumn. Home ranges varied between 34 and 1813 km 2 the year after release, but core-areas, where feeding activity was concentrated, were much smaller. Some bears had exclusive core-areas in summer and autumn, but most showed considerable core-area overlap with animals of the same and/or the opposite sex. Bears selected deciduous forests, mixed and conifer forests were used according to availability, and areas with anthropogenic disturbance were avoided. Most bears settled and some reproduced successfully at the release site, causing high initial population growth, suggesting that reintroduction can help to re-establish a brown bear population in the Italian Alps.

  17. No need to replace an “anomalous” primate (Primates) with an “anomalous” bear (Carnivora, Ursidae)

    Science.gov (United States)

    Gutiérrez, Eliécer E.; Pine, Ronald H.

    2015-01-01

    Abstract By means of mitochondrial 12S rRNA sequencing of putative “yeti”, “bigfoot”, and other “anomalous primate” hair samples, a recent study concluded that two samples, presented as from the Himalayas, do not belong to an “anomalous primate”, but to an unknown, anomalous type of ursid. That is, that they match 12S rRNA sequences of a fossil Polar Bear (Ursus maritimus), but neither of modern Polar Bears, nor of Brown Bears (Ursus arctos), the closest relative of Polar Bears, and one that occurs today in the Himalayas. We have undertaken direct comparison of sequences; replication of the original comparative study; inference of phylogenetic relationships of the two samples with respect to those from all extant species of Ursidae (except for the Giant Panda, Ailuropoda melanoleuca) and two extinct Pleistocene species; and application of a non-tree-based population aggregation approach for species diagnosis and identification. Our results demonstrate that the very short fragment of the 12S rRNA gene sequenced by Sykes et al. is not sufficiently informative to support the hypotheses provided by these authors with respect to the taxonomic identity of the individuals from which these sequences were obtained. We have concluded that there is no reason to believe that the two samples came from anything other than Brown Bears. These analyses afforded an opportunity to test the monophyly of morphologically defined species and to comment on both their phylogenetic relationships and future efforts necessary to advance our understanding of ursid systematics. PMID:25829853

  18. No need to replace an “anomalous” primate (Primates with an “anomalous” bear (Carnivora, Ursidae

    Directory of Open Access Journals (Sweden)

    Eliécer Gutiérrez

    2015-03-01

    Full Text Available By means of mitochondrial 12S rRNA sequencing of putative “yeti”, “bigfoot”, and other “anomalous primate” hair samples, a recent study concluded that two samples, presented as from the Himalayas, do not belong to an “anomalous primate”, but to an unknown, anomalous type of ursid. That is, that they match 12S rRNA sequences of a fossil Polar Bear (Ursus maritimus, but neither of modern Polar Bears, nor of Brown Bears (Ursus arctos, the closest relative of Polar Bears, and one that occurs today in the Himalayas. We have undertaken direct comparison of sequences; replication of the original comparative study; inference of phylogenetic relationships of the two samples with respect to those from all extant species of Ursidae (except for the Giant Panda, Ailuropoda melanoleuca and two extinct Pleistocene species; and application of a non-tree-based population aggregation approach for species diagnosis and identification. Our results demonstrate that the very short fragment of the 12S rRNA gene sequenced by Sykes et al. is not sufficiently informative to support the hypotheses provided by these authors with respect to the taxonomic identity of the individuals from which these sequences were obtained. We have concluded that there is no reason to believe that the two samples came from anything other than Brown Bears. These analyses afforded an opportunity to test the monophyly of morphologically defined species and to comment on both their phylogenetic relationships and future efforts necessary to advance our understanding of ursid systematics.

  19. Interactions between wolves and female grizzly bears with cubs in Yellowstone National Park

    Science.gov (United States)

    Gunther, Kerry A.; Smith, Douglas W.

    2004-01-01

    Gray wolves (Canis lupus) were extirpated from Yellowstone National Park (YNP) by the 1920s through predator control actions (Murie 1940,Young and Goldman 1944, Weaver 1978), then reintroduced into the park from 1995 to 1996 to restore ecological integrity and adhere to legal mandates (Bangs and Fritts 1996, Phillips and Smith 1996, Smith et al. 2000). Prior to reintroduction, the potential effects of wolves on the region’s threatened grizzly bear (Ursus arctos) population were evaluated (Servheen and Knight 1993). In areas where wolves and grizzly bears are sympatric, interspecific killing by both species occasionally occurs (Ballard 1980, 1982; Hayes and Baer 1992). Most agonistic interactions between wolves and grizzly bears involve defense of young or competition for carcasses (Murie 1944, 1981; Ballard 1982; Hornbeck and Horejsi 1986; Hayes and Mossop 1987; Kehoe 1995; McNulty et al. 2001). Servheen and Knight (1993) predicted that reintroduced wolves could reduce the frequency of winter-killed and disease-killed ungulates available for bears to scavenge, and that grizzly bears would occasionally usurp wolf-killed ungulate carcasses. Servheen and Knight (1993) hypothesized that interspecific killing and competition for carcasses would have little or no population level effect on either species.

  20. The influence of climate variability on polar bear (Ursus maritimus) and ringed seal (Pusa hispida) population dynamics

    DEFF Research Database (Denmark)

    Rosing-Asvid, A.

    2006-01-01

    Unusually high polar bear (Ursus maritimus Phipps, 1774) predation on ringed seal (Pusa hispida (Schreber, 1775)) pups and increased survival of polar bear cubs during mild springs is documented in published articles. Strong predation on newborn ringed seal pups in early spring, however, is likely...... to lower the overall energy intake of polar bears if ringed seal pups are their main food, because the energetic value of ringed seal pups increases 7-8 times during the 6 week lactation period. So although hunting success in early spring increases cub survival during the period after den emergence......,when they are most vulnerable, it is likely to increase the number of starving bears later in the season. This negative-feedback effect of strong spring predation will not occur in areas where other seal species are abundant during summer, and polar bears in such areas are likely to exhibit population growth during...

  1. Evaluating estimators for numbers of females with cubs-of-the-year in the Yellowstone grizzly bear population

    Science.gov (United States)

    Cherry, S.; White, G.C.; Keating, K.A.; Haroldson, Mark A.; Schwartz, Charles C.

    2007-01-01

    Current management of the grizzly bear (Ursus arctos) population in Yellowstone National Park and surrounding areas requires annual estimation of the number of adult female bears with cubs-of-the-year. We examined the performance of nine estimators of population size via simulation. Data were simulated using two methods for different combinations of population size, sample size, and coefficient of variation of individual sighting probabilities. We show that the coefficient of variation does not, by itself, adequately describe the effects of capture heterogeneity, because two different distributions of capture probabilities can have the same coefficient of variation. All estimators produced biased estimates of population size with bias decreasing as effort increased. Based on the simulation results we recommend the Chao estimator for model M h be used to estimate the number of female bears with cubs of the year; however, the estimator of Chao and Shen may also be useful depending on the goals of the research.

  2. Use of naturally occurring mercury to determine the importance of cutthroat trout to Yellowstone grizzly bears

    Science.gov (United States)

    Felicetti, L.A.; Schwartz, C.C.; Rye, R.O.; Gunther, K.A.; Crock, J.G.; Haroldson, M.A.; Waits, L.; Robbins, C.T.

    2004-01-01

    Spawning cutthroat trout (Oncorhynchus clarki (Richardson, 1836)) are a potentially important food resource for grizzly bears (Ursus arctos horribilis Ord, 1815) in the Greater Yellowstone Ecosystem. We developed a method to estimate the amount of cutthroat trout ingested by grizzly bears living in the Yellowstone Lake area. The method utilized (i) the relatively high, naturally occurring concentration of mercury in Yellowstone Lake cutthroat trout (508 ± 93 ppb) and its virtual absence in all other bear foods (6 ppb), (ii) hair snares to remotely collect hair from bears visiting spawning cutthroat trout streams between 1997 and 2000, (iii) DNA analyses to identify the individual and sex of grizzly bears leaving a hair sample, (iv) feeding trials with captive bears to develop relationships between fish and mercury intake and hair mercury concentrations, and (v) mercury analyses of hair collected from wild bears to estimate the amount of trout consumed by each bear. Male grizzly bears consumed an average of 5 times more trout/kg bear than did female grizzly bears. Estimated cutthroat trout intake per year by the grizzly bear population was only a small fraction of that estimated by previous investigators, and males consumed 92% of all trout ingested by grizzly bears.

  3. NEW LOCALITY OF CAVE BEAR (Ursus spelaeus Rosenmüller & Heinroth, 1794 IN BOSNIA AND HERZEGOVINA: MORPHO- ANATOMICAL CHARACTERISTICS OF CRANIAL SKELETON FOUND IN CAVE AT VRELO MOKRANJSKA MILJACKA

    Directory of Open Access Journals (Sweden)

    Lada Lukić-Bilela

    2013-10-01

    Full Text Available During the investigation of the Cave at Vrelo Mokranjska Miljacka, the bone remains of the cave bear (Ursus spelaeus Rosenmüller & Heinroth, 1794 was found. This is the new Pleistocene fauna locality of this extinct species in Bosnia and Herzegovina. Almost complete cranial skeleton belongs to a young adult male. Analyzed morphometric proportions completely fit within the variation range of the Pleistocene cave bear populations in Bosnia and Herzegovina.Key words: Ursus spelaeus, skull, teeth, Cave of Vrelo Mokranjska Miljacka

  4. New records on the Abruzzo brown bear range, particularly on Gran Sasso and Laga Mountains / Osservazioni sull'areale dell'orso marsicano, con particolare riferimento al Gran Sasso e ai Monti della Laga

    Directory of Open Access Journals (Sweden)

    Marco Bologna

    1992-07-01

    Full Text Available Abstract New records of Abruzzo brown bear (Ursus arctos marsicanus in some mountain massifs of Central Apennines (Laga, Gran Sasso, Velino, Sirente and Northern Molise are reported. These records are discussed in relation to the recent dispersion of the relictual population, and the probable recolonization of some areas where the brown bear went out in the last two centuries. Riassunto Viene brevemente discusso il fenomeno di dispersione e ricolonizzazione di aree montane centro-appenniniche da parte dell'orso bruno marsicano. Tra i nuovi reperti, particolarmente significativi sono quelli più settentrionali, relativi ai Monti della Laga ed al Gran Sasso, dove la specie era estinta da circa duecento anni.

  5. Using spatial mark-recapture for conservation monitoring of grizzly bear populations in Alberta.

    Science.gov (United States)

    Boulanger, John; Nielsen, Scott E; Stenhouse, Gordon B

    2018-03-26

    One of the challenges in conservation is determining patterns and responses in population density and distribution as it relates to habitat and changes in anthropogenic activities. We applied spatially explicit capture recapture (SECR) methods, combined with density surface modelling from five grizzly bear (Ursus arctos) management areas (BMAs) in Alberta, Canada, to assess SECR methods and to explore factors influencing bear distribution. Here we used models of grizzly bear habitat and mortality risk to test local density associations using density surface modelling. Results demonstrated BMA-specific factors influenced density, as well as the effects of habitat and topography on detections and movements of bears. Estimates from SECR were similar to those from closed population models and telemetry data, but with similar or higher levels of precision. Habitat was most associated with areas of higher bear density in the north, whereas mortality risk was most associated (negatively) with density of bears in the south. Comparisons of the distribution of mortality risk and habitat revealed differences by BMA that in turn influenced local abundance of bears. Combining SECR methods with density surface modelling increases the resolution of mark-recapture methods by directly inferring the effect of spatial factors on regulating local densities of animals.

  6. Serosurvey for selected pathogens in free-ranging American black bears (Ursus americanus) in Maryland, USA.

    Science.gov (United States)

    Bronson, Ellen; Spiker, Harry; Driscoll, Cindy P

    2014-10-01

    American black bears (Ursus americanus) in Maryland, USA, live in forested areas in close proximity to humans and their domestic pets. From 1999 to 2011, we collected 84 serum samples from 63 black bears (18 males; 45 females) in five Maryland counties and tested them for exposure to infectious, including zoonotic, pathogens. A large portion of the bears had antibody to canine distemper virus and Toxoplasma gondii, many at high titers. Prevalences of antibodies to zoonotic agents such as rabies virus and to infectious agents of carnivores including canine adenovirus and canine parvovirus were lower. Bears also had antibodies to vector-borne pathogens common to bears and humans such as West Nile virus, Borrelia burgdorferi, Rickettsia rickettsii, and Anaplasma phagocytophilum. Antibodies were detected to Leptospira interrogans serovars Pomona, Icterohaemorrhagiae, Canicola, Grippotyphosa, and Bratislava. We did not detect antibodies to Brucella canis or Ehrlichia canis. Although this population of Maryland black bears demonstrated exposure to multiple pathogens of concern for humans and domesticated animals, the low levels of clinical disease in this and other free-ranging black bear populations indicate the black bear is likely a spillover host for the majority of pathogens studied. Nevertheless, bear populations living at the human-domestic-wildlife interface with increasing human and domestic animal exposure should continue to be monitored because this population likely serves as a useful sentinel of ecosystem health.

  7. Femoral fracture repair using a locking plate technique in an adult captive polar bear (Ursus maritimus).

    Science.gov (United States)

    Zimmerman, Dawn M; Dew, Terry; Douglass, Michael; Perez, Edward

    2010-02-01

    To report successful femoral fracture repair in a polar bear. Case report. Female polar bear (Ursus maritimus) 5 years and approximately 250 kg. A closed, complete, comminuted fracture of the distal midshaft femur was successfully reduced and stabilized using a compression plating technique with 2 specialized human femur plates offering axial, rotational, and bending support, and allowing the bone to share loads with the implant. Postoperative radiographs were obtained at 11.5 weeks, 11 months, and 24 months. Bone healing characterized by marked periosteal reaction was evident at 11 months with extensive remodeling evident at 24 months. No complications were noted. Distal mid shaft femoral fracture was reduced, stabilized, and healed in an adult polar bear with a locking plate technique using 2 plates. Previously, femoral fractures in polar bears were considered irreparable. Use of 2 plates applied with a locking plate technique can result in successful fracture repair despite large body weight and inability to restrict postoperative activity.

  8. Use of hyaluronidase to improve chemical immobilization of free-ranging polar bears (Ursus maritimus).

    Science.gov (United States)

    Cattet, Marc R L; Obbard, Martyn E

    2010-01-01

    We assessed the efficacy and safety of hyaluronidase to improve chemical immobilization of free-ranging polar bears (Ursus maritimus) captured from helicopter by remote drug delivery along the Ontario coast line of northwestern James Bay and southern Hudson Bay during September 2005 and October 2007. We used a single blind study design in which one person prepared and loaded all darts without the shooter knowing whether hyaluronidase (150 IU per dart) or sterile water was added to the immobilizing drug mixture of xylazine and zolazepam-tiletamine (XZT). We found that we often required more than one dart to immobilize bears in the control group (XZT+sterile water; >1 dart for 15 of 28 captures) versus the treatment group (XZT+hyaluronidase; >1 dart for seven of 26 captures). As a consequence, treatment bears were generally immobilized with smaller XZT dosages (7.9 vs. 9.4 mg/kg; P = 0.08) and shorter induction (10 vs. 15 min; P = 0.004) than control bears. We found no differences in vital rates and serum biochemistry results between control and treatment bears. We did find, however, that induction times correlated directly with rectal temperature at polar bears. Overall we found hyaluronidase to be effective and safe for capture of polar bears. We recommend further study to determine whether effects of hyaluronidase are dose dependent and recommend that others involved with capture of seasonally fat species such as polar bears consider use of hyaluronidase to improve chemical immobilization.

  9. Serosurvey for Trichinella in polar bears (Ursus maritimus) from Svalbard and the Barents Sea.

    Science.gov (United States)

    Asbakk, Kjetil; Aars, Jon; Derocher, Andrew E; Wiig, Oystein; Oksanen, Antti; Born, Erik W; Dietz, Rune; Sonne, Christian; Godfroid, Jacques; Kapel, Christian M O

    2010-09-20

    Blood samples of live-caught polar bears (Ursus maritimus) from Svalbard collected 1991-2000 (Period 1) and 2006-2008 (Period 2) and from the pack ice of the Barents Sea collected in Period 1, were assayed for antibodies against Trichinella spp. by ELISA. Of 54 cubs-of-the-year included in the Period 1 sample, 53 were seronegative, indicating that exposure to Trichinella infected meat is uncommon during the first months of life for polar bears in the Svalbard region. Of 30 mother-offspring pairs, 18 mothers were seropositive with seronegative offspring (n=27), suggesting (1) that maternal antibodies had dropped to levels below detection limit by the time of capture in April (offspring approximately 4 months old), and (2) supporting experimental studies in other animal models showing that vertical transmission of Trichinella spp. is uncommon. Bear 1 year and older had higher prevalence in Svalbard (78%) than in the Barents Sea (51%). There was no temporal change in prevalence for bears from Svalbard during the time between the two periods. The prevalence increased with age in both sexes. A positive correlation was found between anti-Toxoplasma gondii and anti-Trichinella spp. antibodies.

  10. Evaluation of stored body fat in nuisance-killed Japanese black bears (Ursus thibetanus japonicus).

    Science.gov (United States)

    Yamanaka, Atsushi; Asano, Makoto; Suzuki, Masatsugu; Mizoguchi, Toshio; Oi, Toru; Shimozuru, Michito; Tsubota, Toshio

    2011-02-01

    We evaluated the stored body fat of Japanese black bears (Ursus thibetanus japonicus) killed as nuisances in Gifu and Fukushima prefectures, Japan, during 2005-2007. We employed femur marrow fat (FMF), modified kidney fat index (mKFI), and abdominal subcutaneous fat (ASF) as indices for quantitative evaluation. We examined the basic characteristics of these indices, such as seasonality, age and sex dependency, and the quantitative relationship among them. mKFI and ASF increased towards the beginning of the denning period (December), while FMF was relatively stable throughout the sampling period (July-December). In cubs, all indices showed significantly lower values than in the older age classes. There seemed to be a catabolizing order between FMF and mKFI, but not between mKFI and ASF. We also evaluated the yearly change in the indices, and discussed its relevance to the incidence of bear intrusion into human residential areas. Bears nuisance-killed in summer (July-September) 2006 had a significantly larger amount of stored body fat than those killed in summer 2007, although the number of nuisance kills was larger in 2006 than in 2007. This suggests that poor nutritional condition is not a direct cause of bear intrusion.

  11. Anaerobic oral flora in the North American black bear (Ursus americanus) in eastern North Carolina.

    Science.gov (United States)

    Clarke, Elsburgh O; Stoskopf, Michael K; Minter, Larry J; Stringer, Elizabeth M

    2012-06-01

    Microbial flora can provide insight into the ecology and natural history of wildlife in addition to improving understanding of health risks. This study examines the anaerobic oral flora of hunter killed black bears (Ursus americanus) in eastern North Carolina. Oral swabs from the buccal and lingual supragingival tooth surfaces of the first and second mandibular and maxillary molars of 22 black bears were inoculated onto Brucella Blood Agar plates supplemented with hemin and vitamin K after transport from the field using reduced oxoid nutrient broth. Sixteen anaerobic bacterial species, representing nine genera were identified using the RapID ANA II Micromethod Kit system and a number of organisms grown that could not be identified with the system. The most frequently identified anaerobes were Peptostreptococcus prevotii, Streptococcus constellatus, and Porphyromonas gingivalis. The diversity in the anaerobic oral flora of black bear in eastern North Carolina suggests the importance of including these organisms in basic health risk assessment protocols and suggests a potential tool for assessment of bear/habitat interactions. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Activity pattern of the orphaned Asiatic Black Bear Ursus thibetanus (Mammalia: Carnivora: Ursidae cubs during rehabilitation processes.

    Directory of Open Access Journals (Sweden)

    S. Dasgupta

    2014-09-01

    Full Text Available Five Asiatic Black Bear Ursus thibetanus cubs aged between 6.5-15 months were studied for five months using instantaneous scan sampling (n=3049 scans while they were undergoing acclimatization in the rehabilitation areas in Pakke Tiger Reserve, Arunachal Pradesh, India. During the course of the study, feeding, moving, climbing, resting and playing activities were recorded in three consecutive time periods, representing three phases of acclimatization. The frequency of climbing and moving increased considerably towards the third phase, while feeding decreased. These changes can be attributed to a learning process during acclimatization. Time spent on moving and playing differed significantly among the bears, but not climbing or feeding.

  13. Prevalence of antibodies against Brucella spp. in West Greenland polar bears (Ursus maritimus) and East Greenland muskoxen (Ovibos moschatus)

    DEFF Research Database (Denmark)

    Sonne, Christian; Andersen-Ranberg, Emilie; Rajala, Elisabeth L.

    2018-01-01

    impact on human health due to consumption of raw meat or otherwise contact with tissues and fluids of infected game species such as muskoxen and polar bears. Here, we present serological results for Baffin Bay polar bears (Ursus maritimus) (n = 96) and North East Greenland muskoxen (Ovibos moschatus) (n...

  14. Age and seasonal variability of polybrominated diphenyl ethers in free-ranging East Greenland polar bears (Ursus maritimus)

    International Nuclear Information System (INIS)

    Dietz, Rune; Riget, Frank F.; Sonne, Christian; Letcher, Robert J.; Backus, Sean; Born, Erik W.; Kirkegaard, Maja; Muir, Derek C.G.

    2007-01-01

    Polybrominated diphenyl ethers (PBDEs) were analysed in adipose tissue from 92 East Greenland polar bears (Ursus maritimus) sampled during 1999-2001. Mean ΣPBDE concentrations were 70 ng/g lipid weight (lw) (range: 22-192 ng/g lw) and showed no relationship with age or sex. Of the 32 analysed PBDE congeners; BDE47, BDE153, BDE99 and BDE100 dominated, and comprised 99.6% of the ΣPBDE concentration. The ΣPBDE concentration had a highly significant correlation with ΣPCB, ΣCHL, dieldrin, HCB and ΣHCH concentrations. We found a seasonal pattern of median ΣPBDE concentration with 1.2 to 1.8 times higher concentrations in March to July than the rest of the year. The seasonal variation also provides a clue to the seasonal exposure, bio-availability, toxic exposure and degradation. We suggest that future geographical PBDE data comparisons may not need corrections for sex or age, but such data sets should be corrected for seasonal variability, using the presented correctional trigonometric regression. - Mean ΣPBDE concentrations of East Greenland polar bears (Ursus maritimus) were 69.5 ng/g lw (range: 21.7-192 ng/g lw) and showed a seasonal pattern with no relationship with age and sex

  15. Serum corticosteroid binding globulin expression is modulated by fasting in polar bears (Ursus maritimus).

    Science.gov (United States)

    Chow, Brian A; Hamilton, Jason; Cattet, Marc R L; Stenhouse, Gordon; Obbard, Martyn E; Vijayan, Mathilakath M

    2011-01-01

    Polar bears (Ursus maritimus) from several subpopulations undergo extended fasting during the ice-free season. However, the animals appear to conserve protein despite the prolonged fasting, though the mechanisms involved are poorly understood. We hypothesized that elevated concentrations of corticosteroid binding globulin (CBG), the primary cortisol binding protein in circulation, lead to cortisol resistance and provide a mechanism for protein conservation during extended fasting. The metabolic state (feeding vs. fasting) of 16 field sampled male polar bears was determined based on their serum urea to creatinine ratio (>25 for feeding vs. polar bears sampled. Serum CBG expression was greater in lactating females relative to non-lactating females and males. CBG expression was significantly higher in fasting males when compared to non-fasting males. This leads us to suggest that CBG expression may serve as a mechanism to conserve protein during extended fasting in polar bears by reducing systemic free cortisol concentrations. This was further supported by a lower serum glucose concentration in the fasting bears. As well, a lack of an enhanced adrenocortical response to acute capture stress supports our hypothesis that chronic hunger is not a stressor in this species. Overall, our results suggest that elevated serum CBG expression may be an important adaptation to spare proteins by limiting cortisol bioavailability during extended fasting in polar bears. Copyright © 2010 Elsevier Inc. All rights reserved.

  16. Predormancy omnivory in European cave bears evidenced by a dental microwear analysis of Ursus spelaeus from Goyet, Belgium

    Science.gov (United States)

    Peigné, Stéphane; Goillot, Cyrielle; Germonpré, Mietje; Blondel, Cécile; Bignon, Olivier; Merceron, Gildas

    2009-01-01

    Previous morphological and isotopic studies indicate that Late Pleistocene cave bear (Ursus spelaeus) diet ranged from mostly vegetarian to omnivory or even carnivory. However, such analyses do not provide information on seasonal diets, and only provide an average record of diet. A dental microwear analysis of 43 young and adult individuals demonstrate that, during the predormancy period, cave bears from Goyet (Late Pleistocene, Belgium) were not strictly herbivorous, but had a mixed diet composed of hard items (e.g., possibly bone), invertebrates (e.g., insects), meat (ungulates, small vertebrates), and/or plant matter (hard mast, seeds, herbaceous vegetations, and fruits). Therefore, our results indicate that cave bears at Goyet were generalist omnivores during the predormancy period, which is consistent with current data on the dietary ecology of extant bears during this season. These data also raise questions about the ecological role and causes of the extinction of cave bears. PMID:19706401

  17. Conservation status of polar bears (Ursus maritimus) in relation to projected sea-ice declines

    Science.gov (United States)

    Laidre, K. L.; Regehr, E. V.; Akcakaya, H. R.; Amstrup, S. C.; Atwood, T.; Lunn, N.; Obbard, M.; Stern, H. L., III; Thiemann, G.; Wiig, O.

    2016-12-01

    Loss of Arctic sea ice due to climate change is the most serious threat to polar bears (Ursus maritimus) throughout their circumpolar range. We performed a data-based sensitivity analysis with respect to this threat by evaluating the potential response of the global polar bear population to projected sea-ice conditions. We conducted 1) an assessment of generation length for polar bears, 2) developed of a standardized sea-ice metric representing important habitat characteristics for the species; and 3) performed population projections over three generations, using computer simulation and statistical models representing alternative relationships between sea ice and polar bear abundance. Using three separate approaches, the median percent change in mean global population size for polar bears between 2015 and 2050 ranged from -4% (95% CI = -62%, 50%) to -43% (95% CI = -76%, -20%). Results highlight the potential for large reductions in the global population if sea-ice loss continues. They also highlight the large amount of uncertainty in statistical projections of polar bear abundance and the sensitivity of projections to plausible alternative assumptions. The median probability of a reduction in the mean global population size of polar bears greater than 30% over three generations was approximately 0.71 (range 0.20-0.95. The median probability of a reduction greater than 50% was approximately 0.07 (range 0-0.35), and the probability of a reduction greater than 80% was negligible.

  18. Competition between apex predators? Brown bears decrease wolf kill rate on two continents.

    Science.gov (United States)

    Tallian, Aimee; Ordiz, Andrés; Metz, Matthew C; Milleret, Cyril; Wikenros, Camilla; Smith, Douglas W; Stahler, Daniel R; Kindberg, Jonas; MacNulty, Daniel R; Wabakken, Petter; Swenson, Jon E; Sand, Håkan

    2017-02-08

    Trophic interactions are a fundamental topic in ecology, but we know little about how competition between apex predators affects predation, the mechanism driving top-down forcing in ecosystems. We used long-term datasets from Scandinavia (Europe) and Yellowstone National Park (North America) to evaluate how grey wolf ( Canis lupus ) kill rate was affected by a sympatric apex predator, the brown bear ( Ursus arctos ). We used kill interval (i.e. the number of days between consecutive ungulate kills) as a proxy of kill rate. Although brown bears can monopolize wolf kills, we found no support in either study system for the common assumption that they cause wolves to kill more often. On the contrary, our results showed the opposite effect. In Scandinavia, wolf packs sympatric with brown bears killed less often than allopatric packs during both spring (after bear den emergence) and summer. Similarly, the presence of bears at wolf-killed ungulates was associated with wolves killing less often during summer in Yellowstone. The consistency in results between the two systems suggests that brown bear presence actually reduces wolf kill rate. Our results suggest that the influence of predation on lower trophic levels may depend on the composition of predator communities. © 2017 The Authors.

  19. Salmon fishing by bears and the dawn of cooperative predation.

    Science.gov (United States)

    Stringham, Stephen F

    2012-11-01

    Although bears are an epitome of solitary predation, black (Ursus americanus) and brown bears (U. arctos) occasionally act in pairs to capture salmon (Onchorynchous spp.). I sought to identify conditions that promote pairing and how this relates to optimal foraging. This study on Alaskan black bears assessed whether each mode of fishing (solo vs. paired) occurs mainly where it is most efficient at harvesting salmon--that is, whether modal group size (1 vs. 2) is also optimal size. Not in this case. Pairing increased captures per attempt (benefit/cost ratio = profitability) by up to 47% and captures per minute by up to 5.2-fold. Yet, the ratio of paired versus solo fishing was significantly lower than either profitability or chance explains. Modal group size was 1, optimal size was 2. This discrepancy did not result from intervention by other current benefits and costs, but from unnecessary defensiveness toward any rapidly approaching conspecific, even though it was chasing salmon, not threatening. For bears to regularly hunt cooperatively, they would have to more readily habituate to agonistic-like predatory actions, communicate intentions from > 10 m apart, and assess situational variations in benefit/cost ratios for solo versus paired hunting. It would be revealing to discover how social carnivores overcame these challenges.

  20. Barents Sea polar bears (Ursus maritimus: population biology and anthropogenic threats

    Directory of Open Access Journals (Sweden)

    Magnus Andersen

    2016-07-01

    Full Text Available This paper examines how anthropogenic threats, such as disturbance, pollution and climate change, are linked to polar bear (Ursus maritimus population biology in the Svalbard and Barents Sea area, with the aim to increase our understanding of how human activity may impact the population. Overharvesting drastically reduced the population of polar bears in the Barents Sea region from about 1870 to 1970. After harvesting was stopped—in 1956 in Russia and 1973 in Norway—the population grew to an estimated 2650 individuals (95% confidence interval 1900–3600 in 2004, and maternity denning in the Svalbard Archipelago became more widely distributed. During recent decades, the population has faced challenges from a variety of new anthropogenic impacts: a range of pollutants, an increasing level of human presence and activity as well as changes in ice conditions. Contaminants bioaccumulate up through the marine food web, culminating in this top predator that consumes ringed, bearded and harp seals. Females with small cubs use land-fast sea ice for hunting and are therefore vulnerable to disturbance by snowmobile drivers. Sea-ice diminution, associated with climate change, reduces polar bears’ access to denning areas and could negatively affect the survival of cubs. There are clear linkages between population biology and current anthropogenic threats, and we suggest that future research and management should focus on and take into consideration the combined effects of several stressors on polar bears.

  1. Three decades (1983-2010) of contaminant trends in East Greenland polar bears (Ursus maritimus). Part 1: legacy organochlorine contaminants.

    Science.gov (United States)

    Dietz, Rune; Rigét, Frank F; Sonne, Christian; Born, Erik W; Bechshøft, Thea; McKinney, Melissa A; Letcher, Robert J

    2013-09-01

    Legacy organochlorine contaminants were determined in adipose tissues from 294 polar bears (Ursus maritimus) sampled in East Greenland in 23 of the 28years between 1983 and 2010. Of 19 major legacy contaminants and congeners (ΣPCB, 4 PCB congeners (CB153, 180, 170/190), ΣDDT, p,p'-DDE, p,p' -DDD and p,p'-DDT, α- and β-hexachlorocyclohexane (HCH), HCB, octachlorostyrene, dieldrin, oxychlordane, cis- and trans-chlordane, cis- and trans-nonachlor, heptachlor epoxide and BB-153), 18 showed statistically significant average yearly declines of -4.4% (range: -2.0 to -10.8%/year) among subadult polar bears (i.e. femalespolar bear tissues. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Seasonal variation in haematological and biochemical variables in free-ranging subadult brown bears (Ursus arctos) in Sweden.

    Science.gov (United States)

    Græsli, Anne Randi; Evans, Alina L; Fahlman, Åsa; Bertelsen, Mads F; Blanc, Stéphane; Arnemo, Jon M

    2015-12-08

    Free-ranging brown bears exhibit highly contrasting physiological states throughout the year. They hibernate 6 months of the year, experiencing a decrease in body temperature, heart rate, respiratory rate and metabolism. An increase in food consumption and the resulting weight gain (mostly through fat storage) prior to hibernation are also part of the brown bear's annual cycle. Due to these physiological changes, haematological and biochemical variables vary dramatically throughout the year. Seasonal changes in 12 haematological and 34 biochemical variables were evaluated in blood samples collected from 40 free-ranging subadult brown bears (22 females, 18 males) immobilised in Sweden in winter (February-March), spring (April-May), and summer (June). Higher levels of haemoglobin, haematocrit and red blood cell count, and a lower white blood cell count and mean cell volume was found during hibernation than in spring and summer. Lower values of the enzymes; aspartate aminotransferase (AST), alanine transaminase (ALT), alkaline phosphatase (AP), γ-glutamyl transpeptidase (GGT), glutamate dehydrogenase (GD) and amylase, and increased values of β-hydroxybutyrate (β-HBA) and blood lipids; triglycerides, cholesterol and free fatty acids, were present during hibernation compared to spring and summer. This study documents significant shifts in haematological and biochemical variables in samples collected from brown bears anaesthetised in winter (February-March) compared to in spring and summer (April-June), reflecting the lowered metabolic, renal and hepatic activity during hibernation. Lower values of enzymes and higher values of blood lipids during hibernation, likely reflect a lipid-based metabolism.

  3. Seasonal changes in isoform composition of giant proteins of thick and thin filaments and titin (connectin) phosphorylation level in striated muscles of bears (Ursidae, Mammalia).

    Science.gov (United States)

    Salmov, N N; Vikhlyantsev, I M; Ulanova, A D; Gritsyna, Yu V; Bobylev, A G; Saveljev, A P; Makariushchenko, V V; Maksudov, G Yu; Podlubnaya, Z A

    2015-03-01

    Seasonal changes in the isoform composition of thick and thin filament proteins (titin, myosin heavy chains (MyHCs), nebulin), as well as in the phosphorylation level of titin in striated muscles of brown bear (Ursus arctos) and hibernating Himalayan black bear (Ursus thibetanus ussuricus) were studied. We found that the changes that lead to skeletal muscle atrophy in bears during hibernation are not accompanied by a decrease in the content of nebulin and intact titin-1 (T1) isoforms. However, a decrease (2.1-3.4-fold) in the content of T2 fragments of titin was observed in bear skeletal muscles (m. gastrocnemius, m. longissimus dorsi, m. biceps) during hibernation. The content of the stiffer N2B titin isoform was observed to increase relative to the content of its more compliant N2BA isoform in the left ventricles of hibernating bears. At the same time, in spite of the absence of decrease in the total content of T1 in the myocardium of hibernating brown bear, the content of T2 fragments decreased ~1.6-fold. The level of titin phosphorylation only slightly increased in the cardiac muscle of hibernating brown bear. In the skeletal muscles of brown bear, the level of titin phosphorylation did not vary between seasons. However, changes in the composition of MyHCs aimed at increasing the content of slow (I) and decreasing the content of fast (IIa) isoforms of this protein during hibernation of brown bear were detected. Content of MyHCs I and IIa in the skeletal muscles of hibernating Himalayan black bear corresponded to that in the skeletal muscles of hibernating brown bear.

  4. Plant consumption by grizzly bears reduces biomagnification of salmon-derived polychlorinated biphenyls, polybrominated diphenyl ethers, and organochlorine pesticides.

    Science.gov (United States)

    Christensen, Jennie R; Yunker, Mark B; MacDuffee, Misty; Ross, Peter S

    2013-04-01

    The present study characterizes the uptake and loss of persistent organic pollutants (POPs) in grizzly bears (Ursus arctos horribilis) by sampling and analyzing their terrestrial and marine foods and fecal material from a remote coastal watershed in British Columbia, Canada. The authors estimate that grizzly bears consume 341 to 1,120 µg of polychlorinated biphenyls (PCBs) and 3.9 to 33 µg of polybrominated diphenyl ethers daily in the fall when they have access to an abundant supply of returning salmon. The authors also estimate that POP elimination by grizzly bears through defecation is very low following salmon consumption (typically 100% for PCBs and organochlorine pesticides). Excretion of individual POPs is largely driven by a combination of fugacity (differences between bear and food concentrations) and the digestibility of the food. The results of the present study are substantiated by a principal components analysis, which also demonstrates a strong role for log KOW in governing the excretion of different POPs in grizzly bears. Collectively, the present study's results reveal that grizzly bears experience a vegetation-associated drawdown of POPs previously acquired through the consumption of salmon, to such an extent that net biomagnification is reduced. Copyright © 2013 SETAC.

  5. Grizzly bear (Ursus arctos horribilis) locomotion: forelimb joint mechanics across speed in the sagittal and frontal planes.

    Science.gov (United States)

    Shine, Catherine L; Robbins, Charles T; Nelson, O Lynne; McGowan, Craig P

    2017-04-01

    The majority of terrestrial locomotion studies have focused on parasagittal motion and paid less attention to forces or movement in the frontal plane. Our previous research has shown that grizzly bears produce higher medial ground reaction forces (lateral pushing from the animal) than would be expected for an upright mammal, suggesting frontal plane movement may be an important aspect of their locomotion. To examine this, we conducted an inverse dynamics analysis in the sagittal and frontal planes, using ground reaction forces and position data from three high-speed cameras of four adult female grizzly bears. Over the speed range collected, the bears used walks, running walks and canters. The scapulohumeral joint, wrist and the limb overall absorb energy (average total net work of the forelimb joints, -0.97 W kg -1 ). The scapulohumeral joint, elbow and total net work of the forelimb joints have negative relationships with speed, resulting in more energy absorbed by the forelimb at higher speeds (running walks and canters). The net joint moment and power curves maintain similar patterns across speed as in previously studied species, suggesting grizzly bears maintain similar joint dynamics to other mammalian quadrupeds. There is no significant relationship with net work and speed at any joint in the frontal plane. The total net work of the forelimb joints in the frontal plane was not significantly different from zero, suggesting that, despite the high medial ground reaction forces, the forelimb acts as a strut in that plane. © 2017. Published by The Company of Biologists Ltd.

  6. Temporal trends and future predictions of mercury concentrations in Northwest Greenland polar bear (Ursus maritimus) hair.

    Science.gov (United States)

    Dietz, R; Born, E W; Rigét, F; Aubail, A; Sonne, C; Drimmie, R; Basu, N

    2011-02-15

    Hair samples from 117 Northwest Greenland polar bears (Ursus maritimus) were taken during 1892-2008 and analyzed for total mercury (hereafter Hg). The sample represented 28 independent years and the aim of the study was to analyze for temporal Hg trends. Mercury concentrations showed yearly significant increases of 1.6-1.7% (p polar bear Hg exposure is 95.6-96.2% anthropogenic in its origin. Assuming a continued anthropogenic increase, this model estimated concentrations in 2050 and 2100 will be 40- and 92-fold the baseline concentration, respectively, which is equivalent to a 97.5 and 98.9% man-made contribution. None of the 2001-2008 concentrations of Hg in Northwest Greenland polar bear hair exceeded the general guideline values of 20-30 μg/g dry weight for terrestrial wildlife, whereas the neurochemical effect level of 5.4 μg Hg/g dry weight proposed for East Greenland polar bears was exceeded in 93.5% of the cases. These results call for detailed effect studies in main target organs such as brain, liver, kidney, and sexual organs in the Northwest Greenland polar bears.

  7. Dietary protein content alters energy expenditure and composition of the mass gain in grizzly bears (Ursus arctos horribilis).

    Science.gov (United States)

    Felicetti, Laura A; Robbins, Charles T; Shipley, Lisa A

    2003-01-01

    Many fruits contain high levels of available energy but very low levels of protein and other nutrients. The discrepancy between available energy and protein creates a physiological paradox for many animals consuming high-fruit diets, as they will be protein deficient if they eat to meet their minimum energy requirement. We fed young grizzly bears both high-energy pelleted and fruit diets containing from 1.6% to 15.4% protein to examine the role of diet-induced thermogenesis and fat synthesis in dealing with high-energy-low-protein diets. Digestible energy intake at mass maintenance increased 2.1 times, and composition of the gain changed from primarily lean mass to entirely fat when the protein content of the diet decreased from 15.4% to 1.6%. Daily fat gain was up to three times higher in bears fed low-protein diets ad lib., compared with bears consuming the higher-protein diet and gaining mass at the same rate. Thus, bears eating fruit can either consume other foods to increase dietary protein content and reduce energy expenditure, intake, and potentially foraging time or overeat high-fruit diets and use diet-induced thermogenesis and fat synthesis to deal with their skewed energy-to-protein ratio. These are not discrete options but a continuum that creates numerous solutions for balancing energy expenditure, intake, foraging time, fat accumulation, and ultimately fitness, depending on food availability, foraging efficiency, bear size, and body condition.

  8. Using gene transcription to assess ecological and anthropological stressors in brown bears

    Science.gov (United States)

    Bowen, Lizabeth; Miles, A. Keith; Waters, Shannon C.; Gustine, Dave; Joly, Kyle; Hilderbrand, Grant V.

    2017-01-01

    Increasingly, population- and ecosystem-level health assessments are performed using sophisticated molecular tools. Advances in molecular technology enable the identification of synergistic effects of multiple stressors on the individual physiology of different species. Brown bears (Ursus arctos) are an apex predator; thus, they are ideal candidates for detecting potentially ecosystem-level systemic perturbations using molecular-based tools. We used gene transcription to analyze 130 brown bear samples from three National Parks and Preserves in Alaska. Although the populations we studied are apparently stable in abundance and exist within protected and intact environments, differences in transcript profiles were noted. The most prevalent differences were among locations. The transcript patterns among groups reflect the influence of environmental factors, such as nutritional status, disease, and xenobiotic exposure. However, these profiles also likely represent baselines for each unique environment by which future measures can be made to identify early indication of population-level changes due to, for example, increasing Arctic temperatures. Some of those environmental changes are predicted to be potentially positive for brown bears, but other effects such as the manifestation of disease or indirect effects of oceanic acidification may produce negative impacts.

  9. Ancient Hybridization and an Irish Origin for the Modern Polar Bear Matriline

    Science.gov (United States)

    Edwards, Ceiridwen J.; Suchard, Marc A.; Lemey, Philippe; Welch, John J.; Barnes, Ian; Fulton, Tara L.; Barnett, Ross; O’Connell, Tamsin C.; Coxon, Peter; Monaghan, Nigel; Valdiosera, Cristina E.; Lorenzen, Eline D.; Willerslev, Eske; Baryshnikov, Gennady F.; Rambaut, Andrew; Thomas, Mark G.; Bradley, Daniel G.; Shapiro, Beth

    2015-01-01

    Summary Background Polar bears (Ursus maritimus) are among those species most susceptible to the rapidly changing arctic climate, and their survival is of global concern. Despite this, little is known about polar bear species history. Future conservation strategies would significantly benefit from an understanding of basic evolutionary information, such as the timing and conditions of their initial divergence from brown bears (U. arctos) or their response to previous environmental change. Results We used a spatially explicit phylogeographic model to estimate the dynamics of 242 brown bear and polar bear matrilines sampled throughout the last 120,000 years and across their present and past geographic ranges. Our results show that the present distribution of these matrilines was shaped by a combination of regional stability and rapid, long-distance dispersal from ice-age refugia. In addition, hybridization between polar bears and brown bears may have occurred multiple times throughout the Late Pleistocene. Conclusions The reconstructed matrilineal history of brown and polar bears has two striking features. First, it is punctuated by dramatic and discrete climate-driven dispersal events. Second, opportunistic mating between these two species as their ranges overlapped has left a strong genetic imprint. In particular, a likely genetic exchange with extinct Irish brown bears forms the origin of the modern polar bear matriline. This suggests that interspecific hybridization not only may be more common than previously considered but may be a mechanism by which species deal with marginal habitats during periods of environmental deterioration. PMID:21737280

  10. Geographical distribution of organochlorine pesticides (OCPs) in polar bears (Ursus maritimus) in the Norwegian and Russian Arctic

    Science.gov (United States)

    Lie, E.; Bernhoft, A.; Riget, F.; Belikov, Stanislav; Boltunov, Andrei N.; Derocher, A.E.; Garner, G.W.; Wiig, O.; Skaare, J.U.

    2003-01-01

    Geographical variation of organochlorine pesticides (OCPs) was studied in blood samples from 90 adult female polar bear (Ursus maritimus) from Svalbard, Franz Josef Land, Kara Sea, East-Siberian Sea and Chukchi Sea. In all regions, oxychlordane was the dominant OCP. Regional differences in mean levels of HCB, oxychlordane, trans-nonachlor, ??-HCH, ??-HCH and p,p???-DDE were found. The highest levels of oxychlordane, trans-nonachlor and DDE were found in polar bears from Franz Josef Land and Kara Sea. HCB level was lowest in polar bears from Svalbard. Polar bears from Chukchi Sea had the highest level of ??- and ??-HCH. The lowest ??-HCH concentration was found in bears from Kara Sea. In all the bears, ???HCHs was dominated by ??-HCH. The geographical variation in OCP levels and pattern may suggest regional differences in pollution sources and different feeding habits in the different regions. Polar bears from the Western Russian Arctic were exposed to higher levels of chlordanes and p,p???-DDE than polar bears from locations westwards and eastwards from this region. This may imply the presence of a significant pollution source in the Russian Arctic area. The study suggests that the western Russian Arctic is the most contaminated region of the Arctic and warrants further research. ?? 2002 Elsevier Science B.V. All rights reserved.

  11. A new voluntary blood collection method for the Andean bear (Tremarctos ornatus) and Asiatic black bear (Ursus thibetanus).

    Science.gov (United States)

    Otaki, Yusuke; Kido, Nobuhide; Omiya, Tomoko; Ono, Kaori; Ueda, Miya; Azumano, Akinori; Tanaka, Sohei

    2015-01-01

    Various training methods have been developed for animal husbandry and health care in zoos and one of these trainings is blood collection. One training method, recently widely used for blood collection in Ursidae, requires setting up a sleeve outside the cage and gives access to limited blood collection sites. A new voluntary blood collection method without a sleeve was applied to the Andean bear (Tremarctos ornatus) and Asiatic black bear (Ursus thibetanus) with access to various veins at the same time. The present study evaluated the effectiveness of this new method and suggests improvements. Two Andean and two Asiatic black bears in Yokohama and Nogeyama Zoological Gardens, respectively, were trained to hold a bamboo pipe outside their cages. We could, thereby, simultaneously access superficial dorsal veins, the dorsal venous network of the hand, the cephalic vein from the carpal joint, and an area approximately 10 cm proximal to the carpal joint. This allowed us to evaluate which vein was most suitable for blood collection. We found that the cephalic vein, approximately 10 cm proximal to the carpal joint, was the most suitable for blood collection. This new method requires little or no modification of zoo facilities and provides a useful alternative method for blood collection. It could be adapted for use in other clinical examinations such as ultrasound examination. © 2015 Wiley Periodicals, Inc.

  12. Using tri-axial accelerometers to identify wild polar bear behaviors

    Science.gov (United States)

    Pagano, Anthony M.; Rode, Karyn D.; Cutting, A.; Owen, M.A.; Jensen, S.; Ware, J.V.; Robbins, C.T.; Durner, George M.; Atwood, Todd C.; Obbard, M.E.; Middel, K.R.; Thiemann, G.W.; Williams, T.M.

    2017-01-01

    Tri-axial accelerometers have been used to remotely identify the behaviors of a wide range of taxa. Assigning behaviors to accelerometer data often involves the use of captive animals or surrogate species, as their accelerometer signatures are generally assumed to be similar to those of their wild counterparts. However, this has rarely been tested. Validated accelerometer data are needed for polar bears Ursus maritimus to understand how habitat conditions may influence behavior and energy demands. We used accelerometer and water conductivity data to remotely distinguish 10 polar bear behaviors. We calibrated accelerometer and conductivity data collected from collars with behaviors observed from video-recorded captive polar bears and brown bears U. arctos, and with video from camera collars deployed on free-ranging polar bears on sea ice and on land. We used random forest models to predict behaviors and found strong ability to discriminate the most common wild polar bear behaviors using a combination of accelerometer and conductivity sensor data from captive or wild polar bears. In contrast, models using data from captive brown bears failed to reliably distinguish most active behaviors in wild polar bears. Our ability to discriminate behavior was greatest when species- and habitat-specific data from wild individuals were used to train models. Data from captive individuals may be suitable for calibrating accelerometers, but may provide reduced ability to discriminate some behaviors. The accelerometer calibrations developed here provide a method to quantify polar bear behaviors to evaluate the impacts of declines in Arctic sea ice.

  13. Evolutionary history of enigmatic bears in the Tibetan Plateau-Himalaya region and the identity of the yeti.

    Science.gov (United States)

    Lan, Tianying; Gill, Stephanie; Bellemain, Eva; Bischof, Richard; Nawaz, Muhammad Ali; Lindqvist, Charlotte

    2017-12-13

    Although anecdotally associated with local bears ( Ursus arctos and U. thibetanus ), the exact identity of 'hominid'-like creatures important to folklore and mythology in the Tibetan Plateau-Himalaya region is still surrounded by mystery. Recently, two purported yeti samples from the Himalayas showed genetic affinity with an ancient polar bear, suggesting they may be from previously unrecognized, possibly hybrid, bear species, but this preliminary finding has been under question. We conducted a comprehensive genetic survey of field-collected and museum specimens to explore their identity and ultimately infer the evolutionary history of bears in the region. Phylogenetic analyses of mitochondrial DNA sequences determined clade affinities of the purported yeti samples in this study, strongly supporting the biological basis of the yeti legend to be local, extant bears. Complete mitochondrial genomes were assembled for Himalayan brown bear ( U. a. isabellinus ) and black bear ( U. t. laniger ) for the first time. Our results demonstrate that the Himalayan brown bear is one of the first-branching clades within the brown bear lineage, while Tibetan brown bears diverged much later. The estimated times of divergence of the Tibetan Plateau and Himalayan bear lineages overlap with Middle to Late Pleistocene glaciation events, suggesting that extant bears in the region are likely descendants of populations that survived in local refugia during the Pleistocene glaciations. © 2017 The Authors.

  14. Evolutionary history of enigmatic bears in the Tibetan Plateau–Himalaya region and the identity of the yeti

    Science.gov (United States)

    Lan, Tianying; Gill, Stephanie; Bellemain, Eva; Bischof, Richard; Nawaz, Muhammad Ali

    2017-01-01

    Although anecdotally associated with local bears (Ursus arctos and U. thibetanus), the exact identity of ‘hominid’-like creatures important to folklore and mythology in the Tibetan Plateau–Himalaya region is still surrounded by mystery. Recently, two purported yeti samples from the Himalayas showed genetic affinity with an ancient polar bear, suggesting they may be from previously unrecognized, possibly hybrid, bear species, but this preliminary finding has been under question. We conducted a comprehensive genetic survey of field-collected and museum specimens to explore their identity and ultimately infer the evolutionary history of bears in the region. Phylogenetic analyses of mitochondrial DNA sequences determined clade affinities of the purported yeti samples in this study, strongly supporting the biological basis of the yeti legend to be local, extant bears. Complete mitochondrial genomes were assembled for Himalayan brown bear (U. a. isabellinus) and black bear (U. t. laniger) for the first time. Our results demonstrate that the Himalayan brown bear is one of the first-branching clades within the brown bear lineage, while Tibetan brown bears diverged much later. The estimated times of divergence of the Tibetan Plateau and Himalayan bear lineages overlap with Middle to Late Pleistocene glaciation events, suggesting that extant bears in the region are likely descendants of populations that survived in local refugia during the Pleistocene glaciations. PMID:29187630

  15. Hydroxylated polychlorinated biphenyls decrease circulating steroids in female polar bears (Ursus maritimus).

    Science.gov (United States)

    Gustavson, Lisa; Ciesielski, Tomasz M; Bytingsvik, Jenny; Styrishave, Bjarne; Hansen, Martin; Lie, Elisabeth; Aars, Jon; Jenssen, Bjørn M

    2015-04-01

    As a top predator in the Arctic food chain, polar bears (Ursus maritimus) are exposed to high levels of persistent organic pollutants (POPs). Because several of these compounds have been reported to alter endocrine pathways, such as the steroidogenesis, potential disruption of the sex steroid synthesis by POPs may cause implications for reproduction by interfering with ovulation, implantation and fertility. Blood samples were collected from 15 female polar bears in Svalbard (Norway) in April 2008. The concentrations of nine circulating steroid hormones; dehydroepiandrosterone (DHEA), androstenedione (AN), testosterone (TS), dihydrotestosterone (DHT), estrone (E1), 17α-estradiol (αE2), 17β-estradiol (βE2), pregnenolone (PRE) and progesterone (PRO) were determined. The aim of the study was to investigate associations among circulating levels of specific POP compounds and POP-metabolites (hydroxylated PCBs [OH-PCBs] and hydroxylated PBDEs [OH-PBDEs]), steroid hormones, biological and capture variables in female polar bears. Inverse correlations were found between circulating levels of PRE and AN, and circulating levels of OH-PCBs. There were no significant relationships between the steroid concentrations and other analyzed POPs or the variables capture date and capture location (latitude and longitude), lipid content, condition and body mass. Although statistical associations do not necessarily represent direct cause-effect relationships, the present study indicate that OH-PCBs may affect the circulating levels of AN and PRE in female polar bears and that OH-PCBs thus may interfere with the steroid homeostasis. Increase in PRO and a decrease in AN concentrations suggest that the enzyme CYP17 may be a potential target for OH-PCBs. In combination with natural stressors, ongoing climate change and contaminant exposure, it is possible that OH-PCBs may disturb the reproductive potential of polar bears. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Usability of large carnivore as a keystone species in Eastern Black ...

    African Journals Online (AJOL)

    The aim of the study was to investigate the keystone species property of Brown bear (Ursus arctos), Wolf (Canis lupus) and Eurasian lynx (Lynx lynx). The main selecting criteria for keystone species can be summarized as top predator or large carnivore important prey species or provide key resources and species having ...

  17. Identifying and managing an adverse food reaction in a polar bear (Ursus maritimus) by an elimination diet trial.

    Science.gov (United States)

    Monson, Sara; Minter, Larry J; Krouse, Marissa; De Voe, Ryan S

    2014-06-01

    A 16-yr-old polar bear (Ursus maritimus) presented with severe diarrhea shortly following transfer to the North Carolina Zoological Park. Multiple diagnostic procedures were performed over several months and the cause of the chronic diarrhea was inconclusive. Histologically, colonic mucosal biopsies were consistent with severe chronic eosinophilic and lymphoplasmacytic colitis with no evidence of etiologic agents present. A dietary elimination trial was conducted and an adverse food reaction to the dog chow in the diet was confirmed.

  18. Temporal diet changes recorded by stable isotopes in Asiatic black bear (Ursus thibetanus) hair.

    Science.gov (United States)

    Mizukami, R N; Goto, M; Izumiyama, S; Yoh, M; Ogura, N; Hayashi, H

    2005-03-01

    Carbon and nitrogen stable isotope ratios were measured in hair samples of the Asiatic black bear (Ursus thibetanus) inhabiting the Northern Japanese Alps (NJA) (n = 20) and the periphery of Nagano City (NC) (n = 6), in Nagano Prefecture, Japan. The hair of NJA bears, which did not have access to anthropogenic foods, showed lower values of d13C and d15N than that of NC bears which had access to garbage and corn fields, especially during the summer. These results reflect somewhat differing diets between the NJA and NC bears. We attempted to assess the feeding history during the hair growth cycle using the growth section analysis method. Each hair sample had been cut into 3?mm lengths from root to tip, labeled, and analyzed along the hair growth. We measured the carbon and nitrogen stable isotope ratios of each 3?mm length of hair sample from one NC bear which had been killed while raiding a corn field. The sections showed wide ranges of isotope ratios, from -23.2% to -14.6% for delta13C, and from 0.3% to 4.6% for delta15N. It was shown that the diet of this bear shifted dramatically from principally C3 plants to more C4 plants and to foods of animal origin. An analysis of the whole hair reflects just the average feeding habit during hair growth, but the present method can trace its diet history. This method can contribute to obtain precise ecological information of wildlife.

  19. Blood lipid concentrations and lipoprotein patterns in captive and wild American black bears (Ursus americanus).

    Science.gov (United States)

    Frank, Nicholas; Elliott, Sarah B; Allin, Shawn B; Ramsay, Edward C

    2006-02-01

    To compare blood lipid concentrations and lipoprotein patterns for captive and wild American black bears (Ursus americanus). 7 captive and 9 wild adult (> or = 4 years old) black bears. Blood was collected from 2 groups of captive black bears (groups A and B) and 1 group of wild black bears (group C). Blood triglyceride (TG) and cholesterol concentrations were compared among groups. Plasma lipoproteins were isolated by use of a self-generating gradient of iodixanol, and lipoprotein patterns were compared between groups A and B. Captive bears (mean +/- SD, 187.8 +/- 44.4 kg) weighed significantly more than wild bears (mean, 104.8 +/- 41.4 kg), but mean body weight did not differ between groups A and B. Mean blood TG concentrations for groups B (216.8 +/- 16.0 mg/dL) and C (190.7 +/- 34.0 mg/dL) were significantly higher than that of group A (103.9 +/- 25.3 mg/dL). Mean blood cholesterol concentration was also significantly higher for group B (227.8 +/- 8.2 mg/dL) than for groups A (171.7 +/- 35.5 mg/dL) or C (190.8 +/- 26.8 mg/dL). Mean very-low-density lipoprotein TG and low-density lipoprotein cholesterol concentrations were 2- and 3-fold higher, respectively, for group B, compared with concentrations for group A. Blood lipid concentrations vary significantly among populations of black bears. Plasma lipoprotein patterns of captive bears differed significantly between colonies and may have reflected differences in diet or management practices.

  20. Catalogue of polar bear (Ursus maritimus) maternal den locations in the Beaufort Sea and neighboring regions, Alaska, 1910-2010

    Science.gov (United States)

    Durner, George M.; Fischbach, Anthony S.; Amstrup, Steven C.; Douglas, David C.

    2010-01-01

    This report presents data on the approximate locations and methods of discovery of 392 polar bear (Ursus maritimus) maternal dens found in the Beaufort Sea and neighboring regions between 1910 and 2010 that are archived by the U.S. Geological Survey, Alaska Science Center, Anchorage, Alaska. A description of data collection methods, biases associated with collection method, primary time periods, and spatial resolution are provided. Polar bears in the Beaufort Sea and nearby regions den on both the sea ice and on land. Standardized VHF surveys and satellite radio telemetry data provide a general understanding of where polar bears have denned in this region over the past 3 decades. Den observations made during other research activities and anecdotal reports from other government agencies, coastal residents, and industry personnel also are reported. Data on past polar bear maternal den locations are provided to inform the public and to provide information for natural resource agencies in planning activities to avoid or minimize interference with polar bear maternity dens.

  1. Exploitation of pocket gophers and their food caches by grizzly bears

    Science.gov (United States)

    Mattson, D.J.

    2004-01-01

    I investigated the exploitation of pocket gophers (Thomomys talpoides) by grizzly bears (Ursus arctos horribilis) in the Yellowstone region of the United States with the use of data collected during a study of radiomarked bears in 1977-1992. My analysis focused on the importance of pocket gophers as a source of energy and nutrients, effects of weather and site features, and importance of pocket gophers to grizzly bears in the western contiguous United States prior to historical extirpations. Pocket gophers and their food caches were infrequent in grizzly bear feces, although foraging for pocket gophers accounted for about 20-25% of all grizzly bear feeding activity during April and May. Compared with roots individually excavated by bears, pocket gopher food caches were less digestible but more easily dug out. Exploitation of gopher food caches by grizzly bears was highly sensitive to site and weather conditions and peaked during and shortly after snowmelt. This peak coincided with maximum success by bears in finding pocket gopher food caches. Exploitation was most frequent and extensive on gently sloping nonforested sites with abundant spring beauty (Claytonia lanceolata) and yampah (Perdieridia gairdneri). Pocket gophers are rare in forests, and spring beauty and yampah roots are known to be important foods of both grizzly bears and burrowing rodents. Although grizzly bears commonly exploit pocket gophers only in the Yellowstone region, this behavior was probably widespread in mountainous areas of the western contiguous United States prior to extirpations of grizzly bears within the last 150 years.

  2. Low cardiac output as physiological phenomenon in hibernating, free-ranging Scandinavian brown bears (Ursus arctos) - an observational study

    DEFF Research Database (Denmark)

    Jørgensen, Peter Godsk; Arnemo, Jon; Swenson, Jon E

    2014-01-01

    cardiac function associated with metabolic depression in the hibernating vs. active states in free-ranging Scandinavian brown bears. METHODS: We performed echocardiography on seven free-ranging brown bears in Dalarna, Sweden, anesthetized with medetomidine-zolazepam-tiletamine-ketamine during winter.......31) l/min vs. 3.54 (SD: 1.04) l/min (P=0.003), and mean cardiac index 0.63 (SD: 0.21) l/min/kg vs. 2.45 (SD: 0.52) l/min/ m2 (Pdisease...

  3. PREVALENCE OF BABESIA SPP., EHRLICHIA SPP., AND TICK INFESTATIONS IN OKLAHOMA BLACK BEARS (URSUS AMERICANUS).

    Science.gov (United States)

    Skinner, Delaina; Mitcham, Jessica R; Starkey, Lindsay A; Noden, Bruce H; Fairbanks, W Sue; Little, Susan E

    2017-10-01

    American black bears (Ursus americanus) are commonly infested with ticks throughout their range, but there are few surveys for tick-borne disease agents in bears. To characterize tick infestations and determine the prevalence of current infection with Babesia spp. and past or current infection with Ehrlichia spp. in newly re-established populations of black bears in east central and southeastern Oklahoma, US, we identified adult (n=1,048) and immature (n=107) ticks recovered from bears (n=62). We evaluated serum and whole blood samples from a subset (n=49) for antibodies reactive to, and characteristic DNA fragments of, Ehrlichia spp., as well as characteristic DNA fragments of Babesia spp. Amblyomma americanum, the most common tick identified, was found on a majority (56/62; 90%) of bears and accounted for 697/1,048 (66.5%) of all ticks recovered. Other ticks included Dermacentor variabilis (338/1,048; 32.3%) from 36 bears, Amblyomma maculatum (9/1,048; 0.9%) from three bears, and Ixodes scapularis (4/1,048; 0.4%) from three bears. Antibodies reactive to Ehrlichia spp. were detected in every bear tested (49/49; 100%); maximum inverse titers to Ehrlichia chaffeensis ranged from 64-4,096 (geometric mean titer 1,525). However, PCR failed to identify active infection with E. chaffeensis, Ehrlichia ewingii, or an Ehrlichia ruminantium-like agent. Infection with Babesia spp. was detected by PCR in 3/49 (6%) bears. Together these data confirm that tick infestations and infection with tick-borne disease agents are common in bears in the southern US. The significance of these infestations and infections to the health of bears, if any, and the identity of the Ehrlichia spp. responsible for the antibody reactivity seen, warrant further evaluation.

  4. Use of acepromazine and medetomidine in combination for sedation and handling of Rocky Mountain elk (Cervus elaphus nelsoni) and black bears (Ursus americanus).

    Science.gov (United States)

    Wolfe, Lisa L; Johnson, Heather E; Fisher, Mark C; Sirochman, Michael A; Kraft, Benjamin; Miller, Michael W

    2014-10-01

    We opportunistically evaluated a combination of acepromazine maleate and medetomidine HCl for use in sedating Rocky Mountain elk (Cervus elaphus nelsoni) and black bears (Ursus americanus) as an alternative to scheduled drug combinations. This combination was safe and effective with limitations inherent in its sedative rather than anesthetic properties.

  5. Late quaternary brown bear (Ursidae: Ursus cf. arctos) from a cave in the Huachuca Mountains, Arizona

    Science.gov (United States)

    Nicholas J. Czaplewski; Steve Willsey

    2013-01-01

    In 2008, Steve Willsey discovered the fragmentary cranium of a bear loose on the floor of a cave at about 2270 m elevation near the crest of the Huachuca Mountains. In 2009, we revisited the cave to examine the specimen with the intention of identifying the species. We photographed and measured the main pieces and left them in the cave. The skull is from an adult,...

  6. Trophic cascades from wolves to grizzly bears in Yellowstone.

    Science.gov (United States)

    Ripple, William J; Beschta, Robert L; Fortin, Jennifer K; Robbins, Charles T

    2014-01-01

    We explored multiple linkages among grey wolves (Canis lupus), elk (Cervus elaphus), berry-producing shrubs and grizzly bears (Ursus arctos) in Yellowstone National Park. We hypothesized competition between elk and grizzly bears whereby, in the absence of wolves, increases in elk numbers would increase browsing on berry-producing shrubs and decrease fruit availability to grizzly bears. After wolves were reintroduced and with a reduced elk population, we hypothesized there would be an increase in the establishment of berry-producing shrubs, such as serviceberry (Amelanchier alnifolia), which is a major berry-producing plant. We also hypothesized that the percentage fruit in the grizzly bear diet would be greater after than before wolf reintroduction. We compared the frequency of fruit in grizzly bear scats to elk densities prior to wolf reintroduction during a time of increasing elk densities (1968-1987). For a period after wolf reintroduction, we calculated the percentage fruit in grizzly bear scat by month based on scats collected in 2007-2009 (n = 778 scats) and compared these results to scat data collected before wolf reintroduction. Additionally, we developed an age structure for serviceberry showing the origination year of stems in a northern range study area. We found that over a 19-year period, the percentage frequency of fruit in the grizzly diet (6231 scats) was inversely correlated (P wolves and other large carnivores on elk, a reduced and redistributed elk population, decreased herbivory and increased production of plant-based foods that may aid threatened grizzly bears. © 2013 The Authors. Journal of Animal Ecology © 2013 British Ecological Society.

  7. ヒグマをめぐる札幌市民の意識と行動

    OpenAIRE

    亀田, 正人

    2014-01-01

    The goal of this study is to provide basic information on the attitudes and behaviors of residents in Sapporo toward brown bears (Ursus arctos) and bear management and, by doing so, to contribute to more informed management and policy decisions. The author conducted a mail survey among the residents of Sapporo living near the points where bears or their signs were reported in 2010 or 2011. The result showed: (1) the level of acceptance of bears is as high as half in the sample, (2) mass media...

  8. Seroprevalence of Toxoplasma gondii from free-ranging black bears ( Ursus americanus ) from Florida.

    Science.gov (United States)

    Chambers, D L; Ulrey, W A; Guthrie, J M; Kwok, O C H; Cox, J J; Maehr, D S; Dubey, J P

    2012-06-01

    Toxoplasma gondii is a significant worldwide parasitic protozoan. In the present study, prevalence of antibodies of T. gondii was examined from 29 free-ranging black bears ( Ursus americanus ) from south-central Florida where the host species was listed as state threatened during this project. Overall T. gondii prevalence was found to be 44.8%, specifically 46.2% in male and 43.8% in female U. americanus , using a modified agglutination test (1:25 titer). Seroprevalence differences between sexes were not significant (P > 0.05). Results of the present study add supportive data to the growing body of evidence suggesting that U. americanus has one of the highest T. gondii seroprevalences among all known intermediate hosts. In addition, our data emphasize the importance of understanding parasitic disease dynamics from a conservation perspective.

  9. Population-level resource selection by sympatric brown and American black bears in Alaska

    Science.gov (United States)

    Belant, Jerrold L.; Griffith, Brad; Zhang, Yingte; Follmann, Erich H.; Adams, Layne G.

    2010-01-01

    Distribution theory predicts that for two species living in sympatry, the subordinate species would be constrained from using the most suitable resources (e.g., habitat), resulting in its use of less suitable habitat and spatial segregation between species. We used negative binomial generalized linear mixed models with fixed effects to estimate seasonal population-level resource selection at two spatial resolutions for female brown bears (Ursus arctos) and female American black bears (U. americanus) in southcentral Alaska during May–September 2000. Black bears selected areas occupied by brown bears during spring which may be related to spatially restricted (i.e., restricted to low elevations) but dispersed or patchy availability of food. In contrast, black bears avoided areas occupied by brown bears during summer. Brown bears selected areas near salmon streams during summer, presumably to access spawning salmon. Use of areas with high berry production by black bears during summer appeared in response to avoidance of areas containing brown bears. Berries likely provided black bears a less nutritious, but adequate food source. We suggest that during summer, black bears were displaced by brown bears, which supports distribution theory in that black bears appeared to be partially constrained from areas containing salmon, resulting in their use of areas containing less nutritious forage. Spatial segregation of brown and American black bears apparently occurs when high-quality resources are spatially restricted and alternate resources are available to the subordinate species. This and previous work suggest that individual interactions between species can result in seasonal population-level responses.

  10. Laparoscopic cholecystectomy under field conditions in Asiatic black bears (Ursus thibetanus) rescued from illegal bile farming in Vietnam.

    Science.gov (United States)

    Pizzi, R; Cracknell, J; David, S; Laughlin, D; Broadis, N; Rouffignac, M; Duong, D V; Girling, S; Hunt, M

    2011-10-29

    Nine adult Asiatic black bears (Ursus thibetanus) previously rescued from illegal bile farming in Vietnam were examined via abdominal ultrasound and exploratory laparoscopy for liver and gall bladder pathology. Three bears demonstrated notable gall bladder pathology, and minimally invasive cholecystectomies were performed using an open laparoscopic access approach, standard 10 to 12 mmHg carbon dioxide pneumoperitoneum and a four-port technique. A single bear required insertion of an additional 5 mm port and use of a flexible liver retractor due to the presence of extensive adhesions between the gall bladder and quadrate and left and right medial liver lobes. The cystic duct was dissected free and this and the cystic artery were ligated by means of extracorporeal tied Meltzer knot sutures. The gall bladder was dissected free of the liver by blunt and sharp dissection, aided by 3.8 MHz monopolar radiosurgery. Bears that have had open abdominal cholecystectomies are reported as taking four to six weeks before a return to normal activity postoperatively. In contrast, these bears demonstrated rapid unremarkable healing, and were allowed unrestricted access to outside enclosures to climb trees, swim and interact normally with other bears within seven days of surgery.

  11. Phylogeographic and Demographic Analysis of the Asian Black Bear (Ursus thibetanus) Based on Mitochondrial DNA.

    Science.gov (United States)

    Wu, Jiaqi; Kohno, Naoki; Mano, Shuhei; Fukumoto, Yukio; Tanabe, Hideyuki; Hasegawa, Masami; Yonezawa, Takahiro

    2015-01-01

    The Asian black bear Ursus thibetanus is widely distributed in Asia and is adapted to broad-leaved deciduous forests, playing an important ecological role in the natural environment. Several subspecies of U. thibetanus have been recognized, one of which, the Japanese black bear, is distributed in the Japanese archipelago. Recent molecular phylogeographic studies clarified that this subspecies is genetically distantly related to continental subspecies, suggesting an earlier origin. However, the evolutionary relationship between the Japanese and continental subspecies remained unclear. To understand the evolution of the Asian black bear in relation to geological events such as climatic and transgression-regression cycles, a reliable time estimation is also essential. To address these issues, we determined and analyzed the mt-genome of the Japanese subspecies. This indicates that the Japanese subspecies initially diverged from other Asian black bears in around 1.46Ma. The Northern continental population (northeast China, Russia, Korean peninsula) subsequently evolved, relatively recently, from the Southern continental population (southern China and Southeast Asia). While the Japanese black bear has an early origin, the tMRCAs and the dynamics of population sizes suggest that it dispersed relatively recently in the main Japanese islands: during the late Middle and Late Pleistocene, probably during or soon after the extinction of the brown bear in Honshu in the same period. Our estimation that the population size of the Japanese subspecies increased rapidly during the Late Pleistocene is the first evidential signal of a niche exchange between brown bears and black bears in the Japanese main islands. This interpretation seems plausible but was not corroborated by paleontological evidence that fossil record of the Japanese subspecies limited after the Late Pleistocene. We also report here a new fossil record of the oldest Japanese black bear from the Middle Pleistocene

  12. Phylogeographic and Demographic Analysis of the Asian Black Bear (Ursus thibetanus Based on Mitochondrial DNA.

    Directory of Open Access Journals (Sweden)

    Jiaqi Wu

    Full Text Available The Asian black bear Ursus thibetanus is widely distributed in Asia and is adapted to broad-leaved deciduous forests, playing an important ecological role in the natural environment. Several subspecies of U. thibetanus have been recognized, one of which, the Japanese black bear, is distributed in the Japanese archipelago. Recent molecular phylogeographic studies clarified that this subspecies is genetically distantly related to continental subspecies, suggesting an earlier origin. However, the evolutionary relationship between the Japanese and continental subspecies remained unclear. To understand the evolution of the Asian black bear in relation to geological events such as climatic and transgression-regression cycles, a reliable time estimation is also essential. To address these issues, we determined and analyzed the mt-genome of the Japanese subspecies. This indicates that the Japanese subspecies initially diverged from other Asian black bears in around 1.46Ma. The Northern continental population (northeast China, Russia, Korean peninsula subsequently evolved, relatively recently, from the Southern continental population (southern China and Southeast Asia. While the Japanese black bear has an early origin, the tMRCAs and the dynamics of population sizes suggest that it dispersed relatively recently in the main Japanese islands: during the late Middle and Late Pleistocene, probably during or soon after the extinction of the brown bear in Honshu in the same period. Our estimation that the population size of the Japanese subspecies increased rapidly during the Late Pleistocene is the first evidential signal of a niche exchange between brown bears and black bears in the Japanese main islands. This interpretation seems plausible but was not corroborated by paleontological evidence that fossil record of the Japanese subspecies limited after the Late Pleistocene. We also report here a new fossil record of the oldest Japanese black bear from the

  13. A preliminary baseline status of the Syrian Brown Bear Ursus arctos syriacus (Mammalia: Carnivora: Ursidae in Golestanak, Northern Iran

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    Mohammad Sadegh Farhadinia

    2015-01-01

    Full Text Available Baseline information is lacking for the Syrian Brown Bear across the sub-species range, making it difficult to assess at any level.  In the present investigation, our goal was to illustrate the population status of the Brown Bear in the Golestanak area, northern Iran, based on field surveys we conducted during the summers of 2011 and 2012.  We counted a total of 30 and 21 bears in two consecutive years, with family groups consisting of more than half of the identified individuals.  Sub-adults had the lowest contribution among the observed individuals, just below 10%, which may be due to their high dispersal behaviour to avoid adults.  Our results provide a foundation for future systematic baseline investigations on the population status of the brown bear in northern Iran, which can be used in management programs.  Aside from improving monitoring efforts within key habitats of the species, enhancing conservation efforts to secure the population is essential to safeguard this female core area. 

  14. Establishing a definition of polar bear (Ursus maritimus) health: A guide to research and management activities

    Science.gov (United States)

    Patyk, Kelly A.; Duncan, Colleen G.; Nol, Pauline; Sonne, C.; Laidre, Kristin L.; Obbard, Martyn E.; Wiig, Øystein; Aars, Jon; Regehr, Eric V.; Gustafson, L.; Atwood, Todd C.

    2015-01-01

    The meaning of health for wildlife and perspectives on how to assess and measure health, are not well characterized. For wildlife at risk, such as some polar bear (Ursus maritimus) subpopulations, establishing comprehensive monitoring programs that include health status is an emerging need. Environmental changes, especially loss of sea ice habitat, have raised concern about polar bear health. Effective and consistent monitoring of polar bear health requires an unambiguous definition of health. We used the Delphi method of soliciting and interpreting expert knowledge to propose a working definition of polar bear health and to identify current concerns regarding health, challenges in measuring health, and important metrics for monitoring health. The expert opinion elicited through the exercise agreed that polar bear health is defined by characteristics and knowledge at the individual, population, and ecosystem level. The most important threats identified were in decreasing order: climate change, increased nutritional stress, chronic physiological stress, harvest management, increased exposure to contaminants, increased frequency of human interaction, diseases and parasites, and increased exposure to competitors. Fifteen metrics were identified to monitor polar bear health. Of these, indicators of body condition, disease and parasite exposure, contaminant exposure, and reproductive success were ranked as most important. We suggest that a cumulative effects approach to research and monitoring will improve the ability to assess the biological, ecological, and social determinants of polar bear health and provide measurable objectives for conservation goals and priorities and to evaluate progress.

  15. Establishing a definition of polar bear (Ursus maritimus) health: a guide to research and management activities.

    Science.gov (United States)

    Patyk, Kelly A; Duncan, Colleen; Nol, Pauline; Sonne, Christian; Laidre, Kristin; Obbard, Martyn; Wiig, Øystein; Aars, Jon; Regehr, Eric; Gustafson, Lori L; Atwood, Todd

    2015-05-01

    The meaning of health for wildlife and perspectives on how to assess and measure health, are not well characterized. For wildlife at risk, such as some polar bear (Ursus maritimus) subpopulations, establishing comprehensive monitoring programs that include health status is an emerging need. Environmental changes, especially loss of sea ice habitat, have raised concern about polar bear health. Effective and consistent monitoring of polar bear health requires an unambiguous definition of health. We used the Delphi method of soliciting and interpreting expert knowledge to propose a working definition of polar bear health and to identify current concerns regarding health, challenges in measuring health, and important metrics for monitoring health. The expert opinion elicited through the exercise agreed that polar bear health is defined by characteristics and knowledge at the individual, population, and ecosystem level. The most important threats identified were in decreasing order: climate change, increased nutritional stress, chronic physiological stress, harvest management, increased exposure to contaminants, increased frequency of human interaction, diseases and parasites, and increased exposure to competitors. Fifteen metrics were identified to monitor polar bear health. Of these, indicators of body condition, disease and parasite exposure, contaminant exposure, and reproductive success were ranked as most important. We suggest that a cumulative effects approach to research and monitoring will improve the ability to assess the biological, ecological, and social determinants of polar bear health and provide measurable objectives for conservation goals and priorities and to evaluate progress. Published by Elsevier B.V.

  16. Ancient hybridization and an Irish origin for the modern polar bear matriline.

    Science.gov (United States)

    Edwards, Ceiridwen J; Suchard, Marc A; Lemey, Philippe; Welch, John J; Barnes, Ian; Fulton, Tara L; Barnett, Ross; O'Connell, Tamsin C; Coxon, Peter; Monaghan, Nigel; Valdiosera, Cristina E; Lorenzen, Eline D; Willerslev, Eske; Baryshnikov, Gennady F; Rambaut, Andrew; Thomas, Mark G; Bradley, Daniel G; Shapiro, Beth

    2011-08-09

    Polar bears (Ursus maritimus) are among those species most susceptible to the rapidly changing arctic climate, and their survival is of global concern. Despite this, little is known about polar bear species history. Future conservation strategies would significantly benefit from an understanding of basic evolutionary information, such as the timing and conditions of their initial divergence from brown bears (U. arctos) or their response to previous environmental change. We used a spatially explicit phylogeographic model to estimate the dynamics of 242 brown bear and polar bear matrilines sampled throughout the last 120,000 years and across their present and past geographic ranges. Our results show that the present distribution of these matrilines was shaped by a combination of regional stability and rapid, long-distance dispersal from ice-age refugia. In addition, hybridization between polar bears and brown bears may have occurred multiple times throughout the Late Pleistocene. The reconstructed matrilineal history of brown and polar bears has two striking features. First, it is punctuated by dramatic and discrete climate-driven dispersal events. Second, opportunistic mating between these two species as their ranges overlapped has left a strong genetic imprint. In particular, a likely genetic exchange with extinct Irish brown bears forms the origin of the modern polar bear matriline. This suggests that interspecific hybridization not only may be more common than previously considered but may be a mechanism by which species deal with marginal habitats during periods of environmental deterioration. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Use of lodgepole pine cover types by Yellowstone grizzly bears

    Science.gov (United States)

    Mattson, D.J.

    1997-01-01

    Lodgepole pine (Pinus contorta) forests are a large and dynamic part of grizzly bear (Ursus arctos) habitat in the Yellowstone ecosystem. Research in other areas suggests that grizzly bears select for young open forest stands, especially for grazing and feeding on berries. Management guidelines accordingly recommend timber harvest as a technique for improving habitat in areas potentially dominated by lodgepole pine. In this paper I examine grizzly bear use of lodgepole pine forests in the Yellowstone area, and test several hypotheses with relevance to a new generation of management guidelines. Differences in grizzly bear selection of lodgepole pine cover types (defined on the basis of stand age and structure) were not pronounced. Selection furthermore varied among years, areas, and individuals. Positive selection for any lodgepole pine type was uncommon. Estimates of selection took 5-11 years or 4-12 adult females to stabilize, depending upon the cover type. The variances of selection estimates tended to stabilize after 3-5 sample years, and were more-or-less stable to slightly increasing with progressively increased sample area. There was no conclusive evidence that Yellowstone's grizzlies favored young (<40 yr) stands in general or for their infrequent use of berries. On the other hand, these results corroborated previous observations that grizzlies favored open and/or young stands on wet and fertile sites for grazing. These results also supported the proposition that temporally and spatially robust inferences require extensive, long-duration studies, especially for wide-ranging vertebrates like grizzly bears.

  18. Polar bears, Ursus maritimus

    Science.gov (United States)

    Rode, Karyn D.; Stirling, Ian

    2017-01-01

    Polar bears are the largest of the eight species of bears found worldwide and are covered in a pigment-free fur giving them the appearance of being white. They are the most carnivorous of bear species consuming a high-fat diet, primarily of ice-associated seals and other marine mammals. They range throughout the circumpolar Arctic to the southernmost extent of seasonal pack ice.

  19. Grizzly bear corticosteroid binding globulin: Cloning and serum protein expression.

    Science.gov (United States)

    Chow, Brian A; Hamilton, Jason; Alsop, Derek; Cattet, Marc R L; Stenhouse, Gordon; Vijayan, Mathilakath M

    2010-06-01

    Serum corticosteroid levels are routinely measured as markers of stress in wild animals. However, corticosteroid levels rise rapidly in response to the acute stress of capture and restraint for sampling, limiting its use as an indicator of chronic stress. We hypothesized that serum corticosteroid binding globulin (CBG), the primary transport protein for corticosteroids in circulation, may be a better marker of the stress status prior to capture in grizzly bears (Ursus arctos). To test this, a full-length CBG cDNA was cloned and sequenced from grizzly bear testis and polyclonal antibodies were generated for detection of this protein in bear sera. The deduced nucleotide and protein sequences were 1218 bp and 405 amino acids, respectively. Multiple sequence alignments showed that grizzly bear CBG (gbCBG) was 90% and 83% identical to the dog CBG nucleotide and amino acid sequences, respectively. The affinity purified rabbit gbCBG antiserum detected grizzly bear but not human CBG. There were no sex differences in serum total cortisol concentration, while CBG expression was significantly higher in adult females compared to males. Serum cortisol levels were significantly higher in bears captured by leg-hold snare compared to those captured by remote drug delivery from helicopter. However, serum CBG expression between these two groups did not differ significantly. Overall, serum CBG levels may be a better marker of chronic stress, especially because this protein is not modulated by the stress of capture and restraint in grizzly bears. Copyright 2010 Elsevier Inc. All rights reserved.

  20. Bacterial populations and metabolites in the feces of free roaming and captive grizzly bears.

    Science.gov (United States)

    Schwab, Clarissa; Cristescu, Bogdan; Boyce, Mark S; Stenhouse, Gordon B; Gänzle, Michael

    2009-12-01

    Gut physiology, host phylogeny, and diet determine the composition of the intestinal microbiota. Grizzly bears (Ursus arctos horribilis) belong to the Order Carnivora, yet feed on an omnivorous diet. The role of intestinal microflora in grizzly bear digestion has not been investigated. Microbiota and microbial activity were analysed from the feces of wild and captive grizzly bears. Bacterial composition was determined using culture-dependent and culture-independent methods. The feces of wild and captive grizzly bears contained log 9.1 +/- 0.5 and log 9.2 +/- 0.3 gene copies x g(-1), respectively. Facultative anaerobes Enterobacteriaceae and enterococci were dominant in wild bear feces. Among the strict anaerobes, the Bacteroides-Prevotella-Porphyromonas group was most prominent. Enterobacteriaceae were predominant in the feces of captive grizzly bears, at log 8.9 +/- 0.5 gene copies x g(-1). Strict anaerobes of the Bacteroides-Prevotella-Porphyromonas group and the Clostridium coccoides cluster were present at log 6.7 +/- 0.9 and log 6.8 +/- 0.8 gene copies x g(-1), respectively. The presence of lactate and short-chain fatty acids (SCFAs) verified microbial activity. Total SCFA content and composition was affected by diet. SCFA composition in the feces of captive grizzly bears resembled the SCFA composition of prey-consuming wild animals. A consistent data set was obtained that associated fecal microbiota and metabolites with the distinctive gut physiology and diet of grizzly bears.

  1. Polar bears exhibit genome-wide signatures of bioenergetic adaptation to life in the arctic environment.

    Science.gov (United States)

    Welch, Andreanna J; Bedoya-Reina, Oscar C; Carretero-Paulet, Lorenzo; Miller, Webb; Rode, Karyn D; Lindqvist, Charlotte

    2014-02-01

    Polar bears (Ursus maritimus) face extremely cold temperatures and periods of fasting, which might result in more severe energetic challenges than those experienced by their sister species, the brown bear (U. arctos). We have examined the mitochondrial and nuclear genomes of polar and brown bears to investigate whether polar bears demonstrate lineage-specific signals of molecular adaptation in genes associated with cellular respiration/energy production. We observed increased evolutionary rates in the mitochondrial cytochrome c oxidase I gene in polar but not brown bears. An amino acid substitution occurred near the interaction site with a nuclear-encoded subunit of the cytochrome c oxidase complex and was predicted to lead to a functional change, although the significance of this remains unclear. The nuclear genomes of brown and polar bears demonstrate different adaptations related to cellular respiration. Analyses of the genomes of brown bears exhibited substitutions that may alter the function of proteins that regulate glucose uptake, which could be beneficial when feeding on carbohydrate-dominated diets during hyperphagia, followed by fasting during hibernation. In polar bears, genes demonstrating signatures of functional divergence and those potentially under positive selection were enriched in functions related to production of nitric oxide (NO), which can regulate energy production in several different ways. This suggests that polar bears may be able to fine-tune intracellular levels of NO as an adaptive response to control trade-offs between energy production in the form of adenosine triphosphate versus generation of heat (thermogenesis).

  2. Interactions between brown bears and chum salmon at McNeil River, Alaska

    Science.gov (United States)

    Peirce, Joshua M.; Otis, Edward O.; Wipfli, Mark S.; Follmann, Erich H.

    2013-01-01

    Predation on returning runs of adult salmon (Oncorhynchus spp.) can have a large influence on their spawning success. At McNeil River State Game Sanctuary (MRSGS), Alaska, brown bears (Ursus arctos) congregate in high numbers annually along the lower McNeil River to prey upon returning adult chum salmon (O. keta). Low chum salmon escapements into McNeil River since the late 1990s have been proposed as a potential factor contributing to concurrent declines in bear numbers. The objective of this study was to determine the extent of bear predation on chum salmon in McNeil River, especially on pre-spawning fish, and use those data to adjust the escapement goal for the river. In 2005 and 2006, 105 chum salmon were radiotagged at the river mouth and tracked to determine cause and location of death. Below the falls, predators consumed 99% of tagged fish, killing 59% of them before they spawned. Subsequently, the escapement goal was nearly doubled to account for this pre-spawning mortality and to ensure enough salmon to sustain both predators and prey. This approach to integrated fish and wildlife management at MRSGS can serve as a model for other systems where current salmon escapement goals may not account for pre-spawning mortality.

  3. Bacterial diversity in faeces from polar bear (Ursus maritimus in Arctic Svalbard

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    Brusetti Lorenzo

    2010-01-01

    Full Text Available Abstract Background Polar bears (Ursus maritimus are major predators in the Arctic marine ecosystem, feeding mainly on seals, and living closely associated with sea ice. Little is known of their gut microbial ecology and the main purpose of this study was to investigate the microbial diversity in faeces of polar bears in Svalbard, Norway (74-81°N, 10-33°E. In addition the level of blaTEM alleles, encoding ampicillin resistance (ampr were determined. In total, ten samples were collected from ten individual bears, rectum swabs from five individuals in 2004 and faeces samples from five individuals in 2006. Results A 16S rRNA gene clone library was constructed, and all sequences obtained from 161 clones showed affiliation with the phylum Firmicutes, with 160 sequences identified as Clostridiales and one sequence identified as unclassified Firmicutes. The majority of the sequences (70% were affiliated with the genus Clostridium. Aerobic heterotrophic cell counts on chocolate agar ranged between 5.0 × 104 to 1.6 × 106 colony forming units (cfu/ml for the rectum swabs and 4.0 × 103 to 1.0 × 105 cfu/g for the faeces samples. The proportion of ampr bacteria ranged from 0% to 44%. All of 144 randomly selected ampr isolates tested positive for enzymatic β-lactamase activity. Three % of the ampr isolates from the rectal samples yielded positive results when screened for the presence of blaTEM genes by PCR. BlaTEM alleles were also detected by PCR in two out of three total faecal DNA samples from polar bears. Conclusion The bacterial diversity in faeces from polar bears in their natural environment in Svalbard is low compared to other animal species, with all obtained clones affiliating to Firmicutes. Furthermore, only low levels of blaTEM alleles were detected in contrast to their increasing prevalence in some clinical and commensal bacterial populations.

  4. Bacterial diversity in faeces from polar bear (Ursus maritimus) in Arctic Svalbard.

    Science.gov (United States)

    Glad, Trine; Bernhardsen, Pål; Nielsen, Kaare M; Brusetti, Lorenzo; Andersen, Magnus; Aars, Jon; Sundset, Monica A

    2010-01-14

    Polar bears (Ursus maritimus) are major predators in the Arctic marine ecosystem, feeding mainly on seals, and living closely associated with sea ice. Little is known of their gut microbial ecology and the main purpose of this study was to investigate the microbial diversity in faeces of polar bears in Svalbard, Norway (74-81 degrees N, 10-33 degrees E). In addition the level of blaTEM alleles, encoding ampicillin resistance (ampr) were determined. In total, ten samples were collected from ten individual bears, rectum swabs from five individuals in 2004 and faeces samples from five individuals in 2006. A 16S rRNA gene clone library was constructed, and all sequences obtained from 161 clones showed affiliation with the phylum Firmicutes, with 160 sequences identified as Clostridiales and one sequence identified as unclassified Firmicutes. The majority of the sequences (70%) were affiliated with the genus Clostridium. Aerobic heterotrophic cell counts on chocolate agar ranged between 5.0 x 10(4) to 1.6 x 10(6) colony forming units (cfu)/ml for the rectum swabs and 4.0 x 10(3) to 1.0 x 10(5) cfu/g for the faeces samples. The proportion of ampr bacteria ranged from 0% to 44%. All of 144 randomly selected ampr isolates tested positive for enzymatic beta-lactamase activity. Three % of the ampr isolates from the rectal samples yielded positive results when screened for the presence of blaTEM genes by PCR. BlaTEM alleles were also detected by PCR in two out of three total faecal DNA samples from polar bears. The bacterial diversity in faeces from polar bears in their natural environment in Svalbard is low compared to other animal species, with all obtained clones affiliating to Firmicutes. Furthermore, only low levels of blaTEM alleles were detected in contrast to their increasing prevalence in some clinical and commensal bacterial populations.

  5. Bacterial diversity in faeces from polar bear (Ursus maritimus) in Arctic Svalbard

    Science.gov (United States)

    2010-01-01

    Background Polar bears (Ursus maritimus) are major predators in the Arctic marine ecosystem, feeding mainly on seals, and living closely associated with sea ice. Little is known of their gut microbial ecology and the main purpose of this study was to investigate the microbial diversity in faeces of polar bears in Svalbard, Norway (74-81°N, 10-33°E). In addition the level of blaTEM alleles, encoding ampicillin resistance (ampr) were determined. In total, ten samples were collected from ten individual bears, rectum swabs from five individuals in 2004 and faeces samples from five individuals in 2006. Results A 16S rRNA gene clone library was constructed, and all sequences obtained from 161 clones showed affiliation with the phylum Firmicutes, with 160 sequences identified as Clostridiales and one sequence identified as unclassified Firmicutes. The majority of the sequences (70%) were affiliated with the genus Clostridium. Aerobic heterotrophic cell counts on chocolate agar ranged between 5.0 × 104 to 1.6 × 106 colony forming units (cfu)/ml for the rectum swabs and 4.0 × 103 to 1.0 × 105 cfu/g for the faeces samples. The proportion of ampr bacteria ranged from 0% to 44%. All of 144 randomly selected ampr isolates tested positive for enzymatic β-lactamase activity. Three % of the ampr isolates from the rectal samples yielded positive results when screened for the presence of blaTEM genes by PCR. BlaTEM alleles were also detected by PCR in two out of three total faecal DNA samples from polar bears. Conclusion The bacterial diversity in faeces from polar bears in their natural environment in Svalbard is low compared to other animal species, with all obtained clones affiliating to Firmicutes. Furthermore, only low levels of blaTEM alleles were detected in contrast to their increasing prevalence in some clinical and commensal bacterial populations. PMID:20074323

  6. THE USE OF KETAMINE-XYLAZINE OR BUTORPHANOL-AZAPERONE-MEDETOMIDINE TO IMMOBILIZE AMERICAN BLACK BEARS ( URSUS AMERICANUS).

    Science.gov (United States)

    Williamson, Ryan H; Muller, Lisa L; Blair, Coy

    2018-04-04

      Wildlife anesthetic protocols must offer rapid inductions and recoveries, be physiologically safe, and be minimally regulated. With this in mind, we evaluated differences in induction and recovery times and physiological parameters in 33 American black bears ( Ursus americanus) anesthetized with ketamine-xylazine (KX) or immobilized with a commercial drug combination of butorphanol, azaperone, and medetomidine (BAM). Dose was based on mass estimated from field observations. Bears were housed at Appalachian Bear Rescue, Townsend, Tennessee, US, or free-ranging within the Great Smoky Mountains National Park (Tennessee and North Carolina, US) and chemically immobilized for management purposes. From 11 April to 29 June 2016, we immobilized bears with injection via pole syringe or disposable dart projected from an air-powered dart rifle. Once immobilized, we measured each bear's temperature, respiration (breaths/min), heart rate (beats/min), hemoglobin oxygen saturation (via pulse oximetry), arterial blood gases, and mass (kg). We found no differences in the induction parameters, partial pressures of CO 2 , and rectal temperatures. The BAM-treated bears had lower heart and respiratory rates that led to lower hemoglobin oxygen saturation levels (from blood gas analysis, SaO 2 ). The SaO 2 after treatment with BAM (91.1±0.8%) was lower than with KX (93.4±0.9%). After handling, we reversed KX-treated bears with a x̄=0.2±0.02 mg/kg yohimbine and BAM-treated bears with x̄=1.5±0.1 mg/kg atipamezole and 0.8±0.1 mg/kg naltrexone. We found no differences in the recovery times to increased respiration and to the bear assuming a head-up position. The BAM-treated bears stood and recovered quicker than did KX-treated animals. Based on our observations, BAM appears to offer safe, predictable immobilizations with fewer drawbacks and faster recovery times than KX-treated bears.

  7. Decreased bone turnover with balanced resorption and formation prevent cortical bone loss during disuse (hibernation) in grizzly bears (Ursus arctos horribilis).

    Science.gov (United States)

    McGee, Meghan E; Maki, Aaron J; Johnson, Steven E; Nelson, O Lynne; Robbins, Charles T; Donahue, Seth W

    2008-02-01

    Disuse uncouples bone formation from resorption, leading to increased porosity, decreased bone geometrical properties, and decreased bone mineral content which compromises bone mechanical properties and increases fracture risk. However, black bear bone properties are not adversely affected by aging despite annual periods of disuse (i.e., hibernation), which suggests that bears either prevent bone loss during disuse or lose bone and subsequently recover it at a faster rate than other animals. Here we show decreased cortical bone turnover during hibernation with balanced formation and resorption in grizzly bear femurs. Hibernating grizzly bear femurs were less porous and more mineralized, and did not demonstrate any changes in cortical bone geometry or whole bone mechanical properties compared to active grizzly bear femurs. The activation frequency of intracortical remodeling was 75% lower during hibernation than during periods of physical activity, but the normalized mineral apposition rate was unchanged. These data indicate that bone turnover decreases during hibernation, but osteons continue to refill at normal rates. There were no changes in regional variation of porosity, geometry, or remodeling indices in femurs from hibernating bears, indicating that hibernation did not preferentially affect one region of the cortex. Thus, grizzly bears prevent bone loss during disuse by decreasing bone turnover and maintaining balanced formation and resorption, which preserves bone structure and strength. These results support the idea that bears possess a biological mechanism to prevent disuse osteoporosis.

  8. Whitebark pine, population density, and home-range size of grizzly bears in the greater yellowstone ecosystem.

    Directory of Open Access Journals (Sweden)

    Daniel D Bjornlie

    Full Text Available Changes in life history traits of species can be an important indicator of potential factors influencing populations. For grizzly bears (Ursus arctos in the Greater Yellowstone Ecosystem (GYE, recent decline of whitebark pine (WBP; Pinus albicaulis, an important fall food resource, has been paired with a slowing of population growth following two decades of robust population increase. These observations have raised questions whether resource decline or density-dependent processes may be associated with changes in population growth. Distinguishing these effects based on changes in demographic rates can be difficult. However, unlike the parallel demographic responses expected from both decreasing food availability and increasing population density, we hypothesized opposing behavioral responses of grizzly bears with regard to changes in home-range size. We used the dynamic changes in food resources and population density of grizzly bears as a natural experiment to examine hypotheses regarding these potentially competing influences on grizzly bear home-range size. We found that home-range size did not increase during the period of whitebark pine decline and was not related to proportion of whitebark pine in home ranges. However, female home-range size was negatively associated with an index of population density. Our data indicate that home-range size of grizzly bears in the GYE is not associated with availability of WBP, and, for female grizzly bears, increasing population density may constrain home-range size.

  9. Whitebark pine, population density, and home-range size of grizzly bears in the greater Yellowstone ecosystem

    Science.gov (United States)

    Bjornlie, Daniel D.; van Manen, Frank T.; Ebinger, Michael R.; Haroldson, Mark A.; Thompson, Daniel J.; Costello, Cecily M.

    2014-01-01

    Changes in life history traits of species can be an important indicator of potential factors influencing populations. For grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem (GYE), recent decline of whitebark pine (WBP; Pinus albicaulis), an important fall food resource, has been paired with a slowing of population growth following two decades of robust population increase. These observations have raised questions whether resource decline or density-dependent processes may be associated with changes in population growth. Distinguishing these effects based on changes in demographic rates can be difficult. However, unlike the parallel demographic responses expected from both decreasing food availability and increasing population density, we hypothesized opposing behavioral responses of grizzly bears with regard to changes in home-range size. We used the dynamic changes in food resources and population density of grizzly bears as a natural experiment to examine hypotheses regarding these potentially competing influences on grizzly bear home-range size. We found that home-range size did not increase during the period of whitebark pine decline and was not related to proportion of whitebark pine in home ranges. However, female home-range size was negatively associated with an index of population density. Our data indicate that home-range size of grizzly bears in the GYE is not associated with availability of WBP, and, for female grizzly bears, increasing population density may constrain home-range size.

  10. Whitebark pine, population density, and home-range size of grizzly bears in the greater yellowstone ecosystem.

    Science.gov (United States)

    Bjornlie, Daniel D; Van Manen, Frank T; Ebinger, Michael R; Haroldson, Mark A; Thompson, Daniel J; Costello, Cecily M

    2014-01-01

    Changes in life history traits of species can be an important indicator of potential factors influencing populations. For grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem (GYE), recent decline of whitebark pine (WBP; Pinus albicaulis), an important fall food resource, has been paired with a slowing of population growth following two decades of robust population increase. These observations have raised questions whether resource decline or density-dependent processes may be associated with changes in population growth. Distinguishing these effects based on changes in demographic rates can be difficult. However, unlike the parallel demographic responses expected from both decreasing food availability and increasing population density, we hypothesized opposing behavioral responses of grizzly bears with regard to changes in home-range size. We used the dynamic changes in food resources and population density of grizzly bears as a natural experiment to examine hypotheses regarding these potentially competing influences on grizzly bear home-range size. We found that home-range size did not increase during the period of whitebark pine decline and was not related to proportion of whitebark pine in home ranges. However, female home-range size was negatively associated with an index of population density. Our data indicate that home-range size of grizzly bears in the GYE is not associated with availability of WBP, and, for female grizzly bears, increasing population density may constrain home-range size.

  11. Brown bear-human interactions associated with deer hunting on Kodiak Island

    Science.gov (United States)

    Barnes, Victor G.

    1994-01-01

    I compared distribution and range of brown bears (Ursus arctos middendorffi) with temporal and spatial distribution of Sitka black-tailed deer (Odocoileus hemionus sitkensis) hunting activity on westside Kodiak Island, Alaska, to examine impacts of deer hunting on bears. Mean number of bears that annually ranged ≤5 km from the coast, >5 km inland from the coast, or in both areas was 10, 8, and 11, respectively. Bears that exclusively or seasonally occupied the coast zone were usually classed as having moderate or high potential to interact with hunters because most hunter access and effort (>95%) was via the coast. Bears that ranged exclusively inland were considered unlikely to encounter hunters. Animals that ranged in both zones often (39%) moved inland during fall (Oct-Dec) and most bears (70%) denned in the inland zone. Females that denned near the coast entered dens later (x̄ = 22 Nov) than females that denned inland (x̄ = 12 Nov). Two radio-collared bears were known to raid deer-hunting camps and 9 other marked bears were observed by hunters or were located bear during their hunt. Seven to 21% of the respondents reported having a threatening encounter with a bear and 5-26% reported losing deer meat to bears. Human-induced mortality to radio-collared bears occurred more often near the coast (5) than inland (3); 7 bears were harvested by sport hunters and 1 was killed (nonsport) in a Native village. Deer hunters killed 2 unmarked females in defense of life or property situations in the study area. High bear densities and concentrated deer-hunting activity combine to make conflicts unavoidable. Adverse impacts to bears can be minimized by maintaining low levels of human activity in inland areas and improving hunter awareness of bear ecology and behavior.

  12. Black and Brown Bear Activity at Selected Coastal Sites in Glacier Bay National Park and Preserve, Alaska: A Preliminary Assessment Using Noninvasive Procedures

    Science.gov (United States)

    Partridge, Steve; Smith, Tom; Lewis, Tania

    2009-01-01

    A number of efforts in recent years have sought to predict bear activity in various habitats to minimize human disturbance and bear/human conflicts. Alaskan coastal areas provide important foraging areas for bears (Ursus americanus and U. arctos), particularly following den emergence when there may be no snow-free foraging alternatives. Additionally, coastal areas provide important food items for bears throughout the year. Glacier Bay National Park and Preserve (GLBA) in southeastern Alaska has extensive coastal habitats, and the National Park Service (NPS) has been long interested in learning more about the use of these coastal habitats by bears because these same habitats receive extensive human use by park visitors, especially kayaking recreationists. This study provides insight regarding the nature and intensity of bear activity at selected coastal sites within GLBA. We achieved a clearer understanding of bear/habitat relationships within GLBA by analyzing bear activity data collected with remote cameras, bear sign mapping, scat collections, and genetic analysis of bear hair. Although we could not quantify actual levels of bear activity at study sites, agreement among measures of activity (for example, sign counts, DNA analysis, and video record) lends support to our qualitative site assessments. This work suggests that habitat evaluation, bear sign mapping, and periodic scat counts can provide a useful index of bear activity for sites of interest.

  13. Skeletal muscles of hibernating brown bears are unusually resistant to effects of denervation.

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    Lin, David C; Hershey, John D; Mattoon, John S; Robbins, Charles T

    2012-06-15

    Hibernating bears retain most of their skeletal muscle strength despite drastically reduced weight-bearing activity. Regular neural activation of muscles is a potential mechanism by which muscle atrophy could be limited. However, both mechanical loading and neural activity are usually necessary to maintain muscle size. An alternative mechanism is that the signaling pathways related to the regulation of muscle size could be altered so that neither mechanical nor neural inputs are needed for retaining strength. More specifically, we hypothesized that muscles in hibernating bears are resistant to a severe reduction in neural activation. To test this hypothesis, we unilaterally transected the common peroneal nerve, which innervates ankle flexor muscles, in hibernating and summer-active brown bears (Ursus arctos). In hibernating bears, the long digital extensor (LDE) and cranial tibial (CT) musculotendon masses on the denervated side decreased after 11 weeks post-surgery by 18 ± 11 and 25 ± 10%, respectively, compared with those in the intact side. In contrast, decreases in musculotendon masses of summer-active bears after denervation were 61 ± 4 and 58 ± 5% in the LDE and CT, respectively, and significantly different from those of hibernating bears. The decrease due to denervation in summer-active bears was comparable to that occurring in other mammals. Whole-muscle cross-sectional areas (CSAs) measured from ultrasound images and myofiber CSAs measured from biopsies decreased similarly to musculotendon mass. Thus, hibernating bears alter skeletal muscle catabolic pathways regulated by neural activity, and exploration of these pathways may offer potential solutions for disuse atrophy of muscles.

  14. Genomic evidence for island population conversion resolves conflicting theories of polar bear evolution.

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    Cahill, James A; Green, Richard E; Fulton, Tara L; Stiller, Mathias; Jay, Flora; Ovsyanikov, Nikita; Salamzade, Rauf; St John, John; Stirling, Ian; Slatkin, Montgomery; Shapiro, Beth

    2013-01-01

    Despite extensive genetic analysis, the evolutionary relationship between polar bears (Ursus maritimus) and brown bears (U. arctos) remains unclear. The two most recent comprehensive reports indicate a recent divergence with little subsequent admixture or a much more ancient divergence followed by extensive admixture. At the center of this controversy are the Alaskan ABC Islands brown bears that show evidence of shared ancestry with polar bears. We present an analysis of genome-wide sequence data for seven polar bears, one ABC Islands brown bear, one mainland Alaskan brown bear, and a black bear (U. americanus), plus recently published datasets from other bears. Surprisingly, we find clear evidence for gene flow from polar bears into ABC Islands brown bears but no evidence of gene flow from brown bears into polar bears. Importantly, while polar bears contributed bear, they contributed 6.5% of the X chromosome. The magnitude of sex-biased polar bear ancestry and the clear direction of gene flow suggest a model wherein the enigmatic ABC Island brown bears are the descendants of a polar bear population that was gradually converted into brown bears via male-dominated brown bear admixture. We present a model that reconciles heretofore conflicting genetic observations. We posit that the enigmatic ABC Islands brown bears derive from a population of polar bears likely stranded by the receding ice at the end of the last glacial period. Since then, male brown bear migration onto the island has gradually converted these bears into an admixed population whose phenotype and genotype are principally brown bear, except at mtDNA and X-linked loci. This process of genome erosion and conversion may be a common outcome when climate change or other forces cause a population to become isolated and then overrun by species with which it can hybridize.

  15. Genomic evidence for island population conversion resolves conflicting theories of polar bear evolution.

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    James A Cahill

    Full Text Available Despite extensive genetic analysis, the evolutionary relationship between polar bears (Ursus maritimus and brown bears (U. arctos remains unclear. The two most recent comprehensive reports indicate a recent divergence with little subsequent admixture or a much more ancient divergence followed by extensive admixture. At the center of this controversy are the Alaskan ABC Islands brown bears that show evidence of shared ancestry with polar bears. We present an analysis of genome-wide sequence data for seven polar bears, one ABC Islands brown bear, one mainland Alaskan brown bear, and a black bear (U. americanus, plus recently published datasets from other bears. Surprisingly, we find clear evidence for gene flow from polar bears into ABC Islands brown bears but no evidence of gene flow from brown bears into polar bears. Importantly, while polar bears contributed <1% of the autosomal genome of the ABC Islands brown bear, they contributed 6.5% of the X chromosome. The magnitude of sex-biased polar bear ancestry and the clear direction of gene flow suggest a model wherein the enigmatic ABC Island brown bears are the descendants of a polar bear population that was gradually converted into brown bears via male-dominated brown bear admixture. We present a model that reconciles heretofore conflicting genetic observations. We posit that the enigmatic ABC Islands brown bears derive from a population of polar bears likely stranded by the receding ice at the end of the last glacial period. Since then, male brown bear migration onto the island has gradually converted these bears into an admixed population whose phenotype and genotype are principally brown bear, except at mtDNA and X-linked loci. This process of genome erosion and conversion may be a common outcome when climate change or other forces cause a population to become isolated and then overrun by species with which it can hybridize.

  16. Spatial and temporal variation in size of polar bear (Ursus maritimus) sexual organs and its use in pollution and climate change studies.

    Science.gov (United States)

    Sonne, Christian; Dietz, Rune; Born, Erik W; Riget, Frank F; Leifsson, Pall S; Bechshøft, Thea Ø; Kirkegaard, Maja

    2007-11-15

    Sexual organs and their development are susceptible to atmospheric transported environmental xenoendocrine pollutants and climate change (food availability). We therefore investigated sexual organs from 55 male and 44 female East Greenland polar bears (Ursus maritimus) to obtain information about growth/size and sexual maturity. Then, the genitalia size was compared with those previously reported from Canadian and Svalbard polar bears. Growth models showed that East Greenland male polar bears reached sexual maturity around 7 years of age and females around 4 years of age. When comparing East Greenland and Svalbard polar bears, the size of baculum and uterus were significantly lower in the East Greenland polar bears (ANOVA: all p polar bears, a similar baculum pattern was found for East Greenland vs. Canadian polar bears. It is speculated whether this could be a result of the general high variation in polar bear body size, temporal distribution patterns of anthropogenic long-range transported persistent organic pollutants or climate change (decreasing food availability). The present investigation represents conservation and background data for future spatial and temporal assessments of hunting, pollution and climate change scenarios.

  17. Grizzly bear predation rates on caribou calves in northeastern Alaska

    Science.gov (United States)

    Young, Donald D.; McCabe, Thomas R.

    1997-01-01

    During June 1993 and 1994, 11 radiocollared and 7 unmarked grizzly bears (Ursus arctos) were monitored visually (observation) from fixed-wing aircraft to document predation on calves of the Porcupine Caribou (Rangifer tarandus) Herd (PCH) in northeastern Alaska. Twenty-six (72%) grizzly bear observations were completed (???60 min) successfully (median duration = 180 min; ??95% CI = 136-181 min; range = 67-189 min) and 10 were discontinued (duration ???24 min) due to disturbance to the bear, or unfavorable weather conditions. Of the 26 successfully completed observations, 15 (58%) included predatory activity (encounter) directed at caribou calves and 8 (31%) included kills. Of 32 encounters, 9 resulted in kills, for a success rate of 28%. The median duration of encounters was 1 minute (??95% CI = 1-2 min; range = 1-6 min; n = 32;), and the median time spent at a kill was 14 minutes (??95% CI = 9-23 min; range = 6-56 min; n = 9). Sows with young (n = 4) killed more frequently (75%; P = 0.0178) than barren sows, boars, and consorting pairs combined (17%; n = 18). Estimated kill rate was highest for sows with young (6.3 kills/bear/day; n = 4), followed by barren sows (4.6 kills/bear/day; n = 5), boars (1.9 kills/bear/day; n = 5), and, finally, consorting pairs (1.0 kills/bear/day; n = 8). Estimated kill rate obtained via conventional radiotracking point surveys (4.8 kills/bear/day) was higher than that obtained via concurrent bear observations (3.1 kills/bear/day). Our research provides baseline estimates of predation rates by grizzly bears on caribou calves that will enhance the capability of wildlife professionals in managing populations of both predators and their prey.

  18. Methods to estimate distribution and range extent of grizzly bears in the Greater Yellowstone Ecosystem

    Science.gov (United States)

    Haroldson, Mark A.; Schwartz, Charles C.; Thompson, Daniel J.; Bjornlie, Daniel D.; Gunther, Kerry A.; Cain, Steven L.; Tyers, Daniel B.; Frey, Kevin L.; Aber, Bryan C.

    2014-01-01

    The distribution of the Greater Yellowstone Ecosystem grizzly bear (Ursus arctos) population has expanded into areas unoccupied since the early 20th century. Up-to-date information on the area and extent of this distribution is crucial for federal, state, and tribal wildlife and land managers to make informed decisions regarding grizzly bear management. The most recent estimate of grizzly bear distribution (2004) utilized fixed-kernel density estimators to describe distribution. This method was complex and computationally time consuming and excluded observations of unmarked bears. Our objective was to develop a technique to estimate grizzly bear distribution that would allow for the use of all verified grizzly bear location data, as well as provide the simplicity to be updated more frequently. We placed all verified grizzly bear locations from all sources from 1990 to 2004 and 1990 to 2010 onto a 3-km × 3-km grid and used zonal analysis and ordinary kriging to develop a predicted surface of grizzly bear distribution. We compared the area and extent of the 2004 kriging surface with the previous 2004 effort and evaluated changes in grizzly bear distribution from 2004 to 2010. The 2004 kriging surface was 2.4% smaller than the previous fixed-kernel estimate, but more closely represented the data. Grizzly bear distribution increased 38.3% from 2004 to 2010, with most expansion in the northern and southern regions of the range. This technique can be used to provide a current estimate of grizzly bear distribution for management and conservation applications.

  19. Body size and lean mass of brown bears across and within four diverse ecosystems

    Science.gov (United States)

    Hilderbrand, Grant V.; Gustine, David; Mangipane, Buck A.; Joly, Kyle; Leacock, William; Mangipane, Lindsey S.; Erlenbach, Joy; Sorum, Mathew; Cameron, Matthew; Belant, Jerrold L.; Cambier, Troy

    2018-01-01

    Variation in body size across populations of brown bears (Ursus arctos) is largely a function of the availability and quality of nutritional resources while plasticity within populations reflects utilized niche width with implications for population resiliency. We assessed skull size, body length, and lean mass of adult female and male brown bears in four Alaskan study areas that differed in climate, primary food resources, population density, and harvest regime. Full body-frame size, as evidenced by asymptotic skull size and body length, was achieved by 8 to 14 years of age across populations and sexes. Lean body mass of both sexes continued to increase throughout their life. Differences between populations existed for all morphological measures in both sexes, bears in ecosystems with abundant salmon were generally larger. Within all populations, broad variation was seen in body size measures of adults with females displaying roughly a 2-fold difference in lean mass and males showing a 3- to 4-fold difference. The high level of intraspecific variation seen across and within populations suggests the presence of multiple life-history strategies and niche variation relative to resource partitioning, risk tolerance or aversion, and competition. Further, this level of variation indicates broad potential to adapt to changes within a given ecosystem and across the species’ range.

  20. Predicting grizzly bear density in western North America.

    Science.gov (United States)

    Mowat, Garth; Heard, Douglas C; Schwarz, Carl J

    2013-01-01

    Conservation of grizzly bears (Ursus arctos) is often controversial and the disagreement often is focused on the estimates of density used to calculate allowable kill. Many recent estimates of grizzly bear density are now available but field-based estimates will never be available for more than a small portion of hunted populations. Current methods of predicting density in areas of management interest are subjective and untested. Objective methods have been proposed, but these statistical models are so dependent on results from individual study areas that the models do not generalize well. We built regression models to relate grizzly bear density to ultimate measures of ecosystem productivity and mortality for interior and coastal ecosystems in North America. We used 90 measures of grizzly bear density in interior ecosystems, of which 14 were currently known to be unoccupied by grizzly bears. In coastal areas, we used 17 measures of density including 2 unoccupied areas. Our best model for coastal areas included a negative relationship with tree cover and positive relationships with the proportion of salmon in the diet and topographic ruggedness, which was correlated with precipitation. Our best interior model included 3 variables that indexed terrestrial productivity, 1 describing vegetation cover, 2 indices of human use of the landscape and, an index of topographic ruggedness. We used our models to predict current population sizes across Canada and present these as alternatives to current population estimates. Our models predict fewer grizzly bears in British Columbia but more bears in Canada than in the latest status review. These predictions can be used to assess population status, set limits for total human-caused mortality, and for conservation planning, but because our predictions are static, they cannot be used to assess population trend.

  1. Predicting grizzly bear density in western North America.

    Directory of Open Access Journals (Sweden)

    Garth Mowat

    Full Text Available Conservation of grizzly bears (Ursus arctos is often controversial and the disagreement often is focused on the estimates of density used to calculate allowable kill. Many recent estimates of grizzly bear density are now available but field-based estimates will never be available for more than a small portion of hunted populations. Current methods of predicting density in areas of management interest are subjective and untested. Objective methods have been proposed, but these statistical models are so dependent on results from individual study areas that the models do not generalize well. We built regression models to relate grizzly bear density to ultimate measures of ecosystem productivity and mortality for interior and coastal ecosystems in North America. We used 90 measures of grizzly bear density in interior ecosystems, of which 14 were currently known to be unoccupied by grizzly bears. In coastal areas, we used 17 measures of density including 2 unoccupied areas. Our best model for coastal areas included a negative relationship with tree cover and positive relationships with the proportion of salmon in the diet and topographic ruggedness, which was correlated with precipitation. Our best interior model included 3 variables that indexed terrestrial productivity, 1 describing vegetation cover, 2 indices of human use of the landscape and, an index of topographic ruggedness. We used our models to predict current population sizes across Canada and present these as alternatives to current population estimates. Our models predict fewer grizzly bears in British Columbia but more bears in Canada than in the latest status review. These predictions can be used to assess population status, set limits for total human-caused mortality, and for conservation planning, but because our predictions are static, they cannot be used to assess population trend.

  2. Contrafreeloading in grizzly bears: implications for captive foraging enrichment.

    Science.gov (United States)

    McGowan, Ragen T S; Robbins, Charles T; Alldredge, J Richard; Newberry, Ruth C

    2010-01-01

    Although traditional feeding regimens for captive animals were focused on meeting physiological needs to assure good health, more recently emphasis has also been placed on non-nutritive aspects of feeding. The provision of foraging materials to diversify feeding behavior is a common practice in zoos but selective consumption of foraging enrichment items over more balanced "chow" diets could lead to nutrient imbalance. One alternative is to provide balanced diets in a contrafreeloading paradigm. Contrafreeloading occurs when animals choose resources that require effort to exploit when identical resources are freely available. To investigate contrafreeloading and its potential as a theoretical foundation for foraging enrichment, we conducted two experiments with captive grizzly bears (Ursus arctos horribilis). In Experiment 1, bears were presented with five foraging choices simultaneously: apples, apples in ice, salmon, salmon in ice, and plain ice under two levels of food restriction. Two measures of contrafreeloading were considered: weight of earned food consumed and time spent working for earned food. More free than earned food was eaten, with only two bears consuming food extracted from ice, but all bears spent more time manipulating ice containing salmon or apples than plain ice regardless of level of food restriction. In Experiment 2, food-restricted bears were presented with three foraging choices simultaneously: apples, apples inside a box, and an empty box. Although they ate more free than earned food, five bears consumed food from boxes and all spent more time manipulating boxes containing apples than empty boxes. Our findings support the provision of contrafreeloading opportunities as a foraging enrichment strategy for captive wildlife. (c) 2009 Wiley-Liss, Inc.

  3. Dental and Temporomandibular Joint Pathology of the Polar Bear (Ursus maritimus).

    Science.gov (United States)

    Winer, J N; Arzi, B; Leale, D M; Kass, P H; Verstraete, F J M

    2016-01-01

    Museum specimens (maxillae and/or mandibles) from 317 polar bears (Ursus maritimus) were examined macroscopically according to predefined criteria and 249 specimens were included in this study. The specimens were acquired between 1906 and 2011. There were 126 specimens (50.6%) from male animals, 93 (37.3%) from female animals and 30 (12.1%) from animals of unknown sex. The ages of the animals ranged from neonate to adult, with 125 adults (50.2%) and 124 young adults (49.8%) included and neonates/juveniles excluded from the study. The number of teeth available for examination was 7,638 (73.5%); 12.3% of teeth were absent artefactually, 0.8% were deemed absent due to acquired tooth loss and 13.4% were absent congenitally. With respect to tooth morphology, 20 teeth (0.26% of available teeth) in 18 specimens (7.2% of available specimens) were small vestigial structures with crowns that were flush with the level of surrounding alveolar bone. One supernumerary tooth and one tooth with enamel hypoplasia were encountered. Persistent deciduous teeth and teeth with an aberrant number of roots were not found. Relatively few teeth (3.7%) displayed attrition/abrasion, 90% of which were the maxillary and mandibular incisor teeth, in 41 polar bears (16.5%). Nearly twice as many adult specimens exhibited attrition/abrasion as those from young adults; significantly more males were affected than females. Dental fractures were noted in 52 polar bears, affecting 20.9% of specimens and 1.3% of the total number of teeth present. More adult polar bears had dental fractures than young adults. There were 21 specimens (8.4%) that displayed overt periapical disease, affecting a total of 24 dental alveoli (0.23%). Some degree of periodontitis was seen in 199 specimens (79.9%); however, only 12.6% of dental alveoli had bony changes indicative of periodontitis. Lesions consistent with temporomandibular joint osteoarthritis (TMJ-OA) were found in 23 specimens (9.2%). TMJ-OA was significantly

  4. Sexual Maturity and Life Stage Influences Toxic Metal Accumulation in Croatian Brown Bears.

    Science.gov (United States)

    Lazarus, Maja; Sekovanić, Ankica; Orct, Tatjana; Reljić, Slaven; Jurasović, Jasna; Huber, Đuro

    2018-02-01

    The influence of reproductive and (early) life stages on toxic metal levels was investigated in the brown bear (Ursus arctos), the largest mammalian predator species in Croatia. The purpose was to examine critical clusters in a population that might be at a higher risk of adverse health effects caused by metals as environmental contaminants. Levels of cadmium, mercury and lead in muscle, liver and kidney cortex of 325 male and 139 female bears, quantified by inductively coupled plasma mass spectrometry, were analysed according to distinct bear life stages (young: cub, yearling, subadult; mature: adult). Metal levels did not differ among sexes in young animals (< 4 years), except for mercury in muscles (higher in females), and adult females had higher cadmium and mercury. A trend of renal cadmium accumulation with age in immature male animals disappeared once they reached maturity, whereas for females this trend has only slowly declined in mature compared to immature bears. In early life stage (< 1 year), bear cubs had lower cadmium, comparable mercury, and higher lead in the kidneys than the bears of the following age category (yearlings). Due to a higher proportion of renal lead transfer from the mother to the cub compared with cadmium, it may be that the high burden of cadmium found in kidneys of older females has lower toxicological concern for their cubs than the lead content. Sex, reproductive, and life stages of bears were confirmed as important in assessing toxic metal burden.

  5. Estimating grizzly and black bear population abundance and trend in Banff National Park using noninvasive genetic sampling.

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    Michael A Sawaya

    Full Text Available We evaluated the potential of two noninvasive genetic sampling methods, hair traps and bear rub surveys, to estimate population abundance and trend of grizzly (Ursus arctos and black bear (U. americanus populations in Banff National Park, Alberta, Canada. Using Huggins closed population mark-recapture models, we obtained the first precise abundance estimates for grizzly bears (N= 73.5, 95% CI = 64-94 in 2006; N= 50.4, 95% CI = 49-59 in 2008 and black bears (N= 62.6, 95% CI = 51-89 in 2006; N= 81.8, 95% CI = 72-102 in 2008 in the Bow Valley. Hair traps had high detection rates for female grizzlies, and male and female black bears, but extremely low detection rates for male grizzlies. Conversely, bear rubs had high detection rates for male and female grizzlies, but low rates for black bears. We estimated realized population growth rates, lambda, for grizzly bear males (λ= 0.93, 95% CI = 0.74-1.17 and females (λ= 0.90, 95% CI = 0.67-1.20 using Pradel open population models with three years of bear rub data. Lambda estimates are supported by abundance estimates from combined hair trap/bear rub closed population models and are consistent with a system that is likely driven by high levels of human-caused mortality. Our results suggest that bear rub surveys would provide an efficient and powerful means to inventory and monitor grizzly bear populations in the Central Canadian Rocky Mountains.

  6. Estimating grizzly and black bear population abundance and trend in Banff National Park using noninvasive genetic sampling.

    Science.gov (United States)

    Sawaya, Michael A; Stetz, Jeffrey B; Clevenger, Anthony P; Gibeau, Michael L; Kalinowski, Steven T

    2012-01-01

    We evaluated the potential of two noninvasive genetic sampling methods, hair traps and bear rub surveys, to estimate population abundance and trend of grizzly (Ursus arctos) and black bear (U. americanus) populations in Banff National Park, Alberta, Canada. Using Huggins closed population mark-recapture models, we obtained the first precise abundance estimates for grizzly bears (N= 73.5, 95% CI = 64-94 in 2006; N= 50.4, 95% CI = 49-59 in 2008) and black bears (N= 62.6, 95% CI = 51-89 in 2006; N= 81.8, 95% CI = 72-102 in 2008) in the Bow Valley. Hair traps had high detection rates for female grizzlies, and male and female black bears, but extremely low detection rates for male grizzlies. Conversely, bear rubs had high detection rates for male and female grizzlies, but low rates for black bears. We estimated realized population growth rates, lambda, for grizzly bear males (λ= 0.93, 95% CI = 0.74-1.17) and females (λ= 0.90, 95% CI = 0.67-1.20) using Pradel open population models with three years of bear rub data. Lambda estimates are supported by abundance estimates from combined hair trap/bear rub closed population models and are consistent with a system that is likely driven by high levels of human-caused mortality. Our results suggest that bear rub surveys would provide an efficient and powerful means to inventory and monitor grizzly bear populations in the Central Canadian Rocky Mountains.

  7. Dietary breadth of grizzly bears in the Greater Yellowstone Ecosystem

    Science.gov (United States)

    Gunther, Kerry A.; Shoemaker, Rebecca; Frey, Kevin L.; Haroldson, Mark A.; Cain, Steven L.; van Manen, Frank T.; Fortin, Jennifer K.

    2014-01-01

    Grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem (GYE) are opportunistic omnivores that eat a great diversity of plant and animal species. Changes in climate may affect regional vegetation, hydrology, insects, and fire regimes, likely influencing the abundance, range, and elevational distribution of the plants and animals consumed by GYE grizzly bears. Determining the dietary breadth of grizzly bears is important to document future changes in food resources and how those changes may affect the nutritional ecology of grizzlies. However, no synthesis exists of all foods consumed by grizzly bears in the GYE. We conducted a review of available literature and compiled a list of species consumed by grizzly bears in the GYE. We documented >266 species within 200 genera from 4 kingdoms, including 175 plant, 37 invertebrate, 34 mammal, 7 fungi, 7 bird, 4 fish, 1 amphibian, and 1 algae species as well as 1 soil type consumed by grizzly bears. The average energy values of the ungulates (6.8 kcal/g), trout (Oncorhynchus spp., 6.1 kcal/g), and small mammals (4.5 kcal/g) eaten by grizzlies were higher than those of the plants (3.0 kcal/g) and invertebrates (2.7 kcal/g) they consumed. The most frequently detected diet items were graminoids, ants (Formicidae), whitebark pine seeds (Pinus albicaulis), clover (Trifolium spp.), and dandelion (Taraxacum spp.). The most consistently used foods on a temporal basis were graminoids, ants, whitebark pine seeds, clover, elk (Cervus elaphus), thistle (Cirsium spp.), and horsetail (Equisetum spp.). Historically, garbage was a significant diet item for grizzlies until refuse dumps were closed. Use of forbs increased after garbage was no longer readily available. The list of foods we compiled will help managers of grizzly bears and their habitat document future changes in grizzly bear food habits and how bears respond to changing food resources.

  8. Genetic variation, relatedness, and effective population size of polar bears (Ursus maritimus) in the southern Beaufort Sea, Alaska

    Science.gov (United States)

    Cronin, Matthew A.; Amstrup, Steven C.; Talbot, Sandra L.; Sage, George K.; Amstrup, Kristin S.

    2009-01-01

    Polar bears (Ursus maritimus) are unique among bears in that they are adapted to the Arctic sea ice environment. Genetic data are useful for understanding their evolution and can contribute to management. We assessed parentage and relatedness of polar bears in the southern Beaufort Sea, Alaska, with genetic data and field observations of age, sex, and mother–offspring and sibling relationships. Genotypes at 14 microsatellite DNA loci for 226 bears indicate that genetic variation is comparable to other populations of polar bears with mean number of alleles per locus of 7.9 and observed and expected heterozygosity of 0.71. The genetic data verified 60 field-identified mother–offspring pairs and identified 10 additional mother–cub pairs and 48 father–offspring pairs. The entire sample of related and unrelated bears had a mean pairwise relatedness index (rxy) of approximately zero, parent–offspring and siblings had rxy of approximately 0.5, and 5.2% of the samples had rxy values within the range expected for parent-offspring. Effective population size (Ne= 277) and the ratio of Ne to total population size (Ne/N = 0.182) were estimated from the numbers of reproducing males and females. Ne estimates with genetic methods gave variable results. Our results verify and expand field data on reproduction by females and provide new data on reproduction by males and estimates of relatedness and Ne in a polar bear population.

  9. Genetic variation, relatedness, and effective population size of polar bears (Ursus maritimus) in the southern Beaufort Sea, Alaska.

    Science.gov (United States)

    Cronin, Matthew A; Amstrup, Steven C; Talbot, Sandra L; Sage, George K; Amstrup, Kristin S

    2009-01-01

    Polar bears (Ursus maritimus) are unique among bears in that they are adapted to the Arctic sea ice environment. Genetic data are useful for understanding their evolution and can contribute to management. We assessed parentage and relatedness of polar bears in the southern Beaufort Sea, Alaska, with genetic data and field observations of age, sex, and mother-offspring and sibling relationships. Genotypes at 14 microsatellite DNA loci for 226 bears indicate that genetic variation is comparable to other populations of polar bears with mean number of alleles per locus of 7.9 and observed and expected heterozygosity of 0.71. The genetic data verified 60 field-identified mother-offspring pairs and identified 10 additional mother-cub pairs and 48 father-offspring pairs. The entire sample of related and unrelated bears had a mean pairwise relatedness index (r(xy)) of approximately zero, parent-offspring and siblings had r(xy) of approximately 0.5, and 5.2% of the samples had r(xy) values within the range expected for parent-offspring. Effective population size (N(e) = 277) and the ratio of N(e) to total population size (N(e)/N = 0.182) were estimated from the numbers of reproducing males and females. N(e) estimates with genetic methods gave variable results. Our results verify and expand field data on reproduction by females and provide new data on reproduction by males and estimates of relatedness and N(e) in a polar bear population.

  10. An immunohistochemical study of retinol-binding protein (RBP) in livers of free-living polar bears (Ursus maritimus) from east Greenland.

    Science.gov (United States)

    Heier, Annabelle; Sonne, Christian; Gröne, Andrea; Leifsson, Pall S; Dietz, Rune; Born, Erik W; Bacciarini, Luca N

    2005-09-01

    From 1999 to 2002 samples from 114 free-ranging polar bears (Ursus maritimus) were collected in the municipality of Scoresby Sound, East Greenland, to detect levels of organochlorines and potential histopathologic changes. Livers of 16 female polar bears from this group were evaluated histologically and analyzed for hepatic retinol-binding protein by immunohistochemistry. Retinol-binding protein is the main transport protein for retinol, an important vitamin A metabolite in the polar bear. Only mild pathologic changes were noted on histologic evaluation of the livers. Small lymphocytic or lymphohistiocytic infiltrates were present in all the livers. Small lipid granulomas, mild periportal fibrosis, and bile duct proliferation were found in several cases. Immunohistochemistry for retinol-binding protein of hepatic tissue from free-ranging polar bears showed no distinct difference in staining intensity by a number of criteria: age, season (fasting and nonfasting), or lactation status. The staining was diffuse to finely stippled in the cytoplasm and showed very little variation among the animals. Because of the lack of macroscopic changes and the absence of severe histologic liver lesions, these polar bears were assumed to be healthy. The diffuse cytoplasmic retinol-binding protein staining in hepatocytes of free-ranging polar bears varies markedly from the prominent granular, less intense staining of captive polar bears investigated previously.

  11. Morphological variability and molecular identification of Uncinaria spp. (Nematoda: Ancylostomatidae) from grizzly and black bears: new species or phenotypic plasticity?

    Science.gov (United States)

    Catalano, Stefano; Lejeune, Manigandan; van Paridon, Bradley; Pagan, Christopher A; Wasmuth, James D; Tizzani, Paolo; Duignan, Pádraig J; Nadler, Steven A

    2015-04-01

    The hookworms Uncinaria rauschi Olsen, 1968 and Uncinaria yukonensis ( Wolfgang, 1956 ) were formally described from grizzly ( Ursus arctos horribilis) and black bears ( Ursus americanus ) of North America. We analyzed the intestinal tracts of 4 grizzly and 9 black bears from Alberta and British Columbia, Canada and isolated Uncinaria specimens with anatomical traits never previously documented. We applied morphological and molecular techniques to investigate the taxonomy and phylogeny of these Uncinaria parasites. The morphological analysis supported polymorphism at the vulvar region for females of both U. rauschi and U. yukonensis. The hypothesis of morphological plasticity for U. rauschi and U. yukonensis was confirmed by genetic analysis of the internal transcribed spacers (ITS-1 and ITS-2) of the nuclear ribosomal DNA. Two distinct genotypes were identified, differing at 5 fixed sites for ITS-1 (432 base pairs [bp]) and 7 for ITS-2 (274 bp). Morphometric data for U. rauschi revealed host-related size differences: adult U. rauschi were significantly larger in black bears than in grizzly bears. Interpretation of these results, considering the historical biogeography of North American bears, suggests a relatively recent host-switching event of U. rauschi from black bears to grizzly bears which likely occurred after the end of the Wisconsin glaciation. Phylogenetic maximum parsimony (MP) and maximum likelihood (ML) analyses of the concatenated ITS-1 and ITS-2 datasets strongly supported monophyly of U. rauschi and U. yukonensis and their close relationship with Uncinaria stenocephala (Railliet, 1884), the latter a parasite primarily of canids and felids. Relationships among species within this group, although resolved by ML, were unsupported by MP and bootstrap resampling. The clade of U. rauschi, U. yukonensis, and U. stenocephala was recovered as sister to the clade represented by Uncinaria spp. from otariid pinnipeds. These results support the absence of strict

  12. Tissue-specific congener composition of organohalogen and metabolite contaminants in East Greenland polar bears (Ursus maritimus)

    International Nuclear Information System (INIS)

    Gebbink, Wouter A.; Sonne, Christian; Dietz, Rune; Kirkegaard, Maja; Riget, Frank F.; Born, Erik W.; Muir, Derek C.G.; Letcher, Robert J.

    2008-01-01

    Congener patterns of the major organohalogen contaminant classes of PCBs, PBDEs and their metabolites and/or by-products (OH-PCBs, MeSO 2 -PCBs, OH-PBDEs and MeO-PBDEs) were examined in adipose tissue, liver, brain and blood of East Greenland polar bears (Ursus maritimus). PCB, OH-PCB, MeSO 2 -PCB and PBDE congener patterns showed significant differences (p ≤ 0.05) mainly in the liver and the brain relative to the adipose tissue and the blood. OH-PBDEs and MeO-PBDEs were not detected in the brain and liver, but had different patterns in blood versus the adipose tissue. Novel OH-polybrominated biphenyls (OH-PBBs), one tri- and two tetra-brominated OH-PBBs were detected in all tissues and blood. Congener pattern differences among tissues and blood are likely due to a combination of factors, e.g., biotransformation and retention in the liver, retention in the blood and blood-brain barrier transport. Our findings suggest that different congener pattern exposures to these classes of contaminants should be considered with respect to potential target tissue-specific effects in East Greenland polar bears. - Tissues-specific (adipose tissue, liver, brain and blood) differences exist for the congener patterns of PCBs, PBDEs and their metabolites/degradation products in East Greenland polar bears

  13. Polar bear attacks on humans: Implications of a changing climate

    Science.gov (United States)

    Wilder, James; Vongraven, Dag; Atwood, Todd C.; Hansen, Bob; Jessen, Amalie; Kochnev, Anatoly A.; York, Geoff; Vallender, Rachel; Hedman, Daryll; Gibbons, Melissa

    2017-01-01

    Understanding causes of polar bear (Ursus maritimus) attacks on humans is critical to ensuring both human safety and polar bear conservation. Although considerable attention has been focused on understanding black (U. americanus) and grizzly (U. arctos) bear conflicts with humans, there have been few attempts to systematically collect, analyze, and interpret available information on human-polar bear conflicts across their range. To help fill this knowledge gap, a database was developed (Polar Bear-Human Information Management System [PBHIMS]) to facilitate the range-wide collection and analysis of human-polar bear conflict data. We populated the PBHIMS with data collected throughout the polar bear range, analyzed polar bear attacks on people, and found that reported attacks have been extremely rare. From 1870–2014, we documented 73 attacks by wild polar bears, distributed among the 5 polar bear Range States (Canada, Greenland, Norway, Russia, and United States), which resulted in 20 human fatalities and 63 human injuries. We found that nutritionally stressed adult male polar bears were the most likely to pose threats to human safety. Attacks by adult females were rare, and most were attributed to defense of cubs. We judged that bears acted as a predator in most attacks, and that nearly all attacks involved ≤2 people. Increased concern for both human and bear safety is warranted in light of predictions of increased numbers of nutritionally stressed bears spending longer amounts of time on land near people because of the loss of their sea ice habitat. Improved conflict investigation is needed to collect accurate and relevant data and communicate accurate bear safety messages and mitigation strategies to the public. With better information, people can take proactive measures in polar bear habitat to ensure their safety and prevent conflicts with polar bears. This work represents an important first step towards improving our understanding of factors influencing

  14. Predicting the Distribution of Asiatic Cheetah, Persian Leopard and Brown Bear in Response to EnvironmentalFactors in Isfahan Province

    Directory of Open Access Journals (Sweden)

    M. R. Hemami

    2015-12-01

    Full Text Available Distribution modelling is important for assessing threats and conservation status of species and for planning conservation programs. We studied the distribution of suitable habitats of Asiatic cheetah (Acinonyx jubatus venaticus, Persian leopard (Panthera pardus saxicolor and brown bear (Ursus arctos in Isfahan province within and outside the protected areas. Suitable habitats of the three studied carnivores in Isfahan province were mapped in relation to climatic, topographic and anthropogenic variables using MAXENT. Assessing the developed model using the area under the ROC function showed that predictions for the three carnivore species were significantly better than random. Potential suitable habitats of Asiatic cheetah, Persian leopard and brown bear constituted 5.2%, 12% and 3.4% of the Isfahan province area, respectively. Slope was the most important factor determining Persian leopard habitat suitability, while climatic factors (mainly mean autumn and mean annual precipitation were the most important determinants of Asiatic cheetah and brown bear distribution. The protected area network within the province covers 55.7%, 23.7%, and 11.6% of the suitable habitats for Asiatic cheetah, Persian leopard and brown bear, respectively. Parts of suitable habitats of the three species are located outside the protected areas, which could be considered in planning conservation programs as potential movement corridors.

  15. The first detection of Babesia species DNA from Japanese black bears (Ursus thibetanus japonicus) in Japan.

    Science.gov (United States)

    Ikawa, Kazuhito; Aoki, Mikiko; Ichikawa, Madoka; Itagaki, Tadashi

    2011-06-01

    In this study, we tried to detect protozoan blood parasites from the liver or blood of 156 Japanese black bears (Ursus thibetanus japonicus) in Iwate Prefecture of Japan by polymerase chain reaction. Two amplicons (approximately 540 bp and 480 bp) were detected by amplification for V4 hyper-variable regions of the 18S rRNA gene. Approximately 540-bp products were obtained in 119 samples (76.3%) and were considered to be DNA of Hepatozoon ursi. Approximately 480-bp products were obtained in 22 samples (14.1%) and were considered to be DNA of Babesia species. The nucleotide sequences (1635 bp) of the 18S rRNA gene of Babesia sp. were very similar (99.3%) to those (AY190123, AY190124) of Babesia sp. detected previously from Ixodes ovatus. Phylogenetic analysis showed that Babesia sp. detected in this study closely related to Babesia sp. derived from raccoons in Japan and the U.S.A. This is the first report of Babesia species detected from Japanese black bears. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  16. Plasticity in physiological condition of female brown bears across diverse ecosystems

    Science.gov (United States)

    Hilderbrand, Grant V.; Gustine, David; Mangipane, Buck A.; Joly, Kyle; Leacock, William; Mangipane, Lindsey; Erlenbach, Joy; Sorum, Mathew; Cameron, Matthew; Belant, Jerrold L.; Cambier, Troy

    2018-01-01

    Variation in life history strategies facilitates the near global distribution of mammals by expanding realized niche width. We investigated physiological plasticity in the spring body composition of adult female brown bears (Ursus arctos) across 4 diverse Alaskan ecosystems. Brown bears are a highly intelligent omnivore with a historic range spanning much of North America, Europe, and Asia. We hypothesized that body mass, fat mass, lean mass, and total caloric content would increase across populations with increasing food resource availability. Throughout their range, brown bears enter a period of torpor during winter months, decreasing their metabolic rate as an adaptation to this period of reduced food availability. They also give birth to and nourish offspring during this time. Due to this specific life history strategy, we further hypothesized that proportional body fat and the proportion of total calories derived from fat would be consistent across populations. Our results supported our first hypothesis: body, fat, and lean masses, and caloric content of bears across populations increased with the quality and abundance of available food. However, the proportional body fat content and proportion of calories from fat differed across populations indicating population-specific strategies to meet the demands of reduced seasonal food availability, offspring production and rearing, and climate as well as some plasticity to respond to environmental change or ecosystem perturbations. Investigations of body condition and energetics benefit from combined assessments of absolute, proportional, and caloric metrics to understand the nuances of brown bear physiological dynamics across and within populations.

  17. Contributions of vital rates to growth of a protected population of American black bears

    Science.gov (United States)

    Mitchell, M.S.; Pacifici, L.B.; Grand, J.B.; Powell, R.A.

    2009-01-01

    Analyses of large, long-lived animals suggest that adult survival generally has the potential to contribute more than reproduction to population growth rate (??), but because survival varies little, high variability in reproduction can have a greater influence. This pattern has been documented for several species of large mammals, but few studies have evaluated such contributions of vital rates to ?? for American black bears (Ursus americanus). We used variance-based perturbation analyses (life table response experiments, LTRE) and analytical sensitivity and elasticity analyses to examine the actual and potential contributions of variation of vital rates to variation in growth rate (??) of a population of black bears inhabiting the Pisgah Bear Sanctuary in the southern Appalachian Mountains of North Carolina, using a 22-year dataset. We found that recruitment varied more than other vital rates; LTRE analyses conducted over several time intervals thus indicated that recruitment generally contributed at least as much as juvenile and adult survival to observed variation in ??, even though the latter 2 vital rates had the greater potential to affect ??. Our findings are consistent with predictions from studies on polar bears (U. maritimus) and grizzly bears (U. arctos), but contrast with the few existing studies on black bears in ways that suggest levels of protection from human-caused mortality might explain whether adult survival or recruitment contribute most to variation in ?? for this species. We hypothesize that ?? is most strongly influenced by recruitment in protected populations where adult survival is relatively high and constant, whereas adult survival will most influence ?? for unprotected populations. ?? 2009 International Association for Bear Research and Management.

  18. Modeling survival: application of the Andersen-Gill model to Yellowstone grizzly bears

    Science.gov (United States)

    Johnson, Christopher J.; Boyce, Mark S.; Schwartz, Charles C.; Haroldson, Mark A.

    2004-01-01

     Wildlife ecologists often use the Kaplan-Meier procedure or Cox proportional hazards model to estimate survival rates, distributions, and magnitude of risk factors. The Andersen-Gill formulation (A-G) of the Cox proportional hazards model has seen limited application to mark-resight data but has a number of advantages, including the ability to accommodate left-censored data, time-varying covariates, multiple events, and discontinuous intervals of risks. We introduce the A-G model including structure of data, interpretation of results, and assessment of assumptions. We then apply the model to 22 years of radiotelemetry data for grizzly bears (Ursus arctos) of the Greater Yellowstone Grizzly Bear Recovery Zone in Montana, Idaho, and Wyoming, USA. We used Akaike's Information Criterion (AICc) and multi-model inference to assess a number of potentially useful predictive models relative to explanatory covariates for demography, human disturbance, and habitat. Using the most parsimonious models, we generated risk ratios, hypothetical survival curves, and a map of the spatial distribution of high-risk areas across the recovery zone. Our results were in agreement with past studies of mortality factors for Yellowstone grizzly bears. Holding other covariates constant, mortality was highest for bears that were subjected to repeated management actions and inhabited areas with high road densities outside Yellowstone National Park. Hazard models developed with covariates descriptive of foraging habitats were not the most parsimonious, but they suggested that high-elevation areas offered lower risks of mortality when compared to agricultural areas.

  19. Grizzly bears and calving caribou: What is the relation with river corridors?

    Science.gov (United States)

    Young, Donald D.; McCabe, Thomas R.

    1998-01-01

    Researchers have debated the effect of the Trans-Alaska Pipeline (TAP) and associated developments to caribou (Rangifer tarandus) of the central Arctic herd (CAH) since the 1970s. Several studies have demonstrated that cows and calves of the CAH avoided the TAP corridor because of disturbance associated with the pipeline, whereas others have indicated that female caribou of the CAH avoided riparian habitats closely associated with the pipeline. This avoidance was explained as a predator-avoidance strategy. We investigated the relation between female caribou and grizzly bear (Ursus arctos) use of river corridors on the yet undisturbed calving grounds of the Porcupine caribou herd (PCH) in northeastern Alaska. On the coastal plain, caribou were closer to river corridors than expected (P = 0.038), but bear use of river corridors did not differ from expected (P = 0.740). In the foothills, caribou use of river corridors did not differ from expected (P = 0.520), but bears were farther from rivers than expected (P = 0.001). Our results did not suggest an avoidance of river corridors by calving caribou or a propensity for bears to be associated with riparian habitats, presumably for stalking or ambush cover. We propose that PCH caribou reduce the risks of predation to neonates by migrating to a common calving grounds, where predator swamping is the operational antipredator strategy. Consequently, we hypothesize that nutritional demands, not predator avoidance strategies, ultimately regulate habitat use patterns (e.g., use of river corridors) of calving PCH caribou.

  20. Long-distance swimming by polar bears (Ursus maritimus) of the southern Beaufort Sea during years of extensive open water

    Science.gov (United States)

    2014-01-01

    Polar bears (Ursus maritimus Phipps, 1774) depend on sea ice for catching marine mammal prey. Recent sea-ice declines have been linked to reductions in body condition, survival, and population size. Reduced foraging opportunity is hypothesized to be the primary cause of sea-ice-linked declines, but the costs of travel through a deteriorated sea-ice environment also may be a factor. We used movement data from 52 adult female polar bears wearing Global Positioning System (GPS) collars, including some with dependent young, to document long-distance swimming (>50 km) by polar bears in the southern Beaufort and Chukchi seas. During 6 years (2004-2009), we identified 50 long-distance swims by 20 bears. Swim duration and distance ranged from 0.7 to 9.7 days (mean = 3.4 days) and 53.7 to 687.1 km (mean = 154.2 km), respectively. Frequency of swimming appeared to increase over the course of the study. We show that adult female polar bears and their cubs are capable of swimming long distances during periods when extensive areas of open water are present. However, long-distance swimming appears to have higher energetic demands than moving over sea ice. Our observations suggest long-distance swimming is a behavioral response to declining summer sea-ice conditions.

  1. Prevalence and spatio-temporal variation of an alopecia syndrome in polar bears (Ursus maritimus) of the southern Beaufort Sea

    Science.gov (United States)

    Atwood, Todd C.; Peacock, Elizabeth; Burek, K.A.; Shearn-Bochsler, Valerie I.; Bodenstein, Barbara L.; Beckmen, Kimberlee B.; Durner, George M.

    2015-01-01

    Alopecia (hair loss) has been observed in several marine mammal species and has potential energetic consequences for sustaining a normal core body temperature, especially for Arctic marine mammals routinely exposed to harsh environmental conditions. Polar bears (Ursus maritimus) rely on a thick layer of adipose tissue and a dense pelage to ameliorate convective heat loss while moving between sea ice and open water. From 1998 to 2012, we observed an alopecia syndrome in polar bears from the southern Beaufort Sea of Alaska that presented as bilaterally asymmetrical loss of guard hairs and thinning of the undercoat around the head, neck, and shoulders, which, in severe cases, was accompanied by exudation and crusted skin lesions. Alopecia was observed in 49 (3.45%) of the bears sampled during 1,421 captures, and the apparent prevalence varied by years with peaks occurring in 1999 (16%) and 2012 (28%). The probability that a bear had alopecia was greatest for subadults and for bears captured in the Prudhoe Bay region, and alopecic individuals had a lower body condition score than unaffected individuals. The cause of the syndrome remains unknown and future work should focus on identifying the causative agent and potential effects on population vital rates.

  2. Prevalence and spatio-temporal variation of an alopecia syndrome in polar bears (Ursus maritimus) of the southern Beaufort Sea.

    Science.gov (United States)

    Atwood, Todd; Peacock, Elizabeth; Burek-Huntington, Kathy; Shearn-Bochsler, Valerie; Bodenstein, Barbara; Beckmen, Kimberlee; Durner, George

    2015-01-01

    Alopecia (hair loss) has been observed in several marine mammal species and has potential energetic consequences for sustaining a normal core body temperature, especially for Arctic marine mammals routinely exposed to harsh environmental conditions. Polar bears (Ursus maritimus) rely on a thick layer of adipose tissue and a dense pelage to ameliorate convective heat loss while moving between sea ice and open water. From 1998 to 2012, we observed an alopecia syndrome in polar bears from the southern Beaufort Sea of Alaska that presented as bilaterally asymmetrical loss of guard hairs and thinning of the undercoat around the head, neck, and shoulders, which, in severe cases, was accompanied by exudation and crusted skin lesions. Alopecia was observed in 49 (3.45%) of the bears sampled during 1,421 captures, and the apparent prevalence varied by years with peaks occurring in 1999 (16%) and 2012 (28%). The probability that a bear had alopecia was greatest for subadults and for bears captured in the Prudhoe Bay region, and alopecic individuals had a lower body condition score than unaffected individuals. The cause of the syndrome remains unknown and future work should focus on identifying the causative agent and potential effects on population vital rates.

  3. Temporal effects of hunting on foraging behavior of an apex predator: Do bears forego foraging when risk is high?

    Science.gov (United States)

    Hertel, Anne G; Zedrosser, Andreas; Mysterud, Atle; Støen, Ole-Gunnar; Steyaert, Sam M J G; Swenson, Jon E

    2016-12-01

    Avoiding predators most often entails a food cost. For the Scandinavian brown bear (Ursus arctos), the hunting season coincides with the period of hyperphagia. Hunting mortality risk is not uniformly distributed throughout the day, but peaks in the early morning hours. As bears must increase mass for winter survival, they should be sensitive to temporal allocation of antipredator responses to periods of highest risk. We expected bears to reduce foraging activity at the expense of food intake in the morning hours when risk was high, but not in the afternoon, when risk was low. We used fine-scale GPS-derived activity patterns during the 2 weeks before and after the onset of the annual bear hunting season. At locations of probable foraging, we assessed abundance and sugar content, of bilberry (Vaccinium myrtillus), the most important autumn food resource for bears in this area. Bears decreased their foraging activity in the morning hours of the hunting season. Likewise, they foraged less efficiently and on poorer quality berries in the morning. Neither of our foraging measures were affected by hunting in the afternoon foraging bout, indicating that bears did not allocate antipredator behavior to times of comparably lower risk. Bears effectively responded to variation in risk on the scale of hours. This entailed a measurable foraging cost. The additive effect of reduced foraging activity, reduced forage intake, and lower quality food may result in poorer body condition upon den entry and may ultimately reduce reproductive success.

  4. Cardiorespiratory effects of isoflurane in Asiatic black bears (Ursus thibetanus) anesthetized with intramuscular medetomidine and zolazepam/tiletamine.

    Science.gov (United States)

    Jeong, Dong-Hyuk; Yang, Jeong-Jin; Seok, Seong-Hoon; Song, Dong-Joo; Yeon, Seong-Chan

    2017-01-20

    The objective of this study was to determine the dose-dependent effects of isoflurane on various cardiovascular parameters and the stable range of isoflurane concentrations in Asiatic black bears (Ursus thibetanus). Seven Asiatic black bears were intramuscularly injected with medetomidine, zolazepam and tiletamine (MZT) to induce anesthesia, and anesthesia was maintained by administering isoflurane in 100% oxygen (4 l/min) without mechanical ventilation. Several cardiovascular parameters were measured at five end-tidal isoflurane concentrations (0.5, 1.0, 1.5, 2.0, and 2.5%). Blood was collected from the femoral artery before administration of isoflurane and after each administration for immediate blood gas analysis. Isoflurane produced dose-dependent increases in heart rate, respiratory rate, minute volume, end-tidal carbon dioxide (CO 2 ) partial pressure and the partial pressure of arterial CO 2 , and dose-dependent decreases in non-invasive blood pressure and tidal volume. Rectal temperature, oxygenation and acid-base balance were unaffected by isoflurane. All parameters in this study were in a clinically acceptable range at all times. The data show that the combination of MZT and isoflurane is suitable for general anesthesia in Asiatic black bears with spontaneous breathing during prolonged procedures. End-tidal isoflurane concentrations of 0.5 to 2.5% can be used in Asiatic black bears without adverse side effects.

  5. Identification and phylogenetic analysis of Dirofilaria ursi (Nematoda: Filarioidea) from Wisconsin black bears (Ursus americanus) and its Wolbachia endosymbiont.

    Science.gov (United States)

    Michalski, Michelle L; Bain, Odile; Fischer, Kerstin; Fischer, Peter U; Kumar, Sanjay; Foster, Jeremy M

    2010-04-01

    Dirofilaria ursi is a filarial nematode of American black bears (Ursus americanus Pallas, 1780) that is vectored by black flies (Simuliidae) in many parts of the United States. In northwestern Wisconsin, the prevalence of microfilaremic bears during the fall hunting season was 21% (n = 47). Unsheathed blood microfilariae from Wisconsin bears possess characters consistent with the original description of D. ursi, as do adult worms observed histologically and grossly. Immunohistochemistry was used to identify the Wolbachia endosymbiont in the hypodermis and lateral cords of an adult female D. ursi. Amplification of wsp, gatB, coxA, fbpA, and ftsZ bacterial sequences from parasite DNA confirmed the presence of Wolbachia, and molecular phylogenetic analysis of the Wolbachia ftsZ gene groups the endosymbiont with Wolbachia from D. immitis and D. repens. Phylogenetic analysis of D. ursi 5s rDNA sequence confirms the morphological observations grouping this parasite as a member of Dirofilaria, and within the Dirofilaria - Onchocerca clade of filarial nematodes. This is the first report of Wolbachia characterization and molecular phylogeny information for D. ursi.

  6. Revision of the early Middle Pleistocene bears (Ursidae, Mammalia) of Central Europe, with special respect to possible co-occurrence of spelaeoid and arctoid lineages

    Czech Academy of Sciences Publication Activity Database

    Wagner, J.; Čermák, Stanislav

    2012-01-01

    Roč. 87, č. 3 (2012), s. 461-496 ISSN 1214-1119 Institutional research plan: CEZ:AV0Z30130516 Keywords : Ursus deningeri * U. arctos, * Late Biharian * Early Toringian * Middle Pleistocene Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.141, year: 2012 http://www.geology.cz/bulletin/fulltext/1354_Wagner.pdf

  7. Modulation of gene expression in heart and liver of hibernating black bears (Ursus americanus

    Directory of Open Access Journals (Sweden)

    Yan Jun

    2011-03-01

    Full Text Available Abstract Background Hibernation is an adaptive strategy to survive in highly seasonal or unpredictable environments. The molecular and genetic basis of hibernation physiology in mammals has only recently been studied using large scale genomic approaches. We analyzed gene expression in the American black bear, Ursus americanus, using a custom 12,800 cDNA probe microarray to detect differences in expression that occur in heart and liver during winter hibernation in comparison to summer active animals. Results We identified 245 genes in heart and 319 genes in liver that were differentially expressed between winter and summer. The expression of 24 genes was significantly elevated during hibernation in both heart and liver. These genes are mostly involved in lipid catabolism and protein biosynthesis and include RNA binding protein motif 3 (Rbm3, which enhances protein synthesis at mildly hypothermic temperatures. Elevated expression of protein biosynthesis genes suggests induction of translation that may be related to adaptive mechanisms reducing cardiac and muscle atrophies over extended periods of low metabolism and immobility during hibernation in bears. Coordinated reduction of transcription of genes involved in amino acid catabolism suggests redirection of amino acids from catabolic pathways to protein biosynthesis. We identify common for black bears and small mammalian hibernators transcriptional changes in the liver that include induction of genes responsible for fatty acid β oxidation and carbohydrate synthesis and depression of genes involved in lipid biosynthesis, carbohydrate catabolism, cellular respiration and detoxification pathways. Conclusions Our findings show that modulation of gene expression during winter hibernation represents molecular mechanism of adaptation to extreme environments.

  8. Modulation of gene expression in heart and liver of hibernating black bears (Ursus americanus).

    Science.gov (United States)

    Fedorov, Vadim B; Goropashnaya, Anna V; Tøien, Øivind; Stewart, Nathan C; Chang, Celia; Wang, Haifang; Yan, Jun; Showe, Louise C; Showe, Michael K; Barnes, Brian M

    2011-03-31

    Hibernation is an adaptive strategy to survive in highly seasonal or unpredictable environments. The molecular and genetic basis of hibernation physiology in mammals has only recently been studied using large scale genomic approaches. We analyzed gene expression in the American black bear, Ursus americanus, using a custom 12,800 cDNA probe microarray to detect differences in expression that occur in heart and liver during winter hibernation in comparison to summer active animals. We identified 245 genes in heart and 319 genes in liver that were differentially expressed between winter and summer. The expression of 24 genes was significantly elevated during hibernation in both heart and liver. These genes are mostly involved in lipid catabolism and protein biosynthesis and include RNA binding protein motif 3 (Rbm3), which enhances protein synthesis at mildly hypothermic temperatures. Elevated expression of protein biosynthesis genes suggests induction of translation that may be related to adaptive mechanisms reducing cardiac and muscle atrophies over extended periods of low metabolism and immobility during hibernation in bears. Coordinated reduction of transcription of genes involved in amino acid catabolism suggests redirection of amino acids from catabolic pathways to protein biosynthesis. We identify common for black bears and small mammalian hibernators transcriptional changes in the liver that include induction of genes responsible for fatty acid β oxidation and carbohydrate synthesis and depression of genes involved in lipid biosynthesis, carbohydrate catabolism, cellular respiration and detoxification pathways. Our findings show that modulation of gene expression during winter hibernation represents molecular mechanism of adaptation to extreme environments.

  9. Heavy Metals in Brown Bears from the Central European Carpathians

    Directory of Open Access Journals (Sweden)

    O. Čelechovská

    2006-01-01

    Full Text Available The aim of the present study was to assess heavy metal load in the brown bear (Ursus arctos living in the central European Carpathians. Between 2002 and 2004, fifteen bears were examined to evaluate the distribution of cadmium, lead, mercury and copper in the animals' muscles (diaphragm, spleen, liver and kidney. The highest content of cadmium, lead and mercury was found in the kidney (17.4 ± 5.2 mg kg-1, 1.16 ± 0.39 mg kg-1, 0.39 ± 0.25 mg kg-1, whereas the lowest content of the metals was observed in the muscles (0.017 ± 0.009 mg kg-1, 0.299 ± 0.308 mg kg-1, 0.013 ± 0.011 mg kg-1. Second highest concentration of cadmium, lead and mercury was detected in the liver (0.83 ± 0.24 mg kg-1, 0.99 ± 0.61 mg kg-1, 0.11 ± 0.05 mg kg-1. Copper distributions and concentrations in bear tissues were as follows (in descending order: liver (23.9 ± 6.7 mg kg-1, > kidneys (9.0 ± 3.3 mg kg-1, > muscles (1.9 ± 1.6 mg kg-1 and > spleen (1.0 ± 0.2 mg kg-1. As compared with heavy metal load observed in bear tissues between 1988 and 1990, the concentration of cadmium in the muscles and liver was significantly lower (p p p < 0.01. Lead and copper tissue concentrations did not change substantially.

  10. Evaluation of rules to distinguish unique female grizzly bears with cubs in Yellowstone

    Science.gov (United States)

    Schwartz, C.C.; Haroldson, M.A.; Cherry, S.; Keating, K.A.

    2008-01-01

    The United States Fish and Wildlife Service uses counts of unduplicated female grizzly bears (Ursus arctos) with cubs-of-the-year to establish limits of sustainable mortality in the Greater Yellowstone Ecosystem, USA. Sightings are dustered into observations of unique bears based on an empirically derived rule set. The method has never been tested or verified. To evaluate the rule set, we used data from radiocollared females obtained during 1975-2004 to simulate populations under varying densities, distributions, and sighting frequencies. We tested individual rules and rule-set performance, using custom software to apply the rule-set and duster sightings. Results indicated most rules were violated to some degree, and rule-based dustering consistently underestimated the minimum number of females and total population size derived from a nonparametric estimator (Chao2). We conclude that the current rule set returns conservative estimates, but with minor improvements, counts of unduplicated females-with-cubs can serve as a reasonable index of population size useful for establishing annual mortality limits. For the Yellowstone population, the index is more practical and cost-effective than capture-mark-recapture using either DNA hair snagging or aerial surveys with radiomarked bears. The method has useful application in other ecosystems, but we recommend rules used to distinguish unique females be adapted to local conditions and tested.

  11. Characterization of blood lipoproteins and validation of cholesterol and triacylglycerol assays for free-ranging polar bears (Ursus maritimus).

    Science.gov (United States)

    Whiteman, John P; Frank, Nicholas; Greller, Katie A; Harlow, Henry J; Ben-David, Merav

    2013-05-01

    Blood triacylglycerol (TG) and lipoproteins are important variables for evaluating nutritional status of wildlife, but measurements are often expensive and difficult. Performance of a small, portable blood analyzer intended for human medical diagnostics was evaluated in measuring these variables in plasma and serum from free-ranging polar bears (Ursus maritimus), which are experiencing nutritional stress related to sea ice loss. The analyzer accurately tracked changes in concentration of total cholesterol (Ctotal), cholesterol associated with high-density lipoprotein (CHDL), and TG during a validation protocol of diluting samples and spiking them with exogenous cholesterol and glycerol. Values of Ctotal and TG agreed well with values obtained by other methods (ultracentrifugation followed by colorimetric assays); agreement was variable for values of cholesterol associated with specific lipoproteins. Similar to a study of captive polar bears, ultracentrifugation methods revealed greater TG in very low-density lipoproteins than in low-density lipoprotein, which is unusual and merits additional study.

  12. Influence of carbon and lipid sources on variation of mercury and other trace elements in polar bears (Ursus maritimus).

    Science.gov (United States)

    Routti, Heli; Letcher, Robert J; Born, Erik W; Branigan, Marsha; Dietz, Rune; Evans, Thomas J; McKinney, Melissa A; Peacock, Elizabeth; Sonne, Christian

    2012-12-01

    In the present study, the authors investigated the influence of carbon and lipid sources on regional differences in liver trace element (As, Cd, Cu, total Hg, Mn, Pb, Rb, Se, and Zn) concentrations measured in polar bears (Ursus maritimus) (n = 121) from 10 Alaskan, Canadian Arctic, and East Greenland subpopulations. Carbon and lipid sources were assessed using δ(13) C in muscle tissue and fatty acid (FA) profiles in subcutaneous adipose tissue as chemical tracers. A negative relationship between total Hg and δ(13) C suggested that polar bears feeding in areas with higher riverine inputs of terrestrial carbon accumulate more Hg than bears feeding in areas with lower freshwater input. Mercury concentrations were also positively related to the FA 20:1n-9, which is biosynthesized in large amounts in Calanus copepods. This result raises the hypothesis that Calanus glacialis are an important link in the uptake of Hg in the marine food web and ultimately in polar bears. Unadjusted total Hg, Se, and As concentrations showed greater geographical variation among polar bear subpopulations compared with concentrations adjusted for carbon and lipid sources. The Hg concentrations adjusted for carbon and lipid sources in Bering-Chukchi Sea polar bear liver tissue remained the lowest among subpopulations. Based on these findings, the authors suggest that carbon and lipid sources for polar bears should be taken into account when one is assessing spatial and temporal trends of long-range transported trace elements. Copyright © 2012 SETAC.

  13. Improving sperm banking efficiency in endangered species through the use of a sperm selection method in brown bear (Ursus arctos) thawed sperm.

    Science.gov (United States)

    Anel-Lopez, L; Ortega-Ferrusola, C; Álvarez, M; Borragán, S; Chamorro, C; Peña, F J; Morrell, J; Anel, L; de Paz, P

    2017-06-26

    Sperm selection methods such as Single Layer Centrifugation (SLC) have been demonstrated to be a useful tool to improve the quality of sperm samples and therefore to increase the efficiency of other artificial reproductive techniques in several species. This procedure could help to improve the quality of genetic resource banks, which is essential for endangered species. In contrast, these sperm selection methods are optimized and focused on farm animals, where the recovery task is not as important as in endangered species because of their higher sperm availability. The aim of this study was to evaluate two centrifugation methods (300 x g/20 min and 600 x g/10 min) and three concentrations of SLC media (Androcoll-Bear -80, 65 and 50%) to optimise the procedure in order to recover as many sperm with the highest quality as possible. Sperm morphology could be important in the hydrodynamic relationship between the cell and centrifugation medium and thus the effect of sperm head morphometry on sperm yield and its hydrodynamic relationship were studied. The samples selected with Androcoll-Bear 65% showed a very good yield (53.1 ± 2.9) although the yield from Androcoll-Bear 80% was lower (19.3 ± 3.3). The latter showed higher values of motility than the control immediately after post-thawing selection. However, both concentrations of colloid (65 and 80%) showed higher values of viable sperm and viable sperm with intact acrosome than the control. After an incubation of 2 h at 37 °C, the samples from Androcoll-Bear 80% had higher kinematics and proportion of viable sperm with intact acrosome. In the morphometric analysis, the sperm selected by the Androcoll-Bear 80% showed a head with a bigger area which was more elongated than the sperm from other treatments. We conclude that sperm selection with Androcoll-Bear at either 65% or 80% is a suitable technique that allows a sperm population with better quality than the initial sample to be obtained. We recommend the

  14. Demography and genetic structure of a recovering grizzly bear population

    Science.gov (United States)

    Kendall, K.C.; Stetz, J.B.; Boulanger, J.; Macleod, A.C.; Paetkau, David; White, Gary C.

    2009-01-01

    Grizzly bears (brown bears; Ursus arctos) are imperiled in the southern extent of their range worldwide. The threatened population in northwestern Montana, USA, has been managed for recovery since 1975; yet, no rigorous data were available to monitor program success. We used data from a large noninvasive genetic sampling effort conducted in 2004 and 33 years of physical captures to assess abundance, distribution, and genetic health of this population. We combined data from our 3 sampling methods (hair trap, bear rub, and physical capture) to construct individual bear encounter histories for use in Huggins-Pledger closed mark-recapture models. Our population estimate, N?? = 765 (95% CI = 715-831) was more than double the existing estimate derived from sightings of females with young. Based on our results, the estimated known, human-caused mortality rate in 2004 was 4.6% (95% CI = 4.2-4.9%), slightly above the 4% considered sustainable; however, the high proportion of female mortalities raises concern. We used location data from telemetry, confirmed sightings, and genetic sampling to estimate occupied habitat. We found that grizzly bears occupied 33,480 km2 in the Northern Continental Divide Ecosystem (NCDE) during 1994-2007, including 10,340 km beyond the Recovery Zone. We used factorial correspondence analysis to identify potential barriers to gene flow within this population. Our results suggested that genetic interchange recently increased in areas with low gene flow in the past; however, we also detected evidence of incipient fragmentation across the major transportation corridor in this ecosystem. Our results suggest that the NCDE population is faring better than previously thought, and they highlight the need for a more rigorous monitoring program.

  15. The utility of harvest recoveries of marked individuals to assess polar bear (Ursus maritimus) survival

    Science.gov (United States)

    Peacock, Elizabeth; Laake, Jeff; Laidre, Kristin L.; Born, Erik W.; Atkinson, Stephen N.

    2012-01-01

    Management of polar bear (Ursus maritimus) populations requires the periodic assessment of life history metrics such as survival rate. This information is frequently obtained during short-term capture and marking efforts (e.g., over the course of three years) that result in hundreds of marked bears remaining in the population after active marking is finished. Using 10 additional years of harvest recovery subsequent to a period of active marking, we provide updated estimates of annual survival for polar bears in the Baffin Bay population of Greenland and Canada. Our analysis suggests a decline in survival of polar bears since the period of active marking that ended in 1997; some of the decline in survival can likely be attributed to a decline in springtime ice concentration over the continental shelf of Baffin Island. The variance around the survival estimates is comparatively high because of the declining number of marks available; therefore, results must be interpreted with caution. The variance of the estimates of survival increased most substantially in the sixth year post-marking. When survival estimates calculated with recovery-only and recapture-recovery data sets from the period of active marking were compared, survival rates were indistinguishable. However, for the period when fewer marks were available, survival estimates were lower using the recovery-only data set, which indicates that part of the decline we detected for 2003 – 09 may be due to using only harvest recovery data. Nevertheless, the decline in the estimates of survival is consistent with population projections derived from harvest numbers and earlier vital rates, as well as with an observed decline in the extent of sea ice habitat.

  16. Extirpations of grizzly bears in the contiguous United States of America, 1850-2000

    Science.gov (United States)

    Mattson, David J.; Merrill, Troy

    2002-01-01

    We investigated factors associated with the distribution of grizzly bears (Ursus arctos horribilis) in 1850 and their extirpation during 1850–1920 and 1920–1970 in the contiguous United States. We used autologistic regression to describe relations between grizzly bear range in 1850, 1920, and 1970 and potential explanatory factors specified for a comprehensive grid of cells, each 900 km2 in size. We also related persistence, 1920–1970, to range size and shape. Grizzly bear range in 1850 was positively related to occurrence in mountainous ecoregions and the ranges of oaks (Quercus spp.), piñon pines (Pinus edulis and P. monophylla), whitebark pine (P. albicaulis), and bison (Bos bison) and negatively related to occurrence in prairie and hot desert ecoregions. Relations with salmon (Oncorynchus spp.) range and human factors were complex. Persistence of grizzly bear range, 1850–1970, was positively related to occurrence in the Rocky Mountains, whitebark pine range, and local size of grizzly bear range at the beginning of each period, and negatively related to number of humans and the ranges of bison, salmon, and piñon pines. We speculate that foods affected persistence primarily by influencing the frequency of contact between humans and bears. With respect to current conservation, grizzly bears survived from 1920 to 1970 most often where ranges at the beginning of this period were either larger than 20,000 km2 or larger than 7,000 km2 but with a ratio of perimeter to area of grizzly bear range would be as extensive as it is now. Although grizzly bear range in the Yellowstone region is currently the most robust of any to potential future increases in human lethality, bears in this region are threatened by the loss of whitebark pine.

  17. Predators or prey? Spatio-temporal discrimination of human-derived risk by brown bears.

    Science.gov (United States)

    Ordiz, Andrés; Støen, Ole-Gunnar; Delibes, Miguel; Swenson, Jon E

    2011-05-01

    Prey usually adjust anti-predator behavior to subtle variations in perceived risk. However, it is not clear whether adult large carnivores that are virtually free of natural predation adjust their behavior to subtle variations in human-derived risk, even when living in human-dominated landscapes. As a model, we studied resting-site selection by a large carnivore, the brown bear (Ursus arctos), under different spatial and temporal levels of human activity. We quantified horizontal and canopy cover at 440 bear beds and 439 random sites at different distances from human settlements, seasons, and times of the day. We hypothesized that beds would be more concealed than random sites and that beds would be more concealed in relation to human-derived risk. Although human densities in Scandinavia are the lowest within bear ranges in Western Europe, we found an effect of human activity; bears chose beds with higher horizontal and canopy cover during the day (0700-1900 hours), especially when resting closer to human settlements, than at night (2200-0600 hours). In summer/fall (the berry season), with more intensive and dispersed human activity, including hunting, bears rested further from human settlements during the day than in spring (pre-berry season). Additionally, day beds in the summer/fall were the most concealed. Large carnivores often avoid humans at a landscape scale, but total avoidance in human-dominated areas is not possible. Apparently, bears adjust their behavior to avoid human encounters, which resembles the way prey avoid their predators. Bears responded to fine-scale variations in human-derived risk, both on a seasonal and a daily basis.

  18. Decreased bone turnover with balanced resorption and formation prevent cortical bone loss during disuse (hibernation) in grizzly bears (Ursus arctos horribilis)

    OpenAIRE

    McGee, Meghan E.; Maki, Aaron J.; Johnson, Steven E.; Lynne Nelson, O.; Robbins, Charles T.; Donahue, Seth W.

    2007-01-01

    Disuse uncouples bone formation from resorption, leading to increased porosity, decreased bone geometrical properties, and decreased bone mineral content which compromises bone mechanical properties and increases fracture risk. However, black bear bone properties are not adversely affected by aging despite annual periods of disuse (i.e., hibernation), which suggests that bears either prevent bone loss during disuse or lose bone and subsequently recover it at a faster rate than other animals. ...

  19. Elevated expression of protein biosynthesis genes in liver and muscle of hibernating black bears (Ursus americanus).

    Science.gov (United States)

    Fedorov, Vadim B; Goropashnaya, Anna V; Tøien, Øivind; Stewart, Nathan C; Gracey, Andrew Y; Chang, Celia; Qin, Shizhen; Pertea, Geo; Quackenbush, John; Showe, Louise C; Showe, Michael K; Boyer, Bert B; Barnes, Brian M

    2009-04-10

    We conducted a large-scale gene expression screen using the 3,200 cDNA probe microarray developed specifically for Ursus americanus to detect expression differences in liver and skeletal muscle that occur during winter hibernation compared with animals sampled during summer. The expression of 12 genes, including RNA binding protein motif 3 (Rbm3), that are mostly involved in protein biosynthesis, was induced during hibernation in both liver and muscle. The Gene Ontology and Gene Set Enrichment analysis consistently showed a highly significant enrichment of the protein biosynthesis category by overexpressed genes in both liver and skeletal muscle during hibernation. Coordinated induction in transcriptional level of genes involved in protein biosynthesis is a distinctive feature of the transcriptome in hibernating black bears. This finding implies induction of translation and suggests an adaptive mechanism that contributes to a unique ability to reduce muscle atrophy over prolonged periods of immobility during hibernation. Comparing expression profiles in bears to small mammalian hibernators shows a general trend during hibernation of transcriptional changes that include induction of genes involved in lipid metabolism and carbohydrate synthesis as well as depression of genes involved in the urea cycle and detoxification function in liver.

  20. Differences in mercury bioaccumulation between polar bears (Ursus maritimus) from the Canadian high- and sub-Arctic.

    Science.gov (United States)

    St Louis, Vincent L; Derocher, Andrew E; Stirling, Ian; Graydon, Jennifer A; Lee, Caroline; Jocksch, Erin; Richardson, Evan; Ghorpade, Sarah; Kwan, Alvin K; Kirk, Jane L; Lehnherr, Igor; Swanson, Heidi K

    2011-07-15

    Polar bears (Ursus maritimus) are being impacted by climate change and increased exposure to pollutants throughout their northern circumpolar range. In this study, we quantified concentrations of total mercury (THg) in the hair of polar bears from Canadian high- (southern Beaufort Sea, SBS) and sub- (western Hudson Bay, WHB) Arctic populations. Concentrations of THg in polar bears from the SBS population (14.8 ± 6.6 μg g(-1)) were significantly higher than in polar bears from WHB (4.1 ± 1.0 μg g(-1)). On the basis of δ(15)N signatures in hair, in conjunction with published δ(15)N signatures in particulate organic matter and sediments, we estimated that the pelagic and benthic food webs in the SBS are ∼ 4.7 and ∼ 4.0 trophic levels long, whereas in WHB they are only ∼ 3.6 and ∼ 3.3 trophic levels long. Furthermore, the more depleted δ(13)C ratios in hair from SBS polar bears relative to those from WHB suggests that SBS polar bears feed on food webs that are relatively more pelagic (and longer), whereas polar bears from WHB feed on those that are relatively more benthic (and shorter). Food web length and structure accounted for ∼ 67% of the variation we found in THg concentrations among all polar bears across both populations. The regional difference in polar bear hair THg concentrations was also likely due to regional differences in water-column concentrations of methyl Hg (the toxic form of Hg that biomagnifies through food webs) available for bioaccumulation at the base of the food webs. For example, concentrations of methylated Hg at mid-depths in the marine water column of the northern Canadian Arctic Archipelago were 79.8 ± 37.3 pg L(-1), whereas, in HB, they averaged only 38.3 ± 16.6 pg L(-1). We conclude that a longer food web and higher pelagic concentrations of methylated Hg available to initiate bioaccumulation in the BS resulted in higher concentrations of THg in polar bears from the SBS region compared to those inhabiting the western

  1. Reproductive performance in East Greenland polar bears (Ursus maritimus) may be affected by organohalogen contaminants as shown by physiologically-based pharmacokinetic (PBPK) modelling

    DEFF Research Database (Denmark)

    Sonne, Christian; Gustavson, Kim; Rigét, Frank F.

    2009-01-01

    Polar bears (Ursus maritimus) feed mainly on ringed seal (Phoca hispida) and consume large quantities of blubber and consequently have one of the highest tissue concentrations of organohalogen contaminants (OHCs) worldwide. In East Greenland, studies of OHC time trends and organ system health...... effects, including reproductive, were conducted during 1990–2006. However, it has been difficult to determine the nature of the effects induced by OHC exposures on wild caught polar bears using body burden data and associated changes in reproductive organs and systems. We therefore conducted a risk......, oxychlordane, HCHs, HCB, PBDEs and PFOS in East Greenland polar bears based on known OHC pharmacokinetics and dynamics in laboratory rats (Rattus rattus). The results showed that subcutaneous adipose tissue concentrations of dieldrin (range: 79–1271 ng g−1 lw) and PCBs (range: 4128–53 923 ng g−1 lw) reported...

  2. Investigating the mechanism for maintaining eucalcemia despite immobility and anuria in the hibernating American black bear (Ursus americanus).

    Science.gov (United States)

    Seger, Rita L; Cross, Randal A; Rosen, Clifford J; Causey, Robert C; Gundberg, Caren M; Carpenter, Thomas O; Chen, Tai C; Halteman, William A; Holick, Michael F; Jakubas, Walter J; Keisler, Duane H; Seger, Richard M; Servello, Frederick A

    2011-12-01

    Ursine hibernation uniquely combines prolonged skeletal unloading, anuria, pregnancy, lactation, protein recycling, and lipolysis. This study presents a radiographic and biochemical picture of bone metabolism in free-ranging, female American black bears (Ursus americanus) that were active (spring bears and autumn bears) or hibernating (hibernating bears). Hibernating bears included lactating and non-lactating individuals. We measured serum calcium, albumin, inorganic phosphate, creatinine, bone specific alkaline phosphatase (BSALP), CTX, parathyroid hormone, insulin-like growth factor-I (IGF-l), leptin, 25-hydroxyvitamin D [25(OH)D], 1,25-dihydroxyvitamin D [1,25(OH)(2)D] and sclerostin from 35 to 50 tranquilized hibernating bears and 14 to 35 tranquilized spring bears. We compared metacarpal cortical indices (MCI), measured by digital X-ray radiogrammetry, from 60 hunter-killed autumn bears and 79 tranquilized, hibernating bears. MCI was greater in autumn than winter in younger bears, but showed no seasonal difference in older bears. During hibernation eucalcemia was maintained, BSALP was suppressed, and CTX was in the range expected for anuria. During hibernation 1,25(OH)(2)D was produced despite anuria. 1,25(OH)(2)D and IGF-I were less in hibernating than spring bears. In a quarter of hibernating bears, sclerostin was elevated. Leptin was greater in hibernating than spring bears. In hibernating bears, leptin correlated positively with BSALP in non-lactating bears and with CTX in lactating bears. Taken together the biochemical and radiographic findings indicate that during hibernation, bone turnover was persistent, balanced, and suppressed; bone resorption was lower than expected for an unloaded skeleton; and there was no unloading-induced bone loss. The skeleton appears to perceive that it was loaded when it was actually unloaded during hibernation. However, at the level of sclerostin, the skeleton recognized that it was unloaded. During hibernation leptin

  3. Grizzly Bear Noninvasive Genetic Tagging Surveys: Estimating the Magnitude of Missed Detections.

    Directory of Open Access Journals (Sweden)

    Jason T Fisher

    Full Text Available Sound wildlife conservation decisions require sound information, and scientists increasingly rely on remotely collected data over large spatial scales, such as noninvasive genetic tagging (NGT. Grizzly bears (Ursus arctos, for example, are difficult to study at population scales except with noninvasive data, and NGT via hair trapping informs management over much of grizzly bears' range. Considerable statistical effort has gone into estimating sources of heterogeneity, but detection error-arising when a visiting bear fails to leave a hair sample-has not been independently estimated. We used camera traps to survey grizzly bear occurrence at fixed hair traps and multi-method hierarchical occupancy models to estimate the probability that a visiting bear actually leaves a hair sample with viable DNA. We surveyed grizzly bears via hair trapping and camera trapping for 8 monthly surveys at 50 (2012 and 76 (2013 sites in the Rocky Mountains of Alberta, Canada. We used multi-method occupancy models to estimate site occupancy, probability of detection, and conditional occupancy at a hair trap. We tested the prediction that detection error in NGT studies could be induced by temporal variability within season, leading to underestimation of occupancy. NGT via hair trapping consistently underestimated grizzly bear occupancy at a site when compared to camera trapping. At best occupancy was underestimated by 50%; at worst, by 95%. Probability of false absence was reduced through successive surveys, but this mainly accounts for error imparted by movement among repeated surveys, not necessarily missed detections by extant bears. The implications of missed detections and biased occupancy estimates for density estimation-which form the crux of management plans-require consideration. We suggest hair-trap NGT studies should estimate and correct detection error using independent survey methods such as cameras, to ensure the reliability of the data upon which species

  4. Grizzly Bear Noninvasive Genetic Tagging Surveys: Estimating the Magnitude of Missed Detections.

    Science.gov (United States)

    Fisher, Jason T; Heim, Nicole; Code, Sandra; Paczkowski, John

    2016-01-01

    Sound wildlife conservation decisions require sound information, and scientists increasingly rely on remotely collected data over large spatial scales, such as noninvasive genetic tagging (NGT). Grizzly bears (Ursus arctos), for example, are difficult to study at population scales except with noninvasive data, and NGT via hair trapping informs management over much of grizzly bears' range. Considerable statistical effort has gone into estimating sources of heterogeneity, but detection error-arising when a visiting bear fails to leave a hair sample-has not been independently estimated. We used camera traps to survey grizzly bear occurrence at fixed hair traps and multi-method hierarchical occupancy models to estimate the probability that a visiting bear actually leaves a hair sample with viable DNA. We surveyed grizzly bears via hair trapping and camera trapping for 8 monthly surveys at 50 (2012) and 76 (2013) sites in the Rocky Mountains of Alberta, Canada. We used multi-method occupancy models to estimate site occupancy, probability of detection, and conditional occupancy at a hair trap. We tested the prediction that detection error in NGT studies could be induced by temporal variability within season, leading to underestimation of occupancy. NGT via hair trapping consistently underestimated grizzly bear occupancy at a site when compared to camera trapping. At best occupancy was underestimated by 50%; at worst, by 95%. Probability of false absence was reduced through successive surveys, but this mainly accounts for error imparted by movement among repeated surveys, not necessarily missed detections by extant bears. The implications of missed detections and biased occupancy estimates for density estimation-which form the crux of management plans-require consideration. We suggest hair-trap NGT studies should estimate and correct detection error using independent survey methods such as cameras, to ensure the reliability of the data upon which species management and

  5. Seasonal habitat use and selection by grizzly bears in Northern British Columbia

    Science.gov (United States)

    Milakovic, B.; Parker, K.L.; Gustine, D.D.; Lay, R.J.; Walker, A.B.D.; Gillingham, M.P.

    2012-01-01

    We defined patterns of habitat use and selection by female grizzly bears (Ursus arctos) in the Besa-Prophet watershed of northern British Columbia. We fitted 13 adult females with Geographic Positioning System (GPS) radio-collars and monitored them between 2001 and 2004. We examined patterns of habitat selection by grizzly bears relative to topographical attributes and 3 potential surrogates of food availability: land-cover class, vegetation biomass or quality (as measured by the Normalized Difference Vegetation Index), and selection value for prey species themselves (moose [Alces alces], elk [Cervus elaphus], woodland caribou [Rangifer tarandus], Stone's sheep [Ovis dalli stonei]). Although vegetation biomass and quality, and selection values for prey were important in seasonal selection by some individual bears, land-cover class, elevation, aspect, and vegetation diversity most influenced patterns of habitat selection across grizzly bears, which rely on availability of plant foods and encounters with ungulate prey. Grizzly bears as a group avoided conifer stands and areas of low vegetation diversity, and selected for burned land-cover classes and high vegetation diversity across seasons. They also selected mid elevations from what was available within seasonal ranges. Quantifying relative use of different attributes helped place selection patterns within the context of the landscape. Grizzly bears used higher elevations (1,595??31 m SE) in spring and lower elevations (1,436??27 m) in fall; the range of average elevations used among individuals was highest (500 m) during the summer. During all seasons, grizzly bears most frequented aspects with high solar gain. Use was distributed across 10 land-cover classes and depended on season. Management and conservation actions must maintain a diverse habitat matrix distributed across a large elevational gradient to ensure persistence of grizzly bears as levels of human access increase in the northern Rocky Mountains

  6. Ticks and tick-borne pathogens and putative symbionts of black bears (Ursus americanus floridanus) from Georgia and Florida.

    Science.gov (United States)

    Yabsley, Michael J; Nims, Todd N; Savage, Mason Y; Durden, Lance A

    2009-10-01

    Ticks were collected from 38 black bears (Ursus americanus floridanus) from northwestern Florida (n = 18) from 2003 to 2005 and southern Georgia (n = 20) in 2006. Five species (Amblyomma americanum, A. maculatum, Dermacentor variabilis, Ixodes scapularis, and I. affinis) were collected from Florida bears, and 4 species (A. americanum, A. maculatum, D. variabilis, I. scapularis) were collected from bears in Georgia. Ixodes scapularis was the most frequently collected tick, followed by D. variabilis, A. americanum, A. maculatum, and I. affinis. The collection of I. affinis from a Florida bear represents a new host record. A subset of ticks was screened for pathogens and putative symbionts by polymerase chain reaction (PCR). The zoonotic tick-borne pathogens Ehrlichia chaffeensis and Rickettsia parkeri were detected in 1 of 23 (4.3%) A. americanum and 1 of 12 (8.3%) A. maculatum, respectively. The putative zoonotic pathogen "Rickettsia amblyommii" was detected in 4 (17.4%) A. americanum and 1 (8.3%) A. maculatum. Other putative symbiotic rickettsiae detected included R. bellii and R. montanensis in D. variabilis, a Rickettsia cooleyi-like sp. and Rickettsia sp. Is-1 in I. scapularis, and Rickettsia TR39-like sp. in I. scapularis and A. americanum. All ticks were PCR-negative for Anaplasma phagocytophilum, Panola Mountain Ehrlichia sp., E. ewingii, Francisella tularensis, and Borrelia spp.

  7. Life in the fat lane: seasonal regulation of insulin sensitivity, food intake, and adipose biology in brown bears.

    Science.gov (United States)

    Rigano, K S; Gehring, J L; Evans Hutzenbiler, B D; Chen, A V; Nelson, O L; Vella, C A; Robbins, C T; Jansen, H T

    2017-05-01

    Grizzly bears (Ursus arctos horribilis) have evolved remarkable metabolic adaptations including enormous fat accumulation during the active season followed by fasting during hibernation. However, these fluctuations in body mass do not cause the same harmful effects associated with obesity in humans. To better understand these seasonal transitions, we performed insulin and glucose tolerance tests in captive grizzly bears, characterized the annual profiles of circulating adipokines, and tested the anorectic effects of centrally administered leptin at different times of the year. We also used bear gluteal adipocyte cultures to test insulin and beta-adrenergic sensitivity in vitro. Bears were insulin resistant during hibernation but were sensitive during the spring and fall active periods. Hibernating bears remained euglycemic, possibly due to hyperinsulinemia and hyperglucagonemia. Adipokine concentrations were relatively low throughout the active season but peaked in mid-October prior to hibernation when fat content was greatest. Serum glycerol was highest during hibernation, indicating ongoing lipolysis. Centrally administered leptin reduced food intake in October, but not in August, revealing seasonal variation in the brain's sensitivity to its anorectic effects. This was supported by strong phosphorylated signal transducer and activator of transcription 3 labeling within the hypothalamus of hibernating bears; labeling virtually disappeared in active bears. Adipocytes collected during hibernation were insulin resistant when cultured with hibernation serum but became sensitive when cultured with active season serum. Heat treatment of active serum blocked much of this action. Clarifying the cellular mechanisms responsible for the physiology of hibernating bears may inform new treatments for metabolic disorders.

  8. Assays for Detection and Identification of the Causative Agent of Mange in Free-Ranging Black Bears ( Ursus americanus).

    Science.gov (United States)

    Peltier, Sarah K; Brown, Justin D; Ternent, Mark A; Fenton, Heather; Niedringhaus, Kevin D; Yabsley, Michael J

    2018-03-02

    Three mite species ( Demodex ursi, Ursicoptes americanus, and Sarcoptes scabiei) have been associated with mange in black bears ( Ursus americanus). Since the early 1990s, the number and geographic distribution of mange cases in black bears in Pennsylvania has increased; however, the causative mites have yet to be completely defined. We evaluated several diagnostic approaches for detection and identification of mites in 72 black bears with severe lesions consistent with mange. Sarcoptes scabiei was morphologically identified in skin scrapes from 66 of the bears; no mites were identified in the remaining six. Histopathologic lesions consistent with sarcoptic mange were observed in 39 of 40 bear skin samples examined, and intralesional mites were observed in samples from 38 of these bears. Samples were collected from a subset of the 72 bears for PCR testing targeting both the internal transcribed spacer (ITS)-2 region and cytochrome c oxidase I ( cox1) gene including 69 skin scrapes ( ITS-2 only), 56 skin biopsies ( ITS-2 and cox1), and 36 fecal samples ( ITS-2 and cox1). Skin scrapes were a more sensitive sample for PCR detection than either skin biopsies or fecal samples, and the ITS-2 primers proved more sensitive than cox1. Using a commercial indirect enzyme-linked immunosorbent assay, antibodies to S. scabiei were detected in 45/49 (92%) black bears with confirmed mange and 0/62 (0%) cubs with no gross lesions suggestive of mange and which were born to seronegative sows. Sarcoptes scabiei was the predominant mite associated with mange in black bears in Pennsylvania. Diagnostically, cytologic examination of skin scrapes was the most effective approach for diagnosing active mite infestations in black bears. The evaluated serologic assay accurately detected antibodies to S. scabiei in most bears with confirmed S. scabiei infestations. Additional research is needed to determine the usefulness of this approach for larger scale surveys and for asymptomatic bears.

  9. Use of isotopic sulfur to determine whitebark pine consumption by Yellowstone bears: a reassessment

    Science.gov (United States)

    Schwartz, Charles C.; Teisberg, Justin E.; Fortin, Jennifer K.; Haroldson, Mark A.; Servheen, Christopher; Robbins, Charles T.; van Manen, Frank T.

    2014-01-01

    Use of naturally occurring stable isotopes to estimate assimilated diet of bears is one of the single greatest breakthroughs in nutritional ecology during the past 20 years. Previous research in the Greater Yellowstone Ecosystem (GYE), USA, established a positive relationship between the stable isotope of sulfur (δ34S) and consumption of whitebark pine (Pinus albicaulis) seeds. That work combined a limited sample of hair, blood clots, and serum. Here we use a much larger sample to reassess those findings. We contrasted δ34S values in spring hair and serum with abundance of seeds of whitebark pine in samples collected from grizzly (Ursus arctos) and American black bears (U. americanus) in the GYE during 2000–2010. Although we found a positive relationship between δ34S values in spring hair and pine seed abundance for grizzly bears, the coefficients of determination were small (R2 ≤ 0.097); we failed to find a similar relationship with black bears. Values of δ34S in spring hair were larger in black bears and δ34S values in serum of grizzly bears were lowest in September and October, a time when we expect δ34S to peak if whitebark pine seeds were the sole source of high δ34S. The relationship between δ34S in bear tissue and the consumption of whitebark pine seeds, as originally reported, may not be as clean a method as proposed. Data we present here suggest other foods have high values of δ34S, and there is spatial heterogeneity affecting the δ34S values in whitebark pine, which must be addressed.

  10. Linking landscape characteristics to local grizzly bear abundance using multiple detection methods in a hierarchical model

    Science.gov (United States)

    Graves, T.A.; Kendall, Katherine C.; Royle, J. Andrew; Stetz, J.B.; Macleod, A.C.

    2011-01-01

    Few studies link habitat to grizzly bear Ursus arctos abundance and these have not accounted for the variation in detection or spatial autocorrelation. We collected and genotyped bear hair in and around Glacier National Park in northwestern Montana during the summer of 2000. We developed a hierarchical Markov chain Monte Carlo model that extends the existing occupancy and count models by accounting for (1) spatially explicit variables that we hypothesized might influence abundance; (2) separate sub-models of detection probability for two distinct sampling methods (hair traps and rub trees) targeting different segments of the population; (3) covariates to explain variation in each sub-model of detection; (4) a conditional autoregressive term to account for spatial autocorrelation; (5) weights to identify most important variables. Road density and per cent mesic habitat best explained variation in female grizzly bear abundance; spatial autocorrelation was not supported. More female bears were predicted in places with lower road density and with more mesic habitat. Detection rates of females increased with rub tree sampling effort. Road density best explained variation in male grizzly bear abundance and spatial autocorrelation was supported. More male bears were predicted in areas of low road density. Detection rates of males increased with rub tree and hair trap sampling effort and decreased over the sampling period. We provide a new method to (1) incorporate multiple detection methods into hierarchical models of abundance; (2) determine whether spatial autocorrelation should be included in final models. Our results suggest that the influence of landscape variables is consistent between habitat selection and abundance in this system.

  11. Effects of habitat features on size-biased predation on salmon by bears.

    Science.gov (United States)

    Andersson, Luke C; Reynolds, John D

    2017-05-01

    Predators can drive trait divergence among populations of prey by imposing differential selection on prey traits. Habitat characteristics can mediate predator selectivity by providing refuge for prey. We quantified the effects of stream characteristics on biases in the sizes of spawning salmon caught by bears (Ursus arctos and U. americanus) on the central coast of British Columbia, Canada by measuring size-biased predation on spawning chum (Oncorhynchus keta) and pink (O. gorbuscha) salmon in 12 streams with varying habitat characteristics. We tested the hypotheses that bears would catch larger than average salmon (size-biased predation) and that this bias toward larger fish would be higher in streams that provide less protection to spawning salmon from predation (e.g., less pools, wood, undercut banks). We then we tested for how such size biases in turn translate into differences among populations in the sizes of the fish. Bears caught larger-than-average salmon as the spawning season progressed and as predicted, this was most pronounced in streams with fewer refugia for the fish (i.e., wood and undercut banks). Salmon were marginally smaller in streams with more pronounced size-biased predation but this predictor was less reliable than physical characteristics of streams, with larger fish in wider, deeper streams. These results support the hypothesis that selective forces imposed by predators can be mediated by habitat characteristics, with potential consequences for physical traits of prey.

  12. Contrasting past and current numbers of bears visiting Yellowstone cutthroat trout streams

    Science.gov (United States)

    Haroldson, Mark A.; Schwartz, Charles C.; Teisberg, Justin E.; Gunther, Kerry A.; Fortin, Jennifer K.; Robbins, Charles T.

    2014-01-01

    Spawning cutthroat trout (Oncorhynchus clarkii bouvieri) were historically abundant within tributary streams of Yellowstone Lake within Yellowstone National Park and were a highly digestible source of energy and protein for Yellowstone’s grizzly bears (Ursus arctos) and black bears (U. americanus). The cutthroat trout population has subsequently declined since the introduction of non-native lake trout (Salvelinus namaycush), and in response to effects of drought and whirling disease (Myxobolus cerebralis). The trout population, duration of spawning runs, and indices of bear use of spawning streams had declined in some regions of the lake by 1997–2000. We initiated a 3-year study in 2007 to assess whether numbers of spawning fish, black bears, and grizzly bears within and alongside stream corridors had changed since 1997– 2000. We estimated numbers of grizzly bears and black bears by first compiling encounter histories of individual bears visiting 48 hair-snag sites along 35 historically fished streams.We analyzed DNA encounter histories with Pradel-recruitment and Jolly-Seber (POPAN) capture-mark-recapture models. When compared to 1997–2000, the current number of spawning cutthroat trout per stream and the number of streams with cutthroat trout has decreased. We estimated that 48 (95% CI¼42–56) male and 23 (95% CI¼21–27) female grizzly bears visited the historically fished tributary streams during our study. In any 1- year, 46 to 59 independent grizzly bears (8–10% of estimated Greater Yellowstone Ecosystem population) visited these streams. When compared with estimates from the 1997 to 2000 study and adjusted for equal effort, the number of grizzly bears using the stream corridors decreased by 63%. Additionally, the number of black bears decreased between 64% and 84%. We also document an increased proportion of bears of both species visiting front-country (i.e., near human development) streams. With the recovery of cutthroat trout, we suggest bears

  13. Extent, causes and timing of moose calves mortality in western interior Alaska

    Science.gov (United States)

    Osbourne, Timothy O.; Paragi, Thomas F.; Bodkin, James L.; Loranger, Andre J.; Johnson, W.N.

    1991-01-01

    We examined the causes and timing of moose (Alces alces) calf mortality during 1988­ 90 in 2 locations in western interior Alaska. Annual survival rates of all calves in 1988 (0.34, n = 42) and 1989 (0.29, n =47) on the Nowitna National Wildlife Refuge (NWR) and in 1990 (0.25, n = 62) on the Koyukuk NWR were not significantly different. Survival rates of male and female calves were not significantly different during any year. Annual survival of single calves was significantly higher than that for twins in 1989 (0.56 vs. 0.20) and 1990 (0.37 vs. 0.21), but not in 1988. Black bears (Ursus americanus) killed 40% of all calves. Wolves (Canis lupus) killed 9% of the calves, unknown predators killed 8%, grizzly bears (Ursus arctos) killed 3%, and 5% died from other causes.

  14. Persistent organic pollutants and penile bone mineral density in East Greenland and Canadian polar bears (Ursus maritimus) during 1996-2015

    DEFF Research Database (Denmark)

    Daugaard-Petersen, Tobias; Langebaek, Rikke; Riget, Frank F.

    2018-01-01

    Persistent organic pollutants (POPs) are long-range transported to the Arctic via atmospheric and oceanic currents, where they biomagnify to high concentrations in the tissues of apex predators such as polar bears (Ursus maritimus). A major concern of POP exposure is their physiological effects o......) and Western Hudson (WH) Bay subpopulations (all p osteoporosis index for the EG subpopulation using WH bears as a reference group gave a T-score of -1.44 which indicate risk of osteopenia. Concentrations of ΣPCB74(polychlorinated biphenyls), ΣDDT3....... POPs. Other important factors such as nutritional status, body mass and body condition was not available for the statistical modelling. Since on-going environmental changes are known to affect these, future studies need to incorporate nutritional, endocrine and genetic parameters to further understand...

  15. Relationships between POPs, biometrics and circulating steroids in male polar bears (Ursus maritimus) from Svalbard.

    Science.gov (United States)

    Ciesielski, Tomasz M; Hansen, Ingunn Tjelta; Bytingsvik, Jenny; Hansen, Martin; Lie, Elisabeth; Aars, Jon; Jenssen, Bjørn M; Styrishave, Bjarne

    2017-11-01

    The aim of this study was to determine the effects of persistent organic pollutants (POPs) and biometric variables on circulating levels of steroid hormones (androgens, estrogens and progestagens) in male polar bears (Ursus maritimus) from Svalbard, Norway (n = 23). Levels of pregnenolone (PRE), progesterone (PRO), androstenedione (AN), dehydroepiandrosterone (DHEA), testosterone (TS), dihydrotestosterone (DHT), estrone (E1), 17α-estradiol (αE2) and 17β-estradiol (βE2) were quantified in polar bear serum by gas chromatography tandem mass spectrometry (GC-MS/MS), while POPs were measured in plasma. Subsequently, associations between hormone concentrations (9 steroids), POPs (21 polychlorinated biphenyls (PCBs), 8 OH-PCBs, 8 organochlorine pesticides (OCPs) and OCP metabolites, and 2 polybrominated diphenyl ethers (PBDEs)) and biological variables (age, head length, body mass, girth, body condition index), capture date, location (latitude and longitude), lipid content and cholesterol levels were examined using principal component analysis (PCA) and orthogonal projections to latent structures (OPLS) modelling. Average concentrations of androgens, estrogens and progestagens were in the range of 0.57-83.7 (0.57-12.4 for subadults, 1.02-83.7 for adults), 0.09-2.69 and 0.57-2.44 nmol/L, respectively. The steroid profiles suggest that sex steroids were mainly synthesized through the Δ-4 pathway in male polar bears. The ratio between androgens and estrogens significantly depended on sexual maturity with androgen/estrogen ratios being approximately 60 times higher in adult males than in subadult males. PCA plots and OPLS models indicated that TS was positively related to biometrics, such as body condition index in male polar bears. A negative relationship was also observed between POPs and DHT. Consequently, POPs and body condition may potentially affect the endocrinological function of steroids, including development of reproductive tissues and sex organs and the

  16. Serum concentrations of vitamin D metabolites, vitamins A and E, and carotenoids in six canid and four ursid species at four zoos.

    Science.gov (United States)

    Crissey, S; Ange, K; Slifka, K; Bowen, P; Stacewicz-Sapuntzakis, M; Langman, C; Sadler, W; Ward, A

    2001-01-01

    Nutritional status for six captive canid species (n=34) and four captive ursid species (n=18) were analyzed. The species analyzed included: African wild dog (Lycaon pictus), arctic fox (Alopex lagopus), gray wolf (Canis lupus), maned wolf (Chrysocyon brachyurus), Mexican wolf (Canis lupus baleiyi), red wolf (Canis rufus), brown bear (Ursus arctos), polar bear (Ursus maritimus), spectacled bear (Tremarctos ornatus), and sun bear (Ursus malayanus). Diet information was collected for these animals from each participating zoo (Brookfield Zoo, Fort Worth Zoo, Lincoln Park Zoological Gardens, and North Carolina Zoological Park). The nutritional composition of the diet for each species at each institution met probable dietary requirements. Blood samples were collected from each animal and analyzed for vitamin D metabolites 25(OH)D and 1,25(OH)(2)D, vitamin A (retinol, retinyl stearate, retinyl palmitate), vitamin E (alpha-tocopherol and gamma-tocopherol) and selected carotenoids. Family differences were found for 25(OH)D, retinol, retinyl stearate, retinyl palmitate and gamma-tocopherol. Species differences were found for all detectable measurements. Carotenoids were not detected in any species. The large number of animals contributing to these data, provides a substantial base for comparing the nutritional status of healthy animals and the differences among them.

  17. Idiosyncratic responses of grizzly bear habitat to climate change based on projected food resource changes.

    Science.gov (United States)

    Roberts, David R; Nielsen, Scott E; Stenhouse, Gordon B

    2014-07-01

    Climate change vulnerability assessments for species of conservation concern often use species distribution and ecological niche modeling to project changes in habitat. One of many assumptions of these approaches is that food web dependencies are consistent in time and environmental space. Species at higher trophic levels that rely on the availability of species at lower trophic levels as food may be sensitive to extinction cascades initiated by changes in the habitat of key food resources. Here we assess climate change vulnerability for Ursus arctos (grizzly bears) in the southern Canadian Rocky Mountains using projected changes to 17 of the most commonly consumed plant food items. We used presence-absence information from 7088 field plots to estimate ecological niches and to project changes in future distributions of each species. Model projections indicated idiosyncratic responses among food items. Many food items persisted or even increased, although several species were found to be vulnerable based on declines or geographic shifts in suitable habitat. These included Hedysarum alpinum (alpine sweet vetch), a critical spring and autumn root-digging resource when little else is available. Potential habitat loss was also identified for three fruiting species of lower importance to bears: Empetrum nigrum (crowberry), Vaccinium scoparium (grouseberry), and Fragaria virginiana (strawberry). A general trend towards uphill migration of bear foods may result in higher vulnerability to bear populations at low elevations, which are also those that are most likely to have human-bear conflict problems. Regardless, a wide diet breadth of grizzly bears, as well as wide environmental niches of most food items, make climate change a much lower threat to grizzly bears than other bear species such as polar bears and panda bears. We cannot exclude, however, future alterations in human behavior and land use resulting from climate change that may reduce survival rates.

  18. Design of a 9K illumina BeadChip for polar bears (Ursus maritimus) from RAD and transcriptome sequencing.

    Science.gov (United States)

    Malenfant, René M; Coltman, David W; Davis, Corey S

    2015-05-01

    Single-nucleotide polymorphisms (SNPs) offer numerous advantages over anonymous markers such as microsatellites, including improved estimation of population parameters, finer-scale resolution of population structure and more precise genomic dissection of quantitative traits. However, many SNPs are needed to equal the resolution of a single microsatellite, and reliable large-scale genotyping of SNPs remains a challenge in nonmodel species. Here, we document the creation of a 9K Illumina Infinium BeadChip for polar bears (Ursus maritimus), which will be used to investigate: (i) the fine-scale population structure among Canadian polar bears and (ii) the genomic architecture of phenotypic traits in the Western Hudson Bay subpopulation. To this end, we used restriction-site associated DNA (RAD) sequencing from 38 bears across their circumpolar range, as well as blood/fat transcriptome sequencing of 10 individuals from Western Hudson Bay. Six-thousand RAD SNPs and 3000 transcriptomic SNPs were selected for the chip, based primarily on genomic spacing and gene function respectively. Of the 9000 SNPs ordered from Illumina, 8042 were successfully printed, and - after genotyping 1450 polar bears - 5441 of these SNPs were found to be well clustered and polymorphic. Using this array, we show rapid linkage disequilibrium decay among polar bears, we demonstrate that in a subsample of 78 individuals, our SNPs detect known genetic structure more clearly than 24 microsatellites genotyped for the same individuals and that these results are not driven by the SNP ascertainment scheme. Here, we present one of the first large-scale genotyping resources designed for a threatened species. © 2014 John Wiley & Sons Ltd.

  19. It's a bear market: evolutionary and ecological effects of predation on two wild sockeye salmon populations.

    Science.gov (United States)

    Lin, J E; Hard, J J; Naish, K A; Peterson, D; Hilborn, R; Hauser, L

    2016-05-01

    Predation can affect both phenotypic variation and population productivity in the wild, but quantifying evolutionary and demographic effects of predation in natural environments is challenging. The aim of this study was to estimate selection differentials and coefficients associated with brown bear (Ursus arctos) predation in wild sockeye salmon (Oncorhynchus nerka) populations spawning in pristine habitat that is often subject to intense predation pressure. Using reconstructed genetic pedigrees, individual reproductive success (RS) was estimated in two sockeye salmon populations for two consecutive brood years with very different predation intensities across brood years. Phenotypic data on individual adult body length, body depth, stream entry timing and reproductive lifespan were used to calculate selection coefficients based on RS, and genetic variance components were estimated using animal models. Bears consistently killed larger and more recently arrived adults, although selection differentials were small. In both populations, mean RS was higher in the brood year experiencing lower predation intensity. Selection coefficients were similar across brood years with different levels of predation, often indicating stabilizing selection on reproductive lifespan as well as directional selection for longer reproductive lifespan. Despite these selection pressures, genetic covariation of morphology, phenology and lifespan appears to have maintained variation in spawner body size and stream entry timing in both populations. Our results therefore suggest considerable demographic but limited evolutionary effects of bear predation in the two study populations.

  20. Relationship between uterine morphology and peripheral concentrations of sex steroid hormone in wild Japanese black bears (Ursus thibetanus japonicus).

    Science.gov (United States)

    Yamane, Masako; Yamamoto, Yoshio; Tsujimoto, Tsunenori; Osawa, Takeshi

    2009-07-01

    Developing a better understanding of the reproductive physiology and breeding condition peculiar to wild Japanese black bears (Ursus thibetanus japonicus) is crucial for estimation of their habitat distribution. The aim of this study was to clarify the changes in morphology of the genital organs, cellular proliferation in the endometrium and sex steroid hormone concentrations along with the reproductive cycle in Japanese black bears. Samples were collected from a total of 24 female Japanese black bears (1-15 presumptive years old) that were caught in the wild in Iwate prefecture during the period between August 1999 and September 2005. Twenty-two out of the 24 animals were hunted from May to October. The ovaries from the 24 animals and the uteri from 23 animals were observed macroscopically and histologically to examine the relationship between morphology of the genital organs and the month of the year the animal was caught. The staining pattern of proliferating cell nuclear antigen (PCNA) in the endometrium was characterised. Peripheral concentrations of oestradiol-17beta and progesterone were determined by radioimmunoassay. All the animals that had a corpus luteum (n=12) were captured from August to October. The thickness of the endometrium in the animals captured from August to October (n=16) was significantly greater than those in animals captured from May to July (n=5) (Pblack bears.

  1. Population genetic studies of the polar bear (Ursus maritimus): A summary of available data and interpretation of results

    Science.gov (United States)

    Scribner, Kim T.; Garner, G.W.; Amstrup, Steven C.; Cronin, M.A.; Dizon, Andrew E.; Chivers, Susan J.; Perrin, William F.

    1997-01-01

    A summary of existing population genetics literature is presented for polar bears (Ursus maritimus) and interpreted in the context of the species' life-history characteristics and regional heterogeneity in environmental regimes and movement patterns. Several nongenetic data sets including morphology, contaminant levels, geographic variation in reproductive characteristics, and the location and distribution of open-water foraging habitat suggest some degree of spatial structuring. Eleven populations are recognized by the IUCN Polar Bear Specialist Group. Few genetics studies exist for polar bears. Interpretation and generalizations of regional variation in intra- and interpopulation levels of genetic variability are confounded by the paucity of data from many regions and by the fact that no single informative genetic marker has been employed in multiple regions. Early allozyme studies revealed comparatively low levels of genetic variability and no compelling evidence of spatial structuring. Studies employing mitochondrial DNA (mtDNA) also found low levels of genetic variation, a lack of phylogenetic structure, and no significant evidence for spatial variation in haplotype frequency. In contrast, microsatellite variable number of tandem repeat (VNTR) loci have revealed significant heterogeneity in allele frequency among populations in the Canadian Arctic. These regions are characterized by archipelgic patterns of sea-ice movements. Further studies using highly polymorphic loci are needed in regions characterized by greater polar bear dependency on pelagic sea-ice movements and in regions for which no data currently exist (i.e., Laptev and Novaya Zemlya/Franz Josef).

  2. Sex, Diet, and the Social Environment: Factors Influencing Hair Cortisol Concentration in Free-Ranging Black Bears (Ursus americanus).

    Science.gov (United States)

    Lafferty, Diana J R; Laudenslager, Mark L; Mowat, Garth; Heard, Doug; Belant, Jerrold L

    2015-01-01

    Increasingly, measures of glucocorticoid levels (e.g., cortisol), key components of the neuroendocrine stress axis, are being used to measure past hypothalamic-pituitary-adrenal (HPA) activity to index psychological and physiological stress exhibited by wildlife for assessing individual and population-level well-being. However, many intrinsic and extrinsic factors affect HPA activity in animals. Using American black bears (Ursus americanus; n = 116) as an ecological model and hair cortisol concentration (HCC) as an integrative measure of past HPA activity, we evaluated the influence of diet, sex and the social environment on black bear HCC in a free-ranging population that spanned adjoining ecoregions with differing densities of potential conspecific and heterospecific competitors. HCC varied by sex, with female HCC ranging from 0.6 to 10.7 pg/mg (median = 4.5 ± 1.2 mean absolute deviation [MAD]) and male HCC ranging from 0.5 to 35.1 pg/mg (median = 6.2 ± 2.6 MAD). We also observed a three-way interaction among sex, δ14C and ecoregion, which may indicate that some differences in HCC between female and male black bears results from variability in the nutritional needs of larger-bodied males relative to smaller-bodied females, slight differences in food resources use between ecoregions as well as sex-based differences regarding the social environment. Once we understand what drives sex-specific differences in HCC, HCC may aid our understanding of the physiological responses by bears and other wildlife to diverse environmental challenges.

  3. Use of sulfur and nitrogen stable isotopes to determine the importance of whitebark pine nuts to Yellowstone grizzly bears

    Science.gov (United States)

    Felicetti, L.A.; Schwartz, C.C.; Rye, R.O.; Haroldson, M.A.; Gunther, K.A.; Phillips, D.L.; Robbins, C.T.

    2003-01-01

    Whitebark pine (Pinus albicaulis) is a masting species that produces relatively large, fat- and protein-rich nuts that are consumed by grizzly bears (Ursus arctos horribilis). Trees produce abundant nut crops in some years and poor crops in other years. Grizzly bear survival in the Greater Yellowstone Ecosystem is strongly linked to variation in pine-nut availability. Because whitebark pine trees are infected with blister rust (Cronartium ribicola), an exotic fungus that has killed the species throughout much of its range in the northern Rocky Mountains, we used stable isotopes to quantify the importance of this food resource to Yellowstone grizzly bears while healthy populations of the trees still exist. Whitebark pine nuts have a sulfur-isotope signature (9.2 ?? 1.3??? (mean ?? 1 SD)) that is distinctly different from those of all other grizzly bear foods (ranging from 1.9 ?? 1.7??? for all other plants to 3.1 ?? 2.6??? for ungulates). Feeding trials with captive grizzly bears were used to develop relationships between dietary sulfur-, carbon-, and nitrogen-isotope signatures and those of bear plasma. The sulfur and nitrogen relationships were used to estimate the importance of pine nuts to free-ranging grizzly bears from blood and hair samples collected between 1994 and 2001. During years of poor pine-nut availability, 72% of the bears made minimal use of pine nuts. During years of abundant cone availability, 8 ?? 10% of the bears made minimal use of pine nuts, while 67 ?? 19% derived over 51% of their assimilated sulfur and nitrogen (i.e., protein) from pine nuts. Pine nuts and meat are two critically important food resources for Yellowstone grizzly bears.

  4. Spatial patterns of breeding success of grizzly bears derived from hierarchical multistate models.

    Science.gov (United States)

    Fisher, Jason T; Wheatley, Matthew; Mackenzie, Darryl

    2014-10-01

    Conservation programs often manage populations indirectly through the landscapes in which they live. Empirically, linking reproductive success with landscape structure and anthropogenic change is a first step in understanding and managing the spatial mechanisms that affect reproduction, but this link is not sufficiently informed by data. Hierarchical multistate occupancy models can forge these links by estimating spatial patterns of reproductive success across landscapes. To illustrate, we surveyed the occurrence of grizzly bears (Ursus arctos) in the Canadian Rocky Mountains Alberta, Canada. We deployed camera traps for 6 weeks at 54 surveys sites in different types of land cover. We used hierarchical multistate occupancy models to estimate probability of detection, grizzly bear occupancy, and probability of reproductive success at each site. Grizzly bear occupancy varied among cover types and was greater in herbaceous alpine ecotones than in low-elevation wetlands or mid-elevation conifer forests. The conditional probability of reproductive success given grizzly bear occupancy was 30% (SE = 0.14). Grizzly bears with cubs had a higher probability of detection than grizzly bears without cubs, but sites were correctly classified as being occupied by breeding females 49% of the time based on raw data and thus would have been underestimated by half. Repeated surveys and multistate modeling reduced the probability of misclassifying sites occupied by breeders as unoccupied to <2%. The probability of breeding grizzly bear occupancy varied across the landscape. Those patches with highest probabilities of breeding occupancy-herbaceous alpine ecotones-were small and highly dispersed and are projected to shrink as treelines advance due to climate warming. Understanding spatial correlates in breeding distribution is a key requirement for species conservation in the face of climate change and can help identify priorities for landscape management and protection. © 2014 Society

  5. Genetic Characterization of Sarcoptes scabiei from Black Bears (Ursus americanus) and Other Hosts in the Eastern United States.

    Science.gov (United States)

    Peltier, Sarah K; Brown, Justin D; Ternent, Mark; Niedringhaus, Kevin D; Schuler, Krysten; Bunting, Elizabeth M; Kirchgessner, Megan; Yabsley, Michael J

    2017-10-01

    Since the early 1990s there has been an increase in the number of cases and geographic expansion of severe mange in the black bear (Ursus americanus) population in Pennsylvania. Although there are 3 species of mites associated with mange in bears, Sarcoptes scabiei has been identified as the etiologic agent in these Pennsylvania cases. Historically, S. scabiei-associated mange in bears has been uncommon and sporadic, although it is widespread and relatively common in canid populations. To better understand this recent emergence of sarcoptic mange in bears in Pennsylvania and nearby states, we genetically characterized S. scabiei samples from black bears in the eastern United States. These sequences were compared with newly acquired S. scabiei sequences from wild canids (red fox [Vulpes vulpes] and coyote [Canis latrans]) and a porcupine (Erethizon dorsatum) from Pennsylvania and Kentucky and also existing sequences in GenBank. The internal transcribed spacer (ITS)-2 region and cytochrome c oxidase subunit 1 (cox1) gene were amplified and sequenced. Twenty-four ITS-2 sequences were obtained from mites from bears (n = 16), red fox (n = 5), coyote (n = 2), and a porcupine. The sequences from bear samples were identical to each other or differed only at polymorphic bases, whereas S. scabiei from canids were more variable, but 2 were identical to S. scabiei sequences from bears. Eighteen cox1 sequences obtained from mites from bears represented 6 novel haplotypes. Phylogenetic analysis of cox1 sequences revealed 4 clades: 2 clades of mites of human origin from Panama or Australia, a clade of mites from rabbits from China, and a large unresolved clade that included the remaining S. scabiei sequences from various hosts and regions, including sequences from the bears from the current study. Although the cox1 gene was more variable than the ITS-2, phylogenetic analyses failed to detect any clustering of S. scabiei from eastern U.S. hosts. Rather, sequences from black bears

  6. Estimating the success rate of ovulation and early litter loss rate in the Japanese black bear (Ursus thibetanus japonicus) by examining the ovaries and uteri

    OpenAIRE

    Yamanaka, Atsushi; Yamauchi, Kiyoshi; Tsujimoto, Tsunenori; Mizoguchi, Toshio; Oi, Toru; Sawada, Seigo; Shimozuru, Michito; Tsubota, Toshio

    2011-01-01

    In order to develop a method for estimating the success/failure rates of reproductive processes, especially those of ovulation and neonate nurturing, in the Japanese black bear (Ursus thibetanus japonicus), we examined offspring status, corpora lutea (CLs), placental scars (PSs) and corpora albicantia (CAs) in 159 females (0-23 years old) killed as nuisances on Honshu Island of Japan during 2001-2009. PSs were found to remain in the uterus at least until November of the year of...

  7. Detection of human bacterial pathogens in ticks collected from Louisiana black bears (Ursus americanus luteolus).

    Science.gov (United States)

    Leydet, Brian F; Liang, Fang-Ting

    2013-04-01

    There are 4 major human-biting tick species in the northeastern United States, which include: Amblyomma americanum, Amblyomma maculatum, Dermacentor variabilis, and Ixodes scapularis. The black bear is a large mammal that has been shown to be parasitized by all the aforementioned ticks. We investigated the bacterial infections in ticks collected from Louisiana black bears (Ursus americanus subspecies luteolus). Eighty-six ticks were collected from 17 black bears in Louisiana from June 2010 to March 2011. All 4 common human-biting tick species were represented. Each tick was subjected to polymerase chain reaction (PCR) targeting select bacterial pathogens and symbionts. Bacterial DNA was detected in 62% of ticks (n=53). Rickettsia parkeri, the causative agent of an emerging spotted fever group rickettsiosis, was identified in 66% of A. maculatum, 28% of D. variabilis, and 11% of I. scapularis. The Lyme disease bacterium, Borrelia burgdorferi, was detected in 2 I. scapularis, while one A. americanum was positive for Borrelia bissettii, a putative human pathogen. The rickettsial endosymbionts Candidatus Rickettsia andeanae, rickettsial endosymbiont of I. scapularis, and Rickettsia amblyommii were detected in their common tick hosts at 21%, 39%, and 60%, respectively. All ticks were PCR-negative for Anaplasma phagocytophilum, Ehrlichia spp., and Babesia microti. This is the first reported detection of R. parkeri in vector ticks in Louisiana; we also report the novel association of R. parkeri with I. scapularis. Detection of both R. parkeri and B. burgdorferi in their respective vectors in Louisiana demands further investigation to determine potential for human exposure to these pathogens. Copyright © 2013 Elsevier GmbH. All rights reserved.

  8. Home range size variation in female arctic grizzly bears relative to reproductive status and resource availability.

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    Edwards, Mark A; Derocher, Andrew E; Nagy, John A

    2013-01-01

    The area traversed in pursuit of resources defines the size of an animal's home range. For females, the home range is presumed to be a function of forage availability. However, the presence of offspring may also influence home range size due to reduced mobility, increased nutritional need, and behavioral adaptations of mothers to increase offspring survival. Here, we examine the relationship between resource use and variation in home range size for female barren-ground grizzly bears (Ursus arctos) of the Mackenzie Delta region in Arctic Canada. We develop methods to test hypotheses of home range size that address selection of cover where cover heterogeneity is low, using generalized linear mixed-effects models and an information-theoretic approach. We found that the reproductive status of female grizzlies affected home range size but individually-based spatial availability of highly selected cover in spring and early summer was a stronger correlate. If these preferred covers in spring and early summer, a period of low resource availability for grizzly bears following den-emergence, were patchy and highly dispersed, females travelled farther regardless of the presence or absence of offspring. Increased movement to preferred covers, however, may result in greater risk to the individual or family.

  9. Home range size variation in female arctic grizzly bears relative to reproductive status and resource availability.

    Directory of Open Access Journals (Sweden)

    Mark A Edwards

    Full Text Available The area traversed in pursuit of resources defines the size of an animal's home range. For females, the home range is presumed to be a function of forage availability. However, the presence of offspring may also influence home range size due to reduced mobility, increased nutritional need, and behavioral adaptations of mothers to increase offspring survival. Here, we examine the relationship between resource use and variation in home range size for female barren-ground grizzly bears (Ursus arctos of the Mackenzie Delta region in Arctic Canada. We develop methods to test hypotheses of home range size that address selection of cover where cover heterogeneity is low, using generalized linear mixed-effects models and an information-theoretic approach. We found that the reproductive status of female grizzlies affected home range size but individually-based spatial availability of highly selected cover in spring and early summer was a stronger correlate. If these preferred covers in spring and early summer, a period of low resource availability for grizzly bears following den-emergence, were patchy and highly dispersed, females travelled farther regardless of the presence or absence of offspring. Increased movement to preferred covers, however, may result in greater risk to the individual or family.

  10. Grizzly bear habitat selection is scale dependent.

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    Ciarniello, Lana M; Boyce, Mark S; Seip, Dale R; Heard, Douglas C

    2007-07-01

    The purpose of our study is to show how ecologists' interpretation of habitat selection by grizzly bears (Ursus arctos) is altered by the scale of observation and also how management questions would be best addressed using predetermined scales of analysis. Using resource selection functions (RSF) we examined how variation in the spatial extent of availability affected our interpretation of habitat selection by grizzly bears inhabiting mountain and plateau landscapes. We estimated separate models for females and males using three spatial extents: within the study area, within the home range, and within predetermined movement buffers. We employed two methods for evaluating the effects of scale on our RSF designs. First, we chose a priori six candidate models, estimated at each scale, and ranked them using Akaike Information Criteria. Using this method, results changed among scales for males but not for females. For female bears, models that included the full suite of covariates predicted habitat use best at each scale. For male bears that resided in the mountains, models based on forest successional stages ranked highest at the study-wide and home range extents, whereas models containing covariates based on terrain features ranked highest at the buffer extent. For male bears on the plateau, each scale estimated a different highest-ranked model. Second, we examined differences among model coefficients across the three scales for one candidate model. We found that both the magnitude and direction of coefficients were dependent upon the scale examined; results varied between landscapes, scales, and sexes. Greenness, reflecting lush green vegetation, was a strong predictor of the presence of female bears in both landscapes and males that resided in the mountains. Male bears on the plateau were the only animals to select areas that exposed them to a high risk of mortality by humans. Our results show that grizzly bear habitat selection is scale dependent. Further, the

  11. A meta-analysis of studies on attitudes toward bears and wolves across Europe 1976-2012.

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    Dressel, S; Sandström, C; Ericsson, G

    2015-04-01

    The ranges of wolves (Canis lupus) and bears (Ursus arctos) across Europe have expanded recently, and it is important to assess public attitudes toward this expansion because responses toward these species vary widely. General attitudes toward an object are good predictors of broad behavioral patterns; thus, attitudes toward wolves and bears can be used as indicators to assess the social foundation for future conservation efforts. However, most attitude surveys toward bears and wolves are limited in scope, both temporally and spatially, and provide only a snapshot of attitudes. To extend the results of individual surveys over a much larger temporal and geographical range so as to identify transnational patterns and changes in attitudes toward bears and wolves over time, we conducted a meta-analysis. Our analysis included 105 quantitative surveys conducted in 24 countries from 1976 to 2012. Across Europe, people's attitudes were more positive toward bears than wolves. Attitudes toward bears became more positive over time, but attitudes toward wolves seemed to become less favorable the longer people coexisted with them. Younger and more educated people had more positive attitudes toward wolves and bears than people who had experienced damage from these species, and farmers and hunters had less positive attitudes toward wolves than the general public. For bears attitudes among social groups did not differ. To inform conservation of large carnivores, we recommend that standardized longitudinal surveys be established to monitor changes in attitudes over time relative to carnivore population development. Our results emphasize the need for interdisciplinary research in this field and more advanced explanatory models capable of capturing individual and societal responses to changes in large carnivore policy and management. © 2014 Society for Conservation Biology.

  12. Influences of landscape heterogeneity on home-range sizes of brown bears

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    Mangipane, Lindsey S.; Belant, Jerrold L.; Hiller, Tim L.; Colvin, Michael E.; Gustine, David; Mangipane, Buck A.; Hilderbrand, Grant V.

    2018-01-01

    Animal space use is influenced by many factors and can affect individual survival and fitness. Under optimal foraging theory, individuals use landscapes to optimize high-quality resources while minimizing the amount of energy used to acquire them. The spatial resource variability hypothesis states that as patchiness of resources increases, individuals use larger areas to obtain the resources necessary to meet energetic requirements. Additionally, under the temporal resource variability hypothesis, seasonal variation in available resources can reduce distances moved while providing a variety of food sources. Our objective was to determine if seasonal home ranges of brown bears (Ursus arctos) were influenced by temporal availability and spatial distribution of resources and whether individual reproductive status, sex, or size (i.e., body mass) mediated space use. To test our hypotheses, we radio collared brown bears (n = 32 [9 male, 23 female]) in 2014–2016 and used 18 a prioriselected linear models to evaluate seasonal utilization distributions (UD) in relation to our hypotheses. Our top-ranked model by AICc, supported the spatial resource variability hypothesis and included percentage of like adjacency (PLADJ) of all cover types (P  0.17 for males, solitary females, and females with dependent young), and body mass (kg; P = 0.66). Based on this model, for every percentage increase in PLADJ, UD area was predicted to increase 1.16 times for all sex and reproductive classes. Our results suggest that landscape heterogeneity influences brown bear space use; however, we found that bears used larger areas when landscape homogeneity increased, presumably to gain a diversity of food resources. Our results did not support the temporal resource variability hypothesis, suggesting that the spatial distribution of food was more important than seasonal availability in relation to brown bear home range size.

  13. Persistent organic pollutants and penile bone mineral density in East Greenland and Canadian polar bears (Ursus maritimus) during 1996-2015.

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    Daugaard-Petersen, Tobias; Langebæk, Rikke; Rigét, Frank F; Dyck, Markus; Letcher, Robert J; Hyldstrup, Lars; Jensen, Jens-Erik Bech; Dietz, Rune; Sonne, Christian

    2018-05-01

    Persistent organic pollutants (POPs) are long-range transported to the Arctic via atmospheric and oceanic currents, where they biomagnify to high concentrations in the tissues of apex predators such as polar bears (Ursus maritimus). A major concern of POP exposure is their physiological effects on vital organ-tissues posing a threat to the health and survival of polar bears. Here we examined the relationship between selected POPs and baculum bone mineral density (BMD) in the East Greenland and seven Canadian subpopulations of polar bears. BMD was examined in 471 bacula collected between years 1996-2015 while POP concentrations in adipose tissue were determined in 67-192 of these individuals collected from 1999 to -2015. A geographical comparison showed that baculum BMD was significantly lowest in polar bears from East Greenland (EG) when compared to Gulf of Boothia (GB), Southern Hudson (SH) and Western Hudson (WH) Bay subpopulations (all p bears as a reference group gave a T-score of -1.44 which indicate risk of osteopenia. Concentrations of ΣPCB 74 (polychlorinated biphenyls), ΣDDT 3 (dichlorodiphenyltrichloroethanes), p,p'-DDE (dichlorodiphenyldichloroethylene), ΣHCH 3 (hexachlorohexane) and α-HCH was significantly highest in EG bears while ΣPBDE (polybrominated diphenyl ethers), BDE-47 and BDE-153 was significantly highest in SH bears (all p polar bears despite the positive statistical correlations of BMD vs. POPs. Other important factors such as nutritional status, body mass and body condition was not available for the statistical modelling. Since on-going environmental changes are known to affect these, future studies need to incorporate nutritional, endocrine and genetic parameters to further understand how POP exposure may disrupt bone homeostasis and affect baculum BMD across polar bear subpopulations. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Are liver and renal lesions in East Greenland polar bears (Ursus maritimus associated with high mercury levels?

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    Born Erik W

    2007-04-01

    Full Text Available Abstract Background In the Arctic, polar bears (Ursus maritimus bio-accumulate mercury as they prey on polluted ringed seals (Phoca hispida and bearded seals (Erignathus barbatus. Studies have shown that polar bears from East Greenland are among the most mercury polluted species in the Arctic. It is unknown whether these levels are toxic to liver and kidney tissue. Methods We investigated the histopathological impact from anthropogenic long-range transported mercury on East Greenland polar bear liver (n = 59 and kidney (n = 57 tissues. Results Liver mercury levels ranged from 1.1–35.6 μg/g wet weight and renal levels ranged from 1–50 μg/g wet weight, of which 2 liver values and 9 kidney values were above known toxic threshold level of 30 μg/g wet weight in terrestrial mammals. Evaluated from age-correcting ANCOVA analyses, liver mercury levels were significantly higher in individuals with visible Ito cells (p Conclusion Based on these relationships and the nature of the chronic inflammation we conclude that the lesions were likely a result of recurrent infections and ageing but that long-term exposure to mercury could not be excluded as a co-factor. The information is important as it is likely that tropospheric mercury depletion events will continue to increase the concentrations of this toxic heavy metal in the Sub Arctic and Arctic marine food webs.

  15. Density dependence, whitebark pine, and vital rates of grizzly bears

    Science.gov (United States)

    van Manen, Frank T.; Haroldson, Mark A.; Bjornlie, Daniel D.; Ebinger, Michael R.; Thompson, Daniel J.; Costello, Cecily M.; White, Gary C.

    2016-01-01

    Understanding factors influencing changes in population trajectory is important for effective wildlife management, particularly for populations of conservation concern. Annual population growth of the grizzly bear (Ursus arctos) population in the Greater Yellowstone Ecosystem, USA has slowed from 4.2–7.6% during 1983–2001 to 0.3–2.2% during 2002–2011. Substantial changes in availability of a key food source and bear population density have occurred. Whitebark pine (Pinus albicaulis), the seeds of which are a valuable but variable fall food for grizzly bears, has experienced substantial mortality primarily due to a mountain pine beetle (Dendroctonus ponderosae) outbreak that started in the early 2000s. Positive growth rates of grizzly bears have resulted in populations reaching high densities in some areas and have contributed to continued range expansion. We tested research hypotheses to examine if changes in vital rates detected during the past decade were more associated with whitebark pine decline or, alternatively, increasing grizzly bear density. We focused our assessment on known-fate data to estimate survival of cubs-of-the-year (cubs), yearlings, and independent bears (≥2 yrs), and reproductive transition of females from having no offspring to having cubs. We used spatially and temporally explicit indices for grizzly bear density and whitebark pine mortality as individual covariates. Models indicated moderate support for an increase in survival of independent male bears over 1983–2012, whereas independent female survival did not change. Cub survival, yearling survival, and reproductive transition from no offspring to cubs all changed during the 30-year study period, with lower rates evident during the last 10–15 years. Cub survival and reproductive transition were negatively associated with an index of grizzly bear density, indicating greater declines where bear densities were higher. Our analyses did not support a similar relationship for the

  16. Selecting the best stable isotope mixing model to estimate grizzly bear diets in the Greater Yellowstone Ecosystem.

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    Hopkins, John B; Ferguson, Jake M; Tyers, Daniel B; Kurle, Carolyn M

    2017-01-01

    Past research indicates that whitebark pine seeds are a critical food source for Threatened grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem (GYE). In recent decades, whitebark pine forests have declined markedly due to pine beetle infestation, invasive blister rust, and landscape-level fires. To date, no study has reliably estimated the contribution of whitebark pine seeds to the diets of grizzlies through time. We used stable isotope ratios (expressed as δ13C, δ15N, and δ34S values) measured in grizzly bear hair and their major food sources to estimate the diets of grizzlies sampled in Cooke City Basin, Montana. We found that stable isotope mixing models that included different combinations of stable isotope values for bears and their foods generated similar proportional dietary contributions. Estimates generated by our top model suggest that whitebark pine seeds (35±10%) and other plant foods (56±10%) were more important than meat (9±8%) to grizzly bears sampled in the study area. Stable isotope values measured in bear hair collected elsewhere in the GYE and North America support our conclusions about plant-based foraging. We recommend that researchers consider model selection when estimating the diets of animals using stable isotope mixing models. We also urge researchers to use the new statistical framework described here to estimate the dietary responses of grizzlies to declines in whitebark pine seeds and other important food sources through time in the GYE (e.g., cutthroat trout), as such information could be useful in predicting how the population will adapt to future environmental change.

  17. Traditional Knowledge About Polar Bears (Ursus maritimus in East Greenland: Changes in the Catch and Climate Over Two Decades

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    Kristin L. Laidre

    2018-05-01

    Full Text Available In Greenland, polar bears (Ursus maritimus are nutritional, economic, and cultural subsistence resources for Inuit. Traditional Ecological Knowledge (TEK collected from subsistence hunters can provide important insights and improve management decisions when collected systematically. We report on the results of a TEK survey of subsistence polar bear hunters living in the areas around Tasiilaq and Ittoqqortoormiit, East Greenland. Twenty-five full-time polar bear hunters were interviewed between December 2014 and March 2015 in a conversation-style interview, where a local interviewer fluent in the East Greenlandic dialect asked a series of 55 predetermined questions. The primary goals were to (1 gather Inuit perspectives on polar bear subsistence quotas and hunting strategies, (2 understand how climate change is affecting the polar bear subsistence hunt, and (3 document observed changes in polar bear distribution, abundance, and biology. Approximately 40% of the Tasiilaq respondents had caught between 10 and 19 polar bears in their lifetime, while 67% of Ittoqqortoormiit respondents reported lifetime catches of ≥20 bears. In both areas, polar bears were most commonly hunted between February and April. Hunters noted large changes to the climate in the areas where they hunt polar bears. Most hunters reported loss of sea ice, receding glaciers, unstable weather, and warmer temperatures. In Tasiilaq 73% of the hunters said climate changes had affected the polar bear hunt and in Ittoqqortoormiit about 88% of respondents reported the same. Hunters indicated that sea ice loss has created more areas of open water so dog sledges have become unsafe for hunting transportation compared to 10–15 years ago (reported by 100% of hunters in Tasiilaq and 80% in Ittoqqortoormiit. In Ittoqqortoormiit, the distance traveled during polar bear hunting trips has decreased dramatically. In both areas hunters noted that more polar bears are coming into their

  18. Wound healing during hibernation by black bears (Ursus americanus) in the wild: elicitation of reduced scar formation.

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    Iaizzo, Paul A; Laske, Timothy G; Harlow, Henry J; McClay, Carolyn B; Garshelis, David L

    2012-03-01

    Even mildly hypothermic body or limb temperatures can retard healing processes in mammals. Despite this, we observed that hibernating American black bears (Ursus americanus Pallas, 1780) elicit profound abilities in mounting inflammatory responses to infection and/or foreign bodies. In addition, they resolve injuries during hibernation while maintaining mildly hypothermic states (30-35 °C) and without eating, drinking, urinating or defecating. We describe experimental studies on free-ranging bears that document their abilities to completely resolve cutaneous cuts and punctures incurred during or prior to hibernation. We induced small, full-thickness cutaneous wounds (biopsies or incisions) during early denning, and re-biopsied sites 2-3 months later (near the end of denning). Routine histological methods were used to characterize these skin samples. All biopsied sites with respect to secondary intention (open circular biopsies) and primary intention (sutured sites) healed, with evidence of initial eschar (scab) formation, completeness of healed epidermis and dermal layers, dyskeratosis (inclusion cysts), and abilities to produce hair follicles. These healing abilities of hibernating black bears are a clear survival advantage to animals injured before or during denning. Bears are known to have elevated levels of hibernation induction trigger (delta-opioid receptor agonist) and ursodeoxycholic acid (major bile acid within plasma, mostly conjugated with taurine) during hibernation, which may relate to these wound-healing abilities. Further research as to the underlying mechanisms of wound healing during hibernation could have applications in human medicine. Unique approaches may be found to improve healing for malnourished, hypothermic, diabetic and elderly patients or to reduce scarring associated with burns and traumatic injuries. © 2012 ISZS, Blackwell Publishing and IOZ/CAS.

  19. Conflict Misleads Large Carnivore Management and Conservation: Brown Bears and Wolves in Spain.

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    Fernández-Gil, Alberto; Naves, Javier; Ordiz, Andrés; Quevedo, Mario; Revilla, Eloy; Delibes, Miguel

    2016-01-01

    Large carnivores inhabiting human-dominated landscapes often interact with people and their properties, leading to conflict scenarios that can mislead carnivore management and, ultimately, jeopardize conservation. In northwest Spain, brown bears Ursus arctos are strictly protected, whereas sympatric wolves Canis lupus are subject to lethal control. We explored ecological, economic and societal components of conflict scenarios involving large carnivores and damages to human properties. We analyzed the relation between complaints of depredations by bears and wolves on beehives and livestock, respectively, and bear and wolf abundance, livestock heads, number of culled wolves, amount of paid compensations, and media coverage. We also evaluated the efficiency of wolf culling to reduce depredations on livestock. Bear damages to beehives correlated positively to the number of female bears with cubs of the year. Complaints of wolf predation on livestock were unrelated to livestock numbers; instead, they correlated positively to the number of wild ungulates harvested during the previous season, the number of wolf packs, and to wolves culled during the previous season. Compensations for wolf complaints were fivefold higher than for bears, but media coverage of wolf damages was thirtyfold higher. Media coverage of wolf damages was unrelated to the actual costs of wolf damages, but the amount of news correlated positively to wolf culling. However, wolf culling was followed by an increase in compensated damages. Our results show that culling of the wolf population failed in its goal of reducing damages, and suggest that management decisions are at least partly mediated by press coverage. We suggest that our results provide insight to similar scenarios, where several species of large carnivores share the landscape with humans, and management may be reactive to perceived conflicts.

  20. Titin isoform switching is a major cardiac adaptive response in hibernating grizzly bears.

    Science.gov (United States)

    Nelson, O Lynne; Robbins, Charles T; Wu, Yiming; Granzier, Henk

    2008-07-01

    The hibernation phenomenon captures biological as well as clinical interests to understand how organs adapt. Here we studied how hibernating grizzly bears (Ursus arctos horribilis) tolerate extremely low heart rates without developing cardiac chamber dilation. We evaluated cardiac filling function in unanesthetized grizzly bears by echocardiography during the active and hibernating period. Because both collagen and titin are involved in altering diastolic function, we investigated both in the myocardium of active and hibernating grizzly bears. Heart rates were reduced from 84 beats/min in active bears to 19 beats/min in hibernating bears. Diastolic volume, stroke volume, and left ventricular ejection fraction were not different. However, left ventricular muscle mass was significantly lower (300 +/- 12 compared with 402 +/- 14 g; P = 0.003) in the hibernating bears, and as a result the diastolic volume-to-left ventricular muscle mass ratio was significantly greater. Early ventricular filling deceleration times (106.4 +/- 14 compared with 143.2 +/- 20 ms; P = 0.002) were shorter during hibernation, suggesting increased ventricular stiffness. Restrictive pulmonary venous flow patterns supported this conclusion. Collagen type I and III comparisons did not reveal differences between the two groups of bears. In contrast, the expression of titin was altered by a significant upregulation of the stiffer N2B isoform at the expense of the more compliant N2BA isoform. The mean ratio of N2BA to N2B titin was 0.73 +/- 0.07 in the active bears and decreased to 0.42 +/- 0.03 (P = 0.006) in the hibernating bears. The upregulation of stiff N2B cardiac titin is a likely explanation for the increased ventricular stiffness that was revealed by echocardiography, and we propose that it plays a role in preventing chamber dilation in hibernating grizzly bears. Thus our work identified changes in the alternative splicing of cardiac titin as a major adaptive response in hibernating grizzly

  1. Sex, Diet, and the Social Environment: Factors Influencing Hair Cortisol Concentration in Free-Ranging Black Bears (Ursus americanus)

    Science.gov (United States)

    Lafferty, Diana J. R.; Laudenslager, Mark L.; Mowat, Garth; Heard, Doug; Belant, Jerrold L.

    2015-01-01

    Increasingly, measures of glucocorticoid levels (e.g., cortisol), key components of the neuroendocrine stress axis, are being used to measure past hypothalamic-pituitary-adrenal (HPA) activity to index psychological and physiological stress exhibited by wildlife for assessing individual and population-level well-being. However, many intrinsic and extrinsic factors affect HPA activity in animals. Using American black bears (Ursus americanus; n = 116) as an ecological model and hair cortisol concentration (HCC) as an integrative measure of past HPA activity, we evaluated the influence of diet, sex and the social environment on black bear HCC in a free-ranging population that spanned adjoining ecoregions with differing densities of potential conspecific and heterospecific competitors. HCC varied by sex, with female HCC ranging from 0.6 to 10.7 pg/mg (median = 4.5 ± 1.2 mean absolute deviation [MAD]) and male HCC ranging from 0.5 to 35.1 pg/mg (median = 6.2 ± 2.6 MAD). We also observed a three-way interaction among sex, δ14C and ecoregion, which may indicate that some differences in HCC between female and male black bears results from variability in the nutritional needs of larger-bodied males relative to smaller-bodied females, slight differences in food resources use between ecoregions as well as sex-based differences regarding the social environment. Once we understand what drives sex-specific differences in HCC, HCC may aid our understanding of the physiological responses by bears and other wildlife to diverse environmental challenges. PMID:26529405

  2. Sex, Diet, and the Social Environment: Factors Influencing Hair Cortisol Concentration in Free-Ranging Black Bears (Ursus americanus.

    Directory of Open Access Journals (Sweden)

    Diana J R Lafferty

    Full Text Available Increasingly, measures of glucocorticoid levels (e.g., cortisol, key components of the neuroendocrine stress axis, are being used to measure past hypothalamic-pituitary-adrenal (HPA activity to index psychological and physiological stress exhibited by wildlife for assessing individual and population-level well-being. However, many intrinsic and extrinsic factors affect HPA activity in animals. Using American black bears (Ursus americanus; n = 116 as an ecological model and hair cortisol concentration (HCC as an integrative measure of past HPA activity, we evaluated the influence of diet, sex and the social environment on black bear HCC in a free-ranging population that spanned adjoining ecoregions with differing densities of potential conspecific and heterospecific competitors. HCC varied by sex, with female HCC ranging from 0.6 to 10.7 pg/mg (median = 4.5 ± 1.2 mean absolute deviation [MAD] and male HCC ranging from 0.5 to 35.1 pg/mg (median = 6.2 ± 2.6 MAD. We also observed a three-way interaction among sex, δ14C and ecoregion, which may indicate that some differences in HCC between female and male black bears results from variability in the nutritional needs of larger-bodied males relative to smaller-bodied females, slight differences in food resources use between ecoregions as well as sex-based differences regarding the social environment. Once we understand what drives sex-specific differences in HCC, HCC may aid our understanding of the physiological responses by bears and other wildlife to diverse environmental challenges.

  3. Genetic analysis of individual origins supports isolation of grizzly bears in the Greater Yellowstone Ecosystem

    Science.gov (United States)

    Haroldson, Mark A.; Schwartz, Charles; Kendall, Katherine C.; Gunther, Kerry A.; Moody, David S.; Frey, Kevin L.; Paetkau, David

    2010-01-01

    The Greater Yellowstone Ecosystem (GYE) supports the southernmost of the 2 largest remaining grizzly bear (Ursus arctos) populations in the contiguous United States. Since the mid-1980s, this population has increased in numbers and expanded in range. However, concerns for its long-term genetic health remain because of its presumed continued isolation. To test the power of genetic methods for detecting immigrants, we generated 16-locus microsatellite genotypes for 424 individual grizzly bears sampled in the GYE during 1983–2007. Genotyping success was high (90%) and varied by sample type, with poorest success (40%) for hair collected from mortalities found ≥1 day after death. Years of storage did not affect genotyping success. Observed heterozygosity was 0.60, with a mean of 5.2 alleles/marker. We used factorial correspondence analysis (Program GENETIX) and Bayesian clustering (Program STRUCTURE) to compare 424 GYE genotypes with 601 existing genotypes from grizzly bears sampled in the Northern Continental Divide Ecosystem (NCDE) (FST  =  0.096 between GYE and NCDE). These methods correctly classified all sampled individuals to their population of origin, providing no evidence of natural movement between the GYE and NCDE. Analysis of 500 simulated first-generation crosses suggested that over 95% of such bears would also be detectable using our 16-locus data set. Our approach provides a practical method for detecting immigration in the GYE grizzly population. We discuss estimates for the proportion of the GYE population sampled and prospects for natural immigration into the GYE.

  4. Diet and environment shape fecal bacterial microbiota composition and enteric pathogen load of grizzly bears.

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    Clarissa Schwab

    Full Text Available BACKGROUND: Diet and environment impact the composition of mammalian intestinal microbiota; dietary or health disturbances trigger alterations in intestinal microbiota composition and render the host susceptible to enteric pathogens. To date no long term monitoring data exist on the fecal microbiota and pathogen load of carnivores either in natural environments or in captivity. This study investigates fecal microbiota composition and the presence of pathogenic Escherichia coli and toxigenic clostridia in wild and captive grizzly bears (Ursus arctos and relates these to food resources consumed by bears. METHODOLOGY/PRINCIPAL FINDINGS: Feces were obtained from animals of two wild populations and from two captive animals during an active bear season. Wild animals consumed a diverse diet composed of plant material, animal prey and insects. Captive animals were fed a regular granulated diet with a supplement of fruits and vegetables. Bacterial populations were analyzed using quantitative PCR. Fecal microbiota composition fluctuated in wild and in captive animals. The abundance of Clostridium clusters I and XI, and of C. perfringens correlated to regular diet protein intake. Enteroaggregative E. coli were consistently present in all populations. The C. sordellii phospholipase C was identified in three samples of wild animals and for the first time in Ursids. CONCLUSION: This is the first longitudinal study monitoring the fecal microbiota of wild carnivores and comparing it to that of captive individuals of the same species. Location and diet affected fecal bacterial populations as well as the presence of enteric pathogens.

  5. Diet and environment shape fecal bacterial microbiota composition and enteric pathogen load of grizzly bears.

    Science.gov (United States)

    Schwab, Clarissa; Cristescu, Bogdan; Northrup, Joseph M; Stenhouse, Gordon B; Gänzle, Michael

    2011-01-01

    Diet and environment impact the composition of mammalian intestinal microbiota; dietary or health disturbances trigger alterations in intestinal microbiota composition and render the host susceptible to enteric pathogens. To date no long term monitoring data exist on the fecal microbiota and pathogen load of carnivores either in natural environments or in captivity. This study investigates fecal microbiota composition and the presence of pathogenic Escherichia coli and toxigenic clostridia in wild and captive grizzly bears (Ursus arctos) and relates these to food resources consumed by bears. Feces were obtained from animals of two wild populations and from two captive animals during an active bear season. Wild animals consumed a diverse diet composed of plant material, animal prey and insects. Captive animals were fed a regular granulated diet with a supplement of fruits and vegetables. Bacterial populations were analyzed using quantitative PCR. Fecal microbiota composition fluctuated in wild and in captive animals. The abundance of Clostridium clusters I and XI, and of C. perfringens correlated to regular diet protein intake. Enteroaggregative E. coli were consistently present in all populations. The C. sordellii phospholipase C was identified in three samples of wild animals and for the first time in Ursids. This is the first longitudinal study monitoring the fecal microbiota of wild carnivores and comparing it to that of captive individuals of the same species. Location and diet affected fecal bacterial populations as well as the presence of enteric pathogens.

  6. The first finding of Asian black bear (Carnivora, Ursidae, Ursus (Euarctos) thibetanus G. Cuvier, 1823) in the Late Pleistocene of northern Eurasia.

    Science.gov (United States)

    Kosintsev, P A; Tiunov, M P; Gimranov, D O; Panov, V S

    2016-11-01

    An M1 tooth of Asian black bear (Ursus (Euarctos) thibetanus G. Cuvier, 1823) was found in deposits of the Tetyukhinskaya cave (Middle Sikhote-Alin, 44°35'N, 135°36'E). This finding is the first reliable evidence of Asian black bear's presence in Pleistocene of Primorye. Its morphological and morphometric descriptions are given. The period of inhabitation of U. (E.) thibetanus determined based on the radiocarbon date obtained during the study of the tooth, is 39 874 ± 133 BP (NSK-850, UGAMS-21786), which corresponds to the middle of Marine Isotope Stage 3 (MIS 3) of Late Pleistocene. The composition of ancient theriofauna indicates the existence of wide variety of landscapes in Primorye in the middle of Late Pleistocene. A refugium of forest fauna, in which species of taiga, nemoral, and Central Asian mountain-forest theriocomplexes were present, was located in southern Primorye in Late Pleistocene.

  7. Density, distribution, and genetic structure of grizzly bears in the Cabinet-Yaak Ecosystem

    Science.gov (United States)

    Macleod, Amy C.; Boyd, Kristina L.; Boulanger, John; Royle, J. Andrew; Kasworm, Wayne F.; Paetkau, David; Proctor, Michael F.; Annis, Kim; Graves, Tabitha A.

    2016-01-01

    The conservation status of the 2 threatened grizzly bear (Ursus arctos) populations in the Cabinet-Yaak Ecosystem (CYE) of northern Montana and Idaho had remained unchanged since designation in 1975; however, the current demographic status of these populations was uncertain. No rigorous data on population density and distribution or analysis of recent population genetic structure were available to measure the effectiveness of conservation efforts. We used genetic detection data from hair corral, bear rub, and opportunistic sampling in traditional and spatial capture–recapture models to generate estimates of abundance and density of grizzly bears in the CYE. We calculated mean bear residency on our sampling grid from telemetry data using Huggins and Pledger models to estimate the average number of bears present and to correct our superpopulation estimates for lack of geographic closure. Estimated grizzly bear abundance (all sex and age classes) in the CYE in 2012 was 48–50 bears, approximately half the population recovery goal. Grizzly bear density in the CYE (4.3–4.5 grizzly bears/1,000 km2) was among the lowest of interior North American populations. The sizes of the Cabinet (n = 22–24) and Yaak (n = 18–22) populations were similar. Spatial models produced similar estimates of abundance and density with comparable precision without requiring radio-telemetry data to address assumptions of geographic closure. The 2 populations in the CYE were demographically and reproductively isolated from each other and the Cabinet population was highly inbred. With parentage analysis, we documented natural migrants to the Cabinet and Yaak populations by bears born to parents in the Selkirk and Northern Continental Divide populations. These events supported data from other sources suggesting that the expansion of neighboring populations may eventually help sustain the CYE populations. However, the small size, isolation, and inbreeding documented by this study

  8. In vitro assay shows that PCB metabolites completely saturate thyroid hormone transport capacity in blood of wild polar bears (Ursus maritimus).

    Science.gov (United States)

    Gutleb, Arno C; Cenijn, Peter; Velzen, Martin van; Lie, Elisabeth; Ropstad, Erik; Skaare, Janneche Utne; Malmberg, Tina; Bergman, Ake; Gabrielsen, Geir W; Legler, Juliette

    2010-04-15

    Persistent chemicals accumulate in the arctic environment due to their chemical reactivity and physicochemical properties and polychlorinated biphenyls (PCBs) are the most concentrated pollutant class in polar bears (Ursus maritimus). Metabolism of PCB and polybrominated biphenyl ether (PBDE) flame-retardants alter their toxicological properties and these metabolites are known to interfere with the binding of thyroid hormone (TH) to transthyretin (TTR) in rodents and humans. In polar bear plasma samples no binding of [125I]-T(4) to TTR was observed after incubation and PAGE separation. Incubation of the plasma samples with [14C]-4-OH-CB107, a compound with a higher binding affinity to TTR than the endogenous ligand T(4) resulted in competitive binding as proven by the appearance of a radio labeled TTR peak in the gel. Plasma incubation with T(4) up to 1 mM, a concentration that is not physiologically relevant anymore did not result in any visible competition. These results give evidence that the binding sites on TTR for T(4) in wild living polar bears are completely saturated. Such saturation of binding sites can explain observed lowered levels of THs and could lead to contaminant transport into the developing fetus.

  9. Dental and Temporomandibular Joint Pathology of the American Black Bear (Ursus americanus).

    Science.gov (United States)

    Clark, E J; Chesnutt, S R; Winer, J N; Kass, P H; Verstraete, F J M

    Museum specimens (maxillae and/or mandibles) from 371 American black bears (Ursus americanus) acquired between 1889 and 2006 were examined macroscopically according to predefined criteria, and 348 were included in this study. Of the 348 specimens, 126 (36.2%) were from male animals, 106 (30.5%) were from female animals and 116 (33.3%) were from animals of unknown sex. Specimen ages ranged from young adult (n = 63, 18.1%) to adult (n = 285, 81.9%), with juveniles excluded from the study. The number of teeth available for examination was 12,019 (82.2%); 7.0% of teeth were absent artefactually, 0.4% were deemed absent due to acquired tooth loss and 9.7% were absent congenitally. In 43 specimens (12.3%), 82 teeth (0.68%) were small vestigial structures with crowns that were flush with the level of surrounding alveolar bone. The remaining teeth (99.3%) were of normal morphology. Only three supernumerary teeth and three instances of enamel hypoplasia were encountered. Persistent deciduous teeth or teeth with an aberrant number of roots were not encountered in any of the specimens. Approximately one-third of the teeth examined (4,543, 37.8%) displayed attrition/abrasion, affecting nearly all of the specimens (n = 338, 97.1%). Incisor and molar teeth accounted for 52.5% and 34.3% of the affected teeth, respectively, with significantly more adults affected than young adults. Dental fractures were noted in 63 bears, affecting 18.1% of specimens and 1.0% of the total number of present teeth. The canine teeth were most often fractured, with adults having significantly more complicated crown fractures of these teeth than young adults. There were 11 specimens (3.2%) that displayed periapical lesions, affecting 12 (0.1%) dental alveoli. There were 179 specimens (51.4%) displaying bony changes indicative of periodontitis, affecting 816 (6.8%) dental alveoli. The proportion of adult bears affected by periodontitis (57.9%) was significantly greater than that of young adults

  10. A comprehensive analysis of three Asiatic black bear mitochondrial genomes (subspecies ussuricus, formosanus and mupinensis), with emphasis on the complete mtDNA sequence of Ursus thibetanus ussuricus (Ursidae).

    Science.gov (United States)

    Hwang, Dae-Sik; Ki, Jang-Seu; Jeong, Dong-Hyuk; Kim, Bo-Hyun; Lee, Bae-Keun; Han, Sang-Hoon; Lee, Jae-Seong

    2008-08-01

    In the present paper, we describe the mitochondrial genome sequence of the Asiatic black bear (Ursus thibetanus ussuricus) with particular emphasis on the control region (CR), and compared with mitochondrial genomes on molecular relationships among the bears. The mitochondrial genome sequence of U. thibetanus ussuricus was 16,700 bp in size with mostly conserved structures (e.g. 13 protein-coding, two rRNA genes, 22 tRNA genes). The CR consisted of several typical conserved domains such as F, E, D, and C boxes, and a conserved sequence block. Nucleotide sequences and the repeated motifs in the CR were different among the bear species, and their copy numbers were also variable according to populations, even within F1 generations of U. thibetanus ussuricus. Comparative analyses showed that the CR D1 region was highly informative for the discrimination of the bear family. These findings suggest that nucleotide sequences of both repeated motifs and CR D1 in the bear family are good markers for species discriminations.

  11. Influence of whitebark pine decline on fall habitat use and movements of grizzly bears in the Greater Yellowstone Ecosystem

    Science.gov (United States)

    Costello, Cecily M.; van Manen, Frank T.; Haroldson, Mark A.; Ebinger, Michael R.; Cain, Steven L.; Gunther, Kerry A.; Bjornlie, Daniel D.

    2014-01-01

    When abundant, seeds of the high-elevation whitebark pine (WBP; Pinus albicaulis) are an important fall food for grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem. Rates of bear mortality and bear/human conflicts have been inversely associated with WBP productivity. Recently, mountain pine beetles (Dendroctonus ponderosae) have killed many cone-producing WBP trees. We used fall (15 August–30 September) Global Positioning System locations from 89 bear years to investigate temporal changes in habitat use and movements during 2000–2011. We calculated Manly–Chesson (MC) indices for selectivity of WBP habitat and secure habitat (≥500 m from roads and human developments), determined dates of WBP use, and documented net daily movement distances and activity radii. To evaluate temporal trends, we used regression, model selection, and candidate model sets consisting of annual WBP production, sex, and year. One-third of sampled grizzly bears had fall ranges with little or no mapped WBP habitat. Most other bears (72%) had a MC index above 0.5, indicating selection for WBP habitats. From 2000 to 2011, mean MC index decreased and median date of WBP use shifted about 1 week later. We detected no trends in movement indices over time. Outside of national parks, there was no correlation between the MC indices for WBP habitat and secure habitat, and most bears (78%) selected for secure habitat. Nonetheless, mean MC index for secure habitat decreased over the study period during years of good WBP productivity. The wide diet breadth and foraging plasticity of grizzly bears likely allowed them to adjust to declining WBP. Bears reduced use of WBP stands without increasing movement rates, suggesting they obtained alternative fall foods within their local surroundings. However, the reduction in mortality risk historically associated with use of secure, high-elevation WBP habitat may be diminishing for bears residing in multiple-use areas.

  12. Influence of whitebark pine decline on fall habitat use and movements of grizzly bears in the Greater Yellowstone Ecosystem.

    Science.gov (United States)

    Costello, Cecily M; van Manen, Frank T; Haroldson, Mark A; Ebinger, Michael R; Cain, Steven L; Gunther, Kerry A; Bjornlie, Daniel D

    2014-05-01

    When abundant, seeds of the high-elevation whitebark pine (WBP; Pinus albicaulis) are an important fall food for grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem. Rates of bear mortality and bear/human conflicts have been inversely associated with WBP productivity. Recently, mountain pine beetles (Dendroctonus ponderosae) have killed many cone-producing WBP trees. We used fall (15 August-30 September) Global Positioning System locations from 89 bear years to investigate temporal changes in habitat use and movements during 2000-2011. We calculated Manly-Chesson (MC) indices for selectivity of WBP habitat and secure habitat (≥500 m from roads and human developments), determined dates of WBP use, and documented net daily movement distances and activity radii. To evaluate temporal trends, we used regression, model selection, and candidate model sets consisting of annual WBP production, sex, and year. One-third of sampled grizzly bears had fall ranges with little or no mapped WBP habitat. Most other bears (72%) had a MC index above 0.5, indicating selection for WBP habitats. From 2000 to 2011, mean MC index decreased and median date of WBP use shifted about 1 week later. We detected no trends in movement indices over time. Outside of national parks, there was no correlation between the MC indices for WBP habitat and secure habitat, and most bears (78%) selected for secure habitat. Nonetheless, mean MC index for secure habitat decreased over the study period during years of good WBP productivity. The wide diet breadth and foraging plasticity of grizzly bears likely allowed them to adjust to declining WBP. Bears reduced use of WBP stands without increasing movement rates, suggesting they obtained alternative fall foods within their local surroundings. However, the reduction in mortality risk historically associated with use of secure, high-elevation WBP habitat may be diminishing for bears residing in multiple-use areas.

  13. Macronutrient optimization and seasonal diet mixing in a large omnivore, the grizzly bear: a geometric analysis.

    Directory of Open Access Journals (Sweden)

    Sean C P Coogan

    Full Text Available Nutrient balance is a strong determinant of animal fitness and demography. It is therefore important to understand how the compositions of available foods relate to required balance of nutrients and habitat suitability for animals in the wild. These relationships are, however, complex, particularly for omnivores that often need to compose balanced diets by combining their intake from diverse nutritionally complementary foods. Here we apply geometric models to understand how the nutritional compositions of foods available to an omnivorous member of the order Carnivora, the grizzly bear (Ursus arctos L., relate to optimal macronutrient intake, and assess the seasonal nutritional constraints on the study population in west-central Alberta, Canada. The models examined the proportion of macronutrients that bears could consume by mixing their diet from food available in each season, and assessed the extent to which bears could consume the ratio of protein to non-protein energy previously demonstrated using captive bears to optimize mass gain. We found that non-selective feeding on ungulate carcasses provided a non-optimal macronutrient balance with surplus protein relative to fat and carbohydrate, reflecting adaptation to an omnivorous lifestyle, and that optimization through feeding selectively on different tissues of ungulate carcasses is unlikely. Bears were, however, able to dilute protein intake to an optimal ratio by mixing their otherwise high-protein diet with carbohydrate-rich fruit. Some individual food items were close to optimally balanced in protein to non-protein energy (e.g. Hedysarum alpinum roots, which may help explain their dietary prevalence. Ants may be consumed particularly as a source of lipids. Overall, our analysis showed that most food available to bears in the study area were high in protein relative to lipid or carbohydrate, suggesting the lack of non-protein energy limits the fitness (e.g. body size and reproduction and

  14. Macronutrient optimization and seasonal diet mixing in a large omnivore, the grizzly bear: a geometric analysis.

    Science.gov (United States)

    Coogan, Sean C P; Raubenheimer, David; Stenhouse, Gordon B; Nielsen, Scott E

    2014-01-01

    Nutrient balance is a strong determinant of animal fitness and demography. It is therefore important to understand how the compositions of available foods relate to required balance of nutrients and habitat suitability for animals in the wild. These relationships are, however, complex, particularly for omnivores that often need to compose balanced diets by combining their intake from diverse nutritionally complementary foods. Here we apply geometric models to understand how the nutritional compositions of foods available to an omnivorous member of the order Carnivora, the grizzly bear (Ursus arctos L.), relate to optimal macronutrient intake, and assess the seasonal nutritional constraints on the study population in west-central Alberta, Canada. The models examined the proportion of macronutrients that bears could consume by mixing their diet from food available in each season, and assessed the extent to which bears could consume the ratio of protein to non-protein energy previously demonstrated using captive bears to optimize mass gain. We found that non-selective feeding on ungulate carcasses provided a non-optimal macronutrient balance with surplus protein relative to fat and carbohydrate, reflecting adaptation to an omnivorous lifestyle, and that optimization through feeding selectively on different tissues of ungulate carcasses is unlikely. Bears were, however, able to dilute protein intake to an optimal ratio by mixing their otherwise high-protein diet with carbohydrate-rich fruit. Some individual food items were close to optimally balanced in protein to non-protein energy (e.g. Hedysarum alpinum roots), which may help explain their dietary prevalence. Ants may be consumed particularly as a source of lipids. Overall, our analysis showed that most food available to bears in the study area were high in protein relative to lipid or carbohydrate, suggesting the lack of non-protein energy limits the fitness (e.g. body size and reproduction) and population density

  15. Three decades (1983-2010) of contaminant trends in East Greenland polar bears (Ursus maritimus). Part 2: brominated flame retardants.

    Science.gov (United States)

    Dietz, Rune; Rigét, Frank F; Sonne, Christian; Born, Erik W; Bechshøft, Thea; McKinney, Melissa A; Drimmie, Robert J; Muir, Derek C G; Letcher, Robert J

    2013-09-01

    Brominated flame retardants were determined in adipose tissues from 294 polar bears (Ursus maritimus) sampled in East Greenland in 23 of the 28years between 1983 and 2010. Significant linear increases were found for sum polybrominated diphenyl ether (ΣPBDE), BDE100, BDE153, and hexabromocyclododecane (HBCD). Average increases of 5.0% per year (range: 2.9-7.6%/year) were found for the subadult polar bears. BDE47 and BDE99 concentrations did not show a significant linear trend over time, but rather a significant non-linear trend peaking between 2000 and 2004. The average ΣPBDE concentrations increased 2.3 fold from 25.0ng/g lw (95% C.I.: 15.3-34.7ng/g lw) in 1983-1986 to 58.5ng/g lw (95% C.I.: 43.6-73.4ng/g lw) in 2006-2010. Similar but fewer statistically significant trends were found for adult females and adult males likely due to smaller sample size and years. Analyses of δ(15)N and δ(13)C stable isotopes in hair revealed no clear linear temporal trends in trophic level or carbon source, respectively, and non-linear trends differed among sex and age groups. These increasing concentrations of organobromine contaminants contribute to complex organohalogen mixture, already causing health effects to the East Greenland polar bears. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Skull pathology in East Greenland and Svalbard polar bears (Ursus maritimus) during 1892 to 2002 in relation to organochlorine pollution

    International Nuclear Information System (INIS)

    Sonne, Christian; Riget, Frank F.; Dietz, Rune; Wiig, Oystein; Kirkegaard, Maja; Born, Erik W.

    2007-01-01

    East Greenland and Svalbard polar bears (Ursus maritimus) are heavily polluted with long-range transported organochlorines such as PCBs (polychlorinated biphenyls). To investigate the negative health impacts, a time-trend study of skull pathology was conducted on 269 East Greenland and 241 Svalbard polar bears. The skulls were sampled during 1892-2002 and 1964-1992, respectively. Seven different pathological changes were found: adonti, displacement of teeth, caries, osseous proliferations, exostosis, tooth wear and periodontitis. Only tooth wear and periodontitis was in a prevalence that allowed statistical treatment. The most severe cases of tooth wear and periodontitis were accompanied by a substantial loss of alveolar bone structure. The prevalence of tooth wear and periodontitis increased significantly with age (p < 0.001) with incisor wear being more severe than in canines, premolars and molars (p < 0.001). No sex difference was found for tooth wear (p = 0.22) while a significant difference between sexes was found for periodontitis (p = 0.01) with males having higher prevalence than females (odds ratio of 2.5 for males:females). In East Greenland, the prevalence of tooth wear was significantly higher in polar bears collected in the pre pollution period (< 1960) than in bears sampled during polluted periods (1960-1980 and 1981-2002) (p < 0.001). Regarding periodontitis, the prevalence was not significantly different between pre-pollution and pollution periods (p = 0.309). Polar bears from Svalbard had significantly higher prevalence of tooth wear (p < 0.001) and periodontitis (p = 0.02) than polar bears from East Greenland. The tooth wear and periodontitis odds ratios for Svalbard:East Greenland were 135 and 2.6, respectively. Hence, we found a clear age/sex link and geographical difference but no evidence for an association between skull pathology and exposure to organochlorines in East Greenland and Svalbard polar bears

  17. Skull pathology in East Greenland and Svalbard polar bears (Ursus maritimus) during 1892 to 2002 in relation to organochlorine pollution

    Energy Technology Data Exchange (ETDEWEB)

    Sonne, Christian [National Environmental Research Institute, Department of Arctic Environment, Frederiksborgvej 399, DK-4000 Roskilde (Denmark) and Department of Veterinary Basic Sciences, Royal Veterinary and Agricultural University, Buelowsvej 17, DK-1870 Frederiksberg C (Denmark)]. E-mail: csh@dmu.dk; Riget, Frank F. [National Environmental Research Institute, Department of Arctic Environment, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Dietz, Rune [National Environmental Research Institute, Department of Arctic Environment, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Wiig, Oystein [Natural History Museum, University of Oslo, PO Box 1172 Blindern, N-0562 Oslo (Norway); Kirkegaard, Maja [National Environmental Research Institute, Department of Arctic Environment, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Born, Erik W. [Greenland Institute of Natural Resources, PO Box 570, DK-3900 Nuuk, Greenland (Denmark)

    2007-01-01

    East Greenland and Svalbard polar bears (Ursus maritimus) are heavily polluted with long-range transported organochlorines such as PCBs (polychlorinated biphenyls). To investigate the negative health impacts, a time-trend study of skull pathology was conducted on 269 East Greenland and 241 Svalbard polar bears. The skulls were sampled during 1892-2002 and 1964-1992, respectively. Seven different pathological changes were found: adonti, displacement of teeth, caries, osseous proliferations, exostosis, tooth wear and periodontitis. Only tooth wear and periodontitis was in a prevalence that allowed statistical treatment. The most severe cases of tooth wear and periodontitis were accompanied by a substantial loss of alveolar bone structure. The prevalence of tooth wear and periodontitis increased significantly with age (p < 0.001) with incisor wear being more severe than in canines, premolars and molars (p < 0.001). No sex difference was found for tooth wear (p = 0.22) while a significant difference between sexes was found for periodontitis (p = 0.01) with males having higher prevalence than females (odds ratio of 2.5 for males:females). In East Greenland, the prevalence of tooth wear was significantly higher in polar bears collected in the pre pollution period (< 1960) than in bears sampled during polluted periods (1960-1980 and 1981-2002) (p < 0.001). Regarding periodontitis, the prevalence was not significantly different between pre-pollution and pollution periods (p = 0.309). Polar bears from Svalbard had significantly higher prevalence of tooth wear (p < 0.001) and periodontitis (p = 0.02) than polar bears from East Greenland. The tooth wear and periodontitis odds ratios for Svalbard:East Greenland were 135 and 2.6, respectively. Hence, we found a clear age/sex link and geographical difference but no evidence for an association between skull pathology and exposure to organochlorines in East Greenland and Svalbard polar bears.

  18. Fractal analysis of polar bear hairs

    Directory of Open Access Journals (Sweden)

    Wang Qing-Li

    2015-01-01

    Full Text Available Hairs of a polar bear (Ursus maritimus are of superior properties such as the excellent thermal protection. Why do polar bears can resist such cold environment? The paper concludes that its fractal porosity plays an important role, and its fractal dimensions are very close to the golden mean, 1.618, revealing the possible optimal structure of polar bear hair.

  19. Confronting uncertainty in wildlife management: performance of grizzly bear management.

    Science.gov (United States)

    Artelle, Kyle A; Anderson, Sean C; Cooper, Andrew B; Paquet, Paul C; Reynolds, John D; Darimont, Chris T

    2013-01-01

    Scientific management of wildlife requires confronting the complexities of natural and social systems. Uncertainty poses a central problem. Whereas the importance of considering uncertainty has been widely discussed, studies of the effects of unaddressed uncertainty on real management systems have been rare. We examined the effects of outcome uncertainty and components of biological uncertainty on hunt management performance, illustrated with grizzly bears (Ursus arctos horribilis) in British Columbia, Canada. We found that both forms of uncertainty can have serious impacts on management performance. Outcome uncertainty alone--discrepancy between expected and realized mortality levels--led to excess mortality in 19% of cases (population-years) examined. Accounting for uncertainty around estimated biological parameters (i.e., biological uncertainty) revealed that excess mortality might have occurred in up to 70% of cases. We offer a general method for identifying targets for exploited species that incorporates uncertainty and maintains the probability of exceeding mortality limits below specified thresholds. Setting targets in our focal system using this method at thresholds of 25% and 5% probability of overmortality would require average target mortality reductions of 47% and 81%, respectively. Application of our transparent and generalizable framework to this or other systems could improve management performance in the presence of uncertainty.

  20. Confronting uncertainty in wildlife management: performance of grizzly bear management.

    Directory of Open Access Journals (Sweden)

    Kyle A Artelle

    Full Text Available Scientific management of wildlife requires confronting the complexities of natural and social systems. Uncertainty poses a central problem. Whereas the importance of considering uncertainty has been widely discussed, studies of the effects of unaddressed uncertainty on real management systems have been rare. We examined the effects of outcome uncertainty and components of biological uncertainty on hunt management performance, illustrated with grizzly bears (Ursus arctos horribilis in British Columbia, Canada. We found that both forms of uncertainty can have serious impacts on management performance. Outcome uncertainty alone--discrepancy between expected and realized mortality levels--led to excess mortality in 19% of cases (population-years examined. Accounting for uncertainty around estimated biological parameters (i.e., biological uncertainty revealed that excess mortality might have occurred in up to 70% of cases. We offer a general method for identifying targets for exploited species that incorporates uncertainty and maintains the probability of exceeding mortality limits below specified thresholds. Setting targets in our focal system using this method at thresholds of 25% and 5% probability of overmortality would require average target mortality reductions of 47% and 81%, respectively. Application of our transparent and generalizable framework to this or other systems could improve management performance in the presence of uncertainty.

  1. Oak-Black Bear Relationships in Southeastern Uplands

    Science.gov (United States)

    Joseph D. Clark

    2004-01-01

    Bears (Ursus americanus) primarily occur in upland habitats in the Southeast because uplands were the last to be developed for agriculture and were more likely to become publicly owned. National parks and forests created in the early to mid-1900s served as sources to supply surrounding uplands with bears. Bears could not survive in southeastern...

  2. Selecting the best stable isotope mixing model to estimate grizzly bear diets in the Greater Yellowstone Ecosystem.

    Directory of Open Access Journals (Sweden)

    John B Hopkins

    Full Text Available Past research indicates that whitebark pine seeds are a critical food source for Threatened grizzly bears (Ursus arctos in the Greater Yellowstone Ecosystem (GYE. In recent decades, whitebark pine forests have declined markedly due to pine beetle infestation, invasive blister rust, and landscape-level fires. To date, no study has reliably estimated the contribution of whitebark pine seeds to the diets of grizzlies through time. We used stable isotope ratios (expressed as δ13C, δ15N, and δ34S values measured in grizzly bear hair and their major food sources to estimate the diets of grizzlies sampled in Cooke City Basin, Montana. We found that stable isotope mixing models that included different combinations of stable isotope values for bears and their foods generated similar proportional dietary contributions. Estimates generated by our top model suggest that whitebark pine seeds (35±10% and other plant foods (56±10% were more important than meat (9±8% to grizzly bears sampled in the study area. Stable isotope values measured in bear hair collected elsewhere in the GYE and North America support our conclusions about plant-based foraging. We recommend that researchers consider model selection when estimating the diets of animals using stable isotope mixing models. We also urge researchers to use the new statistical framework described here to estimate the dietary responses of grizzlies to declines in whitebark pine seeds and other important food sources through time in the GYE (e.g., cutthroat trout, as such information could be useful in predicting how the population will adapt to future environmental change.

  3. Carnivore re-colonisation: Reality, possibility and a non-equilibrium century for grizzly bears in the southern Yellowstone ecosystem

    Science.gov (United States)

    Pyare, Sanjay; Cain, S.; Moody, D.; Schwartz, C.; Berger, J.

    2004-01-01

    Most large native carnivores have experienced range contractions due to conflicts with humans, although neither rates of spatial collapse nor expansion have been well characterised. In North America, the grizzly bear (Ursus arctos) once ranged from Mexico northward to Alaska, however its range in the continental USA has been reduced by 95-98%. Under the U. S. Endangered Species Act, the Yellowstone grizzly bear population has re-colonised habitats outside Yellowstone National Park. We analysed historical and current records, including data on radio-collared bears, (1) to evaluate changes in grizzly bear distribution in the southern Greater Yellowstone Ecosystem (GYE) over a 100-year period, (2) to utilise historical rates of re-colonisation to project future expansion trends and (3) to evaluate the reality of future expansion based on human limitations and land use. Analysis of distribution in 20-year increments reflects range reduction from south to north (1900-1940) and expansion to the south (1940-2000). Expansion was exponential and the area occupied by grizzly bears doubled approximately every 20 years. A complementary analysis of bear occurrence in Grand Teton National Park also suggests an unprecedented period of rapid expansion during the last 20-30 years. The grizzly bear population currently has re-occupied about 50% of the southern GYE. Based on assumptions of continued protection and ecological stasis, our model suggests total occupancy in 25 years. Alternatively, extrapolation of linear expansion rates from the period prior to protection suggests total occupancy could take > 100 years. Analyses of historical trends can be useful as a restoration tool because they enable a framework and timeline to be constructed to pre-emptively address the social challenges affecting future carnivore recovery. ?? 2004 The Zoological Society of London.

  4. Immobilization of Asiatic Black Bears ( Ursus thibetanus ) with Medetomidine-Zolazepam-Tiletamine in South Korea.

    Science.gov (United States)

    Jeong, Dong-Hyuk; Yang, Jeong-Jin; Seok, Seong-Hoon; Song, Byeung-Cheul; Yeon, Seong-Chan

    2017-07-01

    The Asiatic black bear ( Ursus thibetanus ; ABB) is a globally endangered species for which a restoration program has been ongoing in South Korea since 2001. However, there is little information on immobilization protocols for ABBs. We evaluated the use of medetomidine-zolazepam-tiletamine for their immobilization. During 2005-13, we anesthetized 60 ABBs (32 males, 28 females; 7 mo to 12 yr old) with medetomidine 0.03-0.045 mg/kg and zolazepam-tiletamine 1.54-2.3 mg/kg; reversal of anesthesia was done with atipamezole 0.15-0.225 mg/kg administered intravenously alone or intravenously and intramuscularly (50:50). Mean (and SD) for physiologic collected for 373 immobilizations of at least 60 min were: time to sedation, 7.8 (5.4) min; anesthesia induction time, 13.7 (8.1) min; complete recovery time, 14.8 (12.4) min; respiratory rate, 14 (7) breaths/min; heart rate, 51 (16) beats/min; rectal temperature, 37.3 (1.3) C; and hemoglobin oxygen saturation, 88% (6%). Few cardiopulmonary side effects occurred during immobilization and adequate depth of anesthesia was maintained for >60 min without need for supplementation. The dosage and drug combination used was effective for immobilization of ABBs with minimal adverse effects on vital signs and can be recommended in most clinical applications.

  5. Detecting grizzly bear use of ungulate carcasses using global positioning system telemetry and activity data

    Science.gov (United States)

    Ebinger, Michael R.; Haroldson, Mark A.; van Manen, Frank T.; Costello, Cecily M.; Bjornlie, Daniel D.; Thompson, Daniel J.; Gunther, Kerry A.; Fortin, Jennifer K.; Teisberg, Justin E.; Pils, Shannon R; White, P J; Cain, Steven L.; Cross, Paul C.

    2016-01-01

    Global positioning system (GPS) wildlife collars have revolutionized wildlife research. Studies of predation by free-ranging carnivores have particularly benefited from the application of location clustering algorithms to determine when and where predation events occur. These studies have changed our understanding of large carnivore behavior, but the gains have concentrated on obligate carnivores. Facultative carnivores, such as grizzly/brown bears (Ursus arctos), exhibit a variety of behaviors that can lead to the formation of GPS clusters. We combined clustering techniques with field site investigations of grizzly bear GPS locations (n = 732 site investigations; 2004–2011) to produce 174 GPS clusters where documented behavior was partitioned into five classes (large-biomass carcass, small-biomass carcass, old carcass, non-carcass activity, and resting). We used multinomial logistic regression to predict the probability of clusters belonging to each class. Two cross-validation methods—leaving out individual clusters, or leaving out individual bears—showed that correct prediction of bear visitation to large-biomass carcasses was 78–88%, whereas the false-positive rate was 18–24%. As a case study, we applied our predictive model to a GPS data set of 266 bear-years in the Greater Yellowstone Ecosystem (2002–2011) and examined trends in carcass visitation during fall hyperphagia (September–October). We identified 1997 spatial GPS clusters, of which 347 were predicted to be large-biomass carcasses. We used the clustered data to develop a carcass visitation index, which varied annually, but more than doubled during the study period. Our study demonstrates the effectiveness and utility of identifying GPS clusters associated with carcass visitation by a facultative carnivore.

  6. Grizzly bear management in Yellowstone National Park: The heart of recovery in the Yellowstone Ecosystem

    Science.gov (United States)

    Schwartz, C.C.; Gunther, K.; McCullough, Dale R.; Kaji, Koichi; Yamanaka, Masami

    2006-01-01

    Grizzly bear (Ursus arctos) management in the Greater Yellowstone Ecosystem (GYE) in the past quarter century has resulted in more than doubling of the population from around 200 to more than 500, expansion of range back into habitats where the bear has extirpated more than a century ago, and a move toward removal from the U.S. Endangered Species list. At the center of this success story are the management programs in Yellowstone National Park (YNP). Regulations that restrict human activity, camping, and food storage, elimination of human food and garbage as attractants, and ranger attendance of roadside bears have all resulted in the population of grizzlies in YNP approaching carrying capacity. Recent studies suggest, however, that YNP alone is too small to support the current population, making management beyond the park boundary important and necessary to the demographics of the population as a whole. Demographic analyses suggest a source-sink dynamic exists within the GYE, with YNP and lands outside the park within the Grizzly Bear Recovery Zone (RZ) representing source habitats, whereas lands beyond the RZ constitute sinks. The source-sink demography in the GYE is indicative of carnivore conservation issues worldwide where many national parks or preserves designed to protect out natural resources are inadequate in size or shape to provide all necessary life history requirements for these wide-ranging species. Additionally, wide-ranging behavior and long-distance dispersal seem inherent to large carnivores, so mortality around the edges is virtually inevitable, and conservation in the GYE is inextricably linked to management regimes not only within YNP, but within the GYE as a whole. We discuss those needs here.

  7. Conservation Strategy for Brown Bear and Its Habitat in Nepal

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    Achyut Aryal

    2012-08-01

    Full Text Available The Himalaya region of Nepal encompasses significant habitats for several endangered species, among them the brown bear (Ursus arctos pruinosus. However, owing to the remoteness of the region and a dearth of research, knowledge on the conservation status, habitat and population size of this species is lacking. Our aim in this paper is to report a habitat survey designed to assess the distribution and habitat characteristics of the brown bear in the Nepalese Himalaya, and to summarize a conservation action plan for the species devised at a pair of recent workshops held in Nepal. Results of our survey showed that brown bear were potentially distributed between 3800 m and 5500 m in the high mountainous region of Nepal, across an area of 4037 km2 between the eastern border of Shey Phoksundo National Park (SPNP and the Manasalu Conservation Area (MCA. Of that area, 2066 km2 lie inside the protected area (350 km2 in the MCA; 1716 km2 in the Annapurna Conservation Area and 48% (1917 km2 lies outside the protected area in the Dolpa district. Furthermore, 37% of brown bear habitat also forms a potential habitat for blue sheep (or bharal, Pseudois nayaur, and 17% of these habitats is used by livestock, suggesting a significant potential for resource competition. Several plant species continue to be uprooted by local people for fuel wood. Based on the results of our field survey combined with consultations with local communities and scientists, we propose that government and non-government organizations should implement a three-stage program of conservation activities for the brown bear. This program should: (a Detail research activities in and outside the protected area of Nepal; (b support livelihood and conservation awareness at local and national levels; and (c strengthen local capacity and reduce human-wildlife conflict in the region.

  8. Changes in expression of hepatic genes involved in energy metabolism during hibernation in captive, adult, female Japanese black bears (Ursus thibetanus japonicus).

    Science.gov (United States)

    Shimozuru, Michito; Kamine, Akari; Tsubota, Toshio

    2012-10-01

    Hibernating bears survive up to 6 months without feeding by utilizing stored body fat as fuel. To investigate how bears maintain energy homeostasis during hibernation, we analyzed changes in mRNA expression of hepatic genes involved in energy metabolism throughout the hibernation period in captive, adult, female Japanese black bears (Ursus thibetanus japonicus). Real-time PCR analysis revealed down-regulation of glycolysis- (e.g., glucokinase), amino acid catabolism- (e.g., alanine aminotransferase) and de novo lipogenesis-related genes (e.g., acetyl-CoA carboxylase 1), and up-regulation of gluconeogensis- (e.g., pyruvate carboxylase), β-oxidation- (i.e., uncoupling protein 2) and ketogenesis-related genes (i.e., 3-hydroxy-3-methylglutary-CoA synthase 2), during hibernation, compared to the active period (June). In addition, we found that glycolysis-related genes (i.e., glucokinase and pyruvate kinase) were more suppressed in the early phase of hibernation (January) compared to the late phase (March). One week after the commencement of feeding in April, expression levels of most genes returned to levels comparable to those seen in June, but β-oxidation-related genes were still up-regulated during this period. These results suggest that the modulation of gene expression is not static, but changes throughout the hibernation period. The transcriptional modulation during hibernation represents a unique physiological adaptation to prolonged fasting in bears. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Effect of hibernation and reproductive status on body mass and condition of coastal brown bears

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    Hilderbrand, G.V.; Schwartz, C. C.; Robbins, C.T.; Hanley, Thomas A.

    2000-01-01

    We investigated the effect of hibernation and reproductive status on changes in body mass and composition of adult female brown bears (Ursus arctos) on the Kenai Peninsula, Alaska. This information is fundamental to understanding nutritional ecology of wild brown bear populations. Six adult females handled in the fall and following spring (paired samples) lost 73 ± 22 kg (x̄ ± SD; 32 ± 10%) of fall body mass over 208 ± 19 days. Of this mass loss, 56 ± 22% (55 ± 22 kg) was lipid and 44 ± 22% (43 ± 21 kg) was lean body mass. Catabolism of lipid stores accounted for 88.4 ± 8.1% of the body energy used to meet maintenance demands. Overwinter differences in body composition of adult females assessed only once in either the fall (n = 21) or spring (n = 32) were similar to those of paired samples. Relative fatness of bears entering the den was positively related to the contribution of fat (%) to body mass (P < 0.01) and body energy (P < 0.01) losses during hibernation. Thus, relative fatness at the onset of fasting influences the relative proportion of lipid stores and lean body mass catabolized to meet protein and energy demands during hibernation. In the spring, lone females had greater body and lean masses than females with cubs of the year or yearlings. Lipid content was greatest in lone females in the fall. Studies using body mass and composition as indices of population health should consider season or reproductive class.

  10. Assessing Nutritional Parameters of Brown Bear Diets among Ecosystems Gives Insight into Differences among Populations

    Science.gov (United States)

    López-Alfaro, Claudia; Coogan, Sean C. P.; Robbins, Charles T.; Fortin, Jennifer K.; Nielsen, Scott E.

    2015-01-01

    Food habit studies are among the first steps used to understand wildlife-habitat relationships. However, these studies are in themselves insufficient to understand differences in population productivity and life histories, because they do not provide a direct measure of the energetic value or nutritional composition of the complete diet. Here, we developed a dynamic model integrating food habits and nutritional information to assess nutritional parameters of brown bear (Ursus arctos) diets among three interior ecosystems of North America. Specifically, we estimate the average amount of digestible energy and protein (per kilogram fresh diet) content in the diet and across the active season by bears living in western Alberta, the Flathead River (FR) drainage of southeast British Columbia, and the Greater Yellowstone Ecosystem (GYE). As well, we estimate the proportion of energy and protein in the diet contributed by different food items, thereby highlighting important food resources in each ecosystem. Bear diets in Alberta had the lowest levels of digestible protein and energy through all seasons, which might help explain the low reproductive rates of this population. The FR diet had protein levels similar to the recent male diet in the GYE during spring, but energy levels were lower during late summer and fall. Historic and recent diets in GYE had the most energy and protein, which is consistent with their larger body sizes and higher population productivity. However, a recent decrease in consumption of trout (Oncorhynchus clarki), whitebark pine nuts (Pinus albicaulis), and ungulates, particularly elk (Cervus elaphus), in GYE bears has decreased the energy and protein content of their diet. The patterns observed suggest that bear body size and population densities are influenced by seasonal availability of protein an energy, likely due in part to nutritional influences on mass gain and reproductive success. PMID:26083536

  11. Assessing Nutritional Parameters of Brown Bear Diets among Ecosystems Gives Insight into Differences among Populations.

    Science.gov (United States)

    López-Alfaro, Claudia; Coogan, Sean C P; Robbins, Charles T; Fortin, Jennifer K; Nielsen, Scott E

    2015-01-01

    Food habit studies are among the first steps used to understand wildlife-habitat relationships. However, these studies are in themselves insufficient to understand differences in population productivity and life histories, because they do not provide a direct measure of the energetic value or nutritional composition of the complete diet. Here, we developed a dynamic model integrating food habits and nutritional information to assess nutritional parameters of brown bear (Ursus arctos) diets among three interior ecosystems of North America. Specifically, we estimate the average amount of digestible energy and protein (per kilogram fresh diet) content in the diet and across the active season by bears living in western Alberta, the Flathead River (FR) drainage of southeast British Columbia, and the Greater Yellowstone Ecosystem (GYE). As well, we estimate the proportion of energy and protein in the diet contributed by different food items, thereby highlighting important food resources in each ecosystem. Bear diets in Alberta had the lowest levels of digestible protein and energy through all seasons, which might help explain the low reproductive rates of this population. The FR diet had protein levels similar to the recent male diet in the GYE during spring, but energy levels were lower during late summer and fall. Historic and recent diets in GYE had the most energy and protein, which is consistent with their larger body sizes and higher population productivity. However, a recent decrease in consumption of trout (Oncorhynchus clarki), whitebark pine nuts (Pinus albicaulis), and ungulates, particularly elk (Cervus elaphus), in GYE bears has decreased the energy and protein content of their diet. The patterns observed suggest that bear body size and population densities are influenced by seasonal availability of protein an energy, likely due in part to nutritional influences on mass gain and reproductive success.

  12. Assessing Nutritional Parameters of Brown Bear Diets among Ecosystems Gives Insight into Differences among Populations.

    Directory of Open Access Journals (Sweden)

    Claudia López-Alfaro

    Full Text Available Food habit studies are among the first steps used to understand wildlife-habitat relationships. However, these studies are in themselves insufficient to understand differences in population productivity and life histories, because they do not provide a direct measure of the energetic value or nutritional composition of the complete diet. Here, we developed a dynamic model integrating food habits and nutritional information to assess nutritional parameters of brown bear (Ursus arctos diets among three interior ecosystems of North America. Specifically, we estimate the average amount of digestible energy and protein (per kilogram fresh diet content in the diet and across the active season by bears living in western Alberta, the Flathead River (FR drainage of southeast British Columbia, and the Greater Yellowstone Ecosystem (GYE. As well, we estimate the proportion of energy and protein in the diet contributed by different food items, thereby highlighting important food resources in each ecosystem. Bear diets in Alberta had the lowest levels of digestible protein and energy through all seasons, which might help explain the low reproductive rates of this population. The FR diet had protein levels similar to the recent male diet in the GYE during spring, but energy levels were lower during late summer and fall. Historic and recent diets in GYE had the most energy and protein, which is consistent with their larger body sizes and higher population productivity. However, a recent decrease in consumption of trout (Oncorhynchus clarki, whitebark pine nuts (Pinus albicaulis, and ungulates, particularly elk (Cervus elaphus, in GYE bears has decreased the energy and protein content of their diet. The patterns observed suggest that bear body size and population densities are influenced by seasonal availability of protein an energy, likely due in part to nutritional influences on mass gain and reproductive success.

  13. Isotopic incorporation and the effects of fasting and dietary lipid content on isotopic discrimination in large carnivorous mammals

    Science.gov (United States)

    Rode, Karyn D.; Stricker, Craig A.; Erlenbach, Joy; Robbins, Charles T.; Cherry, Seth; Newsome, Seth D.; Cutting, Amy; Jensen, Shannon; Stenhouse, Gordon; Brooks, Matt; Hash, Amy; Nicassio, Nicole

    2016-01-01

    There has been considerable emphasis on understanding isotopic discrimination for diet estimation in omnivores. However, discrimination may differ for carnivores, particularly species that consume lipid-rich diets. Here, we examined the potential implications of several factors when using stable isotopes to estimate the diets of bears, which can consume lipid-rich diets and, alternatively, fast for weeks to months. We conducted feeding trials with captive brown bears (Ursus arctos) and polar bears (Ursus maritimus). As dietary lipid content increased to ∼90%, we observed increasing differences between blood plasma and diets that had not been lipid extracted (∆13Ctissue-bulk diet) and slightly decreasing differences between plasma δ13C and lipid-extracted diet. Plasma Δ15Ntissue-bulk diet increased with increasing protein content for the four polar bears in this study and data for other mammals from previous studies that were fed purely carnivorous diets. Four adult and four yearling brown bears that fasted 120 d had plasma δ15N values that changed by <±2‰. Fasting bears exhibited no trend in plasma δ13C. Isotopic incorporation in red blood cells and whole blood was ≥6 mo in subadult and adult bears, which is considerably longer than previously measured in younger and smaller black bears (Ursus americanus). Our results suggest that short-term fasting in carnivores has minimal effects on δ13C and δ15N discrimination between predators and their prey but that dietary lipid content is an important factor directly affecting δ13C discrimination and indirectly affecting δ15N discrimination via the inverse relationship with dietary protein content.

  14. Grizzly bear denning chronology and movements in the Greater Yellowstone Ecosystem

    Science.gov (United States)

    Haroldson, Mark A.; Ternent, Mark A.; Gunther, Kerry A.; Schwartz, Charles C.

    2002-01-01

    Den entrance and emergence dates of grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem are important to management agencies that wish to minimize impacts of human activities on bears. Current estimates for grizzly bear denning events use data that were collected from 1975–80. We update these estimates by including data obtained from 1981–99. We used aerial telemetry data to estimate week of den entry and emergence by determining the midpoint between the last known active date and the first known date denned, as well as the last known date denned and the first known active date. We also investigated post emergence movement patterns relative to den locations. Mean earliest and latest week of den entry and emergence were also determined. Den entry for females began during the fourth week in September, with 90% denned by the fourth week of November. Earliest den entry for males occurred during the second week of October, with 90% denned by the second week of December. Mean week of den entry for known pregnant females was earlier than males. Earliest week of den entry for known pregnant females was earlier than other females and males. Earliest den emergence for males occurred during the first week of February, with 90% of males out of dens by the fourth week of April. Earliest den emergence for females occurred during the third week of March; by the first week of May, 90% of females had emerged. Male bears emerged from dens earlier than females. Denning period differed among classes and averaged 171 days for females that emerged from dens with cubs, 151 days for other females, and 131 days for males. Known pregnant females tended to den at higher elevations and, following emergence, remained at higher elevation until late May. Females with cubs remained relatively close (grizzly bear populations in the southern Rocky Mountains. 

  15. Brain region distribution and patterns of bioaccumulative perfluoroalkyl carboxylates and sulfonates in east greenland polar bears (Ursus maritimus).

    Science.gov (United States)

    Greaves, Alana K; Letcher, Robert J; Sonne, Christian; Dietz, Rune

    2013-03-01

    The present study investigated the comparative accumulation of perfluoroalkyl acids (PFAAs) in eight brain regions of polar bears (Ursus maritimus, n = 19) collected in 2006 from Scoresby Sound, East Greenland. The PFAAs studied were perfluoroalkyl carboxylates (PFCAs, C(6) -C(15) chain lengths) and sulfonates (C(4) , C(6) , C(8) , and C(10) chain lengths) as well as selected precursors including perfluorooctane sulfonamide. On a wet-weight basis, blood-brain barrier transport of PFAAs occurred for all brain regions, although inner regions of the brain closer to incoming blood flow (pons/medulla, thalamus, and hypothalamus) contained consistently higher PFAA concentrations compared to outer brain regions (cerebellum, striatum, and frontal, occipital, and temporal cortices). For pons/medulla, thalamus, and hypothalamus, the most concentrated PFAAs were perfluorooctane sulfonate (PFOS), ranging from 47 to 58 ng/g wet weight, and perfluorotridecanoic acid, ranging from 43 to 49 ng/g wet weight. However, PFOS and the longer-chain PFCAs (C(10) -C(15) ) were significantly (p  0.05) different among brain regions. The burden of the sum of PFCAs, perfluoroalkyl sulfonates, and perfluorooctane sulfonamide in the brain (average mass, 392 g) was estimated to be 46 µg. The present study demonstrates that both PFCAs and perfluoroalkyl sulfonates cross the blood-brain barrier in polar bears and that wet-weight concentrations are brain region-specific. Copyright © 2012 SETAC.

  16. Change in body weight of mothers and neonates and in milk composition during denning period in captive Japanese black bears (Ursus thibetanus japonicus).

    Science.gov (United States)

    Iibuchi, Ruriko; Nakano, Noriko; Nakamura, Tadashi; Urashima, Tadasu; Shimozuru, Michito; Murase, Tetsuma; Tsubota, Toshio

    2009-05-01

    Japanese black bears, Ursus thibetanus japonicus, have been classified as a vulnerable species so that data on reproduction are needed to maintain and/or extend their population. They are known to have a peculiar style of reproduction, giving birth to their neonates and raising them during denning, a period of complete fasting. In this study, we investigated the metabolic rate and milk composition of mother bears raising neonates, and the changes in body weight of the neonates under captive conditions. Seven female bears kept in dens were weighed once a month, and the amount of energy they used was calculated. From birth, cubs were also weighed and their growth rate was determined. In addition, the milk composition was analyzed to investigate its characteristics. As a result, it was found that mother bears used 34% more energy than did solitary females. There was no significant difference in the energy used for nursing whether they had single or twin cubs. On the other hand, the body weight gain of single cubs was significantly higher than that of twin cubs, suggesting that the growth of the cubs was highly affected by the suppression of mother's energy consumption during the fasting period. The milk had high fat and low sugar concentrations. This indicates that mother bears used the fat accumulated prior to denning for their main energy source when raising cubs. Considering all results together, Japanese black bears showed remarkable efficiency in the use of energy for reproduction during the fasting period.

  17. Transthyretin-binding activity of contaminants in blood from polar bear (Ursus maritimus) cubs.

    Science.gov (United States)

    Bytingsvik, Jenny; Simon, Eszter; Leonards, Pim E G; Lamoree, Marja; Lie, Elisabeth; Aars, Jon; Derocher, Andrew E; Wiig, Oystein; Jenssen, Bjørn M; Hamers, Timo

    2013-05-07

    We determined the transthyretin (TTR)-binding activity of blood-accumulating contaminants in blood plasma samples of approximately 4-months-old polar bear (Ursus maritimus) cubs from Svalbard sampled in 1998 and 2008. The TTR-binding activity was measured as thyroxine (T4)-like equivalents (T4-EQMeas). Our findings show that the TTR-binding activity related to contaminant levels was significantly lower (45%) in 2008 than in 1998 (mean ± standard error of mean: 1998, 2265 ± 231 nM; 2008, 1258 ± 170 nM). Although we cannot exclude a potential influence of between-year differences in capture location and cub body mass, our findings most likely reflect reductions of TTR-binding contaminants or their precursors in the arctic environment (e.g., polychlorinated biphenyls [PCBs]). The measured TTR-binding activity correlated positively with the cubs' plasma levels of hydroxylated PCBs (OH-PCBs). No such association was found between TTR-binding activity and the plasma levels of perfluoroalkyl substances (PFASs). The OH-PCBs explained 60 ± 7% and 54 ± 4% of the TTR-binding activity in 1998 and 2008, respectively, and PFASs explained ≤1.2% both years. Still, almost half the TTR-binding activity could not be explained by the contaminants we examined. The considerable levels of TTR-binding contaminants warrant further effect directed analysis (EDA) to identify the contaminants responsible for the unexplained part of the observed TTR-binding activity.

  18. Application of large-scale parentage analysis for investigating natal dispersal in highly vagile vertebrates: a case study of American black bears (Ursus americanus).

    Science.gov (United States)

    Moore, Jennifer A; Draheim, Hope M; Etter, Dwayne; Winterstein, Scott; Scribner, Kim T

    2014-01-01

    Understanding the factors that affect dispersal is a fundamental question in ecology and conservation biology, particularly as populations are faced with increasing anthropogenic impacts. Here we collected georeferenced genetic samples (n = 2,540) from three generations of black bears (Ursus americanus) harvested in a large (47,739 km2), geographically isolated population and used parentage analysis to identify mother-offspring dyads (n = 337). We quantified the effects of sex, age, habitat type and suitability, and local harvest density at the natal and settlement sites on the probability of natal dispersal, and on dispersal distances. Dispersal was male-biased (76% of males dispersed) but a small proportion (21%) of females also dispersed, and female dispersal distances (mean ± SE  =  48.9±7.7 km) were comparable to male dispersal distances (59.0±3.2 km). Dispersal probabilities and dispersal distances were greatest for bears in areas with high habitat suitability and low harvest density. The inverse relationship between dispersal and harvest density in black bears suggests that 1) intensive harvest promotes restricted dispersal, or 2) high black bear population density decreases the propensity to disperse. Multigenerational genetic data collected over large landscape scales can be a powerful means of characterizing dispersal patterns and causal associations with demographic and landscape features in wild populations of elusive and wide-ranging species.

  19. Application of large-scale parentage analysis for investigating natal dispersal in highly vagile vertebrates: a case study of American black bears (Ursus americanus.

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    Jennifer A Moore

    Full Text Available Understanding the factors that affect dispersal is a fundamental question in ecology and conservation biology, particularly as populations are faced with increasing anthropogenic impacts. Here we collected georeferenced genetic samples (n = 2,540 from three generations of black bears (Ursus americanus harvested in a large (47,739 km2, geographically isolated population and used parentage analysis to identify mother-offspring dyads (n = 337. We quantified the effects of sex, age, habitat type and suitability, and local harvest density at the natal and settlement sites on the probability of natal dispersal, and on dispersal distances. Dispersal was male-biased (76% of males dispersed but a small proportion (21% of females also dispersed, and female dispersal distances (mean ± SE  =  48.9±7.7 km were comparable to male dispersal distances (59.0±3.2 km. Dispersal probabilities and dispersal distances were greatest for bears in areas with high habitat suitability and low harvest density. The inverse relationship between dispersal and harvest density in black bears suggests that 1 intensive harvest promotes restricted dispersal, or 2 high black bear population density decreases the propensity to disperse. Multigenerational genetic data collected over large landscape scales can be a powerful means of characterizing dispersal patterns and causal associations with demographic and landscape features in wild populations of elusive and wide-ranging species.

  20. Six months of disuse during hibernation does not increase intracortical porosity or decrease cortical bone geometry, strength, or mineralization in black bear (Ursus americanus) femurs.

    Science.gov (United States)

    McGee-Lawrence, Meghan E; Wojda, Samantha J; Barlow, Lindsay N; Drummer, Thomas D; Bunnell, Kevin; Auger, Janene; Black, Hal L; Donahue, Seth W

    2009-07-22

    Disuse typically uncouples bone formation from resorption, leading to bone loss which compromises bone mechanical properties and increases the risk of bone fracture. Previous studies suggest that bears can prevent bone loss during long periods of disuse (hibernation), but small sample sizes have limited the conclusions that can be drawn regarding the effects of hibernation on bone structure and strength in bears. Here we quantified the effects of hibernation on structural, mineral, and mechanical properties of black bear (Ursus americanus) cortical bone by studying femurs from large groups of male and female bears (with wide age ranges) killed during pre-hibernation (fall) and post-hibernation (spring) periods. Bone properties that are affected by body mass (e.g. bone geometrical properties) tended to be larger in male compared to female bears. There were no differences (p>0.226) in bone structure, mineral content, or mechanical properties between fall and spring bears. Bone geometrical properties differed by less than 5% and bone mechanical properties differed by less than 10% between fall and spring bears. Porosity (fall: 5.5+/-2.2%; spring: 4.8+/-1.6%) and ash fraction (fall: 0.694+/-0.011; spring: 0.696+/-0.010) also showed no change (p>0.304) between seasons. Statistical power was high (>72%) for these analyses. Furthermore, bone geometrical properties and ash fraction (a measure of mineral content) increased with age and porosity decreased with age. These results support the idea that bears possess a biological mechanism to prevent disuse and age-related osteoporoses.

  1. Evaluation on the effects of ageing factor, sampling and preservation methods on Asiatic black bear (Ursus thibetanus noninvasive DNA amplification

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    Chih-Chin SHIH

    2017-11-01

    Full Text Available Noninvasive genetic sampling allows studying wildlife without having to catch, handle or even observe individuals. In this study, factors which may affect the quality of noninvasive samples of Asiatic black bear (Ursus thibetanus in the subtropical areas were identified. We collected hair and faecal samples from captive Asiatic black bears and quantitatively evaluated the effects of hair age (from fresh to 60 days, faeces age (from fresh to 14 days, faeces sampling locations (i.e. sample collected from either the surface, inside or a mixture of both the surface and inside of faeces, and faeces preservation methods (frozen or kept at room temperature in 95% ethanol on amplification success rates of mitochondrial DNA fragments of different sizes (450bp, 900bp, and 1600bp. The results showed that the amplification success rates decreased with sample age and amplicon size in both hair and faecal DNA. In subtropical environment, there was no significant difference between amplification success of DNA extracted from fresh and 7-day-old samples of either the hair or faeces. The amplification success rates were not influenced by sampling location of faeces. For faeces preserved in 95% ethanol, the amplification success appeared unaffected by frozen at -20 °C or kept at room temperature in shorter mtDNA fragments, but was significantly influenced when amplicon size was 1600bp. The results of this study will reinforce the optimization of noninvasive sampling approaches in Asiatic black bear research, especially in the subtropics.

  2. Despotism and risk of infanticide influence grizzly bear den-site selection.

    Science.gov (United States)

    Libal, Nathan S; Belant, Jerrold L; Leopold, Bruce D; Wang, Guiming; Owen, Patricia A

    2011-01-01

    Given documented social dominance and intraspecific predation in bear populations, the ideal despotic distribution model and sex hypothesis of sexual segregation predict adult female grizzly bears (Ursus arctos) will avoid areas occupied by adult males to reduce risk of infanticide. Under ideal despotic distribution, juveniles should similarly avoid adult males to reduce predation risk. Den-site selection and use is an important component of grizzly bear ecology and may be influenced by multiple factors, including risk from conspecifics. To test the role of predation risk and the sex hypothesis of sexual segregation, we compared adult female (n = 142), adult male (n = 36), and juvenile (n = 35) den locations in Denali National Park and Preserve, Alaska, USA. We measured elevation, aspect, slope, and dominant land cover for each den site, and used maximum entropy modeling to determine which variables best predicted den sites. We identified the global model as the best-fitting model for adult female (area under curve (AUC) = 0.926) and elevation as the best predictive variable for adult male (AUC = 0.880) den sites. The model containing land cover and elevation best-predicted juvenile (AUC = 0.841) den sites. Adult females spatially segregated from adult males, with dens characterized by higher elevations (mean= 1,412 m, SE = 52) and steeper slopes (mean = 21.9°, SE = 1.1) than adult male (elevation: mean = 1,209 m, SE = 76; slope: mean = 15.6°, SE = 1.9) den sites. Juveniles used a broad range of landscape attributes but did not avoid adult male denning areas. Observed spatial segregation by adult females supports the sex hypothesis of sexual segregation and we suggest is a mechanism to reduce risk of infanticide. Den site selection of adult males is likely related to distribution of food resources during spring.

  3. Implications of the circumpolar genetic structure of polar bears for their conservation in a rapidly warming Arctic.

    Directory of Open Access Journals (Sweden)

    Elizabeth Peacock

    Full Text Available We provide an expansive analysis of polar bear (Ursus maritimus circumpolar genetic variation during the last two decades of decline in their sea-ice habitat. We sought to evaluate whether their genetic diversity and structure have changed over this period of habitat decline, how their current genetic patterns compare with past patterns, and how genetic demography changed with ancient fluctuations in climate. Characterizing their circumpolar genetic structure using microsatellite data, we defined four clusters that largely correspond to current ecological and oceanographic factors: Eastern Polar Basin, Western Polar Basin, Canadian Archipelago and Southern Canada. We document evidence for recent (ca. last 1-3 generations directional gene flow from Southern Canada and the Eastern Polar Basin towards the Canadian Archipelago, an area hypothesized to be a future refugium for polar bears as climate-induced habitat decline continues. Our data provide empirical evidence in support of this hypothesis. The direction of current gene flow differs from earlier patterns of gene flow in the Holocene. From analyses of mitochondrial DNA, the Canadian Archipelago cluster and the Barents Sea subpopulation within the Eastern Polar Basin cluster did not show signals of population expansion, suggesting these areas may have served also as past interglacial refugia. Mismatch analyses of mitochondrial DNA data from polar and the paraphyletic brown bear (U. arctos uncovered offset signals in timing of population expansion between the two species, that are attributed to differential demographic responses to past climate cycling. Mitogenomic structure of polar bears was shallow and developed recently, in contrast to the multiple clades of brown bears. We found no genetic signatures of recent hybridization between the species in our large, circumpolar sample, suggesting that recently observed hybrids represent localized events. Documenting changes in subpopulation

  4. Implications of the circumpolar genetic structure of polar bears for their conservation in a rapidly warming Arctic.

    Science.gov (United States)

    Peacock, Elizabeth; Sonsthagen, Sarah A; Obbard, Martyn E; Boltunov, Andrei; Regehr, Eric V; Ovsyanikov, Nikita; Aars, Jon; Atkinson, Stephen N; Sage, George K; Hope, Andrew G; Zeyl, Eve; Bachmann, Lutz; Ehrich, Dorothee; Scribner, Kim T; Amstrup, Steven C; Belikov, Stanislav; Born, Erik W; Derocher, Andrew E; Stirling, Ian; Taylor, Mitchell K; Wiig, Øystein; Paetkau, David; Talbot, Sandra L

    2015-01-01

    We provide an expansive analysis of polar bear (Ursus maritimus) circumpolar genetic variation during the last two decades of decline in their sea-ice habitat. We sought to evaluate whether their genetic diversity and structure have changed over this period of habitat decline, how their current genetic patterns compare with past patterns, and how genetic demography changed with ancient fluctuations in climate. Characterizing their circumpolar genetic structure using microsatellite data, we defined four clusters that largely correspond to current ecological and oceanographic factors: Eastern Polar Basin, Western Polar Basin, Canadian Archipelago and Southern Canada. We document evidence for recent (ca. last 1-3 generations) directional gene flow from Southern Canada and the Eastern Polar Basin towards the Canadian Archipelago, an area hypothesized to be a future refugium for polar bears as climate-induced habitat decline continues. Our data provide empirical evidence in support of this hypothesis. The direction of current gene flow differs from earlier patterns of gene flow in the Holocene. From analyses of mitochondrial DNA, the Canadian Archipelago cluster and the Barents Sea subpopulation within the Eastern Polar Basin cluster did not show signals of population expansion, suggesting these areas may have served also as past interglacial refugia. Mismatch analyses of mitochondrial DNA data from polar and the paraphyletic brown bear (U. arctos) uncovered offset signals in timing of population expansion between the two species, that are attributed to differential demographic responses to past climate cycling. Mitogenomic structure of polar bears was shallow and developed recently, in contrast to the multiple clades of brown bears. We found no genetic signatures of recent hybridization between the species in our large, circumpolar sample, suggesting that recently observed hybrids represent localized events. Documenting changes in subpopulation connectivity will allow

  5. Implications of the circumpolar genetic structure of polar bears for their conservation in a rapidly warming Arctic

    Science.gov (United States)

    Peacock, Elizabeth; Sonsthagen, Sarah A.; Obbard, Martyn E.; Boltunov, Andrei N.; Regehr, Eric V.; Ovsyanikov, Nikita; Aars, Jon; Atkinson, Stephen N.; Sage, George K.; Hope, Andrew G.; Zeyl, Eve; Bachmann, Lutz; Ehrich, Dorothee; Scribner, Kim T.; Amstrup, Steven C.; Belikov, Stanislav; Born, Erik W.; Derocher, Andrew E.; Stirling, Ian; Taylor, Mitchell K.; Wiig, Øystein; Paetkau, David; Talbot, Sandra L.

    2015-01-01

    We provide an expansive analysis of polar bear (Ursus maritimus) circumpolar genetic variation during the last two decades of decline in their sea-ice habitat. We sought to evaluate whether their genetic diversity and structure have changed over this period of habitat decline, how their current genetic patterns compare with past patterns, and how genetic demography changed with ancient fluctuations in climate. Characterizing their circumpolar genetic structure using microsatellite data, we defined four clusters that largely correspond to current ecological and oceanographic factors: Eastern Polar Basin, Western Polar Basin, Canadian Archipelago and Southern Canada. We document evidence for recent (ca. last 1–3 generations) directional gene flow from Southern Canada and the Eastern Polar Basin towards the Canadian Archipelago, an area hypothesized to be a future refugium for polar bears as climate-induced habitat decline continues. Our data provide empirical evidence in support of this hypothesis. The direction of current gene flow differs from earlier patterns of gene flow in the Holocene. From analyses of mitochondrial DNA, the Canadian Archipelago cluster and the Barents Sea subpopulation within the Eastern Polar Basin cluster did not show signals of population expansion, suggesting these areas may have served also as past interglacial refugia. Mismatch analyses of mitochondrial DNA data from polar and the paraphyletic brown bear (U. arctos) uncovered offset signals in timing of population expansion between the two species, that are attributed to differential demographic responses to past climate cycling. Mitogenomic structure of polar bears was shallow and developed recently, in contrast to the multiple clades of brown bears. We found no genetic signatures of recent hybridization between the species in our large, circumpolar sample, suggesting that recently observed hybrids represent localized events. Documenting changes in subpopulation connectivity will

  6. Immunolocalization of steroidogenic enzymes in the corpus luteum and placenta of the Japanese black bear, Ursus thibetanus japonicus, during pregnancy.

    Science.gov (United States)

    Tsubota, T; Taki, S; Nakayama, K; Mason, J I; Kominami, S; Harada, N; Kita, I

    2001-04-01

    The Japanese black bear, Ursus thibetanus japonicus, is a seasonal breeder and shows delayed implantation for several months during pregnancy. The objective of this study was to clarify the steroidogenic capability of the corpus luteum and placenta during pregnancy, including both delayed implantation and fetal development, by immunolocalization of steroidogenic enzymes in these organs of the Japanese black bear. Ovaries and placentae from 15 wild Japanese black bears, which had been killed legally by hunters and were thought to be pregnant, were used in an immunocytochemical study to localize the cholesterol side chain cleavage cytochrome P450 (P450scc), 3beta-hydroxysteroid dehydrogenase (3betaHSD), 17alpha-hydroxylase cytochrome P450 (P450c17) and aromatase cytochrome P450 (P450arom) by the avidin-biotin-peroxidase complex method using polyclonal antisera raised in mammals against P450scc, 3betaHSD, P450c17 and P450arom. P450scc and 3betaHSD were localized in all luteal cells throughout pregnancy. P450c17 was present in a few luteal cells, especially in the outer area of the corpus luteum throughout pregnancy, but the number of positively immunostained cells decreased during the post-implantation period. Cells positively immunostained for P450c17 were significantly smaller than negatively immunostained cells (P black bear, corpora lutea are a source of progesterone which may play an important role in the maintenance of delayed implantation and fetal development during pregnancy. Corpora lutea have a minimum capability to synthesize androgen in small luteal cells and oestrogen in normal-sized luteal cells during pregnancy, and placentae have the ability to synthesize oestrogen during late pregnancy.

  7. Testing landscape modeling approaches for environmental impact assessment of mining land use on grizzly bears (Ursus arctos horribilis) in the foothills region of west central Alberta

    Energy Technology Data Exchange (ETDEWEB)

    Symbaluk, M.D. [Elk Valley Coal Corp., Hinton, AB (Canada). Cardinal River Operations

    2008-07-01

    The Cheviot open pit coal mine is located on the front range of the Rocky Mountains in Alberta. The environmental impact assessment (EIA) requirements for the mining project included an assessment of the cumulative effects of past, existing, and immanent activities on a 3040 km{sup 2} study area radiating approximately 25 km around the proposed project area. The grizzly bear was identified as a flagship valued ecosystem component (VEC) for assessing the regional cumulative effects of the proposed Cheviot project. In this portion of the study, a grizzly bear habitat effectiveness model was used to monitor grizzly bear response to mining land use in the study area. An investigation of grizzly bear movement paths prior to and during mine disturbances demonstrated that mining land use does not present significant barriers to grizzly bear activities. The study demonstrated the importance of using inductive modelling tools at appropriate scales, as well as the use of site-specific empirical data. It was concluded that continued monitoring of mining sites is needed to ensure that adaptive management processes are improved. A review of the Cheviot cumulative environmental effects (CEA) process was also provided. 17 refs., 1 fig.

  8. Multiple estimates of effective population size for monitoring a long-lived vertebrate: An application to Yellowstone grizzly bears

    Science.gov (United States)

    Kamath, Pauline L.; Haroldson, Mark A.; Luikart, Gordon; Paetkau, David; Whitman, Craig L.; van Manen, Frank T.

    2015-01-01

    Effective population size (Ne) is a key parameter for monitoring the genetic health of threatened populations because it reflects a population's evolutionary potential and risk of extinction due to genetic stochasticity. However, its application to wildlife monitoring has been limited because it is difficult to measure in natural populations. The isolated and well-studied population of grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem provides a rare opportunity to examine the usefulness of different Ne estimators for monitoring. We genotyped 729 Yellowstone grizzly bears using 20 microsatellites and applied three single-sample estimators to examine contemporary trends in generation interval (GI), effective number of breeders (Nb) and Ne during 1982–2007. We also used multisample methods to estimate variance (NeV) and inbreeding Ne (NeI). Single-sample estimates revealed positive trajectories, with over a fourfold increase in Ne (≈100 to 450) and near doubling of the GI (≈8 to 14) from the 1980s to 2000s. NeV (240–319) and NeI (256) were comparable with the harmonic mean single-sample Ne (213) over the time period. Reanalysing historical data, we found NeV increased from ≈80 in the 1910s–1960s to ≈280 in the contemporary population. The estimated ratio of effective to total census size (Ne/Nc) was stable and high (0.42–0.66) compared to previous brown bear studies. These results support independent demographic evidence for Yellowstone grizzly bear population growth since the 1980s. They further demonstrate how genetic monitoring of Ne can complement demographic-based monitoring of Nc and vital rates, providing a valuable tool for wildlife managers.

  9. Effects of biometrics, location and persistent organic pollutants on blood clinical-chemical parameters in polar bears (Ursus maritimus) from Svalbard, Norway.

    Science.gov (United States)

    Ciesielski, Tomasz Maciej; Sonne, Christian; Ormbostad, Ingunn; Aars, Jon; Lie, Elisabeth; Bytingsvik, Jenny; Jenssen, Bjørn Munro

    2018-05-31

    In the present study, blood clinical-chemical parameters (BCCPs) were analysed in 20 female and 18 male Svalbard polar bears (Ursus maritimus) captured in spring 2007. The aim was to study how age, body condition (BC), biometrics, plasma lipid content and geographical location may confound the relationship between persistent organic pollutants (POPs) including PCBs, HCB, chlordanes, DDTs, HCHs, mirex and OH-PCBs and the concentrations of 12 specific BCCPs (hematocrit [HCT], hemoglobin [HB], aspartate aminotransferase [ASAT], alanine aminotransferase [ALAT], γ-glutamyltransferase [GGT], creatine kinase [CK], triglycerides [TG], cholesterol [CHOL], high-density lipoprotein [HDL], creatinine (CREA], urea, potassium (K]), and to investigate if any of these BCCPs may be applied as potential biomarkers for POP exposure in polar bears. Initial PCA and O-PLS modelling showed that age, lipids, BC and geographical location (longitude and latitude) were important parameters explaining BCCPs in females. Following subsequent partial correlation analyses correcting for age and lipids, multiple POPs in females were still significantly correlated with HCT and HDL (all p biometrics, lipids and longitude in males, multiple POPs were significantly correlated with HCT, ASAT, GGT and CHOL (all p < 0.05). In conclusion, several confounding parameters has to be taken into account when studying the relations between BCCPs and POPs in polar bears. When correcting for these, in particular HCT may be used as a simple cost-efficient biomarker of POP exposure in polar bears. Furthermore, decreasing HDL concentrations and increasing CHOL concentration with increasing POP concentrations may indicate responses related to increased risk of cardiovascular disease. We therefore suggest to further study POP exposure and lipidome response to increase knowledge of the risk of cardiometabolic syndrome in polar bears. Copyright © 2018 Elsevier Inc. All rights reserved.

  10. Pitfalls in comparing modern hair and fossil bone collagen C and N isotopic data to reconstruct ancient diets: a case study with cave bears (Ursus spelaeus).

    Science.gov (United States)

    Bocherens, Hervé; Grandal-d'Anglade, Aurora; Hobson, Keith A

    2014-01-01

    Stable isotope analyses provide one of the few means to evaluate diet of extinct taxa. However, interpreting isotope data from bone collagen of extinct animals based on isotopic patterns in different tissues of modern animal proxies is precarious. For example, three corrections are needed before making comparisons of recent hair and ancient bone collagen: calibration of carbon-13 variations in atmospheric CO2, different isotopic discrimination between diet-hair keratin and diet-bone collagen, and time averaging of bone collagen versus short-term record in hair keratin. Recently, Robu et al. [Isotopic evidence for dietary flexibility among European Late Pleistocene cave bears (Ursus spelaeus). Can J Zool. 2013;91:227-234] published an article comparing extant carbon (δ(13)C) and nitrogen (δ(15)N) stable isotopic data of European cave bear bone collagen with those of Yellowstone Park grizzly bear hair in order to test the prevailing assumption of a largely vegetarian diet among cave bears. The authors concluded that cave bears were carnivores. This work is unfortunately unfounded as the authors failed to consider the necessary corrections listed above. When these corrections are applied to the Romanian cave bears, these individuals can be then interpreted without involving consumption of high trophic-level food, and environmental changes are probably the reason for the unusual isotopic composition of these cave bears in comparison with other European cave bears, rather than a change of diet. We caution researchers to pay careful attention to these factors when interpreting feeding ecology of extinct fauna using stable isotope techniques.

  11. Demographic and temporal variations in immunity and condition of polar bears (Ursus maritimus) from the southern Beaufort Sea

    Science.gov (United States)

    Neuman-Lee, Lorin; Terletzky, Patricia; Atwood, Todd C.; Gese, Eric; Smith, Geoffrey; Greenfield, Sydney; Pettit, John; French, Susannah

    2017-01-01

    Assessing the health and condition of animals in their natural environment can be problematic. Many physiological metrics, including immunity, are highly influenced by specific context and recent events to which researchers may be unaware. Thus, using a multifaceted physiological approach and a context-specific analysis encompassing multiple time scales can be highly informative. Ecoimmunological tools in particular can provide important indications to the health of animals in the wild. We collected blood and hair samples from free-ranging polar bears (Ursus maritimus) in the southern Beaufort Sea and examined the influence of sex, age, and reproductive status on metrics of immunity, stress, and body condition during 2013–2015. We examined metrics of innate immunity (bactericidal ability and lysis) and stress (hair cortisol, reactive oxygen species, and oxidative barrier), in relation to indices of body condition considered to be short term (urea to creatinine ratio; UC ratio) and long term (storage energy and body mass index). We found the factors of sex, age, and reproductive status of the bear were critical for interpreting different physiological metrics. Additionally, the metrics of body condition were important predictors for stress indicators. Finally, many of these metrics differed between years, illustrating the need to examine populations on a longer time scale. Taken together, this study demonstrates the complex relationship between multiple facets of physiology and how interpretation requires us to examine individuals within a specific context.

  12. Best management practices in counting urban black bears

    OpenAIRE

    Fusaro, Jonathan L.; Conner, Mary M.; Conover, Michael R.; Taylor, Timothy J.; Kenyon, Marc W., Jr.

    2017-01-01

    DNA-based capture-mark-recapture (CMR) techniques are commonly used to obtain population parameters of black bears (Ursus americanus) in rural and wildland landscapes; however, these techniques have not been implemented in urban clusters (i.e., 2,500 to 50,000 residents). Black bears can readily habituate to urban clusters, and wildlife managers need to monitor and manage these urban bear populations. We modified DNAbased CMR for black bear using hair-snares to take into account the small hom...

  13. Can polar bear hairs absorb environmental energy?

    Directory of Open Access Journals (Sweden)

    He Ji-Huan

    2011-01-01

    Full Text Available A polar bear (Ursus maritimus has superior ability to survive in harsh Arctic regions, why does the animal have such an excellent thermal protection? The present paper finds that the unique labyrinth cavity structure of the polar bear hair plays an important role. The hair can not only prevent body temperature loss but can also absorb energy from the environment.

  14. Trend of the Yellowstone Grizzly Bear Population

    International Nuclear Information System (INIS)

    Eberhardt, L.L.; Breiwick, J.M.

    2010-01-01

    Yellowstone's grizzlies (Ursus arctos) have been studied for more than 40 years. Radio telemetry has been used to obtain estimates of the rate of increase of the population, with results reported by Schwartz et al. (2006). Counts of females with cubs-of-the-year unduplicated also provide an index of abundance and are the primary subject of this report. An exponential model was fitted to n=24 such counts, using nonlinear least squares. Estimates of the rate of increase, r, were about 0.053. 95% confidence intervals, were obtained by several different methods, and all had lower limits substantially above zero, indicating that the population has been increasing steadily, in contrast to the results of Schwartz et al. (2006), which could not exclude a decreasing population. The grizzly data have been repeatedly mis-used in current literature for reasons explained here.

  15. The effect of body size evolution and ecology on encephalization in cave bears and extant relatives.

    Science.gov (United States)

    Veitschegger, Kristof

    2017-06-05

    The evolution of larger brain volumes relative to body size in Mammalia is the subject of an extensive amount of research. Early on palaeontologists were interested in the brain of cave bears, Ursus spelaeus, and described its morphology and size. However, until now, it was not possible to compare the absolute or relative brain size in a phylogenetic context due to the lack of an established phylogeny, comparative material, and phylogenetic comparative methods. In recent years, many tools for comparing traits within phylogenies were developed and the phylogenetic position of cave bears was resolved based on nuclear as well as mtDNA. Cave bears exhibit significantly lower encephalization compared to their contemporary relatives and intraspecific brain mass variation remained rather small. Encephalization was correlated with the combined dormancy-diet score. Body size evolution was a main driver in the degree of encephalization in cave bears as it increased in a much higher pace than brain size. In Ursus spelaeus, brain and body size increase over time albeit differently paced. This rate pattern is different in the highest encephalized bear species within the dataset, Ursus malayanus. The brain size in this species increased while body size heavily decreased compared to its ancestral stage. Early on in the evolution of cave bears encephalization decreased making it one of the least encephalized bear species compared to extant and extinct members of Ursidae. The results give reason to suspect that as herbivorous animals, cave bears might have exhibited a physiological buffer strategy to survive the strong seasonality of their environment. Thus, brain size was probably affected by the negative trade-off with adipose tissue as well as diet. The decrease of relative brain size in the herbivorous Ursus spelaeus is the result of a considerable increase in body size possibly in combination with environmental conditions forcing them to rest during winters.

  16. 捕殺個体を利用したニホンツキノワグマ (Ursus thibetanus japonicus) の 栄養状態および繁殖評価方法に関する研究

    OpenAIRE

    2011-01-01

    The Japanese black bear (Ursus thibetanus japonicus) is a subspecies of the Asiatic blackbear (Ursus thibetanus), which is classified as a vulnerable species in the IUCN red list. Inthe Japanese red list, six local populations of the Japanese black bear are designated asthreatened local populations, although the subspecies as a whole is not listed as threatened.The Japanese black bear is one of the largest mammals in forest ecosystems in Japan, andefforts in their conservation could contribut...

  17. Physiologically-based pharmacokinetic modelling of immune, reproductive and carcinogenic effects from contaminant exposure in polar bears (Ursus maritimus) across the Arctic.

    Science.gov (United States)

    Dietz, Rune; Gustavson, Kim; Sonne, Christian; Desforges, Jean-Pierre; Rigét, Frank F; Pavlova, Viola; McKinney, Melissa A; Letcher, Robert J

    2015-07-01

    Polar bears (Ursus maritimus) consume large quantities of seal blubber and other high trophic marine mammals and consequently have some of the highest tissue concentrations of organohalogen contaminants (OHCs) among Arctic biota. In the present paper we carried out a risk quotient (RQ) evaluation on OHC-exposed polar bears harvested from 1999 to 2008 and from 11 circumpolar subpopulations spanning from Alaska to Svalbard in order to evaluate the risk of OHC-mediated reproductive effects (embryotoxicity, teratogenicity), immunotoxicity and carcinogenicity (genotoxicity). This RQ evaluation was based on the Critical Body Residue (CBR) concept and a Physiologically-Based Pharmacokinetic Modelling (PBPK) approach using OHC concentrations measured in polar bear adipose or liver tissue. The range of OHC concentrations within polar bear populations were as follows for adipose, sum polychlorinated biphenyls ∑PCBs (1797-10,537 ng/g lw), sum methylsulphone-PCB ∑MeSO2-PCBs (110-672 ng/g lw), sum chlordanes ∑CHLs (765-3477 ng/g lw), α-hexachlorocyclohexane α-HCH (8.5-91.3 ng/g lw), β-hexachlorocyclohexane β-HCH (65.5-542 ng/g lw), sum chlorbenzenes ∑ClBzs (145-304 ng/g lw), dichlorodiphenyltrichloroethane ∑DDTs (31.5-206 ng/g lw), dieldrin (69-249 ng/g lw), polybrominated diphenyl ethers ∑PBDEs (4.6-78.4 ng/g lw). For liver, the perfluorooctanesulfonic acid (PFOS) concentrations ranged from 231-2792 ng/g ww. The total additive RQ from all OHCs ranged from 4.3 in Alaska to 28.6 in East Greenland bears for effects on reproduction, immune health and carcinogenicity, highlighting the important result that the toxic effect threshold (i.e. RQ>1) was exceeded for all polar bear populations assessed. PCBs were the main contributors for all three effect categories, contributing from 70.6% to 94.3% of the total risk and a RQ between 3.8-22.5. ∑MeSO2-PCBs were the second highest effect contributor for reproductive and immunological effects (0.17polar bears. We therefore

  18. Blood Chemistry Reference Values for Free-Ranging Asiatic Black Bears ( Ursus thibetanus) by Season, Age, and Sex.

    Science.gov (United States)

    Yang, Jeong-Jin; Jeong, Dong-Hyuk; Lim, Yoon-Kyu

    2018-04-19

    Physiological characteristics, such as blood chemistry values, are valuable for evaluating the health of the animals. To our knowledge, these values have never been reported for the free-ranging Asiatic black bear ( Ursus thibetanus; ABB). Thus, 28 blood chemistry values from 50 free-ranging ABBs captured in Jirisan National Park, Republic of Korea, from 2005 to 2016 were evaluated. The aim of this study was to establish blood chemistry reference values for the free-ranging ABBs during both the hibernating and nonhibernating seasons. During hibernation, mean values of creatinine (CRE), total cholesterol, total protein (TP), albumin (ALB), triglycerides, and Mg were significantly higher than those during nonhibernation; however, mean values of blood urea nitrogen, urea nitrogen to creatinine (U/C) ratio, inorganic phosphorous (IP), aspartate aminotransferase, alanine aminotransferase, gamma-glutamyl transferase, lactate dehydrogenase (LDH), high-density lipoprotein cholesterol, and alkaline phosphatase (ALP) were significantly lower. Age differences (young vs. adult) were found in IP, LDH, TP, and ALB values during hibernation and in the U/C ratio, Ca, IP, ALP, creatine kinase myocardial band, CRE, total bilirubin, and uric acid values during nonhibernation. However, there were no sex differences (male vs. female).

  19. Changes in blood glucose and insulin responses to intravenous glucose tolerance tests and blood biochemical values in adult female Japanese black bears (Ursus thibetanus japonicus).

    Science.gov (United States)

    Kamine, Akari; Shimozuru, Michito; Shibata, Haruki; Tsubota, Toshio

    2012-02-01

    The metabolic mechanisms to circannual changes in body mass of bears have yet to be elucidated. We hypothesized that the Japanese black bear (Ursus thibetanus japonicus) has a metabolic mechanism that efficiently converts carbohydrates into body fat by altering insulin sensitivity during the hyperphagic stage before hibernation. To test this hypothesis, we investigated the changes in blood biochemical values and glucose and insulin responses to intravenous glucose tolerance tests (IVGTT) during the active season (August, early and late November). Four, adult, female bears (5-17 years old) were anesthetized with 6 mg/kg TZ (tiletamine HCl and zolazepam HCl) in combination with 0.1 mg/kg acepromazine maleate. The bears were injected intravenously with glucose (0.5 g/kg of body mass), and blood samples were obtained before, at, and intermittently after glucose injection. The basal triglycerides concentration decreased significantly with increase in body mass from August to November. Basal levels of plasma glucose and serum insulin concentrations were not significantly different among groups. The results of IVGTT demonstrated the increased peripheral insulin sensitivity and glucose tolerance in early November. In contrast, peripheral insulin resistance was indicated by the exaggerated insulin response in late November. Our findings suggest that bears shift their glucose and lipid metabolism from the stage of normal activity to the hyperphagic stage in which they show lipogenic-predominant metabolism and accelerate glucose uptake by increasing the peripheral insulin sensitivity.

  20. Multiple data sources improve DNA-based mark-recapture population estimates of grizzly bears.

    Science.gov (United States)

    Boulanger, John; Kendall, Katherine C; Stetz, Jeffrey B; Roon, David A; Waits, Lisette P; Paetkau, David

    2008-04-01

    A fundamental challenge to estimating population size with mark-recapture methods is heterogeneous capture probabilities and subsequent bias of population estimates. Confronting this problem usually requires substantial sampling effort that can be difficult to achieve for some species, such as carnivores. We developed a methodology that uses two data sources to deal with heterogeneity and applied this to DNA mark-recapture data from grizzly bears (Ursus arctos). We improved population estimates by incorporating additional DNA "captures" of grizzly bears obtained by collecting hair from unbaited bear rub trees concurrently with baited, grid-based, hair snag sampling. We consider a Lincoln-Petersen estimator with hair snag captures as the initial session and rub tree captures as the recapture session and develop an estimator in program MARK that treats hair snag and rub tree samples as successive sessions. Using empirical data from a large-scale project in the greater Glacier National Park, Montana, USA, area and simulation modeling we evaluate these methods and compare the results to hair-snag-only estimates. Empirical results indicate that, compared with hair-snag-only data, the joint hair-snag-rub-tree methods produce similar but more precise estimates if capture and recapture rates are reasonably high for both methods. Simulation results suggest that estimators are potentially affected by correlation of capture probabilities between sample types in the presence of heterogeneity. Overall, closed population Huggins-Pledger estimators showed the highest precision and were most robust to sparse data, heterogeneity, and capture probability correlation among sampling types. Results also indicate that these estimators can be used when a segment of the population has zero capture probability for one of the methods. We propose that this general methodology may be useful for other species in which mark-recapture data are available from multiple sources.

  1. Factors affecting date of implantation, parturition, and den entry estimated from activity and body temperature in free-ranging brown bears.

    Science.gov (United States)

    Friebe, Andrea; Evans, Alina L; Arnemo, Jon M; Blanc, Stéphane; Brunberg, Sven; Fleissner, Günther; Swenson, Jon E; Zedrosser, Andreas

    2014-01-01

    Knowledge of factors influencing the timing of reproduction is important for animal conservation and management. Brown bears (Ursus arctos) are able to vary the birth date of their cubs in response to their fat stores, but little information is available about the timing of implantation and parturition in free-ranging brown bears. Body temperature and activity of pregnant brown bears is higher during the gestation period than during the rest of hibernation and drops at parturition. We compared mean daily body temperature and activity levels of pregnant and nonpregnant females during preimplantation, gestation, and lactation. Additionally we tested whether age, litter size, primiparity, environmental conditions, and the start of hibernation influence the timing of parturition. The mean date of implantation was 1 December (SD = 12), the mean date of parturition was 26 January (SD = 12), and the mean duration of the gestation period was 56 days (SD = 2). The body temperature of pregnant females was higher during the gestation and lactation periods than that of nonpregnant bears. The body temperature of pregnant females decreased during the gestation period. Activity recordings were also used to determine the date of parturition. The parturition dates calculated with activity and body temperature data did not differ significantly and were the same in 50% of the females. Older females started hibernation earlier. The start of hibernation was earlier during years with favorable environmental conditions. Dates of parturition were later during years with good environmental conditions which was unexpected. We suggest that free-ranging pregnant brown bears in areas with high levels of human activities at the beginning of the denning period, as in our study area, might prioritize investing energy in early denning than in early parturition during years with favorable environmental conditions, as a strategy to prevent disturbances caused by human.

  2. Factors affecting date of implantation, parturition, and den entry estimated from activity and body temperature in free-ranging brown bears.

    Directory of Open Access Journals (Sweden)

    Andrea Friebe

    Full Text Available Knowledge of factors influencing the timing of reproduction is important for animal conservation and management. Brown bears (Ursus arctos are able to vary the birth date of their cubs in response to their fat stores, but little information is available about the timing of implantation and parturition in free-ranging brown bears. Body temperature and activity of pregnant brown bears is higher during the gestation period than during the rest of hibernation and drops at parturition. We compared mean daily body temperature and activity levels of pregnant and nonpregnant females during preimplantation, gestation, and lactation. Additionally we tested whether age, litter size, primiparity, environmental conditions, and the start of hibernation influence the timing of parturition. The mean date of implantation was 1 December (SD = 12, the mean date of parturition was 26 January (SD = 12, and the mean duration of the gestation period was 56 days (SD = 2. The body temperature of pregnant females was higher during the gestation and lactation periods than that of nonpregnant bears. The body temperature of pregnant females decreased during the gestation period. Activity recordings were also used to determine the date of parturition. The parturition dates calculated with activity and body temperature data did not differ significantly and were the same in 50% of the females. Older females started hibernation earlier. The start of hibernation was earlier during years with favorable environmental conditions. Dates of parturition were later during years with good environmental conditions which was unexpected. We suggest that free-ranging pregnant brown bears in areas with high levels of human activities at the beginning of the denning period, as in our study area, might prioritize investing energy in early denning than in early parturition during years with favorable environmental conditions, as a strategy to prevent disturbances caused by human.

  3. One-dimensional heat conduction equation of the polar bear hair

    Directory of Open Access Journals (Sweden)

    Zhu Wei-Hong

    2015-01-01

    Full Text Available Hairs of a polar bear (Ursus maritimus possess special membrane-pore structure. The structure enables the polar bear to survive in the harsh Arctic regions. In this paper, the membrane-pore structure be approximately considered as fractal space, 1-D heat conduction equation of the polar bear hair is established and the solution of the equation is obtained.

  4. Satellite monitoring of black bear.

    Science.gov (United States)

    Craighead, J. J.; Craighead, F. C., Jr.; Varney, J. R.; Cote, C. E.

    1971-01-01

    Description of a feasibility experiment recently performed to test the use of a satellite system for telemetering environmental and physiological data from the winter den of a 'hibernating' black bear, Ursus americanus. The instrumentation procedure and evaluations of the equipment performance and sensory data obtained are discussed in detail.

  5. DNA-based population density estimation of black bear at northern ...

    African Journals Online (AJOL)

    The analysis of deoxyribonucleic acid (DNA) microsatellites from hair samples obtained by the non-invasive method of traps was used to estimate the population density of black bears (Ursus americanus eremicus) in a mountain located at the county of Lampazos, Nuevo Leon, Mexico. The genotyping of bears was ...

  6. cDNA, genomic sequence cloning, and overexpression of EIF1 from the giant panda (Ailuropoda Melanoleuca) and the black bear (Ursus Thibetanus Mupinensis).

    Science.gov (United States)

    Hou, Wan-ru; Tang, Yun; Hou, Yi-ling; Song, Yan; Zhang, Tian; Wu, Guang-fu

    2010-07-01

    Eukaryotic initiation factor (eIF) EIF1 is a universally conserved translation factor that is involved in translation initiation site selection. The cDNA and the genomic sequences of EIF1 were cloned successfully from the giant panda (Ailuropoda melanoleuca) and the black bear (Ursus thibetanus mupinensis) using reverse transcription polymerase chain reaction (RT-PCR) technology and touchdown-polymerase chain reaction, respectively. The cDNAs of the EIF1 cloned from the giant panda and the black bear are 418 bp in size, containing an open reading frame (ORF) of 342 bp encoding 113 amino acids. The length of the genomic sequence of the giant panda is 1909 bp, which contains four exons and three introns. The length of the genomic sequence of the black bear is 1897 bp, which also contains four exons and three introns. Sequence alignment indicates a high degree of homology to those of Homo sapiens, Mus musculus, Rattus norvegicus, and Bos Taurus at both amino acid and DNA levels. Topology prediction shows there are one N-glycosylation site, two Casein kinase II phosphorylation sites, and a Amidation site in the EIF1 protein of the giant panda and black bear. In addition, there is a protein kinase C phosphorylation site in EIF1 of the giant panda. The giant panda and the black bear EIF1 genes were overexpressed in E. coli BL21. The results indicated that the both EIF1 fusion proteins with the N-terminally His-tagged form gave rise to the accumulation of two expected 19 kDa polypeptide. The expression products obtained could be used to purify the proteins and study their function further.

  7. Seroepidemiologic study on the prevalence of Toxoplasma gondii and Trichinella spp. infections in black bears (Ursus americanus) in Pennsylvania, USA.

    Science.gov (United States)

    Dubey, Jitender P; Brown, Justin; Ternent, Mark; Verma, Shiv K; Hill, Dolores E; Cerqueira-Cézar, Camila K; Kwok, Oliver C H; Calero-Bernal, Rafael; Humphreys, Jan G

    2016-10-15

    The protozoan Toxoplasma gondii and the metazoan Trichinella spp. infect virtually all warm-blooded animals, including birds, humans, livestock, and marine mammals. Both parasitic infections can cause serious illness in human beings and can be acquired by ingesting under-cooked meat harboring infective stages. Approximately 3500 black bears (Ursus americanus) are legally-harvested each year in Pennsylvania, USA during the November hunting season. Among animals found infected with T. gondii, the prevalence of T. gondii is the highest among black bears in the USA; however, little is currently known of epidemiology of toxoplasmosis in this host species. Serum samples were collected during the winters of 2015 and 2016 from adult female bears and their nursing cubs or yearlings while they were still in their dens. Additionally, archived sera from bear samples collected throughout the year, including hunter-harvested bears in November and trapped bears in the summer, were serologically tested. Antibodies to T. gondii were assayed by the modified agglutination test (MAT, cut-off 1:25) and antibodies to Trichinella spp. were assayed using a commercial enzyme-linked immunosorbent assay (ELISA). Overall, T. gondii antibodies were found in 87.6% (206/235) of adults, and 44.1% (30/68) of yearlings. In March 2015/2016 sampling, antibodies to T. gondii were found in 94% (30/32) adult female bears while in their den. Antibodies were detected in 5% (3/66) of the nursing cubs in the dens of these sows. One positive cub had a MAT titer of 1:160 and two were positive at the 1:25 dilution but not at 1:50. The adult females of these cubs had MAT titers ranging from 1:400 to 1:3200. Antibodies to Trichinella spp. were found in 3% (6/181) of adults and 3.6% (1/28) of yearlings; these 7 bears were also seropositive for T. gondii. No antibodies to Trichinella spp. were detected in the sera of 44 nursing cubs tested. The finding of T. gondii antibodies in only 3 of 66 cubs, and higher

  8. Effect of seasonal differences in dietary meat intake on changes in body mass and composition in wild and captive brown bears

    Science.gov (United States)

    Hilderbrand, G.V.; Jenkins, S.G.; Schwartz, C.C.; Hanley, Thomas A.; Robbins, C.T.

    1999-01-01

    The influence of seasonal dietary meat intake on changes in body mass and composition in wild and captive brown bears (Ursus arctos) was investigated because the importance and availability of meat to brown bear populations is currently an important management consideration in several North American ecosystems. Adult female brown bears on the Kenai Peninsula, Alaska, utilized meat heavily in both spring and fall. Meat accounted for 76.2 ± 26.0% (mean ± 1 SD; primarily moose carrion and calves) of assimilated carbon and nitrogen in the spring and 80.4 ± 22.2% (primarily salmon) in the fall. Mass increases in the spring (71.8 ± 28.2%) were mostly lean body mass, but increases in the fall (81.0 ± 19.5%) were primarily fat. Daily intake by captive brown bears fed meat ad libitum during 12-day trials was positively related to body mass. Mass change was positively related to intake in both seasons, but the composition of the gain varied by season, with spring gains primarily lean body mass (64.2 ± 9.4%), while fall gains were 78.8 ± 19.6% lipid. Absolute rates of gain by wild bears occasionally equaled, but were usually much less than, those of captive bears. This was likely due to a combination of factors, which included the time required to locate and handle meat resources, the limited availability of or access to meat resources, and (or) the duration of meat resource availability. Estimated intake by bears not feeding selectively on high-energy components of moose and salmon were 8.5 ± 1.5 kg/day and 541 ± 156 kg/year and 10.8 ± 4.6 kg/day and 1003 ± 489 kg/year, respectively. Intake would drop by as much as 58% for bears feeding exclusively on salmon roe. Management strategies for areas with brown bears that consume significant amounts of meat should address the perpetuation and availability of these meat resources.

  9. Bear-ly” learning: Limits of abstraction in black bear cognition

    Directory of Open Access Journals (Sweden)

    Jennifer Vonk

    2018-02-01

    Full Text Available We presented two American black bears (Ursus americanus with a serial list learning memory task, and one of the bears with a matching-to-sample task. After extended training, both bears demonstrated some success with the memory task but failed to generalize the overarching rule of the task to novel stimuli. Matching to sample proved even more difficult for our bear to learn. We conclude that, despite previous success in training bears to respond to natural categories, quantity discriminations, and other related tasks, that bears may possess a cognitive limitation with regards to learning abstract rules. Future tests using different procedures are necessary to determine whether this is a limit of bears’ cognitive capacities, or a limitation of the current tasks as presented. Future tests should present a larger number of varying stimuli. Ideally, bears of various species should be tested on these tasks to demonstrate species as well as individual differences.

  10. Grizzly bear

    Science.gov (United States)

    Schwartz, C.C.; Miller, S.D.; Haroldson, M.A.; Feldhamer, G.; Thompson, B.; Chapman, J.

    2003-01-01

    The grizzly bear inspires fear, awe, and respect in humans to a degree unmatched by any other North American wild mammal. Like other bear species, it can inflict serious injury and death on humans and sometimes does. Unlike the polar bear (Ursus maritimus) of the sparsely inhabited northern arctic, however, grizzly bears still live in areas visited by crowds of people, where presence of the grizzly remains physically real and emotionally dominant. A hike in the wilderness that includes grizzly bears is different from a stroll in a forest from which grizzly bears have been purged; nighttime conversations around the campfire and dreams in the tent reflect the presence of the great bear. Contributing to the aura of the grizzly bear is the mixture of myth and reality about its ferocity. unpredictable disposition, large size, strength, huge canines, long claws, keen senses, swiftness, and playfulness. They share characteristics with humans such as generalist life history strategies. extended periods of maternal care, and omnivorous diets. These factors capture the human imagination in ways distinct from other North American mammals. Precontact Native American legends reflected the same fascination with the grizzly bear as modern stories and legends (Rockwell 1991).

  11. Grizzly bear population vital rates and trend in the Northern Continental Divide Ecosystem, Montana

    Science.gov (United States)

    Mace, R.D.; Carney, D.W.; Chilton-Radandt, T.; Courville, S.A.; Haroldson, M.A.; Harris, R.B.; Jonkel, J.; McLellan, B.; Madel, M.; Manley, T.L.; Schwartz, C.C.; Servheen, C.; Stenhouse, G.; Waller, J.S.; Wenum, E.

    2012-01-01

    We estimated grizzly bear (Ursus arctos) population vital rates and trend for the Northern Continental Divide Ecosystem (NCDE), Montana, between 2004 and 2009 by following radio-collared females and observing their fate and reproductive performance. Our estimates of dependent cub and yearling survival were 0.612 (95% CI = 0.300–0.818) and 0.682 (95% CI = 0.258–0.898). Our estimates of subadult and adult female survival were 0.852 (95% CI = 0.628–0.951) and 0.952 (95% CI = 0.892–0.980). From visual observations, we estimated a mean litter size of 2.00 cubs/litter. Accounting for cub mortality prior to the first observations of litters in spring, our adjusted mean litter size was 2.27 cubs/litter. We estimated the probabilities of females transitioning from one reproductive state to another between years. Using the stable state probability of 0.322 (95% CI = 0.262–0.382) for females with cub litters, our adjusted fecundity estimate (mx) was 0.367 (95% CI = 0.273–0.461). Using our derived rates, we estimated that the population grew at a mean annual rate of approximately 3% (λ = 1.0306, 95% CI = 0.928–1.102), and 71.5% of 10,000 Monte Carlo simulations produced estimates of λ > 1.0. Our results indicate an increasing population trend of grizzly bears in the NCDE. Coupled with concurrent studies of population size, we estimate that over 1,000 grizzly bears reside in and adjacent to this recovery area. We suggest that monitoring of population trend and other vital rates using radioed females be continued.

  12. Exposure to mixtures of organohalogen contaminants and associative interactions with thyroid hormones in East Greenland polar bears (Ursus maritimus).

    Science.gov (United States)

    Villanger, Gro D; Jenssen, Bjørn M; Fjeldberg, Rita R; Letcher, Robert J; Muir, Derek C G; Kirkegaard, Maja; Sonne, Christian; Dietz, Rune

    2011-05-01

    We investigated the multivariate relationships between adipose tissue residue levels of 48 individual organohalogen contaminants (OHCs) and circulating thyroid hormone (TH) levels in polar bears (Ursus maritimus) from East Greenland (1999-2001, n=62), using projection to latent structure (PLS) regression for four groupings of polar bears; subadults (SubA), adult females with cubs (AdF_N), adult females without cubs (AdF_S) and adult males (AdM). In the resulting significant PLS models for SubA, AdF_N and AdF_S, some OHCs were especially important in explaining variations in circulating TH levels: polybrominated diphenylether (PBDE)-99, PBDE-100, PBDE-153, polychlorinated biphenyl (PCB)-52, PCB-118, cis-nonachlor, trans-nonachlor, trichlorobenzene (TCB) and pentachlorobenzene (QCB), and both negative and positive relationships with THs were found. In addition, the models revealed that DDTs had a positive influence on total 3,5,3'-triiodothyronine (TT3) in AdF_S, and that a group of 17 higher chlorinated ortho-PCBs had a positive influence on total 3,5,3',5'-tetraiodothyronine (thyroxine, TT4) in AdF_N. TH levels in AdM seemed less influenced by OHCs because of non-significant PLS models. TH levels were also influenced by biological factors such as age, sex, body size, lipid content of adipose tissue and sampling date. When controlling for biological variables, the major relationships from the PLS models for SubA, AdF_N and AdF_S were found significant in partial correlations. The most important OHCs that influenced TH levels in the significant PLS models may potentially act through similar mechanisms on the hypothalamic-pituitary-thyroid (HPT) axis, suggesting that both combined effects by dose and response addition and perhaps synergistic potentiation may be a possibility in these polar bears. Statistical associations are not evidence per se of biological cause-effect relationships. Still, the results of the present study indicate that OHCs may affect circulating

  13. Radio-tracking large wilderness mammals: integration of GPS and Argos technologies

    Science.gov (United States)

    Schwartz, Charles C.; Arthur, Steve M.

    1999-01-01

    We tested 30 prototype global positioning system (GPS) radiocollars on brown bears (Ursus arctos) over a 3-year period on the Kenai Peninsula, Alaska. Collars were of 2 design types: GPS units with an Argos (Argos Data collection and Location System) satellite uplink (n = 19) and GPS units where the data were stored on board (n = 10) for retrieval at a later date. All units also contained a conventional VHF (very high frequency) transmitter and weighed 1.7 kg. GPS-Argos units obtained 10-82% of expected GPS fixes, and fix rate declined significantly (P bears varied more and were lower than fix rates for stationary collars placed in various vegetation types, suggesting that the bear, terrain, and movement all influence both fix and uplink success rate. Application of this new technology to grizzly and brown bear research and comparisons to studies with moose (Alces alces) are discussed.

  14. Multiple estimates of effective population size for monitoring a long-lived vertebrate: an application to Yellowstone grizzly bears.

    Science.gov (United States)

    Kamath, Pauline L; Haroldson, Mark A; Luikart, Gordon; Paetkau, David; Whitman, Craig; van Manen, Frank T

    2015-11-01

    Effective population size (N(e)) is a key parameter for monitoring the genetic health of threatened populations because it reflects a population's evolutionary potential and risk of extinction due to genetic stochasticity. However, its application to wildlife monitoring has been limited because it is difficult to measure in natural populations. The isolated and well-studied population of grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem provides a rare opportunity to examine the usefulness of different N(e) estimators for monitoring. We genotyped 729 Yellowstone grizzly bears using 20 microsatellites and applied three single-sample estimators to examine contemporary trends in generation interval (GI), effective number of breeders (N(b)) and N(e) during 1982-2007. We also used multisample methods to estimate variance (N(eV)) and inbreeding N(e) (N(eI)). Single-sample estimates revealed positive trajectories, with over a fourfold increase in N(e) (≈100 to 450) and near doubling of the GI (≈8 to 14) from the 1980s to 2000s. N(eV) (240-319) and N(eI) (256) were comparable with the harmonic mean single-sample N(e) (213) over the time period. Reanalysing historical data, we found N(eV) increased from ≈80 in the 1910s-1960s to ≈280 in the contemporary population. The estimated ratio of effective to total census size (N(e) /N(c)) was stable and high (0.42-0.66) compared to previous brown bear studies. These results support independent demographic evidence for Yellowstone grizzly bear population growth since the 1980s. They further demonstrate how genetic monitoring of N(e) can complement demographic-based monitoring of N(c) and vital rates, providing a valuable tool for wildlife managers. © 2015 John Wiley & Sons Ltd.

  15. Troublemaking carnivores: conflicts with humans in a diverse assemblage of large carnivores

    Directory of Open Access Journals (Sweden)

    Andrea T. Morehouse

    2017-09-01

    Full Text Available Human-wildlife conflicts are a global conservation and management challenge. Multipredator systems present added complexity to the resolution of human-wildlife conflicts because mitigation strategies often are species-specific. Documenting the type and distribution of such conflicts is an important first step toward ensuring that subsequent management and mitigation efforts are appropriately targeted. We reviewed 16 years of records of complaints about two species of strict carnivores, wolves (Canis lupus and cougars (Puma concolor, and two species of omnivores, grizzly bears (Ursus arctos and black bears (Ursus americanus in southwestern Alberta and evaluated the temporal and spatial distribution of these complaints. Conflicts were most frequently associated with bears (68.7% of complaint records, reflecting a diversity of conflict types attributable to their omnivorous diets. Although grizzly bears killed and injured livestock, the majority of conflicts with bears were attributable to attractants (grain and dead livestock for grizzly bears, garbage for black bears. In contrast, wolf and cougar incidents were almost exclusively related to killing or injury of livestock. Complaints for both bear species have increased over the past 16 years while cougar and wolf complaints have remained relatively constant. Grizzly bear and cougar conflicts have been expanding into private lands used for agriculture. Although community driven, targeted mitigation measures have helped reduce conflicts with grizzly bears at the site level, conflicts at the broader scale have continued to increase and continued work is necessary. Long-term human-carnivore coexistence clearly is possible, facilitated by continued monitoring and local efforts to mitigate conflicts.

  16. Trend of the Yellowstone Grizzly Bear Population

    Directory of Open Access Journals (Sweden)

    L. L. Eberhardt

    2010-01-01

    Full Text Available Yellowstone's grizzlies (Ursus arctos have been studied for more than 40 years. Radiotelemetry has been used to obtain estimates of the rate of increase of the population, with results reported by Schwartz et al. (2006. Counts of females with cubs-of-the-year “unduplicated” also provide an index of abundance and are the primary subject of this report. An exponential model was fitted to n=24 such counts, using nonlinear leastsquares. Estimates of the rate of increase, r, were about 0.053. 95% confidence intervals, were obtained by several different methods, and all had lower limits substantially above zero, indicating that the population has been increasing steadily, in contrast to the results of Schwartz et al. (2006, which could not exclude a decreasing population. The grizzly data have been repeatedly mis-used in current literature for reasons explained here.

  17. Reproductive performance in East Greenland polar bears (Ursus maritimus) may be affected by organohalogen contaminants as shown by physiologically-based pharmacokinetic (PBPK) modelling.

    Science.gov (United States)

    Sonne, Christian; Gustavson, Kim; Rigét, Frank F; Dietz, Rune; Birkved, Morten; Letcher, Robert J; Bossi, Rossana; Vorkamp, Katrin; Born, Erik W; Petersen, Gitte

    2009-12-01

    Polar bears (Ursus maritimus) feed mainly on ringed seal (Phoca hispida) and consume large quantities of blubber and consequently have one of the highest tissue concentrations of organohalogen contaminants (OHCs) worldwide. In East Greenland, studies of OHC time trends and organ system health effects, including reproductive, were conducted during 1990-2006. However, it has been difficult to determine the nature of the effects induced by OHC exposures on wild caught polar bears using body burden data and associated changes in reproductive organs and systems. We therefore conducted a risk quotient (RQ) evaluation to more quantitatively evaluate the effect risk on reproduction (embryotoxicity and teratogenicity) based on the critical body residue (CBR) concept and using a physiologically-based pharmacokinetic (PBPK) model. We applied modelling approaches to PCBs, p,p'-DDE, dieldrin, oxychlordane, HCHs, HCB, PBDEs and PFOS in East Greenland polar bears based on known OHC pharmacokinetics and dynamics in laboratory rats (Rattus rattus). The results showed that subcutaneous adipose tissue concentrations of dieldrin (range: 79-1271 ng g(-1) lw) and PCBs (range: 4128-53,923 ng g(-1) lw) reported in bears in the year 1990 were in the range to elicit possible adverse health effects on reproduction in polar bears in East Greenland (all RQs > or = 1). Similar results were found for PCBs (range: 1928-17,376 ng g(-1) lw) and PFOS (range: 104-2840 ng g(-1) ww) in the year 2000 and for dieldrin (range: 43-640 ng g(-1) lw), PCBs (range: 3491-13,243 ng g(-1) lw) and PFOS (range: 1332-6160 ng g(-1) ww) in the year 2006. The concentrations of oxychlordane, DDTs, HCB and HCHs in polar bears resulted in RQspolar bears correlated to OHC exposure are supported by the present study. This study also indicates that PBPK models may be a supportive tool in the evaluation of possible OHC-mediated health effects for Arctic wildlife.

  18. Natural regeneration on seismic lines influences movement behaviour of wolves and grizzly bears.

    Science.gov (United States)

    Finnegan, Laura; Pigeon, Karine E; Cranston, Jerome; Hebblewhite, Mark; Musiani, Marco; Neufeld, Lalenia; Schmiegelow, Fiona; Duval, Julie; Stenhouse, Gordon B

    2018-01-01

    Across the boreal forest of Canada, habitat disturbance is the ultimate cause of caribou (Rangifer tarandus caribou) declines. Habitat restoration is a focus of caribou recovery efforts, with a goal to finding ways to reduce predator use of disturbances, and caribou-predator encounters. One of the most pervasive disturbances within caribou ranges in Alberta, Canada are seismic lines cleared for energy exploration. Seismic lines facilitate predator movement, and although vegetation on some seismic lines is regenerating, it remains unknown whether vegetation regrowth is sufficient to alter predator response. We used Light Detection and Ranging (LiDAR) data, and GPS locations, to understand how vegetation and other attributes of seismic lines influence movements of two predators, wolves (Canis lupus) and grizzly bears (Ursus arctos). During winter, wolves moved towards seismic lines regardless of vegetation height, while during spring wolves moved towards seismic lines with higher vegetation. During summer, wolves moved towards seismic lines with lower vegetation and also moved faster near seismic lines with vegetation grizzly bears during spring and summer, but there was no relationship between vegetation height and grizzly bear movement rates. These results suggest that wolves use seismic lines for travel during summer, but during winter wolf movements relative to seismic lines could be influenced by factors additional to movement efficiency; potentially enhanced access to areas frequented by ungulate prey. Grizzly bears may be using seismic lines for movement, but could also be using seismic lines as a source of vegetative food or ungulate prey. To reduce wolf movement rate, restoration could focus on seismic lines with vegetation <1 m in height. However our results revealed that seismic lines continue to influence wolf movement behaviour decades after they were built, and even at later stages of regeneration. Therefore it remains unknown at what stage of natural

  19. 77 FR 23432 - Endangered and Threatened Wildlife and Plants; Special Rule for the Polar Bear

    Science.gov (United States)

    2012-04-19

    ... Polar Bear AGENCY: Fish and Wildlife Service, Interior. ACTION: Proposed rule; availability of draft... and advisable to provide for the conservation of the polar bear (Ursus maritimus). The Secretary has the discretion to prohibit by regulation with respect to the polar bear any act prohibited by section...

  20. 78 FR 17708 - Endangered and Threatened Wildlife and Plants; Draft Revised Supplement to the Grizzly Bear...

    Science.gov (United States)

    2013-03-22

    ...] Endangered and Threatened Wildlife and Plants; Draft Revised Supplement to the Grizzly Bear Recovery Plan... Revised Supplement to the Grizzly Bear Recovery Plan. Specifically, this supplement proposes to revise the demographic recovery criteria for the Yellowstone Ecosystem. In the lower 48 States, Grizzly bears (Ursus...

  1. Analyses of fecal and hair glucocorticoids to evaluate short- and long-term stress and recovery of Asiatic black bears (Ursus thibetanus) removed from bile farms in China.

    Science.gov (United States)

    Malcolm, K D; McShea, W J; Van Deelen, T R; Bacon, H J; Liu, F; Putman, S; Zhu, X; Brown, J L

    2013-05-01

    Demand for traditional Chinese medicines has given rise to the practice of maintaining Asiatic black bears (Ursus thibetanus) in captivity to harvest bile. We evaluated hypothalamic-pituitary-adrenal (HPA) activity in Asiatic black bears on a bile farm in China by measuring cortisol in hair. We also monitored hair and fecal glucocorticoid metabolites as bears acclimated to improved husbandry at the Animals Asia Foundation China Bear Rescue Center (CBRC) after removal from other bile farms. Fecal samples were collected twice weekly for ~1 year, and hair was obtained from bears upon arrival at the CBRC and again ≥163 days later. Paired hair samples showed declines in cortisol concentrations of 12-88% in 38 of 45 (84%, pbears after arrival and acclimation at the rehabilitation facility. Concentrations of cortisol in hair from bears on the bile farm were similar to initial concentrations upon arrival at the CBRC but were higher than those collected after bears had been at the CBRC for ≥163 days. Fecal glucocorticoid concentrations varied across months and were highest in April and declined through December, possibly reflecting seasonal patterns, responses to the arrival and socialization of new bears at the CBRC, and/or annual metabolic change. Data from segmental analysis of hair supports the first of these explanations. Our findings indicate that bears produced elevated concentrations of glucocorticoids on bile farms, and that activity of the HPA axis declined following relocation. Thus, hair cortisol analyses are particularly well suited to long-term, retrospective assessments of glucocorticoids in ursids. By contrast, fecal measures were not clearly associated with rehabilitation, but rather reflected more subtle endocrine changes, possibly related to seasonality. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Potentiation of ecological factors on the disruption of thyroid hormones by organo-halogenated contaminants in female polar bears (Ursus maritimus) from the Barents Sea.

    Science.gov (United States)

    Bourgeon, Sophie; Riemer, Astrid Kolind; Tartu, Sabrina; Aars, Jon; Polder, Anuschka; Jenssen, Bjørn Munro; Routti, Heli

    2017-10-01

    As apex predators, polar bears (Ursus maritimus) are among the most heavily polluted organisms in the Arctic. In addition to this anthropogenic stressor, climate warming has been shown to negatively affect their body condition, reproductive output and survival. Among potential underlying physiological mechanisms, thyroid hormones (THs), which control thermoregulation, metabolism and reproduction, can be affected by a variety of both natural and anthropogenic factors. While THs have been extensively used as proxies for pollution exposure in mammals, including polar bears, there is a lack of knowledge of their natural variations. In this context, we examined seasonal variations in body condition and circulating TH concentrations in free-ranging female polar bears. Females with variable reproductive status (i.e., solitary, with cubs of the year or with yearlings) were sampled from locations with contrasted sea ice conditions. Furthermore, we studied THs in relation to levels of organo-halogenated contaminants. As predicted, solitary females were in better condition than females caring for offspring, especially in spring. In addition, TH levels were lower in autumn compared to spring, although this seasonal effect was mainly observed in solitary females. Finally, the negative relationships between organochlorine and perfluoroalkyl substances and some THs suggest a possible alteration of homeostasis of THs. Since the latter relationships were only observed during spring, we emphasize the importance of considering the ecological factors when using THs as proxies for pollution exposure. Yet, the combined effects of natural and anthropogenic stressors on THs might impair the ability of polar bears to adapt to ongoing climate changes. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Isolation and Genetic Characterization of Toxoplasma gondii from Black Bears (Ursus americanus), Bobcats (Lynx rufus), and Feral Cats (Felis catus) from Pennsylvania.

    Science.gov (United States)

    Dubey, Jitender P; Verma, Shiv K; Calero-Bernal, Rafael; Cassinelli, Ana B; Kwok, Oliver C H; Van Why, Kyle; Su, Chunlei; Humphreys, Jan G

    2015-01-01

    Toxoplasma gondii infects virtually all warm-blooded hosts worldwide. Recently, attention has been focused on the genetic diversity of the parasite to explain its pathogenicity in different hosts. It has been hypothesized that interaction between feral and domestic cycles of T. gondii may increase unusual genotypes in domestic cats and facilitate transmission of potentially more pathogenic genotypes to humans, domestic animals, and wildlife. In the present study, we tested black bear (Ursus americanus), bobcat (Lynx rufus), and feral cat (Felis catus) from the state of Pennsylvania for T. gondii infection. Antibodies to T. gondii were found in 32 (84.2%) of 38 bears, both bobcats, and 2 of 3 feral cats tested by the modified agglutination test (cut off titer 1:25). Hearts from seropositive animals were bioassayed in mice, and viable T. gondii was isolated from 3 of 32 bears, 2 of 2 bobcats, and 2 of 3 feral cats. DNA isolated from culture-derived tachyzoites of these isolates was characterized using multilocus PCR-RFLP markers. Three genotypes were revealed, including ToxoDB PCR-RFLP genotype #1 or #3 (Type II, 1 isolate), #5 (Type 12, 3 isolates), and #216 (3 isolates), adding to the evidence of genetic diversity of T. gondii in wildlife in Pennsylvania. Pathogenicity of 3 T. gondii isolates (all #216, 1 from bear, and 2 from feral cat) was determined in outbred Swiss Webster mice; all three were virulent causing 100% mortality. Results indicated that highly mouse pathogenic strains of T. gondii are circulating in wildlife, and these strains may pose risk to infect human through consuming of game meat. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  4. Environmental, biological and anthropogenic effects on grizzly bear body size: temporal and spatial considerations.

    Science.gov (United States)

    Nielsen, Scott E; Cattet, Marc R L; Boulanger, John; Cranston, Jerome; McDermid, Greg J; Shafer, Aaron B A; Stenhouse, Gordon B

    2013-09-08

    Individual body growth is controlled in large part by the spatial and temporal heterogeneity of, and competition for, resources. Grizzly bears (Ursus arctos L.) are an excellent species for studying the effects of resource heterogeneity and maternal effects (i.e. silver spoon) on life history traits such as body size because their habitats are highly variable in space and time. Here, we evaluated influences on body size of grizzly bears in Alberta, Canada by testing six factors that accounted for spatial and temporal heterogeneity in environments during maternal, natal and 'capture' (recent) environments. After accounting for intrinsic biological factors (age, sex), we examined how body size, measured in mass, length and body condition, was influenced by: (a) population density; (b) regional habitat productivity; (c) inter-annual variability in productivity (including silver spoon effects); (d) local habitat quality; (e) human footprint (disturbances); and (f) landscape change. We found sex and age explained the most variance in body mass, condition and length (R(2) from 0.48-0.64). Inter-annual variability in climate the year before and of birth (silver spoon effects) had detectable effects on the three-body size metrics (R(2) from 0.04-0.07); both maternal (year before birth) and natal (year of birth) effects of precipitation and temperature were related with body size. Local heterogeneity in habitat quality also explained variance in body mass and condition (R(2) from 0.01-0.08), while annual rate of landscape change explained additional variance in body length (R(2) of 0.03). Human footprint and population density had no observed effect on body size. These results illustrated that body size patterns of grizzly bears, while largely affected by basic biological characteristics (age and sex), were also influenced by regional environmental gradients the year before, and of, the individual's birth thus illustrating silver spoon effects. The magnitude of the silver

  5. Mating-related behaviour of grizzly bears inhabiting marginal habitat at the periphery of their North American range.

    Science.gov (United States)

    Edwards, Mark A; Derocher, Andrew E

    2015-02-01

    In comparison to core populations, peripheral populations have low density and recruitment, and are subject to different selective pressures, such as environmental conditions, food type and availability, predation, disease, etc., which may result in behavioural modifications to mating. We test the roam-to-mate hypothesis for a peripheral population of grizzly bears (Ursus arctos) at the northern extent of their North American range, in Canada's Arctic. If bears are roaming-to-mate, we predicted greater range size and daily displacement, and more linear movements for receptive animals during the mating period compared to post-mating. In contrast to our predictions, we found that in general range size and displacement increased from mating to post-mating regardless of reproductive status. When considered across both periods, females with cubs-of-the-year had smaller range use metrics than other reproductive groups, which we attribute to a counter-strategy against sexually selected infanticide and the reduced mobility of cubs. Linearity of movements remained near zero during both periods across all groups, suggesting tortuous movements more characteristic of foraging than of mate-searching. We suggest that for this population, finding quality habitat takes precedence over mate-searching in this marginal Arctic landscape. Alternatively, a more monogamous mating system and sequestering behaviour may have obscured movement differences between the two periods. The behavioural differences in mating that we observed from what is typical of core populations may reflect local adaptation to marginal conditions and could benefit the species in the face of ongoing environmental change. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Natural landscape features, human-related attractants, and conflict hotspots: A spatial analysis of human-grizzly bear conflicts

    Science.gov (United States)

    Wilson, S.M.; Madel, M.J.; Mattson, D.J.; Graham, J.M.; Burchfield, J.A.; Belsky, J.M.

    2005-01-01

    There is a long history of conflict in the western United States between humans and grizzly bears (Ursus arctos) involving agricultural attractants. However, little is known about the spatial dimensions of this conflict and the relative importance of different attractants. This study was undertaken to better understand the spatial and functional components of conflict between humans and grizzly bears on privately owned agricultural lands in Montana. Our investigations focused on spatial associations of rivers and creeks, livestock pastures, boneyards (livestock carcass dump sites), beehives, and grizzly bear habitat with reported human-grizzly bear conflicts during 1986-2001. We based our analysis on a survey of 61 of 64 livestock producers in our study in the Rocky Mountain East Front, Montana. With the assistance of livestock and honey producers, we mapped the locations of cattle and sheep pastures, boneyards, and beehives. We used density surface mapping to identify seasonal clusters of conflicts that we term conflict hotspots. Hotspots accounted for 75% of all conflicts and encompassed approximately 8% of the study area. We also differentiated chronic (4 or more years of conflicts) from non-chronic hotspots (fewer than 4 years of conflict). The 10 chronic hotpots accounted for 58% of all conflicts. Based on Monte Carlo simulations, we found that conflict locations were most strongly associated with rivers and creeks followed by sheep lambing areas and fall sheep pastures. Conflicts also were associated with cattle calving areas, spring cow-calf pastures, summer and fall cattle pastures, and boneyards. The Monte Carlo simulations indicated associations between conflict locations and unprotected beehives at specific analysis scales. Protected (fenced) beehives were less likely to experience conflicts than unprotected beehives. Conflicts occurred at a greater rate in riparian and wetland vegetation than would be expected. The majority of conflicts occurred in a

  7. Despotism and risk of infanticide influence grizzly bear den-site selection.

    Directory of Open Access Journals (Sweden)

    Nathan S Libal

    Full Text Available Given documented social dominance and intraspecific predation in bear populations, the ideal despotic distribution model and sex hypothesis of sexual segregation predict adult female grizzly bears (Ursus arctos will avoid areas occupied by adult males to reduce risk of infanticide. Under ideal despotic distribution, juveniles should similarly avoid adult males to reduce predation risk. Den-site selection and use is an important component of grizzly bear ecology and may be influenced by multiple factors, including risk from conspecifics. To test the role of predation risk and the sex hypothesis of sexual segregation, we compared adult female (n = 142, adult male (n = 36, and juvenile (n = 35 den locations in Denali National Park and Preserve, Alaska, USA. We measured elevation, aspect, slope, and dominant land cover for each den site, and used maximum entropy modeling to determine which variables best predicted den sites. We identified the global model as the best-fitting model for adult female (area under curve (AUC = 0.926 and elevation as the best predictive variable for adult male (AUC = 0.880 den sites. The model containing land cover and elevation best-predicted juvenile (AUC = 0.841 den sites. Adult females spatially segregated from adult males, with dens characterized by higher elevations (mean= 1,412 m, SE = 52 and steeper slopes (mean = 21.9°, SE = 1.1 than adult male (elevation: mean = 1,209 m, SE = 76; slope: mean = 15.6°, SE = 1.9 den sites. Juveniles used a broad range of landscape attributes but did not avoid adult male denning areas. Observed spatial segregation by adult females supports the sex hypothesis of sexual segregation and we suggest is a mechanism to reduce risk of infanticide. Den site selection of adult males is likely related to distribution of food resources during spring.

  8. East Greenland and Barents Sea polar bears (Ursus maritimus): adaptive variation between two populations using skull morphometrics as an indicator of environmental and genetic differences.

    Science.gov (United States)

    Pertoldi, Cino; Sonne, Christian; Wiig, Øystein; Baagøe, Hans J; Loeschcke, Volker; Bechshøft, Thea Østergaard

    2012-06-01

    A morphometric study was conducted on four skull traits of 37 male and 18 female adult East Greenland polar bears (Ursus maritimus) collected 1892-1968, and on 54 male and 44 female adult Barents Sea polar bears collected 1950-1969. The aim was to compare differences in size and shape of the bear skulls using a multivariate approach, characterizing the variation between the two populations using morphometric traits as an indicator of environmental and genetic differences. Mixture analysis testing for geographic differentiation within each population revealed three clusters for Barents Sea males and three clusters for Barents Sea females. East Greenland consisted of one female and one male cluster. A principal component analysis (PCA) conducted on the clusters defined by the mixture analysis, showed that East Greenland and Barents Sea polar bear populations overlapped to a large degree, especially with regards to females. Multivariate analyses of variance (MANOVA) showed no significant differences in morphometric means between the two populations, but differences were detected between clusters from each respective geographic locality. To estimate the importance of genetics and environment in the morphometric differences between the bears, a PCA was performed on the covariance matrix derived from the skull measurements. Skull trait size (PC1) explained approx. 80% of the morphometric variation, whereas shape (PC2) defined approx. 15%, indicating some genetic differentiation. Hence, both environmental and genetic factors seem to have contributed to the observed skull differences between the two populations. Overall, results indicate that many Barents Sea polar bears are morphometrically similar to the East Greenland ones, suggesting an exchange of individuals between the two populations. Furthermore, a subpopulation structure in the Barents Sea population was also indicated from the present analyses, which should be considered with regards to future management

  9. Gene transcription in polar bears (Ursus maritimus) from disparate populations

    Science.gov (United States)

    Bowen, Lizabeth; Miles, A. Keith; Waters, Shannon C.; Meyerson, Randi; Rode, Karyn D.; Atwood, Todd C.

    2015-01-01

    Polar bears in the Beaufort (SB) and Chukchi (CS) Seas experience different environments due primarily to a longer history of sea ice loss in the Beaufort Sea. Ecological differences have been identified as a possible reason for the generally poorer body condition and reproduction of Beaufort polar bears compared to those from the Chukchi, but the influence of exposure to other stressors remains unknown. We use molecular technology, quantitative PCR, to identify gene transcription differences among polar bears from the Beaufort and Chukchi Seas as well as captive healthy polar bears. We identified significant transcriptional differences among a priori groups (i.e., captive bears, SB 2012, SB 2013, CS 2013) for ten of the 14 genes of interest (i.e., CaM, HSP70, CCR3, TGFβ, COX2, THRα, T-bet, Gata3, CD69, and IL17); transcription levels of DRβ, IL1β, AHR, and Mx1 did not differ among groups. Multivariate analysis also demonstrated separation among the groups of polar bears. Specifically, we detected transcript profiles consistent with immune function impairment in polar bears from the Beaufort Sea, when compared with Chukchi and captive polar bears. Although there is no strong indication of differential exposure to contaminants or pathogens between CS and SB bears, there are clearly differences in important transcriptional responses between populations. Further investigation is warranted to refine interpretation of potential effects of described stress-related conditions for the SB population.

  10. Effects of Aversive Conditioning on Behavior of Nuisance Louisiana Black Bears

    OpenAIRE

    Leigh, Jennifer; Chamberlain, Michael J.

    2008-01-01

    Complaints associated with nuisance activity by Louisiana black bears (Ursus americanus luteolus) in south Louisiana have steadily increased since 2000, demanding intervention by state and federal agencies. As a federally threatened species, Louisiana black bears that are a nuisance require nonlethal management, referred to as aversive conditioning. We used rubber buckshot and dogs to test the effectiveness of management techniques used by the state of Louisiana to deter nuisance bear activit...

  11. Rebuttal of "Polar bear population forecasts: a public-policy forecasting audit"

    Science.gov (United States)

    Steven C. Amstrup; Hal Caswell; Eric DeWeaver; Ian Stirling; David C. Douglas; Bruce G. Marcot; Christine M. Hunter

    2009-01-01

    Observed declines in the Arctic sea ice have resulted in a variety of negative effects on polar bears (Ursus maritimus). Projections for additional future declines in sea ice resulted in a proposal to list polar bears as a threatened species under the United States Endangered Species Act. To provide information for the Department of the Interior...

  12. On the palaeobiology of the extinct cave bear Ursus spelaeus ROSENMÜLLER. Insights from stable isotope analysis

    Science.gov (United States)

    Grandal-D'Anglade, Aurora; Pérez-Rama, Marta; Fernández-Mosquera, Daniel

    2010-05-01

    Isotopic signatures (δ13C, δ15N) of bone collagen are used more and more to obtain the paleobiological data of fossil species. By means of these signatures, for example, the diet type of an extint species may be inferred. Also, the climate in which this species developed may greatly influence on the isotopic signature of its bone collagen. This influence is firstly produced in the initial material of the trophic chain but also may produce variations due to physiological changes caused by climatic changes in the species involved in this trophic chain. The cave bear (Ursus spelaeus ROSENMÜLLER) is a species of broad distribution in the European Pleistocene sites that has been studied from the isotopic point of view, trying to establish its diet type. For the moment, the results vary: though in most cases the isotopic values indicate a preferably herbivore diet type, differences exist between sites of different geographic zones and chronologies. Taking into account that climate influences on the cave bear's physiology through the physiological mechanism of hibernation, it is expected that in bears that lived in different climatic phases, the isotopic signatures will be also different. During hibernation a recycling of nitrogenised compounds is produced for protein synthesis, including bone collagen, so it is expected that the isotopic signature, at least of Nitrogen, will be altered with respect to the synthesized collagen when the bear is active and feeds normally. However, it is difficult to establish up to what extent the isotopic signatures due to hibernation or diet are overlapped. To study the physiological effect of hibernation on isotopic signatures we have selected bone remains of cave bears from populations whose chronologies correspond to different climatic moments, and in different ontogenetic stages, coming from Galician caves (NW of the Iberian Peninsula). Adult individuals show different isotopic signatures depending on their chronology. Juvenile

  13. Radiotracking large wilderness mammals: Integration of GPS and Argos technology

    Science.gov (United States)

    Schwartz, Charles C.; Arthur, Steve M.

    1999-01-01

    We tested 30 prototype global positioning system (GPS) radiocollars on brown bears (Ursus arctos) over a 3-year period on the Kenai Peninsula, Alaska. Collars were of 2 design types: GPS with an Argos (Argos Data collection and Location System) satellite uplink (n=19) and GPS unites where the data were stored on board (n=10) for retrieval at a later date. All units also contained a conventional VHF (very high frequency) transmitter and weighed 1.7 kg. GPS-Argos united obtained 10-82% of expected GPS fixes, and fix rate declined significantly (Pbears varied more and were lower than fix rates for stationary collars placed in various vegetation types, suggesting that the bear, terrain, and movement all influence both fix and uplink success rate. Application of this new technology to grizzly and brown bear research and comparisons to studies with moose (Alces alces) are discussed.

  14. Hunting promotes sexual conflict in brown bears.

    Science.gov (United States)

    Gosselin, Jacinthe; Leclerc, Martin; Zedrosser, Andreas; Steyaert, Sam M J G; Swenson, Jon E; Pelletier, Fanie

    2017-01-01

    The removal of individuals through hunting can destabilize social structure, potentially affecting population dynamics. Although previous studies have shown that hunting can indirectly reduce juvenile survival through increased sexually selected infanticide (SSI), very little is known about the spatiotemporal effects of male hunting on juvenile survival. Using detailed individual monitoring of a hunted population of brown bears (Ursus arctos) in Sweden (1991-2011), we assessed the spatiotemporal effect of male removal on cub survival. We modelled cub survival before, during and after the mating season. We used three proxies to evaluate spatial and temporal variation in male turnover; distance and timing of the closest male killed and number of males that died around a female's home range centre. Male removal decreased cub survival only during the mating season, as expected in seasonal breeders with SSI. Cub survival increased with distance to the closest male killed within the previous 1·5 years, and it was lower when the closest male killed was removed 1·5 instead of 0·5 year earlier. We did not detect an effect of the number of males killed. Our results support the hypothesis that social restructuring due to hunting can reduce recruitment and suggest that the distribution of the male deaths might be more important than the overall number of males that die. As the removal of individuals through hunting is typically not homogenously distributed across the landscape, spatial heterogeneity in hunting pressure may cause source-sink dynamics, with lower recruitment in areas of high human-induced mortality. © 2016 The Authors. Journal of Animal Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society.

  15. Bioaccumulation and biotransformation of brominated and chlorinated contaminants and their metabolites in ringed seals (Pusa hispida) and polar bears (Ursus maritimus) from East Greenland.

    Science.gov (United States)

    Letcher, Robert J; Gebbink, Wouter A; Sonne, Christian; Born, Erik W; McKinney, Melissa A; Dietz, Rune

    2009-11-01

    We report on the comparative bioaccumulation, biotransformation and/or biomagnification from East Greenland ringed seal (Pusa hispida) blubber to polar bear (Ursus maritimus) tissues (adipose, liver and brain) of various classes and congeners of persistent chlorinated and brominated contaminants and metabolic by-products: polychlorinated biphenyls (PCBs), chlordanes (CHLs), hydroxyl (OH-) and methylsulfonyl (MeSO(2)-) PCBs, polybrominated biphenyls (PBBs), OH-PBBs, polybrominated diphenyl ether (PBDE) and hexabromocyclododecane (HBCD) flame retardants and OH- and methoxyl (MeO-) PBDEs, 2,2-dichloro-bis(4-chlorophenyl)ethene (p,p'-DDE), 3-MeSO(2)-p,p'-DDE, pentachlorophenol (PCP) and 4-OH-heptachlorostyrene (4-OH-HpCS). We detected all of the investigated contaminants in ringed seal blubber with high frequency, the main diet of East Greenland bears, with the exception of OH-PCBs and 4-OH-HpCS, which indicated that these phenolic contaminants were likely of metabolic origin and formed in the bears from accumulated PCBs and octachlorostyrene (OCS), respectively, rather than being bioaccumulated from a seal blubber diet. For all of the detectable sum of classes or individual organohalogens, in general, the ringed seal to polar bear mean BMFs for SigmaPCBs, p,p'-DDE, SigmaCHLs, SigmaMeSO(2)-PCBs, 3-MeSO(2)-p,p'-DDE, PCP, SigmaPBDEs, total-(alpha)-HBCD, SigmaOH-PBDEs, SigmaMeO-PBDEs and SigmaOH-PBBs indicated that these organohalogens bioaccumulate, and in some cases there was tissue-specific biomagnification, e.g., BMFs for bear adipose and liver ranged from 2 to 570. The blood-brain barrier appeared to be effective in minimizing brain accumulation as BMFs were bear tissues appeared to be mainly accumulated from the seal blubber rather than being metabolic formed from PBDEs in the bears. In vitro PBDE depletion assays using polar bear hepatic microsomes, wherein the rate of oxidative metabolism of PBDE congeners was very slow, supported the probability that accumulation

  16. Combined thin layer chromatography and gas chromatography with mass spectrometric analysis of lipid classes and fatty acids in malnourished polar bears (Ursus maritimus) which swam to Iceland.

    Science.gov (United States)

    Eibler, Dorothee; Krüger, Sabine; Skírnisson, Karl; Vetter, Walter

    2017-03-01

    Between 2008 and 2011, four polar bears (Ursus maritimus) from the Greenland population swam and/or drifted on ice to Iceland where they arrived in very poor body condition. Body fat resources in these animals were only between 0% and 10% of the body weight (usually 25%). Here we studied the lipid composition in different tissues (adipose tissue if available, liver, kidney and muscle). Lipid classes were determined by thin layer chromatography (TLC) and on-column gas chromatography with mass spectrometry (GC/MS). The fatty acid pattern of total lipids and free fatty acids was analyzed by GC/MS in selected ion monitoring (SIM) mode. Additionally, cholesteryl esters and native fatty acid methyl esters, initially detected as zones in thin layer chromatograms, were enriched by solid phase extraction and quantified by GC/MS. The ratio of free fatty acids to native fatty acid methyl esters could be correlated with the remained body lipids in the polar bears and thus may also serve as a marker for other starving animals or even for humans. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Increased cardiac alpha-myosin heavy chain in left atria and decreased myocardial insulin-like growth factor (Igf-I) expression accompany low heart rate in hibernating grizzly bears.

    Science.gov (United States)

    Barrows, N D; Nelson, O L; Robbins, C T; Rourke, B C

    2011-01-01

    Grizzly bears (Ursus arctos horribilis) tolerate extended periods of extremely low heart rate during hibernation without developing congestive heart failure or cardiac chamber dilation. Left ventricular atrophy and decreased left ventricular compliance have been reported in this species during hibernation. We evaluated the myocardial response to significantly reduced heart rate during hibernation by measuring relative myosin heavy-chain (MyHC) isoform expression and expression of a set of genes important to muscle plasticity and mass regulation in the left atria and left ventricles of active and hibernating bears. We supplemented these data with measurements of systolic and diastolic function via echocardiography in unanesthetized grizzly bears. Atrial strain imaging revealed decreased atrial contractility, decreased expansion/reservoir function (increased atrial stiffness), and decreased passive-filling function (increased ventricular stiffness) in hibernating bears. Relative MyHC-α protein expression increased significantly in the atrium during hibernation. The left ventricle expressed 100% MyHC-β protein in both groups. Insulin-like growth factor (IGF-I) mRNA expression was reduced by ∼50% in both chambers during hibernation, consistent with the ventricular atrophy observed in these bears. Interestingly, mRNA expression of the atrophy-related ubiquitin ligases Muscle Atrophy F-box (MAFBx) and Muscle Ring Finger 1 did not increase, nor did expression of myostatin or hypoxia-inducible factor 1α (HIF-1α). We report atrium-specific decreases of 40% and 50%, respectively, in MAFBx and creatine kinase mRNA expression during hibernation. Decreased creatine kinase expression is consistent with lowered energy requirements and could relate to reduced atrial emptying function during hibernation. Taken together with our hemodynamic assessment, these data suggest a potential downregulation of atrial chamber function during hibernation to prevent fatigue and dilation

  18. 75 FR 24545 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for the Polar Bear...

    Science.gov (United States)

    2010-05-05

    ... Critical Habitat for the Polar Bear in the United States AGENCY: Fish and Wildlife Service, Interior... designation of critical habitat for the polar bear (Ursus maritimus) under the Endangered Species Act of 1973... for the polar bear and on the DEA, and an amended required determinations section of the proposal. We...

  19. Comparing urban and wildland bear densities with a DNA-based capture-mark-recapture approach

    OpenAIRE

    Fusaro, Jonathan L.; Conner, Mary M.; Conover, Michael R.; Taylor, Timothy J.; Kenyon, Marc W., Jr.; Sherman, Jamie R.; Ernest, Holly B.

    2017-01-01

    California’s black bear (Ursus americanus) population has tripled over the last 3 decades, causing an increased incidence of human–bear conflicts, many of which now occur in urban areas. Consequently, it is imperative that bear managers have the ability to monitor population parameters in both wildland and urban environments to help manage bears. Capture-mark-recapture (CMR) methods using uniquely typed genetic samples (DNA) collected via hair-snares have been widely used to monitor bears in ...

  20. Growth of bear-damaged trees in a mixed plantation of Douglas-fir and red alder.

    Science.gov (United States)

    Richard E. Miller; Harry W. Anderson; Donald L. Reukema; Timothy A. Max

    2007-01-01

    Incidence and effects of tree damage by black bear (Ursus americanus altifrontalis) in a 50-year-old, coast Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) plantation are described. Bears girdled or partially girdled 35 dominant or codominant Douglas-fir trees per acre, but only in that...

  1. Changing numbers of spawning cutthroat trout in tributary streams of Yellowstone Lake and estimates of grizzly bears visiting streams from DNA

    Science.gov (United States)

    Haroldson, M.A.; Gunther, K.A.; Reinhart, Daniel P.; Podruzny, S.R.; Cegelski, C.; Waits, L.; Wyman, T.C.; Smith, J.

    2005-01-01

    Spawning Yellowstone cutthroat trout (Oncorhynchus clarki) provide a source of highly digestible energy for grizzly bears (Ursus arctos) that visit tributary streams to Yellowstone Lake during the spring and early summer. During 1985–87, research documented grizzly bears fishing on 61% of the 124 tributary streams to the lake. Using track measurements, it was estimated that a minimum of 44 grizzly bears fished those streams annually. During 1994, non-native lake trout (Salvelinus namaycush) were discovered in Yellowstone Lake. Lake trout are efficient predators and have the potential to reduce the native cutthroat population and negatively impact terrestrial predators that use cutthroat trout as a food resource. In 1997, we began sampling a subset of streams (n = 25) from areas of Yellowstone Lake surveyed during the previous study to determine if changes in spawner numbers or bear use had occurred. Comparisons of peak numbers and duration suggested a considerable decline between study periods in streams in the West Thumb area of the lake. The apparent decline may be due to predation by lake trout. Indices of bear use also declined on West Thumb area streams. We used DNA from hair collected near spawning streams to estimate the minimum number of bears visiting the vicinity of spawning streams. Seventy-four individual bears were identified from 429 hair samples. The annual number of individuals detected ranged from 15 in 1997 to 33 in 2000. Seventy percent of genotypes identified were represented by more than 1 sample, but only 31% of bears were documented more than 1 year of the study. Sixty-two (84%) bears were only documented in 1 segment of the lake, whereas 12 (16%) were found in 2–3 lake segments. Twenty-seven bears were identified from hair collected at multiple streams. One bear was identified on 6 streams in 2 segments of the lake and during 3 years of the study. We used encounter histories derived from DNA and the Jolly-Seber procedure in Program MARK

  2. Trans Fatty Acids Provide Evidence of Anthropogenic Feeding by Black Bears

    OpenAIRE

    Thiemann, Gregory W.; Stahl, Randal S.; Baruch-Mordo, Sharon; Breck, Stewart W.

    2008-01-01

    Bears (Ursus spp.) that become conditioned to anthropogenic food sources pose a risk to human safety and generally need to be relocated, rehabilitated, or destroyed. Identifying food-conditioned bears may be difficult if the animal is not captured or killed while immediately engaged in the nuisance behavior. Fatty acid signature analysis has been used to examine the dietary habits of bears and other carnivores and is based on the predictable incorporation of ingested fatty acids into the cons...

  3. Black Bear Reactions to Venomous and Non-venomous Snakes in Eastern North America

    OpenAIRE

    Rogers, Lynn L; Mansfield, Susan A; Hornby, Kathleen; Hornby, Stewart; Debruyn, Terry D; Mize, Malvin; Clark, Rulon; Burghardt, Gordon M

    2014-01-01

    Bears are often considered ecological equivalents of large primates, but the latter often respond with fear, avoidance, and alarm calls to snakes, both venomous and non-venomous, there is sparse information on how bears respond to snakes. We videotaped or directly observed natural encounters between black bears (Ursus americanus) and snakes. Inside the range of venomous snakes in Arkansas and West Virginia, adolescent and adult black bears reacted fearfully in seven of seven encounters upon b...

  4. Effects of intramuscular administration of tiletamine-zolazepam with and without sedative pretreatment on plasma and serum biochemical values and glucose tolerance test results in Japanese black bears (Ursus thibetanus japonicus).

    Science.gov (United States)

    Kamine, Akari; Shimozuru, Michito; Shibata, Haruki; Tsubota, Toshio

    2012-08-01

    To establish a safe anesthetic protocol with little effect on blood biochemical values and IV glucose tolerance test (IVGTT) results in Japanese black bears (Ursus thibetanus japonicus). 16 captive female Japanese black bears (5 to 17 years of age). Bears were randomly assigned to 4 treatment groups (4 bears/group) in which various treatment combinations were administered via blow dart: tiletamine HCl and zolazepam HCl (9 mg/kg) alone (TZ), TZ (6 mg/kg) and acepromazine maleate (0.1 mg/kg), TZ (6 mg/kg) and butorphanol tartrate (0.3 mg/kg), or TZ (3 mg/kg) and medetomidine HCl (40 μg/kg). Glucose injection for the IVGTT was started 130 minutes after TZ administration. Blood samples were obtained before, at, and intermittently after glucose injection for measurement of biochemical variables as well as plasma glucose and serum insulin concentrations during the IVGTT. Rectal temperature, pulse rate, and respiratory rate were assessed every 15 minutes during the experiment. Induction and maintenance of anesthesia were safely achieved with little adverse effect on cardiopulmonary function when each of the 4 anesthetic regimens was used, although mild hypothermia was induced. No difference was evident between treatment groups in blood biochemical values. Blood glucose and insulin concentration profiles during the IVGTT were similar among the bears given TZ, with or without acepromazine or butorphanol, but hyperglycemia and hypoinsulinemia developed in bears given TZ with medetomidine. All 4 anesthetic regimens yielded chemical restraint without affecting clinical and biochemical values in bears, but medetomidine appeared to affect IVGTT results. For this reason, medetomidine should not be used when anesthetizing bears for IVGTTs.

  5. Effects of sample size and sampling frequency on studies of brown bear home ranges and habitat use

    Science.gov (United States)

    Arthur, Steve M.; Schwartz, Charles C.

    1999-01-01

    We equipped 9 brown bears (Ursus arctos) on the Kenai Peninsula, Alaska, with collars containing both conventional very-high-frequency (VHF) transmitters and global positioning system (GPS) receivers programmed to determine an animal's position at 5.75-hr intervals. We calculated minimum convex polygon (MCP) and fixed and adaptive kernel home ranges for randomly-selected subsets of the GPS data to examine the effects of sample size on accuracy and precision of home range estimates. We also compared results obtained by weekly aerial radiotracking versus more frequent GPS locations to test for biases in conventional radiotracking data. Home ranges based on the MCP were 20-606 km2 (x = 201) for aerial radiotracking data (n = 12-16 locations/bear) and 116-1,505 km2 (x = 522) for the complete GPS data sets (n = 245-466 locations/bear). Fixed kernel home ranges were 34-955 km2 (x = 224) for radiotracking data and 16-130 km2 (x = 60) for the GPS data. Differences between means for radiotracking and GPS data were due primarily to the larger samples provided by the GPS data. Means did not differ between radiotracking data and equivalent-sized subsets of GPS data (P > 0.10). For the MCP, home range area increased and variability decreased asymptotically with number of locations. For the kernel models, both area and variability decreased with increasing sample size. Simulations suggested that the MCP and kernel models required >60 and >80 locations, respectively, for estimates to be both accurate (change in area bears. Our results suggest that the usefulness of conventional radiotracking data may be limited by potential biases and variability due to small samples. Investigators that use home range estimates in statistical tests should consider the effects of variability of those estimates. Use of GPS-equipped collars can facilitate obtaining larger samples of unbiased data and improve accuracy and precision of home range estimates.

  6. A demographic comparison of two black bear populations in the Interior Highlands of Arkansas

    Science.gov (United States)

    Clark, Joseph D.; Smith, Kimberly G.

    1994-01-01

    The Ozark and Ouachita mountain regions of western Arkansas, collectively known as the Interior Highlands, historically supported large numbers of black bears (Ursus americanus). Indiscriminate killing of bears by early settlers and subsequent habitat reductions due to extensive logging and changes in land use resulted in their decline (Smith et al. 1991). By the late 1940's, bears had been extirpated from both regions (Holder 1951).

  7. Borreliosis in free-ranging black bears from Wisconsin.

    Science.gov (United States)

    Kazmierczak, J J; Amundson, T E; Burgess, E C

    1988-04-01

    Blood, kidney and tick samples were obtained from 18 hunter-killed black bears (Ursus americanus) from three sites in northern Wisconsin. A Borrelia sp., morphologically and antigenically similar to Borrelia burgdorferi, was isolated from the blood of two of the animals, and from the kidney of a third. Ixodes dammini and Dermacentor variabilis were found on the bears. This is the first report of borreliosis in the Ursidae, and of the primary vector of Lyme disease, I. dammini, from this host.

  8. Evolution of major histocompatibility complex class I and class II genes in the brown bear

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    Kuduk Katarzyna

    2012-10-01

    Full Text Available Abstract Background Major histocompatibility complex (MHC proteins constitute an essential component of the vertebrate immune response, and are coded by the most polymorphic of the vertebrate genes. Here, we investigated sequence variation and evolution of MHC class I and class II DRB, DQA and DQB genes in the brown bear Ursus arctos to characterise the level of polymorphism, estimate the strength of positive selection acting on them, and assess the extent of gene orthology and trans-species polymorphism in Ursidae. Results We found 37 MHC class I, 16 MHC class II DRB, four DQB and two DQA alleles. We confirmed the expression of several loci: three MHC class I, two DRB, two DQB and one DQA. MHC class I also contained two clusters of non-expressed sequences. MHC class I and DRB allele frequencies differed between northern and southern populations of the Scandinavian brown bear. The rate of nonsynonymous substitutions (dN exceeded the rate of synonymous substitutions (dS at putative antigen binding sites of DRB and DQB loci and, marginally significantly, at MHC class I loci. Models of codon evolution supported positive selection at DRB and MHC class I loci. Both MHC class I and MHC class II sequences showed orthology to gene clusters found in the giant panda Ailuropoda melanoleuca. Conclusions Historical positive selection has acted on MHC class I, class II DRB and DQB, but not on the DQA locus. The signal of historical positive selection on the DRB locus was particularly strong, which may be a general feature of caniforms. The presence of MHC class I pseudogenes may indicate faster gene turnover in this class through the birth-and-death process. South–north population structure at MHC loci probably reflects origin of the populations from separate glacial refugia.

  9. Evolution of major histocompatibility complex class I and class II genes in the brown bear.

    Science.gov (United States)

    Kuduk, Katarzyna; Babik, Wiesław; Bojarska, Katarzyna; Sliwińska, Ewa B; Kindberg, Jonas; Taberlet, Pierre; Swenson, Jon E; Radwan, Jacek

    2012-10-02

    Major histocompatibility complex (MHC) proteins constitute an essential component of the vertebrate immune response, and are coded by the most polymorphic of the vertebrate genes. Here, we investigated sequence variation and evolution of MHC class I and class II DRB, DQA and DQB genes in the brown bear Ursus arctos to characterise the level of polymorphism, estimate the strength of positive selection acting on them, and assess the extent of gene orthology and trans-species polymorphism in Ursidae. We found 37 MHC class I, 16 MHC class II DRB, four DQB and two DQA alleles. We confirmed the expression of several loci: three MHC class I, two DRB, two DQB and one DQA. MHC class I also contained two clusters of non-expressed sequences. MHC class I and DRB allele frequencies differed between northern and southern populations of the Scandinavian brown bear. The rate of nonsynonymous substitutions (dN) exceeded the rate of synonymous substitutions (dS) at putative antigen binding sites of DRB and DQB loci and, marginally significantly, at MHC class I loci. Models of codon evolution supported positive selection at DRB and MHC class I loci. Both MHC class I and MHC class II sequences showed orthology to gene clusters found in the giant panda Ailuropoda melanoleuca. Historical positive selection has acted on MHC class I, class II DRB and DQB, but not on the DQA locus. The signal of historical positive selection on the DRB locus was particularly strong, which may be a general feature of caniforms. The presence of MHC class I pseudogenes may indicate faster gene turnover in this class through the birth-and-death process. South-north population structure at MHC loci probably reflects origin of the populations from separate glacial refugia.

  10. Evolution of major histocompatibility complex class I and class II genes in the brown bear

    Science.gov (United States)

    2012-01-01

    Background Major histocompatibility complex (MHC) proteins constitute an essential component of the vertebrate immune response, and are coded by the most polymorphic of the vertebrate genes. Here, we investigated sequence variation and evolution of MHC class I and class II DRB, DQA and DQB genes in the brown bear Ursus arctos to characterise the level of polymorphism, estimate the strength of positive selection acting on them, and assess the extent of gene orthology and trans-species polymorphism in Ursidae. Results We found 37 MHC class I, 16 MHC class II DRB, four DQB and two DQA alleles. We confirmed the expression of several loci: three MHC class I, two DRB, two DQB and one DQA. MHC class I also contained two clusters of non-expressed sequences. MHC class I and DRB allele frequencies differed between northern and southern populations of the Scandinavian brown bear. The rate of nonsynonymous substitutions (dN) exceeded the rate of synonymous substitutions (dS) at putative antigen binding sites of DRB and DQB loci and, marginally significantly, at MHC class I loci. Models of codon evolution supported positive selection at DRB and MHC class I loci. Both MHC class I and MHC class II sequences showed orthology to gene clusters found in the giant panda Ailuropoda melanoleuca. Conclusions Historical positive selection has acted on MHC class I, class II DRB and DQB, but not on the DQA locus. The signal of historical positive selection on the DRB locus was particularly strong, which may be a general feature of caniforms. The presence of MHC class I pseudogenes may indicate faster gene turnover in this class through the birth-and-death process. South–north population structure at MHC loci probably reflects origin of the populations from separate glacial refugia. PMID:23031405

  11. Space-time clusters for early detection of grizzly bear predation.

    Science.gov (United States)

    Kermish-Wells, Joseph; Massolo, Alessandro; Stenhouse, Gordon B; Larsen, Terrence A; Musiani, Marco

    2018-01-01

    Accurate detection and classification of predation events is important to determine predation and consumption rates by predators. However, obtaining this information for large predators is constrained by the speed at which carcasses disappear and the cost of field data collection. To accurately detect predation events, researchers have used GPS collar technology combined with targeted site visits. However, kill sites are often investigated well after the predation event due to limited data retrieval options on GPS collars (VHF or UHF downloading) and to ensure crew safety when working with large predators. This can lead to missing information from small-prey (including young ungulates) kill sites due to scavenging and general site deterioration (e.g., vegetation growth). We used a space-time permutation scan statistic (STPSS) clustering method (SaTScan) to detect predation events of grizzly bears ( Ursus arctos ) fitted with satellite transmitting GPS collars. We used generalized linear mixed models to verify predation events and the size of carcasses using spatiotemporal characteristics as predictors. STPSS uses a probability model to compare expected cluster size (space and time) with the observed size. We applied this method retrospectively to data from 2006 to 2007 to compare our method to random GPS site selection. In 2013-2014, we applied our detection method to visit sites one week after their occupation. Both datasets were collected in the same study area. Our approach detected 23 of 27 predation sites verified by visiting 464 random grizzly bear locations in 2006-2007, 187 of which were within space-time clusters and 277 outside. Predation site detection increased by 2.75 times (54 predation events of 335 visited clusters) using 2013-2014 data. Our GLMMs showed that cluster size and duration predicted predation events and carcass size with high sensitivity (0.72 and 0.94, respectively). Coupling GPS satellite technology with clusters using a program based

  12. Bear phalanx traumatically introduced into a living human: Prehistoric evidence.

    Science.gov (United States)

    Richards, Gary D; Ojeda, Hillary M; Jabbour, Rebecca S; Ibarra, Caitlin L; Horton, Caroline F

    2013-03-01

    Traumatically induced skeletal injuries are common and can be ascribed to a normal range of events occurring in an individual's lifetime. A subset of these trauma-induced injuries provides enhanced insight into cultural history. Such cases might include those referable to medico-surgical and religious/ritualistic practices. We describe prehistoric evidence and cultural implications of the traumatic insertion of an Ursus manual phalanx into the elbow of a living human. The injury healed and the phalanx remained in situ until death. The individual derives from the Ellis Landing shellmound and dates to a subphase of the Middle Period (≈500BC-300AD) in the California cultural sequence. The remains are of a 30-40 year-old female. Comparative data on arm morphology and pathological conditions present were collected (n=159). Three Ursus subspecies (n=15) were examined to identify the taxon represented by the phalanx. The described individual was probably wearing bear paw ornaments at the time she was crushed by a heavy object. During this event, a bear claw was driven into her cubital fossa, the basal phalangeal tubercle being impressed into the humerus. The wound healed completely. The presence of Ursus body parts indicates an elevated societal role for this female; most likely she was a shaman or healer. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Combined use of mark-recapture and genetic analyses reveals response of a black bear population to changes in food productivity

    Science.gov (United States)

    Barbara S. McCall; Michael S. Mitchell; Michael K. Schwartz; Jim Hayden; Samuel A. Cushman; Pete Zager; Wayne F. Kasworm

    2013-01-01

    We used mark-recapture analysis to investigate the dynamics of a black bear (Ursus americanus) population in northern Idaho where food availability varies seasonally and annually. We conducted noninvasive genetic sampling (NGS) during 2003-2006 in the Purcell Mountains of Idaho to collect black bear DNA samples for individual identification of bears. We used a...

  14. Stable isotope and trace element studies of black bear hair, Big Bend ecosystem, Texas and Mexico

    Science.gov (United States)

    Shanks, W.C. Pat; Hellgren, Eric C.; Stricker, Craig A.; Gemery-Hill, Pamela A.; Onorato, David P.

    2008-01-01

    Hair from black bears (Ursus americanus), collected from four areas in the Big Bend ecosystem, has been analyzed for stable isotopes of carbon, nitrogen, and sulfur to determine major food sources and for trace metals to infer possible effects of environmental contaminants. Results indicate that black bears are largely vegetarian, feeding on desert plants, nuts, and berries. Mercury concentrations in bear hair are below safe level standards (

  15. Mitochondrial genomes reveal an explosive radiation of extinct and extant bears near the Miocene-Pliocene boundary.

    Science.gov (United States)

    Krause, Johannes; Unger, Tina; Noçon, Aline; Malaspinas, Anna-Sapfo; Kolokotronis, Sergios-Orestis; Stiller, Mathias; Soibelzon, Leopoldo; Spriggs, Helen; Dear, Paul H; Briggs, Adrian W; Bray, Sarah C E; O'Brien, Stephen J; Rabeder, Gernot; Matheus, Paul; Cooper, Alan; Slatkin, Montgomery; Pääbo, Svante; Hofreiter, Michael

    2008-07-28

    Despite being one of the most studied families within the Carnivora, the phylogenetic relationships among the members of the bear family (Ursidae) have long remained unclear. Widely divergent topologies have been suggested based on various data sets and methods. We present a fully resolved phylogeny for ursids based on ten complete mitochondrial genome sequences from all eight living and two recently extinct bear species, the European cave bear (Ursus spelaeus) and the American giant short-faced bear (Arctodus simus). The mitogenomic data yield a well-resolved topology for ursids, with the sloth bear at the basal position within the genus Ursus. The sun bear is the sister taxon to both the American and Asian black bears, and this clade is the sister clade of cave bear, brown bear and polar bear confirming a recent study on bear mitochondrial genomes. Sequences from extinct bears represent the third and fourth Pleistocene species for which complete mitochondrial genomes have been sequenced. Moreover, the cave bear specimen demonstrates that mitogenomic studies can be applied to Pleistocene fossils that have not been preserved in permafrost, and therefore have a broad application within ancient DNA research. Molecular dating of the mtDNA divergence times suggests a rapid radiation of bears in both the Old and New Worlds around 5 million years ago, at the Miocene-Pliocene boundary. This coincides with major global changes, such as the Messinian crisis and the first opening of the Bering Strait, and suggests a global influence of such events on species radiations.

  16. Mitochondrial genomes reveal an explosive radiation of extinct and extant bears near the Miocene-Pliocene boundary

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    Rabeder Gernot

    2008-07-01

    Full Text Available Abstract Background Despite being one of the most studied families within the Carnivora, the phylogenetic relationships among the members of the bear family (Ursidae have long remained unclear. Widely divergent topologies have been suggested based on various data sets and methods. Results We present a fully resolved phylogeny for ursids based on ten complete mitochondrial genome sequences from all eight living and two recently extinct bear species, the European cave bear (Ursus spelaeus and the American giant short-faced bear (Arctodus simus. The mitogenomic data yield a well-resolved topology for ursids, with the sloth bear at the basal position within the genus Ursus. The sun bear is the sister taxon to both the American and Asian black bears, and this clade is the sister clade of cave bear, brown bear and polar bear confirming a recent study on bear mitochondrial genomes. Conclusion Sequences from extinct bears represent the third and fourth Pleistocene species for which complete mitochondrial genomes have been sequenced. Moreover, the cave bear specimen demonstrates that mitogenomic studies can be applied to Pleistocene fossils that have not been preserved in permafrost, and therefore have a broad application within ancient DNA research. Molecular dating of the mtDNA divergence times suggests a rapid radiation of bears in both the Old and New Worlds around 5 million years ago, at the Miocene-Pliocene boundary. This coincides with major global changes, such as the Messinian crisis and the first opening of the Bering Strait, and suggests a global influence of such events on species radiations.

  17. Forecasting the Range-wide Status of Polar Bears at Selected Times in the 21st Century

    Science.gov (United States)

    Steven C. Amstrup; Bruce G. Marcot; David C. Douglas

    2007-01-01

    To inform the U.S. Fish and Wildlife Service decision whether or not to list polar bears as threatened under the Endangered Species Act (ESA), we forecast the status of the world's polar bear (Ursus maritimus) populations 45, 75 and 100 years into the future. We applied the best available information about predicted changes in sea ice in the...

  18. Ecology of Florida black bears in the Okefenokee-Osceola ecosystem

    Science.gov (United States)

    Dobey, S.; Masters, D.V.; Scheick, B.K.; Clark, J.D.; Pelton, M.R.; Sunquist, M.E.

    2005-01-01

    The population status of the Florida black bear (Ursus americanus floridanus) is problematic within many portions of its range and its potential listing as a federally threatened species has been the subject of legal debate. We studied Florida black bears in 2 areas in the Okefenokee-Osceola ecosystem in southeast Georgia (i.e.,Okefenokee) and north Florida (i.e., Osceola) from 1995 to 1999 to evaluate relationships between population characteristics, habitat conditions, and human activities. Bears in Okefenokee were hunted and those in Osceola were not. We captured 205 different black bears (124M:81F) 345 times from June 1995 to September  1998. We obtained 13,573 radiolocations from 87 (16M:71F) individual bears during the study.

  19. Validation of mercury tip-switch and accelerometer activity sensors for identifying resting and active behavior in bears

    Science.gov (United States)

    Jasmine Ware,; Rode, Karyn D.; Pagano, Anthony M.; Bromaghin, Jeffrey F.; Robbins, Charles T.; Joy Erlenbach,; Shannon Jensen,; Amy Cutting,; Nicole Nicassio-Hiskey,; Amy Hash,; Owen, Megan A.; Heiko Jansen,

    2015-01-01

    Activity sensors are often included in wildlife transmitters and can provide information on the behavior and activity patterns of animals remotely. However, interpreting activity-sensor data relative to animal behavior can be difficult if animals cannot be continuously observed. In this study, we examined the performance of a mercury tip-switch and a tri-axial accelerometer housed in collars to determine whether sensor data can be accurately classified as resting and active behaviors and whether data are comparable for the 2 sensor types. Five captive bears (3 polar [Ursus maritimus] and 2 brown [U. arctos horribilis]) were fitted with a collar specially designed to internally house the sensors. The bears’ behaviors were recorded, classified, and then compared with sensor readings. A separate tri-axial accelerometer that sampled continuously at a higher frequency and provided raw acceleration values from 3 axes was also mounted on the collar to compare with the lower resolution sensors. Both accelerometers more accurately identified resting and active behaviors at time intervals ranging from 1 minute to 1 hour (≥91.1% accuracy) compared with the mercury tip-switch (range = 75.5–86.3%). However, mercury tip-switch accuracy improved when sampled at longer intervals (e.g., 30–60 min). Data from the lower resolution accelerometer, but not the mercury tip-switch, accurately predicted the percentage of time spent resting during an hour. Although the number of bears available for this study was small, our results suggest that these activity sensors can remotely identify resting versus active behaviors across most time intervals. We recommend that investigators consider both study objectives and the variation in accuracy of classifying resting and active behaviors reported here when determining sampling interval.

  20. Assessment of neurotoxic effects of mercury in beluga whales (Delphinapterus leucas), ringed seals (Pusa hispida), and polar bears (Ursus maritimus) from the Canadian Arctic.

    Science.gov (United States)

    Krey, Anke; Ostertag, Sonja K; Chan, Hing Man

    2015-03-15

    Marine mammals are indicator species of the Arctic ecosystem and an integral component of the traditional Inuit diet. The potential neurotoxic effects of increased mercury (Hg) in beluga whales (Delphinapterus leucas), ringed seals (Pusa hispida), and polar bears (Ursus maritimus) are not clear. We assessed the risk of Hg-associated neurotoxicity to these species by comparing their brain Hg concentrations with threshold concentrations for toxic endpoints detected in laboratory animals and field observations: clinical symptoms (>6.75 mg/kg wet weight (ww)), neuropathological signs (>4 mg/kg ww), neurochemical changes (>0.4 mg/kg ww), and neurobehavioral changes (>0.1mg/kg ww). The total Hg (THg) concentrations in the cerebellum and frontal lobe of ringed seals and polar bears were 3mg/kg ww. Our results suggest that brain THg levels in polar bears are below levels that induce neurobehavioral effects as reported in the literature, while THg concentrations in ringed seals are within the range that elicit neurobehavioral effects and individual ringed seals exceed the threshold for neurochemical changes. The relatively high THg concentration in beluga whales exceeds all of the neurotoxicity thresholds assessed. High brain selenium (Se):Hg molar ratios were observed in all three species, suggesting that Se could protect the animals from Hg-associated neurotoxicity. This assessment was limited by several factors that influence neurotoxic effects in animals, including: animal species; form of Hg in the brain; and interactions with modifiers of Hg-associated toxicity, such as Se. Comparing brain Hg concentrations in wildlife with concentrations of appropriate laboratory studies can be used as a tool for risk characterization of the neurotoxic effects of Hg in Arctic marine mammals. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. The influence of sulfur and hair growth on stable isotope diet estimates for grizzly bears.

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    Garth Mowat

    Full Text Available Stable isotope ratios of grizzly bear (Ursus arctos guard hair collected from bears on the lower Stikine River, British Columbia (BC were analyzed to: 1 test whether measuring δ34S values improved the precision of the salmon (Oncorhynchus spp. diet fraction estimate relative to δ15N as is conventionally done, 2 investigate whether measuring δ34S values improves the separation of diet contributions of moose (Alces alces, marmot (Marmota caligata, and mountain goat (Oreamnos americanus and, 3 examine the relationship between collection date and length of hair and stable isotope values. Variation in isotope signatures among hair samples from the same bear and year were not trivial. The addition of δ34S values to mixing models used to estimate diet fractions generated small improvement in the precision of salmon and terrestrial prey diet fractions. Although the δ34S value for salmon is precise and appears general among species and areas, sulfur ratios were strongly correlated with nitrogen ratios and therefore added little new information to the mixing model regarding the consumption of salmon. Mean δ34S values for the three terrestrial herbivores of interest were similar and imprecise, so these data also added little new information to the mixing model. The addition of sulfur data did confirm that at least some bears in this system ate marmots during summer and fall. We show that there are bears with short hair that assimilate >20% salmon in their diet and bears with longer hair that eat no salmon living within a few kilometers of one another in a coastal ecosystem. Grizzly bears are thought to re-grow hair between June and October however our analysis of sectioned hair suggested at least some hairs begin growing in July or August, not June and, that hair of wild bears may grow faster than observed in captive bears. Our hair samples may have been from the year of sampling or the previous year because samples were collected in summer when

  2. The influence of sulfur and hair growth on stable isotope diet estimates for grizzly bears.

    Science.gov (United States)

    Mowat, Garth; Curtis, P Jeff; Lafferty, Diana J R

    2017-01-01

    Stable isotope ratios of grizzly bear (Ursus arctos) guard hair collected from bears on the lower Stikine River, British Columbia (BC) were analyzed to: 1) test whether measuring δ34S values improved the precision of the salmon (Oncorhynchus spp.) diet fraction estimate relative to δ15N as is conventionally done, 2) investigate whether measuring δ34S values improves the separation of diet contributions of moose (Alces alces), marmot (Marmota caligata), and mountain goat (Oreamnos americanus) and, 3) examine the relationship between collection date and length of hair and stable isotope values. Variation in isotope signatures among hair samples from the same bear and year were not trivial. The addition of δ34S values to mixing models used to estimate diet fractions generated small improvement in the precision of salmon and terrestrial prey diet fractions. Although the δ34S value for salmon is precise and appears general among species and areas, sulfur ratios were strongly correlated with nitrogen ratios and therefore added little new information to the mixing model regarding the consumption of salmon. Mean δ34S values for the three terrestrial herbivores of interest were similar and imprecise, so these data also added little new information to the mixing model. The addition of sulfur data did confirm that at least some bears in this system ate marmots during summer and fall. We show that there are bears with short hair that assimilate >20% salmon in their diet and bears with longer hair that eat no salmon living within a few kilometers of one another in a coastal ecosystem. Grizzly bears are thought to re-grow hair between June and October however our analysis of sectioned hair suggested at least some hairs begin growing in July or August, not June and, that hair of wild bears may grow faster than observed in captive bears. Our hair samples may have been from the year of sampling or the previous year because samples were collected in summer when bears were

  3. Forecasting the relative influence of environmental and anthropogenic stressors on polar bears

    Science.gov (United States)

    Todd C. Atwood; Bruce G. Marcot; David C. Douglas; Steven C. Amstrup; Karyn D. Rode; George M. Durner; Jeffrey F. Bromaghin

    2016-01-01

    Effective conservation planning requires understanding and ranking threats to wildlife populations. We developed a Bayesian network model to evaluate the relative influence of environmental and anthropogenic stressors, and their mitigation, on the persistence of polar bears (Ursus maritimus). Overall sea ice conditions, affected by rising global...

  4. A complete mitochondrial genome sequence of Asian black bear Sichuan subspecies (Ursus thibetanus mupinensis)

    Science.gov (United States)

    Hou, Wan-ru; Chen, Yu; Wu, Xia; Hu, Jin-chu; Peng, Zheng-song; Yang, Jung; Tang, Zong-xiang; Zhou, Cai-Quan; Li, Yu-ming; Yang, Shi-kui; Du, Yu-jie; Kong, Ling-lu; Ren, Zheng-long; Zhang, Huai-yu; Shuai, Su-rong

    2007-01-01

    We obtained the complete mitochondrial genome of U.thibetanus mupinensis by DNA sequencing based on the PCR fragments of 18 primers we designed. The results indicate that the mtDNA is 16 868 bp in size, encodes 13 protein genes, 22 tRNA genes, and 2 rRNA genes, with an overall H-strand base composition of 31.2% A, 25.4% C, 15.5% G and 27.9% T. The sequence of the control region (CR) located between tRNA-Pro and tRNA-Phe is 1422 bp in size, consists of 8.43% of the whole genome, GC content is 51.9% and has a 6bp tandem repeat and two 10bp tandem repeats identified by using the Tandem Repeats Finder. U. thibetanus mupinensis mitochondrial genome shares high similarity with those of three other Ursidae: U. americanus (91.46%), U. arctos (89.25%) and U. maritimus (87.66%). PMID:17205108

  5. Prevalence of Toxoplasma gondii infections in Pennsylvania black bears, Ursus americanus.

    Science.gov (United States)

    Briscoe, N; Humphreys, J G; Dubey, J P

    1993-10-01

    Serum samples from 665 hunter-killed black bears killed in 1989 to 1992 throughout Pennsylvania (USA) were tested for Toxoplasma gondii antibodies by the agglutination test in dilutions of 1:25, 1:50, and 1:500. Toxoplasma gondii antibodies were found in 535 of 665 (80%) bears. Considering the highest dilutions at which antibodies were detected, prevalences were 10% at 1:25, 37% at 1:50 and 33% at 1:500. No significant difference in antibody prevalence was found between males (79%) and females (80%), but a significant difference was found between juvenile (65%) and adult (83%) bears.

  6. Lumbar laminectomy in a captive, adult polar bear (Ursus maritimus).

    Science.gov (United States)

    Morrison, John F; Vakharia, Kunal; Moreland, Douglas B

    2017-01-01

    Animals held in captivity tend to live longer than do their wild counterparts, and as such, are prone to developing age-related degenerative injuries. Here, we present a case of an adult female polar bear with symptomatic lumbar stenosis. There is a paucity of literature on large mammalian spine surgery, and anatomical differences between humans and other vertebrates must be taken into consideration. A 24-year-old female polar bear residing at the zoo was found to have decreased motor function in her hind legs. Diagnostic myelography performed at the L7/S1 level demonstrated lumbar stenosis at L5/6 for which a laminectomy was performed. Postoperatively, she returned to premorbid functional level, with no apparent associated adverse sequelae. To our knowledge, this is the first reported case of spine surgery in a polar bear and demonstrates that neurosurgical diagnostic and operative techniques developed for humans can also be applied to large mammals with successful results.

  7. Microhabitat features influencing habitat use by Florida black bears

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    Dana L. Karelus

    2018-01-01

    Full Text Available Understanding fine-scale habitat needs of species and the factors influencing heterogeneous use of habitat within home range would help identify limiting resources and inform habitat management practices. This information is especially important for large mammals living in fragmented habitats where resources may be scarcer and more patchily distributed than in contiguous habitats. Using bihourly Global Position System (GPS location data collected from 10 individuals during 2011–2014, we investigated microhabitat features of areas within home ranges that received high vs. low intensity of use by Florida black bears (Ursus americanus floridanus in north-central, Florida. We identified areas receiving high and low levels of use by bears based on their utilization distributions estimated with the dynamic Brownian bridge movement model, and performed vegetation sampling at bear locations within high- and low-use areas. Using univariate analyses and generalized linear mixed models, we found that (1 canopy cover, visual obstruction, and hardwood density were important in defining high-use sites; (2 the probability of high use was positively associated with principal components that represented habitat closer to creeks and with high canopy and shrub cover and higher hardwood densities, likely characteristic of forested wetlands; and (3 the probability of high use was, to a lesser extent, associated with principal components that represented habitat with high canopy cover, high pine density, and low visual obstruction and hardwood density; likely representing sand pine and pine plantations. Our results indicate that the high bear-use sites were in forested wetlands, where cover and food resources for bears are likely to occur in higher abundance. Habitat management plans whereby bears are a focal species should aim to increase the availability and quality of forested wetlands. Keywords: Habitat selection, Heterogeneous habitat use, Forest management

  8. Stable isotopes to detect food-conditioned bears and to evaluate human-bear management

    Science.gov (United States)

    Hopkins, John B.; Koch, Paul L.; Schwartz, Charles C.; Ferguson, Jake M.; Greenleaf, Schuyler S.; Kalinowski, Steven T.

    2012-01-01

    We used genetic and stable isotope analysis of hair from free-ranging black bears (Ursus americanus) in Yosemite National Park, California, USA to: 1) identify bears that consume human food, 2) estimate the diets of these bears, and 3) evaluate the Yosemite human–bear management program. Specifically, we analyzed the isotopic composition of hair from bears known a priori to be food-conditioned or non-food-conditioned and used these data to predict whether bears with an unknown management status were food-conditioned (FC) or non-food-conditioned (NFC). We used a stable isotope mixing model to estimate the proportional contribution of natural foods (plants and animals) versus human food in the diets of FC bears. We then used results from both analyses to evaluate proactive (population-level) and reactive (individual-level) human–bear management, and discussed new metrics to evaluate the overall human–bear management program in Yosemite. Our results indicated that 19 out of 145 (13%) unknown bears sampled from 2005 to 2007 were food-conditioned. The proportion of human food in the diets of known FC bears likely declined from 2001–2003 to 2005–2007, suggesting proactive management was successful in reducing the amount of human food available to bears. In contrast, reactive management was not successful in changing the management status of known FC bears to NFC bears, or in reducing the contribution of human food to the diets of FC bears. Nine known FC bears were recaptured on 14 occasions from 2001 to 2007; all bears were classified as FC during subsequent recaptures, and human–bear management did not reduce the amount of human food in the diets of FC bears. Based on our results, we suggest Yosemite continue implementing proactive human–bear management, reevaluate reactive management, and consider removing problem bears (those involved in repeated bear incidents) from the population.

  9. Negative binomial models for abundance estimation of multiple closed populations

    Science.gov (United States)

    Boyce, Mark S.; MacKenzie, Darry I.; Manly, Bryan F.J.; Haroldson, Mark A.; Moody, David W.

    2001-01-01

    Counts of uniquely identified individuals in a population offer opportunities to estimate abundance. However, for various reasons such counts may be burdened by heterogeneity in the probability of being detected. Theoretical arguments and empirical evidence demonstrate that the negative binomial distribution (NBD) is a useful characterization for counts from biological populations with heterogeneity. We propose a method that focuses on estimating multiple populations by simultaneously using a suite of models derived from the NBD. We used this approach to estimate the number of female grizzly bears (Ursus arctos) with cubs-of-the-year in the Yellowstone ecosystem, for each year, 1986-1998. Akaike's Information Criteria (AIC) indicated that a negative binomial model with a constant level of heterogeneity across all years was best for characterizing the sighting frequencies of female grizzly bears. A lack-of-fit test indicated the model adequately described the collected data. Bootstrap techniques were used to estimate standard errors and 95% confidence intervals. We provide a Monte Carlo technique, which confirms that the Yellowstone ecosystem grizzly bear population increased during the period 1986-1998.

  10. Does learning or instinct shape habitat selection?

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    Scott E Nielsen

    Full Text Available Habitat selection is an important behavioural process widely studied for its population-level effects. Models of habitat selection are, however, often fit without a mechanistic consideration. Here, we investigated whether patterns in habitat selection result from instinct or learning for a population of grizzly bears (Ursus arctos in Alberta, Canada. We found that habitat selection and relatedness were positively correlated in female bears during the fall season, with a trend in the spring, but not during any season for males. This suggests that habitat selection is a learned behaviour because males do not participate in parental care: a genetically predetermined behaviour (instinct would have resulted in habitat selection and relatedness correlations for both sexes. Geographic distance and home range overlap among animals did not alter correlations indicating that dispersal and spatial autocorrelation had little effect on the observed trends. These results suggest that habitat selection in grizzly bears are partly learned from their mothers, which could have implications for the translocation of wildlife to novel environments.

  11. Land use planning: A potential force for retaining habitat connectivity in the Greater Yellowstone Ecosystem and Beyond

    Directory of Open Access Journals (Sweden)

    Craig L. Shafer

    2015-01-01

    Full Text Available The grizzly bear (Ursus arctos horribilis population in the Greater Yellowstone Ecosystem (GYE is perceived to have been isolated from the population in the Northern Continental Divide Ecosystem for a century. Better land use planning is needed to thwart progressive intra- and inter-ecosystem habitat fragmentation, especially due to private land development. The dilemma of private lands being intermixed in large landscapes is addressed. This review attempts to identify some land use planning levels and tools which might facilitate dispersal by the grizzly bear and other large mammals. The planning levels discussed include national, regional, state, county and municipal, and federal land management agency. Specific potential federal tools mentioned include zoning, Landscape Conservation Cooperatives, the Endangered Species Act, beyond boundary authority, land exchanges, less-than-fee acquisition and other incentives, the Northern Rockies Ecosystem Protection Act, and federal land annexation. Besides summarizing existing recommendations, some derived observations are offered.

  12. Detecting genotyping errors and describing black bear movement in northern Idaho

    Science.gov (United States)

    Michael K. Schwartz; Samuel A. Cushman; Kevin S. McKelvey; Jim Hayden; Cory Engkjer

    2006-01-01

    Non-invasive genetic sampling has become a favored tool to enumerate wildlife. Genetic errors, caused by poor quality samples, can lead to substantial biases in numerical estimates of individuals. We demonstrate how the computer program DROPOUT can detect amplification errors (false alleles and allelic dropout) in a black bear (Ursus americanus) dataset collected in...

  13. Population growth of Yellowstone grizzly bears: Uncertainty and future monitoring

    Science.gov (United States)

    Harris, R.B.; White, Gary C.; Schwartz, C.C.; Haroldson, M.A.

    2007-01-01

    Grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem of the US Rocky Mountains have recently increased in numbers, but remain vulnerable due to isolation from other populations and predicted reductions in favored food resources. Harris et al. (2006) projected how this population might fare in the future under alternative survival rates, and in doing so estimated the rate of population growth, 1983–2002. We address issues that remain from that earlier work: (1) the degree of uncertainty surrounding our estimates of the rate of population change (λ); (2) the effect of correlation among demographic parameters on these estimates; and (3) how a future monitoring system using counts of females accompanied by cubs might usefully differentiate between short-term, expected, and inconsequential fluctuations versus a true change in system state. We used Monte Carlo re-sampling of beta distributions derived from the demographic parameters used by Harris et al. (2006) to derive distributions of λ during 1983–2002 given our sampling uncertainty. Approximate 95% confidence intervals were 0.972–1.096 (assuming females with unresolved fates died) and 1.008–1.115 (with unresolved females censored at last contact). We used well-supported models of Haroldson et al. (2006) and Schwartz et al. (2006a,b,c) to assess the strength of correlations among demographic processes and the effect of omitting them in projection models. Incorporating correlations among demographic parameters yielded point estimates of λ that were nearly identical to those from the earlier model that omitted correlations, but yielded wider confidence intervals surrounding λ. Finally, we suggest that fitting linear and quadratic curves to the trend suggested by the estimated number of females with cubs in the ecosystem, and using AICc model weights to infer population sizes and λ provides an objective means to monitoring approximate population trajectories in addition to demographic

  14. A review of bear farming and bear trade in Lao People's Democratic Republic

    Directory of Open Access Journals (Sweden)

    E. Livingstone

    2018-01-01

    Full Text Available This study reviews the bear farming industry in Lao PDR with the objective of documenting the current number of commercial bear facilities (i.e. captive bear facilities judged to be trading in bear bile and/or bears and bear parts and the number of bears contained within these facilities, noting changes since it was last examined between 2000 and 2012 by Livingstone and Shepherd (2014. We surveyed all known commercial bear facilities and searched for previously unrecorded facilities. We compared our records with Livingstone and Shepherd (2014 and corrected some duplicate records from their study. In 2017, we recorded seven commercial facilities; four dedicated bear farms, and three tiger farms that were reportedly also keeping bears. We found that between 2012 and 2017 the recorded number of dedicated bear farms reduced by two, and the recorded number of tiger farms also keeping bears increased by one. Within the same period, the total number of captive bears among all facilities in Lao PDR hardly changed (+one, but the number of bears within each facility did. The northern facilities, owned by ethnic Chinese, have expanded since 2012, and central and southern facilities have downsized or closed. While bear farming appears to be downsizing in Lao PDR overall, efforts to phase it out are undermined by the expansion of foreign owned facilities in the north, within Special and Specific Economic Zones that largely cater to a Chinese market, and where the Lao government's efforts to enforce laws and protect wildlife appear to be lacking. Closing the facilities in the north will require political will and decisive law enforcement. Keywords: Bear farms, Bear bile, Gall bladder, Urso-deoxycholic acid, Bear bile extraction facilities, Lao PDR, Ursus thibetanus

  15. Use of DNA from bite marks can determine species and individual animals that attack humans

    Science.gov (United States)

    Farley, Sean; Talbot, Sandra L.; Sage, George K.; Sinnott, Rick; Coltrane, Jessica

    2014-01-01

    During the summer of 2008, 6 documented attacks and close encounters with brown bears (Ursus arctos) occurred in the greater Anchorage, Alaska (USA) area. We discuss findings from 2 incidents in which people were mauled within 2 km of each other over a 6-week period and in which it was assumed that a single animal was responsible. To ensure public safety, authorities killed a brown bear implicated in the attacks by circumstantial evidence, though it was not known a priori that the animal was responsible. We extracted DNA from hairs and bite sites on the clothing of both victims and determined species and individual identity of the animal(s) involved in both incidents. Genetic data indicated the brown bear killed by authorities was responsible for one of the maulings, but not both. This research demonstrates that DNA-based techniques, with appropriate sampling, can provide unambiguous identification of animals involved in attacks, as well as provide reasonable justification for excluding others. Because DNA-based techniques can unequivocally identify individual bears carrying out attacks, they should be considered a standard method employed in wildlife attack investigations.

  16. The magnitude and selectivity of natural and multiple anthropogenic mortality causes in hunted brown bears.

    Science.gov (United States)

    Bischof, Richard; Swenson, Jon E; Yoccoz, Nigel G; Mysterud, Atle; Gimenez, Olivier

    2009-05-01

    1. The population dynamic and evolutionary effects of harvesting are receiving growing attention among biologists. Cause-specific estimates of mortality are necessary to determine and compare the magnitude and selectivity of hunting and other types of mortalities. In addition to the logistic and financial constraints on longitudinal studies, they are complicated by the fact that nonhunting mortality in managed populations usually consists of a mix of natural and human-caused factors. 2. We used multistate capture-recapture (MCR) models to estimate cause-specific survival of brown bears (Ursus arctos) in two subpopulations in Sweden over a 23-year period. In our analysis, we distinguished between legal hunting and other sources of mortality, such as intraspecific predation, accidents, poaching, and damage control removals. We also tested whether a strong increase in harvest quotas after 1997 in one of the subpopulations affected vulnerability to legal hunting. 3. Although only a fraction of mortalities other than legal hunting could be considered natural, this group of causes showed a general pattern of demographic selectivity expected from natural mortality regimes in populations of long-lived species, namely greater vulnerability of young animals. On the other hand, demographic effects on hunting vulnerability were weak and inconsistent. Our findings support the assumption that hunting and other mortalities were additive. 4. As expected, an increase in hunting pressure coincided with a correspondingly large increase in vulnerability to hunting in the affected subpopulation. Because even unbiased harvest can lead to selective pressures on life-history traits, such as size at primiparity, increasing harvest quotas may not only affect population growth directly, but could also alter optimal life-history strategies in brown bears and other carnivores. 5. Legal hunting is the most conveniently assessed and the most easily managed cause of mortality in many wild

  17. Resilience and risk: a demographic model to inform conservation planning for polar bears

    Science.gov (United States)

    Regehr, Eric V.; Wilson, Ryan R.; Rode, Karyn D.; Runge, Michael C.

    2015-01-01

    Climate change is having widespread ecological effects, including loss of Arctic sea ice. This has led to listing of the polar bear (Ursus maritimus) and other ice-dependent marine mammals under the U.S. Endangered Species Act (ESA). Methods are needed to evaluate the effects of climate change on population persistence to inform recovery planning for listed species. For polar bears, this includes understanding interactions between climate and secondary factors, such as subsistence harvest, which provide economic, nutritional, or cultural value to humans.

  18. Can polar bears use terrestrial foods to offset lost ice-based hunting opportunities?

    OpenAIRE

    Rode, Karyn D.; Robbins, Charles T.; Nelson, Lynne; Amstrup, Steven C.

    2015-01-01

    Increased land use by polar bears (Ursus maritimus) due to climate‐change‐induced reduction of their sea‐ice habitat illustrates the impact of climate change on species distributions and the difficulty of conserving a large, highly specialized carnivore in the face of this global threat. Some authors have suggested that terrestrial food consumption by polar bears will help them withstand sea‐ice loss as they are forced to spend increasing amounts of time on land. Here, we evaluate the nutriti...

  19. ARCTOS: a relational database relating specimens, specimen-based science, and archival documentation

    Science.gov (United States)

    Jarrell, Gordon H.; Ramotnik, Cindy A.; McDonald, D.L.

    2010-01-01

    Data are preserved when they are perpetually discoverable, but even in the Information Age, discovery of legacy data appropriate to particular investigations is uncertain. Secure Internet storage is necessary but insufficient. Data can be discovered only when they are adequately described, and visibility increases markedly if the data are related to other data that are receiving usage. Such relationships can be built within (1) the framework of a relational database, or (1) they can be built among separate resources, within the framework of the Internet. Evolving primarily around biological collections, Arctos is a database that does both of these tasks. It includes data structures for a diversity of specimen attributes, essentially all collection-management tasks, plus literature citations, project descriptions, etc. As a centralized collaboration of several university museums, Arctos is an ideal environment for capitalizing on the many relationships that often exist between items in separate collections. Arctos is related to NIH’s DNA-sequence repository (GenBank) with record-to-record reciprocal linkages, and it serves data to several discipline-specific web portals, including the Global Biodiversity Information Network (GBIF). The University of Alaska Museum’s paleontological collection is Arctos’s recent extension beyond the constraints of neontology. With about 1.3 million cataloged items, additional collections are being added each year.

  20. Greenhouse gas mitigation can reduce sea-ice loss and increase polar bear persistence

    Science.gov (United States)

    Steven C. Amstrup; Eric T. DeWeaver; David C. Douglas; Bruce G. Marcot; George M. Durner; Cecilia M. Bitz; David A. Bailey

    2010-01-01

    On the basis of projected losses of their essential sea-ice habitats, a United States Geological Survey research team concluded in 2007 that two-thirds of the world's polar bears (Ursus maritimus) could disappear by mid-century if business-as-usual greenhouse gas emissions continue. That projection, however, did not consider the possible...