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Sample records for habitat preference affects

  1. Global habitat preferences of commercially valuable tuna

    KAUST Repository

    Arrizabalaga, Haritz

    2015-03-01

    In spite of its pivotal role in future implementations of the Ecosystem Approach to Fisheries Management, current knowledge about tuna habitat preferences remains fragmented and heterogeneous, because it relies mainly on regional or local studies that have used a variety of approaches making them difficult to combine. Therefore in this study we analyse data from six tuna species in the Pacific, Atlantic and Indian Oceans in order to provide a global, comparative perspective of habitat preferences. These data are longline catch per unit effort from 1958 to 2007 for albacore, Atlantic bluefin, southern bluefin, bigeye, yellowfin and skipjack tunas. Both quotient analysis and Generalised Additive Models were used to determine habitat preference with respect to eight biotic and abiotic variables. Results confirmed that, compared to temperate tunas, tropical tunas prefer warm, anoxic, stratified waters. Atlantic and southern bluefin tuna prefer higher concentrations of chlorophyll than the rest. The two species also tolerate most extreme sea surface height anomalies and highest mixed layer depths. In general, Atlantic bluefin tuna tolerates the widest range of environmental conditions. An assessment of the most important variables determining fish habitat is also provided. © 2014 Elsevier Ltd.

  2. Synergistic effects of habitat preference and gregarious behaviour on habitat use in coral reef cardinalfish

    Science.gov (United States)

    Gardiner, N. M.; Jones, G. P.

    2010-12-01

    Spatial distributions of coral reef fish species are potentially determined by habitat preferences and behavioural interactions. However, the relative importance of these factors and whether or not behavioural interactions reinforce or disrupt habitat associations are poorly understood. This paper explores the degree to which habitat and social preferences explain the association that three common coral reef cardinalfish species ( Zoramia leptacanthus, Archamia zosterophora and Cheilodipterus quinquelineatus; family Apogonidae) have with coral substrata at Lizard Island, Great Barrier Reef. At diurnal resting sites, species were strongly associated with branching corals, with 80-90% of each species inhabiting one branching coral species, Porites cylindrica. Species were also highly gregarious, forming large con-specific and hetero-specific aggregations in coral heads, potentially reinforcing habitat associations. Three-way choice experiments were conducted to test fishes habitat preferences for living coral over dead substrata, for particular coral species, and the influence of gregarious behaviour on these habitat choices. The strength of habitat preferences differed among species, with Z. leptacanthus preferring live coral and P. cylindrica, A. zosterophora preferring P. cylindrica, whether live or dead and C. quinquelineatus exhibiting no preferences. All species were attracted to conspecifics, and for C. quinquelineatus and A. zosterophora, conspecific attraction resulted in stronger preferences for live corals. Gregarious behaviour also increased C. quinquelineatus associations with P. cylindrica. The relative strength of social attraction versus habitat preferences was investigated by comparing fish habitat preferences in the presence and/or absence of conspecifics. The presence of conspecifics on non-preferred rubble habitat reduced each species association with live coral. This study’s results indicate that in the field, habitat preferences and

  3. Habitat preference of Roan Antelope (Hippotragus equinus ...

    African Journals Online (AJOL)

    (Musila et al., 2001). A major problem facing wildlife conservation is increasing rate of habitat loss due to human activities through the destruction of their natural ..... water and feeding in Riparian habitat during dry season. It was also observed that Roan frequently visited salt licks close to Roan gate and Oli river complex.

  4. Habitat preferences and movement of adult yellowfishes in the Vaal River, South Africa

    Directory of Open Access Journals (Sweden)

    Gordon C. O'Brien

    2013-07-01

    Full Text Available The yellowfishes of the Vaal River (Labeobarbus kimberleyensis and L. aeneus are charismatic, socially and economically important fishes, but very little is known about their interspecies habitat preferences and movement. This study is the first behavioural study of yellowfish in the Vaal River using radio transmitters to characterise habitat preferences and movement patterns. A total of 22 adult L. kimberleyensis and 13 adult L. aeneus individuals were tracked for between 1 month and 1 year from 23 September 2006 to 16 May 2010. Radio telemetry revealed that yellowfish established routine daily behavioural patterns through which the habitat preferences and movement of the species could be established. Home ranges of the yellowfish ranged from 1 km to more than 12 km in the Vaal River depending on the species and habitat availability. Habitat preferences varied between species and included deep slow-flowing habitats with associated cover features particularly in winter for L. kimberleyensis and shallow fast-flowing habitats particularly for L. aeneus in spring, summer and autumn. Changes in flows, habitat availability and atmospheric pressure affected the movement of yellowfish. The biology and ecology of the yellowfish in the Vaal River is noticeably more complicated and dynamic than previously documented. We recommend that the behavioural ecology of these and other yellowfish populations in the Vaal River should continue to be characterised, and the use of the movement of yellowfish be developed as an indicator of ecosystem change.

  5. Habitat preference and distribution of mammals in California chaparral

    Science.gov (United States)

    Ronald D. Quinn

    1990-01-01

    Forty-nine species of mammals regularly occur in California chaparral, but none lives only in chaparral. Among the 49 species, 7 are found primarily in mature chaparral, 9 in young chaparral or along ecotones between chaparral and other plant communities, and 19 in riparian areas. Five species occur in many habitats but prefer chaparral in California,and 9 have wide...

  6. Diurnal lighting patterns and habitat alter opsin expression and colour preferences in a killifish.

    Science.gov (United States)

    Johnson, Ashley M; Stanis, Shannon; Fuller, Rebecca C

    2013-07-22

    Spatial variation in lighting environments frequently leads to population variation in colour patterns, colour preferences and visual systems. Yet lighting conditions also vary diurnally, and many aspects of visual systems and behaviour vary over this time scale. Here, we use the bluefin killifish (Lucania goodei) to compare how diurnal variation and habitat variation (clear versus tannin-stained water) affect opsin expression and the preference to peck at different-coloured objects. Opsin expression was generally lowest at midnight and dawn, and highest at midday and dusk, and this diurnal variation was many times greater than variation between habitats. Pecking preference was affected by both diurnal and habitat variation but did not correlate with opsin expression. Rather, pecking preference matched lighting conditions, with higher preferences for blue at noon and for red at dawn/dusk, when these wavelengths are comparatively scarce. Similarly, blue pecking preference was higher in tannin-stained water where blue wavelengths are reduced. In conclusion, L. goodei exhibits strong diurnal cycles of opsin expression, but these are not tightly correlated with light intensity or colour. Temporally variable pecking preferences probably result from lighting environment rather than from opsin production. These results may have implications for the colour pattern diversity observed in these fish.

  7. Spatial variability of Chinook salmon spawning distribution and habitat preferences

    Science.gov (United States)

    Cram, Jeremy M.; Torgersen, Christian; Klett, Ryan S.; Pess, George R.; May, Darran; Pearsons, Todd N.; Dittman, Andrew H.

    2017-01-01

    We investigated physical habitat conditions associated with the spawning sites of Chinook Salmon Oncorhynchus tshawytscha and the interannual consistency of spawning distribution across multiple spatial scales using a combination of spatially continuous and discrete sampling methods. We conducted a census of aquatic habitat in 76 km of the upper main-stem Yakima River in Washington and evaluated spawning site distribution using redd survey data from 2004 to 2008. Interannual reoccupation of spawning areas was high, ranging from an average Pearson’s correlation of 0.62 to 0.98 in channel subunits and 10-km reaches, respectively. Annual variance in the interannual correlation of spawning distribution was highest in channel units and subunits, but it was low at reach scales. In 13 of 15 models developed for individual years (2004–2008) and reach lengths (800 m, 3 km, 6 km), stream power and depth were the primary predictors of redd abundance. Multiple channels and overhead cover were patchy but were important secondary and tertiary predictors of reach-scale spawning site selection. Within channel units and subunits, pool tails and thermal variability, which may be associated with hyporheic exchange, were important predictors of spawning. We identified spawning habitat preferences within reaches and channel units that are relevant for salmonid habitat restoration planning. We also identified a threshold (i.e., 2-km reaches) beyond which interannual spawning distribution was markedly consistent, which may be informative for prioritizing habitat restoration or conservation. Management actions may be improved through enhanced understanding of spawning habitat preferences and the consistency with which Chinook Salmon reoccupy spawning areas at different spatial scales.

  8. Quantitative Assessment of Habitat Preferences for the Puerto Rican Terrestrial Frog, Eleutherodactylus coqui

    Science.gov (United States)

    Karen H. Beard; Sarah Mccullough; Anne K. Eschtruth

    2003-01-01

    We conducted a quantitative analysis of adult and juvenile Eleutherodactylus coqui (coquí) habitat preferences in Puerto Rico. The analysis consisted of two surveys: one to quantify potential habitat and another to quantify habitat use. Coquís were found to use most habitats available to them; however, adults and juveniles preferred different...

  9. Red-shouldered hawk nesting habitat preference in south Texas

    Science.gov (United States)

    Strobel, Bradley N.; Boal, Clint W.

    2010-01-01

    We examined nesting habitat preference by red-shouldered hawks Buteo lineatus using conditional logistic regression on characteristics measured at 27 occupied nest sites and 68 unused sites in 2005–2009 in south Texas. We measured vegetation characteristics of individual trees (nest trees and unused trees) and corresponding 0.04-ha plots. We evaluated the importance of tree and plot characteristics to nesting habitat selection by comparing a priori tree-specific and plot-specific models using Akaike's information criterion. Models with only plot variables carried 14% more weight than models with only center tree variables. The model-averaged odds ratios indicated red-shouldered hawks selected to nest in taller trees and in areas with higher average diameter at breast height than randomly available within the forest stand. Relative to randomly selected areas, each 1-m increase in nest tree height and 1-cm increase in the plot average diameter at breast height increased the probability of selection by 85% and 10%, respectively. Our results indicate that red-shouldered hawks select nesting habitat based on vegetation characteristics of individual trees as well as the 0.04-ha area surrounding the tree. Our results indicate forest management practices resulting in tall forest stands with large average diameter at breast height would benefit red-shouldered hawks in south Texas.

  10. The adaptive value of habitat preferences from a multi-scale spatial perspective: insights from marsh-nesting avian species.

    Science.gov (United States)

    Jedlikowski, Jan; Brambilla, Mattia

    2017-01-01

    Habitat selection and its adaptive outcomes are crucial features for animal life-history strategies. Nevertheless, congruence between habitat preferences and breeding success has been rarely demonstrated, which may result from the single-scale evaluation of animal choices. As habitat selection is a complex multi-scale process in many groups of animal species, investigating adaptiveness of habitat selection in a multi-scale framework is crucial. In this study, we explore whether habitat preferences acting at different spatial scales enhance the fitness of bird species, and check the appropriateness of single vs. multi-scale models. We expected that variables found to be more important for habitat selection at individual scale(s), would coherently play a major role in affecting nest survival at the same scale(s). We considered habitat preferences of two Rallidae species, little crake (Zapornia parva) and water rail (Rallus aquaticus), at three spatial scales (landscape, territory, and nest-site) and related them to nest survival. Single-scale versus multi-scale models (GLS and glmmPQL) were compared to check which model better described adaptiveness of habitat preferences. Consistency between the effect of variables on habitat selection and on nest survival was checked to investigate their adaptive value. In both species, multi-scale models for nest survival were more supported than single-scale ones. In little crake, the multi-scale model indicated vegetation density and water depth at the territory scale, as well as vegetation height at nest-site scale, as the most important variables. The first two variables were among the most important for nest survival and habitat selection, and the coherent effects suggested the adaptive value of habitat preferences. In water rail, the multi-scale model of nest survival showed vegetation density at territory scale and extent of emergent vegetation within landscape scale as the most important ones, although we found a

  11. Habitat preferences of baleen whales in a mid-latitude habitat

    Science.gov (United States)

    Prieto, Rui; Tobeña, Marta; Silva, Mónica A.

    2017-07-01

    Understanding the dynamics of baleen whale distribution is essential to predict how environmental changes can affect their ecology and, in turn, ecosystem functioning. Recent work showed that mid-latitude habitats along migratory routes may play an important role on the feeding ecology of baleen whales. This study aimed to investigate the function of a mid-latitude habitat for blue (Balaenoptera musculus), fin (Balaenoptera physalus) and sei (Balaenoptera borealis) whales occurring in sympatry during spring and summer months and to what extent their environmental niches overlap. We addressed those questions by developing environmental niche models (ENM) for each species and then making pairwise comparisons of niche overlap and relative habitat patch importance among the three species. ENMs were created using sightings from the Azorean Fisheries Observer Program from May to November, between 2004 and 2009, and a set of 18 predictor environmental variables. We then assessed monthly (April-July) overlap among ENMs using a modified Hellinger's distance metric (I). Results show that the habitat niches of blue and fin whales are strongly influenced by primary productivity and sea surface temperature and are highly dynamic both spatially and temporally due to the oceanography of the region. Niche overlap analyses show that blue and fin whale environmental niches are similar and that the suitable habitats for the two species have high degree of spatial coincidence. These results in combination suggest that this habitat may function as a mid-latitude feeding ground to both species while conditions are adequate. The sei whale model, on the other hand, did not include variables considered to be proxies for prey distribution and little environmental niche overlap was found between this species and the other two. We argue that these results suggest that the region holds little importance as a foraging habitat for the sei whale.

  12. Innate Host Habitat Preference in the Parasitoid Diachasmimorpha longicaudata: Functional Significance and Modifications through Learning

    Science.gov (United States)

    Segura, Diego F.; Nussenbaum, Ana L.; Viscarret, Mariana M.; Devescovi, Francisco; Bachmann, Guillermo E.; Corley, Juan C.; Ovruski, Sergio M.; Cladera, Jorge L.

    2016-01-01

    Parasitoids searching for polyphagous herbivores can find their hosts in a variety of habitats. Under this scenario, chemical cues from the host habitat (not related to the host) represent poor indicators of host location. Hence, it is unlikely that naïve females show a strong response to host habitat cues, which would become important only if the parasitoids learn to associate such cues to the host presence. This concept does not consider that habitats can vary in profitability or host nutritional quality, which according to the optimal foraging theory and the preference-performance hypothesis (respectively) could shape the way in which parasitoids make use of chemical cues from the host habitat. We assessed innate preference in the fruit fly parasitoid Diachasmimorpha longicaudata among chemical cues from four host habitats (apple, fig, orange and peach) using a Y-tube olfactometer. Contrary to what was predicted, we found a hierarchic pattern of preference. The parasitism rate realized on these fruit species and the weight of the host correlates positively, to some extent, with the preference pattern, whereas preference did not correlate with survival and fecundity of the progeny. As expected for a parasitoid foraging for generalist hosts, habitat preference changed markedly depending on their previous experience and the abundance of hosts. These findings suggest that the pattern of preference for host habitats is attributable to differences in encounter rate and host quality. Host habitat preference seems to be, however, quite plastic and easily modified according to the information obtained during foraging. PMID:27007298

  13. Innate Host Habitat Preference in the Parasitoid Diachasmimorpha longicaudata: Functional Significance and Modifications through Learning.

    Directory of Open Access Journals (Sweden)

    Diego F Segura

    Full Text Available Parasitoids searching for polyphagous herbivores can find their hosts in a variety of habitats. Under this scenario, chemical cues from the host habitat (not related to the host represent poor indicators of host location. Hence, it is unlikely that naïve females show a strong response to host habitat cues, which would become important only if the parasitoids learn to associate such cues to the host presence. This concept does not consider that habitats can vary in profitability or host nutritional quality, which according to the optimal foraging theory and the preference-performance hypothesis (respectively could shape the way in which parasitoids make use of chemical cues from the host habitat. We assessed innate preference in the fruit fly parasitoid Diachasmimorpha longicaudata among chemical cues from four host habitats (apple, fig, orange and peach using a Y-tube olfactometer. Contrary to what was predicted, we found a hierarchic pattern of preference. The parasitism rate realized on these fruit species and the weight of the host correlates positively, to some extent, with the preference pattern, whereas preference did not correlate with survival and fecundity of the progeny. As expected for a parasitoid foraging for generalist hosts, habitat preference changed markedly depending on their previous experience and the abundance of hosts. These findings suggest that the pattern of preference for host habitats is attributable to differences in encounter rate and host quality. Host habitat preference seems to be, however, quite plastic and easily modified according to the information obtained during foraging.

  14. Comparison of two methods for estimating the abundance, diversity and habitat preference of fluvial macroinvertebrates in contrasting habitats

    NARCIS (Netherlands)

    Alonso, A.; Camargo, J.A.

    2010-01-01

    In this research we evaluate the effects of the method used for estimating the potential surface available for benthic macroinvertebrates in macrophyte and unvegetated habitats on several metrics and habitat preference of aquatic macroinvertebrates in the upper catchment of the Henares River

  15. Hydrologic habitat preferences of select southeastern USA fishes resilient to river ecosystem fragmentation

    Science.gov (United States)

    Andrew L. Rypel; David R. Bayne

    2009-01-01

    Large-scale habitat preferences of riverine taxa are not always revealed by examining community data. Here, we show how lipid and growth can be used to evaluate hydrologic habitat preferences of fishes resilient to river fragmentation (i.e. species that can tolerate river fragmentation by dams, but not collapse). Lipid content was examined for seven fishes in a major...

  16. Plant functional traits reveal the relative contribution of habitat and food preferences to the diet of grasshoppers.

    Science.gov (United States)

    Ibanez, Sébastien; Manneville, Olivier; Miquel, Christian; Taberlet, Pierre; Valentini, Alice; Aubert, Serge; Coissac, Eric; Colace, Marie-Pascale; Duparc, Quentin; Lavorel, Sandra; Moretti, Marco

    2013-12-01

    Food preferences and food availability are two major determinants of the diet of generalist herbivores and of their spatial distribution. How do these factors interact and eventually lead to diet differentiation in co-occurring herbivores? We quantified the diet of four grasshopper species co-occurring in subalpine grasslands using DNA barcoding of the plants contained in the faeces of individuals sampled in the field. The food preferences of each grasshopper species were assessed by a choice (cafeteria) experiment from among 24 plant species common in five grassland plots, in which the four grasshoppers were collected, while the habitat was described by the relative abundance of plant species in the grassland plots. Plant species were characterised by their leaf economics spectrum (LES), quantifying their nutrient vs. structural tissue content. The grasshoppers' diet, described by the mean LES of the plants eaten, could be explained by their plant preferences but not by the available plants in their habitat. The diet differed significantly across four grasshopper species pairs out of six, which validates food preferences assessed in standardised conditions as indicators for diet partitioning in nature. In contrast, variation of the functional diversity (FD) for LES in the diet was mostly correlated to the FD of the available plants in the habitat, suggesting that diet mixing depends on the environment and is not an intrinsic property of the grasshopper species. This study sheds light on the mechanisms determining the feeding niche of herbivores, showing that food preferences influence niche position whereas habitat diversity affects niche breadth.

  17. Habitat adaptation rather than genetic distance correlates with female preference in fire salamanders (Salamandra salamandra

    Directory of Open Access Journals (Sweden)

    Weitere Markus

    2009-06-01

    Full Text Available Abstract Background Although some mechanisms of habitat adaptation of conspecific populations have been recently elucidated, the evolution of female preference has rarely been addressed as a force driving habitat adaptation in natural settings. Habitat adaptation of fire salamanders (Salamandra salamandra, as found in Middle Europe (Germany, can be framed in an explicit phylogeographic framework that allows for the evolution of habitat adaptation between distinct populations to be traced. Typically, females of S. salamandra only deposit their larvae in small permanent streams. However, some populations of the western post-glacial recolonization lineage use small temporary ponds as larval habitats. Pond larvae display several habitat-specific adaptations that are absent in stream-adapted larvae. We conducted mate preference tests with females from three distinct German populations in order to determine the influence of habitat adaptation versus neutral genetic distance on female mate choice. Two populations that we tested belong to the western post-glacial recolonization group, but are adapted to either stream or pond habitats. The third population is adapted to streams but represents the eastern recolonization lineage. Results Despite large genetic distances with FST values around 0.5, the stream-adapted females preferred males from the same habitat type regardless of genetic distance. Conversely, pond-adapted females did not prefer males from their own population when compared to stream-adapted individuals of either lineage. Conclusion A comparative analysis of our data showed that habitat adaptation rather than neutral genetic distance correlates with female preference in these salamanders, and that habitat-dependent female preference of a specific pond-reproducing population may have been lost during adaptation to the novel environmental conditions of ponds.

  18. Habitat adaptation rather than genetic distance correlates with female preference in fire salamanders (Salamandra salamandra).

    Science.gov (United States)

    Caspers, Barbara A; Junge, Claudia; Weitere, Markus; Steinfartz, Sebastian

    2009-06-29

    Although some mechanisms of habitat adaptation of conspecific populations have been recently elucidated, the evolution of female preference has rarely been addressed as a force driving habitat adaptation in natural settings. Habitat adaptation of fire salamanders (Salamandra salamandra), as found in Middle Europe (Germany), can be framed in an explicit phylogeographic framework that allows for the evolution of habitat adaptation between distinct populations to be traced. Typically, females of S. salamandra only deposit their larvae in small permanent streams. However, some populations of the western post-glacial recolonization lineage use small temporary ponds as larval habitats. Pond larvae display several habitat-specific adaptations that are absent in stream-adapted larvae. We conducted mate preference tests with females from three distinct German populations in order to determine the influence of habitat adaptation versus neutral genetic distance on female mate choice. Two populations that we tested belong to the western post-glacial recolonization group, but are adapted to either stream or pond habitats. The third population is adapted to streams but represents the eastern recolonization lineage. Despite large genetic distances with FST values around 0.5, the stream-adapted females preferred males from the same habitat type regardless of genetic distance. Conversely, pond-adapted females did not prefer males from their own population when compared to stream-adapted individuals of either lineage. A comparative analysis of our data showed that habitat adaptation rather than neutral genetic distance correlates with female preference in these salamanders, and that habitat-dependent female preference of a specific pond-reproducing population may have been lost during adaptation to the novel environmental conditions of ponds.

  19. Strong Predictability Of Spatially Distributed Physical Habitat Preferences For O. Mykiss Spawning Across Three Spatial Scales

    Science.gov (United States)

    Kammel, L.; Pasternack, G. B.; Wyrick, J. R.; Massa, D.; Bratovich, P.; Johnson, T.

    2012-12-01

    Currently accepted perception assumes Oncorhynchus mykiss prefer different ranges of similar physical habitat elements for spawning than Chinook salmon (Oncorhynchus tshawytscha), taking into account their difference in size. While there is increasing research interest regarding O. mykiss habitat use and migratory behavior, research conducted to date distinguishing the physical habitat conditions utilized for O. mykiss spawning has not provided quantified understanding of their spawning habitat preferences. The purpose of this study was to use electivity indices and other measures to assess the physical habitat characteristics preferred for O. mykiss spawning in terms of both 1-m scale microhabitat attributes, and landforms at different spatial scales from 0.1-100 times channel width. The testbed for this study was the 37.5-km regulated gravel-cobble Lower Yuba River (LYR). Using spatially distributed 2D hydrodynamic model results, substrate mapping, and a census of O. mykiss redds from two years of observation, micro- and meso-scale representations of physical habitat were tested for their ability to predict spawning habitat preference and avoidance. Overall there was strong stratification of O. mykiss redd occurrence for all representation types of physical habitat. A strong preference of hydraulic conditions was shown for mean water column velocities of 1.18-2.25 ft/s, and water depths of 1.25-2.76 ft. There was a marked preference for the two most upstream alluvial reaches of the LYR (out of 8 total reaches), accounting for 92% of all redds observed. The preferred morphological units (MUs) for O. mykiss spawning were more variable than for Chinook salmon and changed with increasing discharge, demonstrating that O. mykiss shift spawning to different MUs in order to utilize their preferred hydraulic conditions. The substrate range preferred for O. mykiss spawning was within 32-90 mm. Overall, O. mykiss spawning behavior was highly predictable and required a

  20. Short Communication: Habitat preferences of twenty-three grass ...

    African Journals Online (AJOL)

    Some grass species occur more frequently in certain habitats than in others, but uncertainty as to exactly which factors are responsible for this phenomenon exist. Species composition as well as habitat data were collected from plots situated on the mild slopes of the study area, and the data were analysed by means of a ...

  1. Reptile habitat preference in heathland: implications for heathland management

    NARCIS (Netherlands)

    Stumpel, A.H.P.; Werf, van der D.C.

    2012-01-01

    A two-year reptile survey was conducted in a heathland in the north of the Netherlands, using artificial refuges placed in different habitats. The studied habitats differed in their botanical composition and physical structure. Five reptile species were recorded: slow worm (Anguis fragilis),

  2. Species, functional groups, and habitat preferences of birds in five agroforestry classes in Tabasco, Mexico

    NARCIS (Netherlands)

    Wal, van der J.C.; Peña-Álvarez, B.; Arriaga-Weiss, S.L.; Hernández-Daumás, S.

    2012-01-01

    We studied species, functional groups, and habitat preferences of birds in five classes of agroforestry systems: agroforests, animal agroforestry, linear agroforestry, sequential agroforestry, and crops under tree cover in Tabasco, Mexico. Sampling sites were >2 km from natural forest fragments.

  3. Indo-Pacific bottlenose dolphin (Tursiops aduncus) habitat preference in a heterogeneous, urban, coastal environment

    OpenAIRE

    Cribb, Nardi; Miller, Cara; Seuront, Laurent

    2013-01-01

    Background Limited information is available regarding the habitat preference of the Indo-Pacific bottlenose dolphin (Tursiops aduncus) in South Australian estuarine environments. The need to overcome this paucity of information is crucial for management and conservation initiatives. This preliminary study investigates the space-time patterns of habitat preference by the Indo-Pacific bottlenose dolphin in the Port Adelaide River-Barker Inlet estuary, a South Australian, urbanised, coastal envi...

  4. Factors affecting diet, habitat selection and breeding success of the ...

    African Journals Online (AJOL)

    Factors affecting diet, habitat selection and breeding success of the African Crowned Eagle Stephanoaetus coronatus in a fragmented landscape. Christopher J Swatridge, Ara Monadjem, David J Steyn, Garth R Batchelor, Ian CW Hardy ...

  5. Diet preferences of goats in a subtropical dry forest and implications for habitat management

    Science.gov (United States)

    Genie M. Fleming; Joseph Wunderle Jr.; David N. Ewert

    2016-01-01

    As part of an experimental study of using controlled goat grazing to manage winter habitat of the Kirtland’s warbler (Setophaga kirtlandii), an endangered Nearctic neotropical migratory bird, we evaluated diet preferences of domesticated goats within early successional subtropical dry forest in The Bahamas. We expected goats would show a low preference for two plants (...

  6. Habitat preferences of three sympatric lacertid lizards in the arid ...

    African Journals Online (AJOL)

    The area was surveyed by walking transects through different habitat types and recording all active lizards. For each lizard observed, the species was identified and a photograph was taken of its microhabitat. At the end of the sampling period the microhabitats in which lizards were found were sorted into distinct types on the ...

  7. The distribution, abundance, and habitat preference of lovebirds ...

    African Journals Online (AJOL)

    SARAH

    2014-04-30

    Apr 30, 2014 ... habitat. This result agrees with Franklin and Steadman,. (2010), who worked on forest plant and bird communities in Lau, Fiji. From this study observation, lovebirds were usually sighted early in the morning foraging in GLS, FLV, and WLS for few hours. A returned visit to the same spot for further verification ...

  8. Climate change expands the spatial extent and duration of preferred thermal habitat for lake Superior fishes.

    Directory of Open Access Journals (Sweden)

    Timothy J Cline

    Full Text Available Climate change is expected to alter species distributions and habitat suitability across the globe. Understanding these shifting distributions is critical for adaptive resource management. The role of temperature in fish habitat and energetics is well established and can be used to evaluate climate change effects on habitat distributions and food web interactions. Lake Superior water temperatures are rising rapidly in response to climate change and this is likely influencing species distributions and interactions. We use a three-dimensional hydrodynamic model that captures temperature changes in Lake Superior over the last 3 decades to investigate shifts in habitat size and duration of preferred temperatures for four different fishes. We evaluated habitat changes in two native lake trout (Salvelinus namaycush ecotypes, siscowet and lean lake trout, Chinook salmon (Oncorhynchus tshawytscha, and walleye (Sander vitreus. Between 1979 and 2006, days with available preferred thermal habitat increased at a mean rate of 6, 7, and 5 days per decade for lean lake trout, Chinook salmon, and walleye, respectively. Siscowet lake trout lost 3 days per decade. Consequently, preferred habitat spatial extents increased at a rate of 579, 495 and 419 km(2 per year for the lean lake trout, Chinook salmon, and walleye while siscowet lost 161 km(2 per year during the modeled period. Habitat increases could lead to increased growth and production for three of the four fishes. Consequently, greater habitat overlap may intensify interguild competition and food web interactions. Loss of cold-water habitat for siscowet, having the coldest thermal preference, could forecast potential changes from continued warming. Additionally, continued warming may render more suitable conditions for some invasive species.

  9. Climate change expands the spatial extent and duration of preferred thermal habitat for lake Superior fishes.

    Science.gov (United States)

    Cline, Timothy J; Bennington, Val; Kitchell, James F

    2013-01-01

    Climate change is expected to alter species distributions and habitat suitability across the globe. Understanding these shifting distributions is critical for adaptive resource management. The role of temperature in fish habitat and energetics is well established and can be used to evaluate climate change effects on habitat distributions and food web interactions. Lake Superior water temperatures are rising rapidly in response to climate change and this is likely influencing species distributions and interactions. We use a three-dimensional hydrodynamic model that captures temperature changes in Lake Superior over the last 3 decades to investigate shifts in habitat size and duration of preferred temperatures for four different fishes. We evaluated habitat changes in two native lake trout (Salvelinus namaycush) ecotypes, siscowet and lean lake trout, Chinook salmon (Oncorhynchus tshawytscha), and walleye (Sander vitreus). Between 1979 and 2006, days with available preferred thermal habitat increased at a mean rate of 6, 7, and 5 days per decade for lean lake trout, Chinook salmon, and walleye, respectively. Siscowet lake trout lost 3 days per decade. Consequently, preferred habitat spatial extents increased at a rate of 579, 495 and 419 km(2) per year for the lean lake trout, Chinook salmon, and walleye while siscowet lost 161 km(2) per year during the modeled period. Habitat increases could lead to increased growth and production for three of the four fishes. Consequently, greater habitat overlap may intensify interguild competition and food web interactions. Loss of cold-water habitat for siscowet, having the coldest thermal preference, could forecast potential changes from continued warming. Additionally, continued warming may render more suitable conditions for some invasive species.

  10. Indo-Pacific bottlenose dolphin (Tursiops aduncus) habitat preference in a heterogeneous, urban, coastal environment

    Science.gov (United States)

    2013-01-01

    Background Limited information is available regarding the habitat preference of the Indo-Pacific bottlenose dolphin (Tursiops aduncus) in South Australian estuarine environments. The need to overcome this paucity of information is crucial for management and conservation initiatives. This preliminary study investigates the space-time patterns of habitat preference by the Indo-Pacific bottlenose dolphin in the Port Adelaide River-Barker Inlet estuary, a South Australian, urbanised, coastal environment. More specifically, the study aim was to identify a potential preference between bare sand substrate and seagrass beds, the two habitat types present in this environment, through the resighting frequency of recognisable individual dolphins. Results Photo-identification surveys covering the 118 km2 sanctuary area were conducted over 2 survey periods May to August 2006 and from March 2009 to February 2010. Sighting frequency of recognisable individual Indo-Pacific bottlenose dolphins established a significant preference for the bare sand habitat. More specifically, 72 and 18% of the individuals sighted at least on two occasions were observed in the bare sand and seagrass habitats respectively. This trend was consistently observed at both seasonal and annual scales, suggesting a consistency in the distinct use of these two habitats. Conclusions It is anticipated that these results will benefit the further development of management and conservation strategies. PMID:23369354

  11. Habitat preferences of bats in a rural area of Sicily determined by acoustic surveys

    Directory of Open Access Journals (Sweden)

    Ivy Di Salvo

    2010-06-01

    Full Text Available Abstract The bat fauna of a 60 km2 wide area representing the typical rural landscape of inland Sicily and including the small “Rocche di Entella” karstic plateau (Natural Reserve and SAC was surveyed between May 2006 and September 2007. Sampling was carried out at 95 sites, distributed proportionally in six main habitats. Bat calls were time-expanded with a D980 bat detector and then identified to species level by a Discriminant Function Analysis. We recorded 305 bat passes and identified 96.4% of recorded calls. Moon phase, cloud cover and their interaction did not affect total bat activity, nor did the sampling period. Aquatic and riparian habitats were preferred, whilst Eucalyptus plantations and vineyards were avoided. At species level, all bats selected the former habitats, except H. savii, and avoided field crops, except Myotis sp. Thermo-Mediterranean shrub formations showed the highest species richness, whereas vineyards had the lowest. Our study emphasizes the value of riparian habitats and low-intensity farming for bat conservation.
    Riassunto Preferenze ambientali dei chirotteri in un’area rurale della Sicilia. Il presente lavoro espone i risultati di un’analisi di selezione del habitat da parte della chirotterofauna in un’area di 60 km2 rappresentativa del tipico paesaggio rurale dell’entroterra siciliano e comprensiva del plateau carsico "Rocche di Entella" (Riserva Naturale e SIC. Da maggio a settembre 2006 e 2007, abbiamo effettuato campionamenti mediante bat detector (Pettersson D980 in 95 stazioni distribuite proporzionalmente alla disponibilità di habitat. I segnali sono stati identificati mediante Analisi della Funzione Discriminante. Abbiamo re- gistrato 305 passaggi, identificandone il 96.4% a livello di specie. Né la fase lunare, né la nuvolosità o l’interazione tra queste hanno influenzato

  12. Habitat degradation affects the summer activity of polar bears

    Science.gov (United States)

    Ware, Jasmine V.; Rode, Karyn D.; Bromaghin, Jeffrey F.; Douglas, David C.; Wilson, Ryan R.; Regehr, Eric V.; Amstrup, Steven C.; Durner, George M.; Pagano, Anthony M.; Olson, Jay; Robbins, Charles T.; Jansen, Heiko T

    2017-01-01

    Understanding behavioral responses of species to environmental change is critical to forecasting population-level effects. Although climate change is significantly impacting species’ distributions, few studies have examined associated changes in behavior. Polar bear (Ursus maritimus) subpopulations have varied in their near-term responses to sea ice decline. We examined behavioral responses of two adjacent subpopulations to changes in habitat availability during the annual sea ice minimum using activity data. Location and activity sensor data collected from 1989 to 2014 for 202 adult female polar bears in the Southern Beaufort Sea (SB) and Chukchi Sea (CS) subpopulations were used to compare activity in three habitat types varying in prey availability: (1) land; (2) ice over shallow, biologically productive waters; and (3) ice over deeper, less productive waters. Bears varied activity across and within habitats with the highest activity at 50–75% sea ice concentration over shallow waters. On land, SB bears exhibited variable but relatively high activity associated with the use of subsistence-harvested bowhead whale carcasses, whereas CS bears exhibited low activity consistent with minimal feeding. Both subpopulations had fewer observations in their preferred shallow-water sea ice habitats in recent years, corresponding with declines in availability of this substrate. The substantially higher use of marginal habitats by SB bears is an additional mechanism potentially explaining why this subpopulation has experienced negative effects of sea ice loss compared to the still-productive CS subpopulation. Variability in activity among, and within, habitats suggests that bears alter their behavior in response to habitat conditions, presumably in an attempt to balance prey availability with energy costs.

  13. Habitat degradation affects the summer activity of polar bears.

    Science.gov (United States)

    Ware, Jasmine V; Rode, Karyn D; Bromaghin, Jeffrey F; Douglas, David C; Wilson, Ryan R; Regehr, Eric V; Amstrup, Steven C; Durner, George M; Pagano, Anthony M; Olson, Jay; Robbins, Charles T; Jansen, Heiko T

    2017-05-01

    Understanding behavioral responses of species to environmental change is critical to forecasting population-level effects. Although climate change is significantly impacting species' distributions, few studies have examined associated changes in behavior. Polar bear (Ursus maritimus) subpopulations have varied in their near-term responses to sea ice decline. We examined behavioral responses of two adjacent subpopulations to changes in habitat availability during the annual sea ice minimum using activity data. Location and activity sensor data collected from 1989 to 2014 for 202 adult female polar bears in the Southern Beaufort Sea (SB) and Chukchi Sea (CS) subpopulations were used to compare activity in three habitat types varying in prey availability: (1) land; (2) ice over shallow, biologically productive waters; and (3) ice over deeper, less productive waters. Bears varied activity across and within habitats with the highest activity at 50-75% sea ice concentration over shallow waters. On land, SB bears exhibited variable but relatively high activity associated with the use of subsistence-harvested bowhead whale carcasses, whereas CS bears exhibited low activity consistent with minimal feeding. Both subpopulations had fewer observations in their preferred shallow-water sea ice habitats in recent years, corresponding with declines in availability of this substrate. The substantially higher use of marginal habitats by SB bears is an additional mechanism potentially explaining why this subpopulation has experienced negative effects of sea ice loss compared to the still-productive CS subpopulation. Variability in activity among, and within, habitats suggests that bears alter their behavior in response to habitat conditions, presumably in an attempt to balance prey availability with energy costs.

  14. Selection Indicates Preference in Diverse Habitats: A Ground-Nesting Bird (Charadrius melodus) Using Reservoir Shoreline

    OpenAIRE

    Michael J Anteau; Sherfy, Mark H.; Wiltermuth, Mark T.

    2012-01-01

    Animals use proximate cues to select resources that maximize individual fitness. When animals have a diverse array of available habitats, those selected could give insights into true habitat preferences. Since the construction of the Garrison Dam on the Missouri River in North Dakota, Lake Sakakawea (SAK) has become an important breeding area for federally threatened piping plovers (Charadrius melodus; hereafter plovers). We used conditional logistic regression to examine nest-site selection ...

  15. Factors Affecting Public Preferences for Grassland Landscape Heterogeneity in the Great Plains

    Science.gov (United States)

    Joshi, Omkar; Becerra, Terrie A.; Engle, David M.; Fuhlendorf, Samuel D.; Elmore, R. Dwayne

    2017-11-01

    Agricultural intensification has fragmented rangelands in the Great Plains, which has contributed to uniform and homogeneous landscapes and decreased biodiversity. Alternative land management practices involving fire-grazing interactions can help maintain biodiversity without affecting livestock productivity. A survey was designed to understand the factors that influence preferences among the general population towards grassland landscape heterogeneity. Given the ordinal nature of survey responses, requisite data were analyzed using a generalized ordinal logit model. Results suggested that respondents who valued open space and those who recognized a need for a varying mix of uniform grasses and grasslands preferred landscape heterogeneity. Female respondents were about two times as likely to prefer heterogeneous landscapes compared to male respondents. In contrast, population groups that preferred wildlife habitat did not desire heterogeneous landscapes. Results suggest the need for extension and outreach activities to educate certain segments of the general population regarding benefits of alternative management practices that support landscape heterogeneity in the Great Plains.

  16. Habitat preferences of common native fishes in a tropical river in Southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Marcus Rodrigues da Costa

    Full Text Available We determined in this study the habitat preferences of seven native fish species in a regulated river in Southeastern Brazil. We tested the hypothesis that fishes differ in habitat preference and that they use stretches of the river differing in hydraulic characteristics and substrate type. We surveyed fishes in four 1-km long river stretches encompassing different habitat traits, where we also measured water depth, velocity, and substrate type. We investigated preference patterns of four Siluriformes (Loricariichthys castaneus, Hoplosternum littorale, Pimelodus maculatus, and Trachelyopterus striatulus and three Characiformes (Astyanax aff. bimaculatus, Oligosarcus hepsetus, and Hoplias malabaricus, representing approximately 70% of the total number of fishes and 64% of the total biomass. We classified fishes into four habitat guilds: (1 a slow-flowing water guild that occupied mud-sand substrate, composed of two Siluriformes in either shallow ( 8 m, L. castaneus waters; (2 a run-dwelling guild that occurs in deep backwaters with clay-mud substrate, composed of the Characiformes A. aff. bimaculatus and O. hepsetus; (3 a run-dwelling guild that occurs in sandy and shallow substrate, composed of T. striatulus; and (4 a fast-flowing guild that occurs primarily along shorelines with shallow mud bottoms, composed of H. malabaricus and P. maculatus. Our hypothesis was confirmed, as different habitat preferences by fishes appear to occur in this regulated river.

  17. Habitat preferences of foraging red-cockaded woodpeckers at the Savannah River Site, South Carolina.

    Energy Technology Data Exchange (ETDEWEB)

    Franzreb, Kathleen, E.

    2004-12-31

    Franzreb, Kathleen, E. 2004. Habitat preferences of foraging red-cockaded woodpeckers at the Savannah River Site, South Carolina. In: Red-cockaded woodpecker; Road to Recovery. Proceedings of the 4th Red-cockaded woodpecker Symposium. Ralph Costa and Susan J. Daniels, eds. Savannah, Georgia. January, 2003. Chapter 9. Habitat Management and Habitat Relationships. Pp 553-561. Abstract: I constructed a foraging study to examine habitat use of red-cockaded woodpeckers at the Savannah River Site, South Carolina. Because much of the land had been harvested in the late 1940s and early 1950s prior to being sold to the Department of Energy, the available habitat largely consisted of younger trees (e.g., less than 40 years old). From 1992 to 1995, I examined the foraging behavior and reproductive success of 7 groups of red-cockaded woodpeckers.

  18. Diversity and habitat preferences of Carabidae and Staphylinidae (Coleoptera in two agroecosystems Diversidade e preferência de habitat de Carabidae e Staphylinidae (Coleoptera em dois agroecossistemas

    Directory of Open Access Journals (Sweden)

    Ivan Carlos Fernandes Martins

    2012-01-01

    Full Text Available The present study had as objective determine the diversity and abundance of adults Carabidae and Staphylinidae in two areas, constituted by forest fragment and soybean/corn crops under conventional tillage and no-tillage systems and to analyze the distribution and preference of those beetles for the habitat. The beetles were sampled with 48 pitfall traps. In both experimental areas, two parallel transects of pitfall traps were installed. Each transect had 100 m in the crop and 100 m in the forest fragment. Four traps were close to each other (1 m in the edge between the crop and the forest fragment, the other traps were installed each 10 m. The obtained data were submitted to the faunistic analysis and the preference of the species by habitat was obtained by cluster analysis. The results demonstrated that the type of crop system (conventional tillage or no-tillage might have influenced the diversity of species of Carabidae and Staphylinidae. The cluster analysis evidenced that the carabids may prefer a specific habitat. In the present study, the distribution of carabids and staphylinids in the three habitats showed that these beetles have potential to be dispersed at great distances inside the crop.Este estudo teve como objetivo determinar a diversidade e abundância de adultos de Carabidae e Staphylinidae em duas áreas, constituídas por fragmentos florestais e culturas de soja/milho sob sistemas de plantio convencional e direto, e analisar a distribuição e a preferência desses insetos para o habitat. Os besouros foram amostrados com o uso de 48 armadilhas de solo do tipo Pitfall. Em ambas as áreas experimentais, foram instalados dois transectos paralelos de armadilhas; cada transecto teve 100 m na culturas e 100 m no fragmento florestal. Na borda entre a cultura e o fragmento de floresta foram instaladas quatro armadilhas, que ficaram distantes entre si por 1 m e as outras armadilhas, a cada 10 m. Os dados obtidos foram submetidos à an

  19. Habitat preferences of a corallivorous reef fish: predation risk versus food quality

    Science.gov (United States)

    Brooker, R. M.; Munday, P. L.; Mcleod, I. M.; Jones, G. P.

    2013-09-01

    Many animals preferentially select a habitat from a range of those potentially available. However, the consequences of these preferences for distribution and abundance, and the underlying basis of habitat preferences are often unknown. The present study, conducted at Great Keppel Island, Australia, examined how distribution and abundance of an obligate corallivorous filefish, Oxymonacanthus longirostris, relates to coral architecture and diversity. The main drivers of the distribution and abundance of O. longirostris among reefs were coral species richness and availability of branching coral. Feeding territories had a higher percentage of Acropora coral than surrounding habitat. In addition, feeding territories had a higher percentage of the structurally important branching coral, Acropora nobilis, and a primary prey species, Acropora millepora. A series of pair-wise choice experiments in which both structural complexity and coral tissue quality were independently manipulated showed that habitat choice was primarily based on structural complexity and shelter characteristics. In addition, the choice for the preferred coral ( A. nobilis) was stronger in the presence of a piscivorous fish. These results indicate that species-diverse coral habitats, which provide sufficient structural complexity along with nutritionally important prey, are essential for population persistence of this small, corallivorous reef fish.

  20. Selection indicates preference in diverse habitats: a ground-nesting bird (Charadrius melodus) using reservoir shoreline.

    Science.gov (United States)

    Anteau, Michael J; Sherfy, Mark H; Wiltermuth, Mark T

    2012-01-01

    Animals use proximate cues to select resources that maximize individual fitness. When animals have a diverse array of available habitats, those selected could give insights into true habitat preferences. Since the construction of the Garrison Dam on the Missouri River in North Dakota, Lake Sakakawea (SAK) has become an important breeding area for federally threatened piping plovers (Charadrius melodus; hereafter plovers). We used conditional logistic regression to examine nest-site selection at fine scales (1, 3, and 10 m) during summers 2006-2009 by comparing characteristics at 351 nests to those of 668 random sites within nesting territories. Plovers selected sites (1 m(2)) that were lower than unused random sites, increasing the risk of nest inundation. Plovers selected nest sites that were flat, had little silt, and at least 1 cobble; they also selected for 3-m radius nest areas that were relatively flat and devoid of vegetation and litter. Ninety percent of nests had <38% coverage of silt and <10% slope at the site, and <15% coverage of vegetation or litter and <31% slope within the 3-m radius. Gravel was selected for at nest sites (11% median), but against in the area 10-m from the nest, suggesting plovers select for patches or strips of gravel. Although elevation is rarely evaluated in studies of ground-nesting birds, our results underscore its importance in habitat-selection studies. Relative to where plovers historically nested, habitat at SAK has more diverse topography, substrate composition, vegetation communities, and greater water-level fluctuations. Accordingly, our results provide an example of how habitat-selection results can be interpreted as habitat preferences because they are not influenced by desired habitats being scarce or absent. Further, our results will be useful for directing habitat conservation for plovers and interpreting other habitat-selection studies.

  1. Selection indicates preference in diverse habitats: a ground-nesting bird (Charadrius melodus using reservoir shoreline.

    Directory of Open Access Journals (Sweden)

    Michael J Anteau

    Full Text Available Animals use proximate cues to select resources that maximize individual fitness. When animals have a diverse array of available habitats, those selected could give insights into true habitat preferences. Since the construction of the Garrison Dam on the Missouri River in North Dakota, Lake Sakakawea (SAK has become an important breeding area for federally threatened piping plovers (Charadrius melodus; hereafter plovers. We used conditional logistic regression to examine nest-site selection at fine scales (1, 3, and 10 m during summers 2006-2009 by comparing characteristics at 351 nests to those of 668 random sites within nesting territories. Plovers selected sites (1 m(2 that were lower than unused random sites, increasing the risk of nest inundation. Plovers selected nest sites that were flat, had little silt, and at least 1 cobble; they also selected for 3-m radius nest areas that were relatively flat and devoid of vegetation and litter. Ninety percent of nests had <38% coverage of silt and <10% slope at the site, and <15% coverage of vegetation or litter and <31% slope within the 3-m radius. Gravel was selected for at nest sites (11% median, but against in the area 10-m from the nest, suggesting plovers select for patches or strips of gravel. Although elevation is rarely evaluated in studies of ground-nesting birds, our results underscore its importance in habitat-selection studies. Relative to where plovers historically nested, habitat at SAK has more diverse topography, substrate composition, vegetation communities, and greater water-level fluctuations. Accordingly, our results provide an example of how habitat-selection results can be interpreted as habitat preferences because they are not influenced by desired habitats being scarce or absent. Further, our results will be useful for directing habitat conservation for plovers and interpreting other habitat-selection studies.

  2. Diversity and habitat preferences of Carabidae and Staphylinidae (Coleoptera in two agroecosystems

    Directory of Open Access Journals (Sweden)

    Ivan Carlos Fernandes Martins

    2012-01-01

    Full Text Available The present study had as objective determine the diversity and abundance of adults Carabidae and Staphylinidae in two areas, constituted by forest fragment and soybean/corn crops under conventional tillage and no-tillage systems and to analyze the distribution and preference of those beetles for the habitat. The beetles were sampled with 48 pitfall traps. In both experimental areas, two parallel transects of pitfall traps were installed. Each transect had 100 m in the crop and 100 m in the forest fragment. Four traps were close to each other (1 m in the edge between the crop and the forest fragment, the other traps were installed each 10 m. The obtained data were submitted to the faunistic analysis and the preference of the species by habitat was obtained by cluster analysis. The results demonstrated that the type of crop system (conventional tillage or no-tillage might have influenced the diversity of species of Carabidae and Staphylinidae. The cluster analysis evidenced that the carabids may prefer a specific habitat. In the present study, the distribution of carabids and staphylinids in the three habitats showed that these beetles have potential to be dispersed at great distances inside the crop.

  3. Gender, Gender Roles Affecting Mate Preferences in Turkish College Students

    Science.gov (United States)

    Gazioglu, A. Esra Ismen

    2008-01-01

    The subject of this study is gender and gender roles affecting mate preferences. The sample of the study consists of 300 undergraduates and master students. To identify students' gender roles the Sex Role Evaluation Inventory (Bem, 1974) is used. The Question List (Bacanli 2001; Buss et. al., 1990) is applied to the sample group to determine the…

  4. How music affects soundscape: Musical preferences in Skadarlija

    Directory of Open Access Journals (Sweden)

    Dumnić Marija

    2017-01-01

    Full Text Available In this article I analyze musical preferences in the context of tavern performances in Skadarlija, a popular tourist quarter in Belgrade, Serbia, on the basis of ethnographic data collection. I argue that this specific musicscape relies on communicative and affective aspects of particular performances. I pay special attention to the repertoires performed and the way in which they interweave. The aim of this article is to demonstrate how musical preferences influence sound environment, especially in the context of the tourism industry. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 177004: Serbian Musical Identities Within Local and Global Frameworks: Traditions, Changes, Challenges

  5. Alien Species of Lepidium in the Flora of Romania: Invasion History and Habitat Preference

    OpenAIRE

    Culiţă SÎRBU; Adrian OPREA; Cristian Valeriu PATRICHE; Costel SAMUIL; Vasile VÎNTU

    2014-01-01

    The history of spread and habitat preferences during invasion of four alien species of Lepidium in Romania, namely L. densiflorum, L. oblongum, L. sativum, and L. virginicum are presented in this paper. The floristic records of these species, collected between 1816 and 2013, were used in the study. L. sativum was sporadically mentioned by earlier botanic references, as a casual alien plant in ruderal places. L. oblongum was reported from a single locality, but it may be considered a potential...

  6. Cognitive skills affect economic preferences, strategic behavior, and job attachment.

    Science.gov (United States)

    Burks, Stephen V; Carpenter, Jeffrey P; Goette, Lorenz; Rustichini, Aldo

    2009-05-12

    Economic analysis has so far said little about how an individual's cognitive skills (CS) are related to the individual's economic preferences in different choice domains, such as risk taking or saving, and how preferences in different domains are related to each other. Using a sample of 1,000 trainee truckers we report three findings. First, there is a strong and significant relationship between an individual's CS and preferences. Individuals with better CS are more patient, in both short- and long-run. Better CS are also associated with a greater willingness to take calculated risks. Second, CS predict social awareness and choices in a sequential Prisoner's Dilemma game. Subjects with better CS more accurately forecast others' behavior and differentiate their behavior as a second mover more strongly depending on the first-mover's choice. Third, CS, and in particular, the ability to plan, strongly predict perseverance on the job in a setting with a substantial financial penalty for early exit. Consistent with CS being a common factor in all of these preferences and behaviors, we find a strong pattern of correlation among them. These results, taken together with the theoretical explanation we offer for the relationships we find, suggest that higher CS systematically affect preferences and choices in ways that favor economic success.

  7. Habitat preferences and conservation threats to Black-necked Cranes wintering in Bhutan.

    Science.gov (United States)

    Namgay, Rinchen; Wangchuk, Sangay

    2016-01-01

    Black-necked Crane (Grus nigricollis) is a vulnerable Red list species whose populations are declining. However, little is known about Black-necked Cranes' habitat requirements or the causes of their population decline. We identified Black-necked Cranes' winter roost and foraging preferences of Black-necked Cranes in Bhutan during the winter of 2013-2014. Black-necked Cranes' roosts were recorded using Garmin GPSmap 60CSx, while foraging preferences and threats to the birds were identified based on a survey of household heads (n = 107) residing within a 3 km radius of roost sites. We grouped the threats identified by the communities into four major categories, viz. biological, social, political and natural threats based on the relevance. Of the four major threats, communities residing within the roosting and foraging habitat of the Black-necked Crane reported biological threat as major. Biological threats as reported by communities include loss of habitat, food shortage and competition from other animals. We recommend the present roosting areas be designated as part of the conservation areas for Black-necked Crane wintering in Bumthang district. In addition to preserving these areas, government should also encourage farming in foraging habitats of Black-necked Crane, because they mainly feed on barley, wheat, paddy, potatoes and buckwheat, besides roots, tubers and insects in the wetlands.

  8. [Estimation of spur dike-affected fish habitat area].

    Science.gov (United States)

    Ray-Shyan, Wu; Yan-Ru, Chen; Yi-Liang, Ge

    2012-04-01

    Based on the HEC-RAS and River 2D modes, and taking 5% change rate of weighted usable area (WUA) as the threshold to define the spur dike- affected area of target fish species Acrossocheilus paradoxus in Fazi River in Taiwan, this paper studied the affected area of the fish habitat by spur dike, and, in combining with the references about the installations of spur dikes in Taiwan in recent 10 years, analyzed the relative importance of related affecting factors such as dike height, dike length (water block rate), average slope gradient of river way, single or double spur dike, and flow discharge. In spite of the length of the dike, the affected area in downstream was farther, and was about 2-6 times as large as that in upstream. The ratio of the affected area in downstream / upstream decreased with increasing slope gradient, but increased with increasing dike length and flow discharge. When the discharge was approximate to 10 years return periods, the ratio of the affected area would be close to a constant of 2. Building double spur dike would produce a better WUA than building single spur dike.

  9. Effect of substrate size on sympatric sand darter benthic habitat preferences

    Science.gov (United States)

    Thompson, Patricia A.; Welsh, Stuart A.; Rizzo, Austin A.; Smith, Dustin M.

    2017-01-01

    The western sand darter, Ammocrypta clara, and the eastern sand darter, A. pellucida, are sand-dwelling fishes that have undergone range-wide population declines, presumably owing to habitat loss. Habitat use studies have been conducted for the eastern sand darter, but literature on the western sand darter remains sparse. To evaluate substrate selection and preference, western and eastern sand darters were collected from the Elk River, West Virginia, one of the few remaining rivers where both species occur sympatrically. In the laboratory, individuals were given the choice to bury into five equally available and randomly positioned substrates ranging from fine sand to granule gravel (0.12–4.0 mm). The western sand darter selected for coarse and medium sand, while the eastern sand darter was more of a generalist selecting for fine, medium, and coarse sand. Substrate selection was significantly different (p = 0.02) between species in the same environment, where the western sand darter preferred coarser substrate more often compared to the eastern sand darter. Habitat degradation is often a limiting factor for many species of rare freshwater fish, and results from this study suggest that western and eastern sand darters may respond differently to variations in benthic substrate composition.

  10. Advancing Affect Modeling via Preference Learning and Unsupervised Feature Extraction

    DEFF Research Database (Denmark)

    Martínez, Héctor Pérez

    over the other examined methods. The second challenge addressed in this thesis refers to the extraction of relevant information from physiological modalities. Deep learning is proposed as an automatic approach to extract input features for models of affect from physiological signals. Experiments...... difficulties, ordinal reports such as rankings and ratings can yield more reliable affect annotations than alternative tools. This thesis explores preference learning methods to automatically learn computational models from ordinal annotations of affect. In particular, an extensive collection of training...... the complexity of hand-crafting feature extractors that combine information across dissimilar modalities of input. Frequent sequence mining is presented as a method to learn feature extractors that fuse physiological and contextual information. This method is evaluated in a game-based dataset and compared...

  11. Habitat Preferences of the Grey Parrot in Heterogeneous Vegetation Landscapes and Their Conservation Implications

    Directory of Open Access Journals (Sweden)

    Simon A. Tamungang

    2016-01-01

    Full Text Available The wild Grey Parrot Psittacus erithacus Linnaeus suffers from many habitat use challenges in the wake of extensive deforestation in its endemic range of West and Central African rainforests. To determine effects of these challenges on the bird species, seasonal densities of the Grey Parrot were determined using line transects in major heterogeneous vegetation types in the Korup Rainforest, south-western Cameroon. Results of the study highlight habitat preferences of this species on a seasonal base and under different situations of human activity intensity in the landscape. This information can be used to understand the causes of changes in the distribution and abundance of endangered species and also to determine sustainable conservation strategies. It is concluded that the parrot needs diverse vegetation types for survival in the wild state, as it depends on specific tree species for specific habitat resources such as food, roosts, security, and nests at specific periods of the year. Hence, the continuous survival of the Grey Parrot in the range states is not certain, if sustainable measures are not taken to conserve the parrot and its habitat resources both in and outside protected areas.

  12. Reproductive constraints influence habitat accessibility, segregation, and preference of sympatric albatross species.

    Science.gov (United States)

    Kappes, Michelle A; Shaffer, Scott A; Tremblay, Yann; Foley, David G; Palacios, Daniel M; Bograd, Steven J; Costa, Daniel P

    2015-01-01

    The spatiotemporal distribution of animals is dependent on a suite of factors, including the distribution of resources, interactions within and between species, physiological limitations, and requirements for reproduction, dispersal, or migration. During breeding, reproductive constraints play a major role in the distribution and behavior of central place foragers, such as pelagic seabirds. We examined the foraging behavior and marine habitat selection of Laysan (Phoebastria immutabilis) and black-footed (P. nigripes) albatrosses throughout their eight month breeding cycle at Tern Island, Northwest Hawaiian Islands to evaluate how variable constraints of breeding influenced habitat availability and foraging decisions. We used satellite tracking and light-based geolocation to determine foraging locations of individuals, and applied a biologically realistic null usage model to generate control locations and model habitat preference under a case-control design. Remotely sensed oceanographic data were used to characterize albatross habitats in the North Pacific. Individuals of both species ranged significantly farther and for longer durations during incubation and chick-rearing compared to the brooding period. Interspecific segregation of core foraging areas was observed during incubation and chick-rearing, but not during brooding. At-sea activity patterns were most similar between species during brooding; neither species altered foraging effort to compensate for presumed low prey availability and high energy demands during this stage. Habitat selection during long-ranging movements was most strongly associated with sea surface temperature for both species, with a preference for cooler ocean temperatures compared to overall availability. During brooding, lower explanatory power of habitat models was likely related to the narrow range of ocean temperatures available for selection. Laysan and black-footed albatrosses differ from other albatross species in that they breed

  13. Current distribution and habitat preferences of red deer and eurasian elk in the Czech Republic

    Directory of Open Access Journals (Sweden)

    Dušan Romportl

    2017-06-01

    Full Text Available Here we determine the distribution, numbers and habitat preferences of two of the largest species in the family Cervidae present in the Czech Republic, red deer and Eurasian elk. Red deer occurs predominantly in vast areas of forest, i.e. mainly in the mountains bordering this country and several large forest units in the interior. The range of this species has been increasing along with the size of its population. Areas of its permanent occurrence may be generally characterized as regions largely covered with deciduous and coniferous forests and pastures, and regions with a more diverse landscape. Red deer does not occur in areas that are mainly arable or urban, or in areas covered with extensive water bodies and wetlands. As these animals prefer large forests, they occur mainly at high altitudes where the terrain is rugged. The Eurasian elk permanently occurs in the Czech Republic in a single area located between the state border and the right bank of the Lipno Dam. Its home range has been diminishing, presumably along with its numbers. The area of its permanent occurrence is characterized by an abundance of coniferous trees, some pastures and water bodies. The Eurasian elk does not occur in areas covered with arable and urban land but also surprisingly in areas with mainly deciduous forest. Both species prefer high altitudes, but Eurasian elk prefers areas with little difference in the terrain vertically.

  14. Diversity and habitat preference of brachyuran crabs in Gulf of Kutch, Gujarat, India

    Directory of Open Access Journals (Sweden)

    J. N. Trivedi

    2012-03-01

    Full Text Available The biodiversity of Gulf of Kutch is studied well with special reference to scleretinia and mollusca but the brachyuran crab taxa are rather neglected. Gulf of Kutch is very rich in floral and faunal diversity and comprises different types of communities and habitats like very unique coral reefs, mangroves, sandy shores, rocky shores and mudflats. Brachyuran crabs are the most diverse group among marine fauna having 5000 species world wide. Some studies on the intertidal fauna, including brachyuran crabs, have been carried out in Gulf of Kutch but the findings were not sufficient to draw out taxonomic diversity. Present work on Gulf of Kutch is an initiative to scan the entire coastal Gujarat and establish directory of brachyuran crab diversity. Since the Gulf habitat is diverse and distinct, eight different stations (16 sample sites were sampled. The selection of the sample site was done on the basis of habitat type which included mangrove mudflats, open mudflats and rocky shores. A total of 19 species belonging to 8 families and 15 genera were recorded. Open mud flats were most preferred by the crabs followed by the mangrove mud flats and rocky shore.

  15. Habitat Preferences, Distribution Pattern, and Root Weight Estimation of Pasak Bumi (Eurycoma longifolia Jack.

    Directory of Open Access Journals (Sweden)

    Siti Masitoh Kartikawati

    2014-04-01

    Full Text Available Pasak bumi (Eurycoma longifolia Jack is one of non timber forest products with “indeterminate” conservation status and commercially traded in West Kalimantan. The research objective was to determine the potential of pasak bumi root per hectare and its ecological condition under natural habitat. Root weight of E. longifolia Jack was estimated using simple linear regression and exponential equation with stem diameter and height as independent variables. The results showed that the individual number of the population was 114 with the majority in seedling stage with 71 individuals (62.28%. The distribution was found in clumped pattern. Conditions of the habitat could be described as follows: daily average temperature of 25.6oC, daily average relative humidity of 73.6%, light intensity of 0.9 klx, and red-yellow podsolic soil with texture ranged from clay to sandy clay. The selected estimator model for E. longifolia Jack root weight used exponential equation with stem height as independent variable using the equation of Y= 21.99T0,010 and determination coefficient of 0.97. After height variable was added, the potential of E. longifolia Jack minimum root weight that could be harvested per hectare was 0.33 kg.Keywords: Eurycoma longifolia, habitat preference, distribution pattern, root weight

  16. How spatio-temporal habitat connectivity affects amphibian genetic structure

    Science.gov (United States)

    Watts, Alexander G.; Schlichting, P; Billerman, S; Jesmer, B; Micheletti, S; Fortin, M.-J.; Funk, W.C.; Hapeman, P; Muths, Erin L.; Murphy, M.A.

    2015-01-01

    Heterogeneous landscapes and fluctuating environmental conditions can affect species dispersal, population genetics, and genetic structure, yet understanding how biotic and abiotic factors affect population dynamics in a fluctuating environment is critical for species management. We evaluated how spatio-temporal habitat connectivity influences dispersal and genetic structure in a population of boreal chorus frogs (Pseudacris maculata) using a landscape genetics approach. We developed gravity models to assess the contribution of various factors to the observed genetic distance as a measure of functional connectivity. We selected (a) wetland (within-site) and (b) landscape matrix (between-site) characteristics; and (c) wetland connectivity metrics using a unique methodology. Specifically, we developed three networks that quantify wetland connectivity based on: (i) P. maculata dispersal ability, (ii) temporal variation in wetland quality, and (iii) contribution of wetland stepping-stones to frog dispersal. We examined 18 wetlands in Colorado, and quantified 12 microsatellite loci from 322 individual frogs. We found that genetic connectivity was related to topographic complexity, within- and between-wetland differences in moisture, and wetland functional connectivity as contributed by stepping-stone wetlands. Our results highlight the role that dynamic environmental factors have on dispersal-limited species and illustrate how complex asynchronous interactions contribute to the structure of spatially-explicit metapopulations.

  17. Habitat Preferences of Boros schneideri (Coleoptera: Boridae) in the Natural Tree Stands of the Białowieża Forest

    Science.gov (United States)

    Gutowski, Jerzy M.; Sućko, Krzysztof; Zub, Karol; Bohdan, Adam

    2014-01-01

    Abstract We analyzed habitat requirements of Boros schneideri (Panzer, 1796) (Coleoptera: Boridae) in the natural forests of the continental biogeographical region, using data collected in the Białowieża Forest. This species has been found on the six host trees, but it preferred dead, standing pine trees, characterized by large diameter, moderately moist and moist phloem but avoided trees in sunny locations. It occurred mostly in mesic and wet coniferous forests. This species demonstrated preferences for old tree stands (over 140-yr old), and its occurrence in younger tree-stand age classes (minimum 31–40-yr old) was not significantly different from random distribution. B. schneideri occupied more frequently locations distant from the forest edge, which were less affected by logging. Considering habitat requirements, character of occurrence, and decreasing number of occupied locations in the whole range of distribution, this species can be treated as relict of primeval forests. PMID:25527586

  18. Adult Movement Pattern and Habitat Preferences of the Maghribian Endemic Gomphus lucasii (Odonata: Gomphidae)

    Science.gov (United States)

    Zebsa, Rabah; Khelifa, Rassim; Kahalerras, Amin

    2015-01-01

    The Algerian Cubtail (Gomphus lucasii Selys) (Odonata: Gomphidae) is a river-dwelling dragonfly and one of the least known gomphid in the Palearctic. A survey of the movement patterns and habitat requirements of adults was conducted in the largest currently known population, located in the Seybouse River (Northeast Algeria). Daily mark-release-resighting surveys along a 2.5 km stretch of the watercourse and within plots in terrestrial habitats were carried out; a total of 1,316 individuals were marked. The resighting rate along the watercourse was 8.13% and did not significantly vary with sex and age. Adult spatial distribution differed according to sex and age. Mature females were significantly further from the water than males. Mature males were observed not only along the watercourse but also far from the water, up to 450 m where reproductive pairs in copula were recorded. Preferred maturation and foraging sites were open grasslands and dense wheat fields. Philopatry to reproductive sites had a mean of 1.11%, while philopatry to emergence site was lower (0.4%) and noted only in males. The mean distance of natal dispersal (from emergence to reproductive areas) was 596.5 ± 4.94 m. The mean dispersal distance from one reproductive site to another was 180.97 ± 238.54 m. Both mature males and females preferred fast flowing water, but females were observed to oviposit in relatively small watercourses.

  19. Habitat preferences among three top predators inhabiting a degraded ecosystem, the Black Sea

    Directory of Open Access Journals (Sweden)

    Alicia Sánchez-Cabanes

    2017-06-01

    Full Text Available This study investigated whether there is evidence of widespread niche partitioning based on environmental factors in the Black Sea and tested the hypothesis that physiographic factors may be employed as predictors. It addresses poorly researched areas with good habitat potential for the only three cetacean subspecies living in this area: the Black Sea short-beaked common dolphin (Delphinus delphis spp. ponticus, the Black Sea bottlenose dolphin (Tursiops truncatus spp. ponticus and the Black Sea harbour porpoise (Phocoena phocoena spp. relicta. Generalized additive models (GAMs were used to analyse data collected from multiple sources. In total, 745 sightings of the three species between 1998 and 2010 throughout the Black Sea were included. The analysis found depth and sea surface temperature to be the most important variables for separating the occurrence of the three species. Common dolphins occurred mainly in deep waters and in areas where the sea surface temperature was low, bottlenose dolphins were distributed primarily in shallower and warmer waters than common dolphins, and harbour porpoises were distributed in shallower waters with lower sea surface temperature than bottlenose dolphins. This study suggests strong niche segregation among the three cetacean species. The study is also the first contribution to the basic information of cetacean species distribution and habitat preferences in the Black Sea as a whole. Knowledge of the distribution of the three dolphin species in the study area is essential to establish conservation measures for these populations.

  20. Leaf energy balance modelling as a tool to infer habitat preference in the early angiosperms.

    Science.gov (United States)

    Lee, Alexandra P; Upchurch, Garland; Murchie, Erik H; Lomax, Barry H

    2015-03-22

    Despite more than a century of research, some key aspects of habitat preference and ecology of the earliest angiosperms remain poorly constrained. Proposed growth ecology has varied from opportunistic weedy species growing in full sun to slow-growing species limited to the shaded understorey of gymnosperm forests. Evidence suggests that the earliest angiosperms possessed low transpiration rates: gas exchange rates for extant basal angiosperms are low, as are the reconstructed gas exchange rates for the oldest known angiosperm leaf fossils. Leaves with low transpirational capacity are vulnerable to overheating in full sun, favouring the hypothesis that early angiosperms were limited to the shaded understorey. Here, modelled leaf temperatures are used to examine the thermal tolerance of some of the earliest angiosperms. Our results indicate that small leaf size could have mitigated the low transpirational cooling capacity of many early angiosperms, enabling many species to survive in full sun. We propose that during the earliest phases of the angiosperm leaf record, angiosperms may not have been limited to the understorey, and that some species were able to compete with ferns and gymnosperms in both shaded and sunny habitats, especially in the absence of competition from more rapidly growing and transpiring advanced lineages of angiosperms.

  1. Habitat Complexity in Aquatic Microcosms Affects Processes Driven by Detritivores.

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    Lorea Flores

    Full Text Available Habitat complexity can influence predation rates (e.g. by providing refuge but other ecosystem processes and species interactions might also be modulated by the properties of habitat structure. Here, we focussed on how complexity of artificial habitat (plastic plants, in microcosms, influenced short-term processes driven by three aquatic detritivores. The effects of habitat complexity on leaf decomposition, production of fine organic matter and pH levels were explored by measuring complexity in three ways: 1. as the presence vs. absence of habitat structure; 2. as the amount of structure (3 or 4.5 g of plastic plants; and 3. as the spatial configuration of structures (measured as fractal dimension. The experiment also addressed potential interactions among the consumers by running all possible species combinations. In the experimental microcosms, habitat complexity influenced how species performed, especially when comparing structure present vs. structure absent. Treatments with structure showed higher fine particulate matter production and lower pH compared to treatments without structures and this was probably due to higher digestion and respiration when structures were present. When we explored the effects of the different complexity levels, we found that the amount of structure added explained more than the fractal dimension of the structures. We give a detailed overview of the experimental design, statistical models and R codes, because our statistical analysis can be applied to other study systems (and disciplines such as restoration ecology. We further make suggestions of how to optimise statistical power when artificially assembling, and analysing, 'habitat complexity' by not confounding complexity with the amount of structure added. In summary, this study highlights the importance of habitat complexity for energy flow and the maintenance of ecosystem processes in aquatic ecosystems.

  2. Experimental evaluation of imprinting and the role innate preference plays in habitat selection in a coral reef fish.

    Science.gov (United States)

    Dixson, Danielle L; Jones, Geoffrey P; Munday, Philip L; Planes, Serge; Pratchett, Morgan S; Thorrold, Simon R

    2014-01-01

    When facing decisions about where to live, juveniles have a strong tendency to choose habitats similar to where their parents successfully bred. Developing larval fishes can imprint on the chemical cues from their natal habitat. However, to demonstrate that imprinting is ecologically important, it must be shown that settlers respond and distinguish among different imprinted cues, and use imprinting for decisions in natural environments. In addition, the potential role innate preferences play compared to imprinted choices also needs to be examined. As environmental variability increases due to anthropogenic causes these two recognition mechanisms, innate and imprinting, could provide conflicting information. Here we used laboratory rearing and chemical choice experiments to test imprinting in larval anemonefish (Amphiprion percula). Individuals exposed to a variety of benthic habitat or novel olfactory cues as larvae either developed a preference for (spent >50% of their time in the cue) or increased their attraction to (increased preference but did not spend >50% of their time in the cue) the cue when re-exposed as settlers. Results indicate not only the capacity for imprinting but also the ability to adjust innate preferences after early exposure to a chemical cue. To test ecological relevance in the natural system, recruits were collected from anemones and related to their parents, using genetic parentage analysis, providing information on the natal anemone species and the species chosen at settlement. Results demonstrated that recruits did not preferentially return to their natal species, conflicting with laboratory results indicating the importance imprinting might have in habitat recognition.

  3. Urban habitat complexity affects species richness but not environmental filtering of morphologically-diverse ants

    Science.gov (United States)

    Nash, Michael A.; Christie, Fiona J.; Hahs, Amy K.; Livesley, Stephen J.

    2015-01-01

    Habitat complexity is a major determinant of structure and diversity of ant assemblages. Following the size-grain hypothesis, smaller ant species are likely to be advantaged in more complex habitats compared to larger species. Habitat complexity can act as an environmental filter based on species size and morphological traits, therefore affecting the overall structure and diversity of ant assemblages. In natural and semi-natural ecosystems, habitat complexity is principally regulated by ecological successions or disturbance such as fire and grazing. Urban ecosystems provide an opportunity to test relationships between habitat, ant assemblage structure and ant traits using novel combinations of habitat complexity generated and sustained by human management. We sampled ant assemblages in low-complexity and high-complexity parks, and high-complexity woodland remnants, hypothesizing that (i) ant abundance and species richness would be higher in high-complexity urban habitats, (ii) ant assemblages would differ between low- and high-complexity habitats and (iii) ants living in high-complexity habitats would be smaller than those living in low-complexity habitats. Contrary to our hypothesis, ant species richness was higher in low-complexity habitats compared to high-complexity habitats. Overall, ant assemblages were significantly different among the habitat complexity types investigated, although ant size and morphology remained the same. Habitat complexity appears to affect the structure of ant assemblages in urban ecosystems as previously observed in natural and semi-natural ecosystems. However, the habitat complexity filter does not seem to be linked to ant morphological traits related to body size. PMID:26528416

  4. Brand Preference Affects the Threshold for Perceptual Awareness

    DEFF Research Database (Denmark)

    Ramsøy, Thomas Z.; Skov, Martin

    2014-01-01

    , the Perception Awareness Scale, it is found that brand names for which there is either a positive and negative preference, subjects report seeing the name more clearly. Interestingly, and much to the contrary of studies of basic emotions, this effect is strongest for positive preference. Our results......Despite decades of scientific scrutiny, much is still unknown about the effects that brands have on perception. Brands are known to lead to changes in attention and mnemonic processing and by altering emotional preferences they imbue products with value. Less, however, is known about the exact...... mechanism through which this occurs. Here, a novel and unexpected finding is provided in which subjective brand preference alters the likelihood that a brand name will be consciously seen. By presenting brand names at brief durations, and having them respond using a graded evaluation of conscious perception...

  5. How forest marsupials are affected by habitat degradation and fragmentation? A meta-analysis

    Science.gov (United States)

    Fontúrbel, Francisco E.; Candia, Alina B.; Salazar, Daniela A.; Malebrán, Javiera; González-Browne, Catalina; Botto-Mahan, Carezza

    2014-07-01

    Habitat fragmentation and degradation are important biodiversity change drivers worldwide. Their effects have been described for many animal groups, but little is known about marsupials. We conducted a meta-analysis aiming to evaluate the actual effects of habitat fragmentation and degradation on forest marsupials. From a literature survey, we obtained 85 case studies reporting disturbance comparisons. We found a negative overall effect, as well as a negative effect for habitat fragmentation, but not for habitat degradation. Marsupials from Oceania were negatively affected by habitat disturbance, whereas there was no effect for those from South America. Arboreal marsupials were negatively affected, whereas terrestrial marsupials did not. Species from the families Dasyuridae ( Antechinus spp.) and Microbiotheriidae ( Dromiciops gliroides) showed to be sensitive to habitat disturbance.

  6. How forest marsupials are affected by habitat degradation and fragmentation? A meta-analysis.

    Science.gov (United States)

    Fontúrbel, Francisco E; Candia, Alina B; Salazar, Daniela A; Malebrán, Javiera; González-Browne, Catalina; Botto-Mahan, Carezza

    2014-07-01

    Habitat fragmentation and degradation are important biodiversity change drivers worldwide. Their effects have been described for many animal groups, but little is known about marsupials. We conducted a meta-analysis aiming to evaluate the actual effects of habitat fragmentation and degradation on forest marsupials. From a literature survey, we obtained 85 case studies reporting disturbance comparisons. We found a negative overall effect, as well as a negative effect for habitat fragmentation, but not for habitat degradation. Marsupials from Oceania were negatively affected by habitat disturbance, whereas there was no effect for those from South America. Arboreal marsupials were negatively affected, whereas terrestrial marsupials did not. Species from the families Dasyuridae (Antechinus spp.) and Microbiotheriidae (Dromiciops gliroides) showed to be sensitive to habitat disturbance.

  7. Ghost of habitat past: historic habitat affects the contemporary distribution of giant garter snakes in a modified landscape.

    Science.gov (United States)

    Halstead, Brian J.; Wylie, Glenn D.; Casazza, Michael L.

    2014-01-01

    Historic habitat conditions can affect contemporary communities and populations, but most studies of historic habitat are based on the reduction in habitat extent or connectivity. Little is known about the effects of historic habitat on contemporary species distributions when historic habitat has been nearly completely removed, but species persist in a highly altered landscape. More than 93% of the historic wetlands in the Central Valley of California, USA, have been drained and converted to agricultural and other uses, but agricultural wetlands, such as rice and its supporting infrastructure of canals, allow some species to persist. Little is known about the distribution of giant garter snakes Thamnophis gigas, a rare aquatic snake species inhabiting this predominantly agricultural landscape, or the variables that affect where this species occurs. We used occupancy modeling to examine the distribution of giant garter snakes at the landscape scale in the Sacramento Valley (northern portion of the Central Valley) of California, with an emphasis on the relative strength of historic and contemporary variables (landscape-scale habitat, local microhabitat, vegetation composition and relative prey counts) for predicting giant garter snake occurrence. Proximity to historic marsh best explained variation in the probability of occurrence of giant garter snakes at the landscape scale, with greater probability of occurrence near historic marsh. We suspect that the importance of distance to historic marsh represents dispersal limitations of giant garter snakes. These results suggest that preserving and restoring areas near historic marsh, and minimizing activities that reduce the extent of marsh or marsh-like (e.g. rice agriculture, canal) habitats near historic marsh may be advantageous to giant garter snakes.

  8. Ski areas affect Pacific marten movement, habitat use, and density

    Science.gov (United States)

    Keith M. Slauson; William J. Zielinski; Michael K. Schwartz

    2017-01-01

    Alpine ski recreation is one of the most popular outdoor winter sports globally but often involves habitat modification and dense human activity, both of which can harm wildlife. We investigated the effects of ski area development and winter recreation activities on movement, occupancy, and density of Pacific martens (Martes caurina) in the Lake...

  9. Distribution and habitat preferences of tiger beetles (Coleoptera: Cicindelidae of the riverine ecosystems of Sri Lanka

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    C.D. Dangalle

    2014-08-01

    Full Text Available Tiger beetles have been observed in many riverine ecosystems of Sri Lanka. However, current locations, species, distribution of species, habitat preferences and possible interactions between species are unknown. The present study intends to investigate these details and provide information that can be used in further studies. Tiger beetles are sampled from 15 riverine locations and examined for identification, body weight and body length. The riverine locations are analysed for locational, climatic and soil parameters and microhabitat details are recorded. Statistical analysis using One-Way Analysis of Variance and Tukey’s pair comparison method of Minitab 16.0 statistical software package is conducted to compare the body sizes of species. Further, a statistical comparison between the climatic and soil parameters of the locations of Cylindera (Ifasina labioaenea and that of other species are carried out. The study reveals five tiger beetle species Cylindera (Ifasina labioaenea Horn, Cylindera (Ifasina willeyi Horn, Cylindera (Ifasina waterhousei Horn, Calomera cardoni Fleutiaux, Calomera angulata Fabricius, from the riverine ecosystems of Sri Lanka. Cylindera labioaenea is the most common species; C. willeyi and C. waterhousei are endemic to Sri Lanka. Cylindera labioaenea, C. willeyi and C. waterhousei are small, while Calomera cardoni and Calomera angulata are medium in size. Cylindera labioaenea is significantly smaller than C. willeyi and C. waterhousei, and resides in locations with significantly higher air temperatures, solar radiations and significantly lower relative humidity than the other two species. An optimal temperature range for the riverine tiger beetles is suggested and their preferences to soil moisture, soil temperature, soil colour and soil salinity are discussed. The occurrence of C. labioaenea as a single species population while the fact that other species co-exist may be due to a defensive strategy.

  10. Breeding habitat preference of preimaginal black flies (Diptera: Simuliidae) in Peninsular Malaysia.

    Science.gov (United States)

    Ya'cob, Zubaidah; Takaoka, Hiroyuki; Pramual, Pairot; Low, Van Lun; Sofian-Azirun, Mohd

    2016-01-01

    To investigate the breeding habitat preference of black flies, a comprehensive black fly survey was conducted for the first time in Peninsular Malaysia. Preimaginal black flies (pupae and larvae) were collected manually from 180 stream points encompassing northern, southern, central and east coast of the Peninsular Malaysia. A total of 47 black fly species were recorded in this study. The predominant species were Simulium trangense (36.7%) and Simulium angulistylum (33.3%). Relatively common species were Simulium cheongi (29.4%), Simulium tani (25.6%), Simulium nobile (16.2%), Simulium sheilae (14.5%) and Simulium bishopi (10.6%). Principal Component Analysis (PCA) of all stream variables revealed four PCs that accounted for 69.3% of the total intersite variance. Regression analysis revealed that high species richness is associated with larger, deeper, faster and higher discharge streams with larger streambed particles, more riparian vegetation and low pH (F=22.7, d.f.=1, 173; P10% of the sampling sites) was assessed. Forward logistic regression analysis indicated that four species were significantly related to the stream variables. S. nobile and S. tani prefer large, fast flowing streams with higher pH, large streambed particles and riparian trees. S. bishopi was commonly found at high elevation with cooler stream, low conductivity, higher conductivity and more riparian trees. In contrast, S. sheilae was negatively correlated with PC-2, thus, this species commonly found at low elevation, warmer stream with low conductivity and less riparian trees. The results of this study are consistent with previous studies from other geographic regions, which indicated that both physical and chemical stream conditions are the key factors for black fly ecology. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Habitat characteristics affecting fish assemblages on a Hawaiian coral reef

    Science.gov (United States)

    Friedlander, A.M.; Parrish, J.D.

    1998-01-01

    Habitat characteristics of a reef were examined as potential influences on fish assemblage structure, using underwater visual census to estimate numbers and biomass of all fishes visible on 42 benthic transects and making quantitative measurements of 13 variables of the corresponding physical habitat and sessile biota. Fish assemblages in the diverse set of benthic habitats were grouped by detrended correspondence analysis, and associated with six major habitat types. Statistical differences were shown between a number of these habitat types for various ensemble variables of the fish assemblages. Overall, both for complete assemblages and for component major trophic and mobility guilds, these variables tended to have higher values where reef substratum was more structurally or topographically complex, and closer to reef edges. When study sites were separately divided into five depth strata, the deeper strata tended to have statistically higher values of ensemble variables for the fish assemblages. Patterns with depth varied among the various trophic and mobility guilds. Multiple linear regression models indicated that for the complete assemblages and for most trophic and mobility guilds, a large part of the variability for most ensemble variables was explained by measures of holes in the substratum, with important contributions from measured substratum rugosity and depth. A strong linear relationship found by regression of mean fish length on mean volume of holes in the reef surface emphasized the importance of shelter for fish assemblages. Results of this study may have practical applications in designing reserve areas as well as theoretical value in helping to explain the organization of reef fish assemblages.

  12. Habitat use and preferences of cetaceans along the continental slope and the adjacent pelagic waters in the western Ligurian Sea

    Science.gov (United States)

    Azzellino, A.; Gaspari, S.; Airoldi, S.; Nani, B.

    2008-03-01

    The physical habitat of cetaceans occurring along the continental slope in the western Ligurian Sea was investigated. Data were collected from two different sighting platforms, one of the two being a whale-watching boat. Surveys, conducted from May to October and from 1996 to 2000, covered an area of approximately 3000 km 2 with a mean effort of about 10,000 km year -1. A total of 814 sightings was reported, including all the species occurring in the area: Stenella coeruleoalba, Balaenoptera physalus, Physeter macrocephalus, Globicephala melas, Grampus griseus, Ziphius cavirostris, Tursiops truncatus, Delphinus delphis. A Geographic Information System was used to integrate sighting data to a set of environmental characteristics, which included bottom gradient, area between different isobaths, and length and linearity of the isobaths within a cell unit. Habitat use was analysed by means of a multi-dimensional scaling, MDS, analysis. Significant differences were found in the habitat preference of most of the species regularly occurring in the area. Bottlenose dolphin, Risso's dolphin, sperm whale and Cuvier's beaked whale were found strongly associated to well-defined depth and slope gradient characteristics of the shelf-edge and the upper and lower slope. The hypothesis of habitat segregation was considered for Risso's dolphin, sperm whale and Cuvier's beaked whale. Canonical discriminant functions using depth and slope as predictors outlined clear and not overlapping habitat preferences for Risso's dolphin and Cuvier's beaked whale, whereas a partial overlapping of the habitat of the other two species was observed for sperm whale. Such a partitioning of the upper and lower slope area may be the result of the common feeding habits and suggests a possible competition of these three species. A temporal segregation in the use of the slope area was also observed for sperm whales and Risso's dolphins. Fin whales, and the occasionally encountered common dolphin and long

  13. An Initial Classification of Neotropical Water Mites (Acari: Hydrachnidia Based on Habitat Preferences

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    Hugo R. Fernández

    2011-01-01

    Full Text Available Existing classifications of benthic and interstitial freshwater invertebrates are described and discussed. A classification is proposed for southern neotropical (south of latitude S 15 water mites in relation to their life style and habitat preferences. The classification includes planktonic, superficial, benthic, thermal, and subterranean forms. The diversity of the Hydrachnidia family and genera (22 families, 97 genera, and 521 species is then analyzed using the new classification. Ubiquitous stygobites deserve special consideration because they move through ecotone zones and tolerate extreme conditions. Water mite communities from a north-western Argentinean stream were first described using a surber net and consequently considered as benthic. Nineteen Hydrachnidia species (from benthic to stygobite were collected and classified. The vertical distribution observed during the year confirmed the permanent presence of benthic Hydrachnidia, even during the first flood, which is of special importance in running waters. The functional classification we propose will facilitate comparison of fauna from different areas that have different faunistic composition but may have similar functional distribution.

  14. Aquatic environmental DNA detects seasonal fish abundance and habitat preference in an urban estuary.

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    Mark Y Stoeckle

    Full Text Available The difficulty of censusing marine animal populations hampers effective ocean management. Analyzing water for DNA traces shed by organisms may aid assessment. Here we tested aquatic environmental DNA (eDNA as an indicator of fish presence in the lower Hudson River estuary. A checklist of local marine fish and their relative abundance was prepared by compiling 12 traditional surveys conducted between 1988-2015. To improve eDNA identification success, 31 specimens representing 18 marine fish species were sequenced for two mitochondrial gene regions, boosting coverage of the 12S eDNA target sequence to 80% of local taxa. We collected 76 one-liter shoreline surface water samples at two contrasting estuary locations over six months beginning in January 2016. eDNA was amplified with vertebrate-specific 12S primers. Bioinformatic analysis of amplified DNA, using a reference library of GenBank and our newly generated 12S sequences, detected most (81% locally abundant or common species and relatively few (23% uncommon taxa, and corresponded to seasonal presence and habitat preference as determined by traditional surveys. Approximately 2% of fish reads were commonly consumed species that are rare or absent in local waters, consistent with wastewater input. Freshwater species were rarely detected despite Hudson River inflow. These results support further exploration and suggest eDNA will facilitate fine-scale geographic and temporal mapping of marine fish populations at relatively low cost.

  15. Zoogeographic distribution and habitat preferences of Orthoptera species (Insecta from Danube Delta Biosphere Reserve (Romania

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    Lupu Gabriel

    2013-12-01

    Full Text Available Arthropods belonging to the class Insecta, Orthoptera species, develop a variety of preferences towards the type of habitat impressive for most of the time. They inhabit the majority of latitudinal (from the equator to the Polar Regions near and altitudinal (from the dry areas below sea level and up to the alpine region biotopes. On the other hand, the species of Orthoptera are very diversified in terms of geographical spread, with all major types of distribution – from the endemic forms, characteristic only of a certain areas (exp.: Isophya dobrogensis until holopalearctic forms with a wide spread across Europe, North Africa and Asia, Palearctic (Gryllus campestris,Tettigonia viridissima, Gryllotalpa gryllotalpa, Tetrix tenuicornis, Calliptamus italicus, Oedipoda caerulescens, Aiolopus thalassinus, Chorthippus brunneus etc.. The Romanian ortopterofauna it was classified in 5 principal classes, each from these containing from 2 to 5 types of near zoogeographic elements: Palearctic, European, central-Asiatic-European, Mediterranean, and Carpatic elements. The classification is based on the fundamental types of distribution, group items from the biogeographic macrozoning of Europe, most of the time, however, taking into account the areas of interference of biogeographic place. Danube Delta Biosphere Reserve territory characterized by the presence of a single endemic species (Isophya dobrogensis on Popina Island constitute an impressive reservoir of spontaneous genetic resources for an area with a relatively small surface area,Orthoptera species with widespread (at national level in some cases finding here favorable conditions for the manifestation of the presence.

  16. Habitat Preferences and Growth of Ruditapes bruguieri (Bivalvia: Veneridae at the Northern Boundary of Its Range

    Directory of Open Access Journals (Sweden)

    Alla V. Silina

    2014-01-01

    Full Text Available This work is the first attempt to study growth and some morphological parameters of the clam Ruditapes bruguieri, as well as its habitat preferences. It is found that R. bruguieri lives on bottom sediments including pebble and coarse- and medium-grained sand with a slight admixture of silt. At the study area, this bivalve inhabits sea waters with good aeration, stable oceanic water salinity, and a high oxygen concentration. The annual fluctuations of the water temperature from 13-14°C (in winter to 22–29°C (in summer are close to the threshold temperature values, within which the species can exist. Near the boundary of the species range, along the Jeju Island coasts, south of Republic of Korea, 83.8% of all clams die during the coldest period of the year. Here, annual rings are formed on R. bruguieri shells during winter. The maximum age of R. bruguieri, determined during the study, is 6.5 years, but the clam samples contain mainly individuals at 3.0–3.5 years of age (34%. The largest clam dimensions are 36.0 × 26.5 mm (length × height of shell. At the study area, a usual shell length is 20.0–32.0 mm (75% of all the collected individuals.

  17. Aquatic environmental DNA detects seasonal fish abundance and habitat preference in an urban estuary.

    Science.gov (United States)

    Stoeckle, Mark Y; Soboleva, Lyubov; Charlop-Powers, Zachary

    2017-01-01

    The difficulty of censusing marine animal populations hampers effective ocean management. Analyzing water for DNA traces shed by organisms may aid assessment. Here we tested aquatic environmental DNA (eDNA) as an indicator of fish presence in the lower Hudson River estuary. A checklist of local marine fish and their relative abundance was prepared by compiling 12 traditional surveys conducted between 1988-2015. To improve eDNA identification success, 31 specimens representing 18 marine fish species were sequenced for two mitochondrial gene regions, boosting coverage of the 12S eDNA target sequence to 80% of local taxa. We collected 76 one-liter shoreline surface water samples at two contrasting estuary locations over six months beginning in January 2016. eDNA was amplified with vertebrate-specific 12S primers. Bioinformatic analysis of amplified DNA, using a reference library of GenBank and our newly generated 12S sequences, detected most (81%) locally abundant or common species and relatively few (23%) uncommon taxa, and corresponded to seasonal presence and habitat preference as determined by traditional surveys. Approximately 2% of fish reads were commonly consumed species that are rare or absent in local waters, consistent with wastewater input. Freshwater species were rarely detected despite Hudson River inflow. These results support further exploration and suggest eDNA will facilitate fine-scale geographic and temporal mapping of marine fish populations at relatively low cost.

  18. An experimental test of whether habitat corridors affect pollen transfer.

    Energy Technology Data Exchange (ETDEWEB)

    Townsend, Patricia A.; Levey, Douglas J.

    2005-02-01

    Abstract. Negative effects of habitat fragmentation are thought to be diminished when habitat patches are joined by a corridor. A key assumption is that corridors facilitate exchange rates of organisms between otherwise isolated patches. If the organisms are pollinators, corridors may be important for maintaining genetically viable populations of the plants that they pollinate. We tested the hypothesis that corridors increase the movement of insect pollinators into patches of habitat and thereby increase pollen transfer for two species of plants, one pollinated by butterflies (Lantana camara) and the other by bees and wasps (Rudbeckia hirta). We worked in an experimental landscape consisting of 40 greater than or equal to 1-ha patches of early-successional habitat in a matrix of forest. Within each of eight experimental units, two patches were connected by a corridor (150 X 25 m), and three were not. Patch shape varied to control for the area added by the presence of a corridor. Differences in patch shape also allowed us to test alternative hypotheses of how corridors might function. The Traditional Corridor Hypothesis posits that corridors increase immigration and emigration by functioning as movement conduits between patches. The Drift Fence Hypothesis posits that corridors function by ‘‘capturing’’ organisms dispersing through the matrix, redirecting them into associated habitat patches. Using fluorescent powder to track pollen, we found that pollen transfer by butterflies between patches connected by a corridor was significantly higher than between unconnected patches (all values mean plus or minus 1 SE: 59% plus or minus 9.2% vs. 25% plus or minus 5.2% of flowers receiving pollen). Likewise, pollen transfer by bees and wasps was significantly higher between connected patches than between unconnected patches (30% plus or minus 4.2% vs. 14.5% plus or minus 2.2%). These results support the Traditional Corridor Hypothesis. There was little support, however

  19. Habitat Preferences and Distribution of the Freshwater Shrimps of the Genus Caridina (Crustacea: Decapoda: Atyidae in Lake Lindu, Sulawesi, Indonesia

    Directory of Open Access Journals (Sweden)

    Annawaty

    2016-04-01

    Full Text Available The objectives of this study were to reveal ecological preferences and distribution of all species of Caridina found in Lake Lindu and their catchment area. Specimens from 39 sampling sites were caught using tray net and hand net. There are three species of Caridina found in the lake system, i.e. Caridina linduensis, Caridina kaili and Caridina dali. There is no overlapping distribution among the species. Caridina kaili is a true riverine species and it is never encountered sympatric with C. dali nor C. linduensis. This species is abundant in streams and ditches with moderate flow running water and gravel–cobble substrate. It is mainly spread within streams west to the lake. Both C. dali and C. linduensis can be found in the lake and streams with very slow current to almost stagnant water, muddy sand substrate and associated with roots of water plants and leaf litter. However, C. dali is never occurred together with C. linduensis and they are less abundant compare to C. kaili. Distribution of Caridina spp. in Lake Lindu is probably affected by the temperature of their habitats and the occurrence of introduced fish such as Mozambique tilapia (Oreochromis mossambicus, common carp (Cyprinus carpio, and an alien riceland prawn (Macrobrachium lanchesteri. These introduced and alien species can have the potency to become predators or competitors for the Caridina spp. It is also the first record for M. lanchesteri present in Lake Lindu.

  20. How does typeface familiarity affect reading performance and reader preference?

    DEFF Research Database (Denmark)

    Beier, Sofie

    2013-01-01

    the reading speed and preferences of participants. Participants were tested twice with common and uncommon letter shapes, once before and once after spending 20 minutes reading a story with the font. The results indicate that the exposure period has an effect on the speed of reading, but the uncommon letter...

  1. Yielding to Desire: The Durability of Affective Preferences

    Science.gov (United States)

    Rapp, David N.; Jacovina, Matthew E.; Slaten, Daniel G.; Krause, Elise

    2014-01-01

    People's expectations about the future are guided not just by the contingencies of situations but also by what they hope or wish will happen next. These preferences can inform predictions that run counter to what should or must occur based on the logic of unfolding events. Effects of this type have been regularly identified in studies of judgment…

  2. Factors Affecting Recreation Preferences and Expectations of Disabled Adult Learners

    Science.gov (United States)

    Arslan, Sibel

    2014-01-01

    Generalizing recreation services, one of the essential well-being sources of disabled persons who experience deprivation in many dimensions of life and which fulfill their learning needs, is a social responsibility. The present study aims to determine factors effective on recreation preferences and expectations of the disabled individuals who…

  3. Factors affecting stem borer parasitoid species diversity and parasitism in cultivated and natural habitats.

    Science.gov (United States)

    Mailafiya, Duna Madu; Le Ru, Bruno Pierre; Kairu, Eunice Waitherero; Calatayud, Paul-André; Dupas, Stéphane

    2010-02-01

    The effects of biotic and abiotic factors on stem borer parasitoid diversity, abundance, and parasitism were studied in cultivated and natural habitats in four agroecological zones in Kenya. Comparing habitat types, we found partial support for the "natural enemy" hypothesis, whereby, across all localities, parasitoid diversity was higher in more diverse host plant communities in natural habitats, whereas parasitoid abundance was higher in cultivated habitats. For both habitats, parasitoid richness was mainly influenced by stem borer density and/or its interaction with stem borer richness, whereas parasitoid abundance was mainly affected by stem borer abundance. Parasitoid richness was higher in localities (with bimodal rainfall distribution) with increased spatial and temporal availability of host plants that harbored the borers. Across seasons, parasitoid richness was lower in both cultivated and natural habitats in the driest locality, Mtito Andei. Overall, parasitoid diversity was low in Suam and Mtito Andei, where maize cultivation was practiced on a commercial scale and intense grazing activities persist across seasons, respectively. Across localities, habitats, and seasons, stem borer parasitism was positively correlated with parasitoid richness and abundance. Furthermore, the interaction of rainfall and altitude influenced the presence and absence of parasitoids, and consequently, stem borer parasitism. Parasitism was positively and negatively correlated with temperature in cultivated and natural habitats, respectively. Overall, natural habitats seem to serve as important refugia for sustaining parasitoid diversity, which in turn can affect stem borer parasitism in the cereal cropping system.

  4. Fine-scale habitat preference of green sturgeon (Acipenser medirostris) within three spawning locations in the Sacramento River, California

    Science.gov (United States)

    Wyman, Megan T.; Thomas, Michael J.; McDonald, Richard R.; Hearn, Alexander R.; Battleson, Ryan D.; Chapman, Eric D.; Kinzel, Paul J.; Minear, J. Tobey; Mora, Ethan A.; Nelson, Jonathan M.; Pagel, Matthew D.; Klimley, A. Peter

    2017-01-01

    Vast sections of the Sacramento River have been listed as critical habitat by the National Marine Fisheries Service for green sturgeon spawning (Acipenser medirostris), yet spawning is known to occur at only a few specific locations. This study reveals the range of physical habitat variables selected by adult green sturgeon during their spawning period. We integrated fine-scale fish positions, physical habitat characteristics, discharge, bathymetry, and simulated velocity and depth using a 2-dimensional hydraulic model (FaSTMECH). The objective was to create habitat suitability curves for depth, velocity, and substrate type within three known spawning locations over two years. An overall cumulative habitat suitability score was calculated that averaged the depth, velocity, and substrate scores over all fish, sites, and years. A weighted usable area (WUA) index was calculated throughout the sampling periods for each of the three sites. Cumulative results indicate that the microhabitat characteristics most preferred by green sturgeon in these three spawning locations were velocities between 1.0-1.1 m/s, depths of 8-9 m, and gravel and sand substrate. This study provides guidance for those who may in the future want to increase spawning habitat for green sturgeon within the Sacramento River.

  5. Policies Affect Preferences: Evidence from Random Variation in Abortion Jurisprudence

    OpenAIRE

    Chen, Daniel L.; Levonyan, Vardges; Yeh, Susan

    2016-01-01

    Whether policies shift preferences is relevant to policy design. We exploit the random assignment of U.S. federal judges creating geographically local precedent and the fact that judges’ politics, religion, and race predict decision-making in abortion jurisprudence. Instrumenting for abortion jurisprudence with exogenous judicial characteristics, we estimate the impact of abortion jurisprudence on state laws, campaign donations, and abortion attitudes. We verify information transmission in th...

  6. Microplastics Affect the Ecological Functioning of an Important Biogenic Habitat.

    Science.gov (United States)

    Green, Dannielle Senga; Boots, Bas; O'Connor, Nessa E; Thompson, Richard

    2017-01-03

    Biological effects of microplastics on the health of bivalves have been demonstrated elsewhere, but ecological impacts on the biodiversity and ecosystem functioning of bivalve-dominated habitats are unknown. Thus, we exposed intact sediment cores containing European flat oysters (Ostrea edulis) or blue mussels (Mytilus edulis) in seawater to two different densities (2.5 or 25 μg L(-1)) of biodegradable or conventional microplastics in outdoor mesocosms. We hypothesized that filtration rates of the bivalves, inorganic nitrogen cycling, primary productivity of sediment dwelling microphytobenthos, and the structure of invertebrate benthic assemblages would be influenced by microplastics. After 50 days, filtration by M. edulis was significantly less when exposed to 25 μg L(-1) of either type of microplastics, but there were no effects on ecosystem functioning or the associated invertebrate assemblages. Contrastingly, filtration by O. edulis significantly increased when exposed to 2.5 or 25 μg L(-1) of microplastics, and porewater ammonium and biomass of benthic cyanobacteria decreased. Additionally the associated infaunal invertebrate assemblages differed, with significantly less polychaetes and more oligochaetes in treatments exposed to microplastics. These findings highlight the potential of microplastics to impact the functioning and structure of sedimentary habitats and show that such effects may depend on the dominant bivalve present.

  7. How does ocean seasonality drive habitat preferences of highly mobile top predators? Part II: The eastern North-Atlantic

    Science.gov (United States)

    Lambert, C.; Pettex, E.; Dorémus, G.; Laran, S.; Stéphan, E.; Canneyt, O. Van; Ridoux, V.

    2017-07-01

    Marine ecosystems are characterised by strong heterogeneity and variability, both spatially and temporally. In particular, seasonal variations may lead to severe constraints for predators which have to cope with these variations, for example through migration to avoid unfavourable seasons, or adaptation to local modification of the ecosystem. In the Bay of Biscay and English Channel, ecosystem seasonality is well marked, especially over the shelf. Cetacean and seabird communities within the Bay of Biscay, Celtic Sea and English Channel were studied during aerial surveys conducted in winter 2011-2012 and summer 2012, following a strip-transect methodology deployed from the coast to oceanic waters. We explored seasonal variations of habitat preferences of four cetacean and six seabird groups through Generalised Additive Models, using physiographic variables and weekly- and monthly-averaged oceanographic predictors for both seasons. Our results provided the first overview at such a large scale of the variation of habitat preferences in response to the seasonality of the ocean by seabirds in that region, at such a large scale. Habitat models resulted in explained deviances from 13 to 55%. Predators answered the seasonality of their environment in different ways. Long-finned pilot whales and Risso's dolphins were the only studied group exhibiting no habitat variations between seasons, targeting the shelf break throughout the year. The other groups modulated their habitat preferences between seasons to optimise the compromise between the ocean seasonal variations and their own constraints: common and striped dolphins, bottlenose dolphins and harbour porpoises for cetaceans; northern gannets, auks, northern fulmars and kittiwakes for seabirds. For shearwaters, the seasonality had an extreme impact, inducing a complete absence from the region during the unfavourable season.

  8. Diurnal behavior and habitat preferences of Erebia aethiops, an aberrant lowland species of a mountain butterfly clade

    Czech Academy of Sciences Publication Activity Database

    Slámová, Irena; Klečka, Jan; Konvička, Martin

    2011-01-01

    Roč. 24, č. 3 (2011), s. 230-246 ISSN 0892-7553 R&D Projects: GA MŠk LC06073; GA ČR GD206/08/H044; GA ČR GAP505/10/2248 Institutional research plan: CEZ:AV0Z50070508 Keywords : butterfly activity * habitat preferences * diurnal behavior Subject RIV: EH - Ecology, Behaviour Impact factor: 0.963, year: 2011

  9. Detecting forest canopy layering: applying lidar remote sensing to further understand the role of vertical structure in species habitat preference

    Science.gov (United States)

    Whitehurst, A. S.; Dubayah, R.; Swatantran, A.

    2011-12-01

    Full waveform lidar reflects off all forest canopy elements, showing not only height, but also the structure within the canopy from the top to the forest floor, making it an ideal remote sensing technology for research in forest ecosystem dynamics. Vertical stratification or canopy layering has long been noted as an essential element in the forest ecosystem and of importance for species habitat. This project explores the utility of lidar for characterizing forest canopy layering and applying canopy layering information to better understand species habitat preference. Canopy layering will be mapped across the landscape using full-waveform lidar remote sensing data from the NASA Goddard Space Flight Center Laser Vegetation Imaging Sensor (LVIS). Two methods for quantifying layering have been developed from LVIS data collected during the summer of 2009 for Hubbard Brook Experimental Forest, New Hampshire. The two layering datasets (one categorical, one continuous) describe how vertical stratification varies across the forest with canopy height and elevation. The relationships between of canopy layering and avian species habitat preference will also be assessed for bird species within Hubbard Brook Experimental forest. These results will provide ecologically meaningful information and a relevant method for quantifying canopy layering at the landscape scale, which will aid in a better understanding of forest ecosystem dynamics for forest management and species habitat research.

  10. Habitat modeling for brown trout population in alpine region of Slovenia with focus on determination of preference functions, fuzzy rules and fuzzy sets

    Science.gov (United States)

    Santl, Saso; Carf, Masa; Preseren, Tanja; Jenic, Aljaz

    2013-04-01

    Water withdrawals and consequently reduction of discharges in river streams for different water uses (hydro power, irrigation, etc.) usually impoverish habitat suitability for naturally present river fish fauna. In Slovenia reduction of suitable habitats resulting from water abstractions frequently impacts local brown trout (Salmo truta) populations. This is the reason for establishment of habitat modeling which can qualitatively and quantitatively support decision making for determination of the environmental flow and other mitigation measures. Paper introduces applied methodology for habitat modeling where input data preparation and elaboration with required accuracy has to be considered. For model development four (4) representative and heterogeneous sampling sites were chosen. Two (2) sampling sections were located within the sections with small hydropower plants and were considered as sections affected by water abstractions. The other two (2) sampling sections were chosen where there are no existing water abstractions. Precise bathymetric mapping for chosen river sections has been performed. Topographic data and series of discharge and water level measurements enabled establishment of calibrated hydraulic models, which provide data on water velocities and depths for analyzed discharges. Brief field measurements were also performed to gather required data on dominant and subdominant substrate size and cover type. Since the accuracy of fish distribution on small scale is very important for habitat modeling, a fish sampling method had to be selected and modified for existing river microhabitats. The brown trout specimen's locations were collected with two (2) different sampling methods. A method of riverbank observation which is suitable for adult fish in pools and a method of electro fishing for locating small fish and fish in riffles or hiding in cover. Ecological and habitat requirements for fish species vary regarding different fish populations as well as eco

  11. Factors affecting vegetable preference in adolescents: stages of change and social cognitive theory.

    Science.gov (United States)

    Woo, Taejung; Lee, Kyung-Hea

    2017-08-01

    Despite the importance of consuming sufficient amounts of vegetables, daily vegetable intake among adolescents in Korea is lower than the current dietary recommendation. The objective of this study was to examine determinants affecting vegetable preference in order to suggest a stage-tailored education strategy that can promote vegetable consumption in adolescents. Adolescents (n = 400, aged 16-17 years) from two high schools participated in a cross-sectional study. Survey variables were vegetable preference, the social cognitive theory (SCT) and stages of change (SOC) constructs. Based on vegetable preference, subjects were classified into two groups: a low-preference group (LPG) and a high-preference group (HPG). SOC was subdivided into pre-action and action/maintenance stages. To compare SCT components and SOC related to vegetable preference, chi-squared and t-tests, along with stepwise multiple-regression analysis, were applied. In the LPG, a similar number of subjects were classified into each stage. Significant differences in self-efficacy, affective attitudes, and vegetable accessibility at home and school were detected among the stages. Subjects in the HPG were mainly at the maintenance stage (81%), and there were significant differences among the stages regarding self-efficacy, affective attitudes, and parenting practice. In the predictions of vegetable preference, self-efficacy and parenting practice had a significant effect in the "pre-action" stage. In the action/maintenance stage, outcome expectation, affective attitudes, and vegetable accessibility at school had significant predictive value. In predicting the vegetable preference for all subjects, 42.8% of the predictive variance was accounted for by affective attitudes, self-efficacy, and vegetable accessibility at school. The study revealed that different determinants affect adolescent vegetable preference in each stage. Self-efficacy and affective attitudes are important determinants affecting

  12. Habitats as complex odour environments: how does plant diversity affect herbivore and parasitoid orientation?

    Directory of Open Access Journals (Sweden)

    Nicole Wäschke

    Full Text Available Plant diversity is known to affect success of host location by pest insects, but its effect on olfactory orientation of non-pest insect species has hardly been addressed. First, we tested in laboratory experiments the hypothesis that non-host plants, which increase odour complexity in habitats, affect the host location ability of herbivores and parasitoids. Furthermore, we recorded field data of plant diversity in addition to herbivore and parasitoid abundance at 77 grassland sites in three different regions in Germany in order to elucidate whether our laboratory results reflect the field situation. As a model system we used the herb Plantago lanceolata, the herbivorous weevil Mecinus pascuorum, and its larval parasitoid Mesopolobus incultus. The laboratory bioassays revealed that both the herbivorous weevil and its larval parasitoid can locate their host plant and host via olfactory cues even in the presence of non-host odour. In a newly established two-circle olfactometer, the weeviĺs capability to detect host plant odour was not affected by odours from non-host plants. However, addition of non-host plant odours to host plant odour enhanced the weeviĺs foraging activity. The parasitoid was attracted by a combination of host plant and host volatiles in both the absence and presence of non-host plant volatiles in a Y-tube olfactometer. In dual choice tests the parasitoid preferred the blend of host plant and host volatiles over its combination with non-host plant volatiles. In the field, no indication was found that high plant diversity disturbs host (plant location by the weevil and its parasitoid. In contrast, plant diversity was positively correlated with weevil abundance, whereas parasitoid abundance was independent of plant diversity. Therefore, we conclude that weevils and parasitoids showed the sensory capacity to successfully cope with complex vegetation odours when searching for hosts.

  13. Human recreation affects spatio-temporal habitat use patterns in red deer (Cervus elaphus.

    Directory of Open Access Journals (Sweden)

    Joy Coppes

    Full Text Available The rapid spread and diversification of outdoor recreation can impact on wildlife in various ways, often leading to the avoidance of disturbed habitats. To mitigate human-wildlife conflicts, spatial zonation schemes can be implemented to separate human activities from key wildlife habitats, e.g., by designating undisturbed wildlife refuges or areas with some level of restriction to human recreation and land use. However, mitigation practice rarely considers temporal differences in human-wildlife interactions. We used GPS telemetry data from 15 red deer to study the seasonal (winter vs. summer and diurnal (day vs. night variation in recreation effects on habitat use in a study region in south-western Germany where a spatial zonation scheme has been established. Our study aimed to determine if recreation infrastructure and spatial zonation affected red deer habitat use and whether these effects varied daily or seasonally. Recreation infrastructure did not affect home range selection in the study area, but strongly determined habitat use within the home range. The spatial zonation scheme was reflected in both of these two levels of habitat selection, with refuges and core areas being more frequently used than the border zones. Habitat use differed significantly between day and night in both seasons. Both summer and winter recreation trails, and nearby foraging habitats, were avoided during day, whereas a positive association was found during night. We conclude that human recreation has an effect on red deer habitat use, and when designing mitigation measures daily and seasonal variation in human-wildlife interactions should be taken into account. We advocate using spatial zonation in conjunction with temporal restrictions (i.e., banning nocturnal recreation activities and the creation of suitable foraging habitats away from recreation trails.

  14. Human recreation affects spatio-temporal habitat use patterns in red deer (Cervus elaphus).

    Science.gov (United States)

    Coppes, Joy; Burghardt, Friedrich; Hagen, Robert; Suchant, Rudi; Braunisch, Veronika

    2017-01-01

    The rapid spread and diversification of outdoor recreation can impact on wildlife in various ways, often leading to the avoidance of disturbed habitats. To mitigate human-wildlife conflicts, spatial zonation schemes can be implemented to separate human activities from key wildlife habitats, e.g., by designating undisturbed wildlife refuges or areas with some level of restriction to human recreation and land use. However, mitigation practice rarely considers temporal differences in human-wildlife interactions. We used GPS telemetry data from 15 red deer to study the seasonal (winter vs. summer) and diurnal (day vs. night) variation in recreation effects on habitat use in a study region in south-western Germany where a spatial zonation scheme has been established. Our study aimed to determine if recreation infrastructure and spatial zonation affected red deer habitat use and whether these effects varied daily or seasonally. Recreation infrastructure did not affect home range selection in the study area, but strongly determined habitat use within the home range. The spatial zonation scheme was reflected in both of these two levels of habitat selection, with refuges and core areas being more frequently used than the border zones. Habitat use differed significantly between day and night in both seasons. Both summer and winter recreation trails, and nearby foraging habitats, were avoided during day, whereas a positive association was found during night. We conclude that human recreation has an effect on red deer habitat use, and when designing mitigation measures daily and seasonal variation in human-wildlife interactions should be taken into account. We advocate using spatial zonation in conjunction with temporal restrictions (i.e., banning nocturnal recreation activities) and the creation of suitable foraging habitats away from recreation trails.

  15. Habitat preferences of birds in a montane forest mosaic in the ...

    African Journals Online (AJOL)

    However, some montane species did not show any clear habitat associations and thus can be viewed as local habitat generalists. This study shows that many restricted-range species (including endangered endemics) are able to live in fragmented landscapes, which cover a substantial part of the Bamenda Highlands.

  16. Updated taxonomic descriptions, iconography, and habitat preferences of Brachypodium distachyon, B. stacei, and B. hybridum (Poaceae

    Directory of Open Access Journals (Sweden)

    Catalán, Pilar

    2016-06-01

    Full Text Available We present an updated morphological revision of the three annual species of the genus Brachypodium (Poaceae: B. distachyon, B. tacei, and B. hybridum, which were recently segregated as independent species from the single-species complex B. distachyon s.l. These three species have been proposed as a model system for grass polyploid speciation, and their genomes have been sequenced. However, despite the increasing number of genomic and population-genetic studies conducted for each of these species, no taxonomic updating has been done on them since their original descriptions. B. stacei, the rarest species of the complex, has a protologue based only on the study of specimens from its type locality in Torrent (Formentera, Spain. In this study we update the taxonomic descriptions of the three species using morphoanatomical data from specimens collected throughout their respective native circum-Mediterranean distributions as well as in other localities where they are non-autochthonous. We also provide icons for each species and information about their habitat preferences and geographic distributions.Presentamos una revisión morfológica actualizada de las tres especies anuales del género Brachypodium (Poaceae, B. distachyon, B. stacei y B. ybridum. Estas dos últimas han sido recientemente segregadas como especies independientes dentro del complejo B. distachyon s.l. Las tres especies han sido propuestas como grupo modelo de especiación poliploide en gramíneas y sus genomas han sido secuenciados. Sin embargo, pese al incremento de estudios genómicos y genético-poblacionales desarrollados en poblaciones de estas especies, no se ha llevado a cabo todavía ninguna actualización taxonómica para las mismas desde que se describieron. El protólogo de B. stacei, la especie más rara del complejo, está basado únicamente en el estudio de especímenes de su localidad clásica en Torrent (Formentera, España. En este estudio actualizamos las

  17. Habitat Preferences and Distribution of the Freshwater Shrimps of the Genus Caridina (Crustacea: Decapoda: Atyidae in Lake Lindu, Sulawesi, Indonesia

    Directory of Open Access Journals (Sweden)

    Annawaty Annawaty

    2016-04-01

    Full Text Available The objectives of this study were to reveal ecological preferences and distribution of all species of Caridina found in Lake Lindu and their catchment area. Specimens from 39 sampling sites were caught using tray net and hand net. There are three species of Caridina found in the lake system, i.e. Caridina linduensis, Caridina kaili and Caridina dali. There is no overlapping distribution among the species. Caridina kaili is a true riverine species and it is never encountered sympatric with C. dali nor C. linduensis. This species is abundant in streams and ditches with moderate flow running water and gravel–cobble substrate. It is mainly spread within streams west to the lake. Both C. dali and C. linduensis can be found in the lake and streams with very slow current to almost stagnant water, muddy sand substrate and associated with roots of water plants and leaf litter. However, C. dali is never occurred together with C. linduensis and they are less abundant compare to C. kaili. Distribution of Caridina spp. in Lake Lindu is probably affected by the temperature of their habitats and the occurrence of introduced fish such as Mozambique tilapia (Oreochromis mossambicus, common carp (Cyprinus carpio, and an alien riceland prawn (Macrobrachium lanchesteri. These introduced and alien species can have the potency to become predators or competitors for the Caridina spp. It is also the first record for M. lanchesteri present in Lake Lindu.

  18. Drawing versus Writing: The Role of Preference in Regulating Short-Term Affect

    Science.gov (United States)

    Drake, Jennifer E.; Hodge, Adeline

    2015-01-01

    In a pilot study we investigated whether the most effective medium for regulating short-term affect depends on one's preference for drawing or writing, and also investigated the emotion regulation strategy (distraction versus expression) spontaneously chosen when drawing and writing. Eighty undergraduates indicated their preference for drawing or…

  19. Threat affects risk preferences in movement decision making

    Directory of Open Access Journals (Sweden)

    Megan K. O'Brien

    2015-06-01

    Full Text Available Emotional states such as sadness, anger, and threat have been shown to play a critical role in decision-making processes. Here we addressed the question of whether risk preferences are influenced by postural threat and whether this influence generalizes across motor tasks. We examined risk attitudes in the context of arm-reaching and whole-body leaning movements, expecting that increased postural threat would lead to proportionally similar changes in risk-sensitivity for each motor task. Healthy young adults were shown a series of two-alternative forced-choice lotteries, where they were asked to choose between a riskier lottery and a safer lottery on each trial. Our lotteries consisted of different monetary rewards and target sizes. Subjects performed each choice task at ground level and atop an elevated platform. In the presence of this postural threat, increased physiological arousal was correlated with decreased movement variability. To determine risk-sensitivity, we quantified the frequency with which a subject chose the riskier lottery and fit lottery responses to a choice model based on cumulative prospect theory. Subjects exhibited idiosyncratic changes in risk-sensitivity between motor tasks and between elevations. However, we found that overweighting of small probabilities increased with postural threat in the whole-body task, indicating a more cautious, risk-averse strategy is ascribed to the possibility of a fall. Subjects were also more risk-seeking in the whole-body movements than in arm-reaching at low elevation; this behavior does not seem to derive from consistent distortions in utility or probability representations but may be explained by subjects’ inaccurate estimation of their own motor variability. Overall, our findings suggest that implicit threat can modify risk attitudes in the motor domain, and the threat may induce risk-aversion in salient movement tasks.

  20. Habitat preference of the endangered Ethiopian walia ibex (Capra walie in the Simien Mountains National Park, Ethiopia

    Directory of Open Access Journals (Sweden)

    Ejigu, D.

    2015-04-01

    Full Text Available Walia ibex (Capra walie is an endangered and endemic species restricted to the Simien Mountains National Park, Ethiopia. Recent expansion of human populations and livestock grazing in the park has prompted concerns that the range and habitats used by walia ibex have changed. We performed observations of walia ibex, conducted pellet counts of walia ibex and livestock, and measured vegetation and classified habitat characteristics at sample points during wet and dry seasons from October 2009 to November 2011. We assessed the effect of habitat characteristics on the presence of pellets of walia ibex, and then used a spatial model to create a predictive map to determine areas of high potential to support walia ibex. Rocky and shrubby habitats were more preferred than herbaceous habitats. Pellet distribution indicated that livestock and walia ibex were not usually found at the same sample point (i.e. 70% of quadrats with walia pellets were without livestock droppings; 73% of quadrats with livestock droppings did not have walia pellets. The best model to describe probability of presence of walia pellets included effects of herb cover (β = 0.047, shrub cover (β = 0.030, distance to cliff (β = –0.001, distance to road (β = 0.001, and altitude (β = 0.004. Walia ibexes have shifted to the eastern, steeper areas of the park, appearing to coincide with the occurrence of more intense, human–related activities in lowlands. Our study shows the complexities of managing areas that support human populations while also serving as a critical habitat for species of conservation concern.

  1. Macro-habitat preferences by the African manatee and crocodiles – ecological and conservation implications

    Directory of Open Access Journals (Sweden)

    L. Luiselli

    2012-07-01

    Full Text Available African manatees (Trichechus senegalensis and crocodiles are threatened species in parts of their range. In West Africa, crocodiles may constitute the main predators for manatees apart from humans. Here, we explore the macro-habitat selection of manatees and two species of crocodiles (West African crocodiles Crocodylus suchus and dwarf crocodile Osteolaemus tetraspis in the Niger Delta (Nigeria, testing the hypotheses that (i manatees may avoid crocodiles in order to minimize risks of predation, and (ii the two crocodile species do compete. The study was carried out between 1994 and 2010 with a suite of different field techniques. We observed that the main macro-habitat types were freshwater rivers and coastal lagoons for manatees, mangroves for West African crocodiles, and rivers and creeks for dwarf crocodiles, with (i the three species differing significantly in terms of their macro-habitat type selection, and (ii significant seasonal influence on habitat selection of each species. Null models for niche overlap showed a significantly lower overlap in macro-habitat type use between manatee and crocodiles, whereas the two crocodiles were relatively similar. Null model analyses did not indicate any competitive interactions between crocodiles. On the other hand, manatees avoided macro-habitats where crocodiles, and especially West African crocodiles, are abundant.

  2. ‘Beauty Is No Quality in Things Themselves’: Epistemic Motivation Affects Implicit Preferences for Art

    Science.gov (United States)

    Chirumbolo, Antonio; Brizi, Ambra; Mastandrea, Stefano; Mannetti, Lucia

    2014-01-01

    Art preferences are affected by a number of subjective factors. This paper reports two studies which investigated whether need for closure shapes implicit art preferences. It was predicted that higher need for closure would negatively affect implicit preferences for abstract art. In study one, 60 participants were tested for dispositional need for closure and then completed an Implicit Association Test (IAT) task to measure their implicit preference for abstract (vs. figurative) paintings. In study two, 54 participants completed the same IAT task. In this experiment need for closure was both manipulated by cognitive load and tapped as a dispositional trait. Results of the studies converged in showing that after controlling for other important individual factors such as participants'expertise and cognitive ability, need for closure, both as a dispositional trait and as a situationally induced motivational state, was negatively associated with implicit preference for abstract art. PMID:25360697

  3. 'Beauty is no quality in things themselves': epistemic motivation affects implicit preferences for art.

    Science.gov (United States)

    Chirumbolo, Antonio; Brizi, Ambra; Mastandrea, Stefano; Mannetti, Lucia

    2014-01-01

    Art preferences are affected by a number of subjective factors. This paper reports two studies which investigated whether need for closure shapes implicit art preferences. It was predicted that higher need for closure would negatively affect implicit preferences for abstract art. In study one, 60 participants were tested for dispositional need for closure and then completed an Implicit Association Test (IAT) task to measure their implicit preference for abstract (vs. figurative) paintings. In study two, 54 participants completed the same IAT task. In this experiment need for closure was both manipulated by cognitive load and tapped as a dispositional trait. Results of the studies converged in showing that after controlling for other important individual factors such as participants'expertise and cognitive ability, need for closure, both as a dispositional trait and as a situationally induced motivational state, was negatively associated with implicit preference for abstract art.

  4. Diversity, habitat preferences, and conservation of the primates of Southern Assam, India: The story of a primate paradise

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    Muhammed Khairujjaman Mazumder

    2014-12-01

    Full Text Available The southern part of Assam in India, a part of the Indo-Burma Biodiversity hotspot, harbors a myriad number of wild plant and animal species. Although there is only one protected area, the Barail Wildlife Sanctuary (Cachar district and a few reserve forests (RFs, there are as many as eight primates inhabiting the region – a diversity hardly found elsewhere. In addition to the protected area and RFs, tea gardens and secondary forests also serve as habitats for animals. The border areas of the region with the states of Manipur, Mizoram, Meghalaya, and Tripura are among the most important abodes of these primates. Unfortunately, these primates are under constant threat from multiple sources. The present article provides an extensive survey of the available literature on the primates of southern Assam with reference to their distribution, habitat preferences, threats, and conservation. Additionally, data from field observations of the author are also presented.

  5. Carcass Type Affects Local Scavenger Guilds More than Habitat Connectivity.

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    Zachary H Olson

    Full Text Available Scavengers and decomposers provide an important ecosystem service by removing carrion from the environment. Scavenging and decomposition are known to be temperature-dependent, but less is known about other factors that might affect carrion removal. We conducted an experiment in which we manipulated combinations of patch connectivity and carcass type, and measured responses by local scavenger guilds along with aspects of carcass depletion. We conducted twelve, 1-month trials in which five raccoon (Procyon lotor, Virginia opossum (Didelphis virginiana, and domestic rabbit (Oryctolagus spp. carcasses (180 trials total were monitored using remote cameras in 21 forest patches in north-central Indiana, USA. Of 143 trials with complete data, we identified fifteen species of vertebrate scavengers divided evenly among mammalian (N = 8 and avian species (N = 7. Fourteen carcasses (9.8% were completely consumed by invertebrates, vertebrates exhibited scavenging behavior at 125 carcasses (87.4%, and four carcasses (2.8% remained unexploited. Among vertebrates, mammals scavenged 106 carcasses, birds scavenged 88 carcasses, and mammals and birds scavenged 69 carcasses. Contrary to our expectations, carcass type affected the assemblage of local scavenger guilds more than patch connectivity. However, neither carcass type nor connectivity explained variation in temporal measures of carcass removal. Interestingly, increasing richness of local vertebrate scavenger guilds contributed moderately to rates of carrion removal (≈6% per species increase in richness. We conclude that scavenger-specific differences in carrion utilization exist among carcass types and that reliable delivery of carrion removal as an ecosystem service may depend on robust vertebrate and invertebrate communities acting synergistically.

  6. Clothing preference affects vitamin D status of young women.

    Science.gov (United States)

    Buyukuslu, Nihal; Esin, Kubra; Hizli, Hilal; Sunal, Nihal; Yigit, Pakize; Garipagaoglu, Muazzez

    2014-08-01

    Vitamin D deficiency is associated with several chronic diseases, which include cardiovascular, autoimmune diseases, and cancer. Several factors such as exposure to sunlight, skin color, dietary habits, and cultural factors affect serum vitamin D levels. We hypothesized that serum vitamin D levels in young women are associated with clothing styles and investigated this via a cross-sectional study that included 100 female students at Istanbul Medipol University. Our study used a questionnaire in order to collect demographic information. Serum calcium, 25-hydroxyvitamin D, alkaline phosphatase, and parathyroid hormone levels were determined via standard laboratory tests. We deployed bioelectrical impedance analysis to measure body composition, and we then determined the body mass index (BMI), waist circumference, and total body fat values. The mean age was 20.9 ± 2.1 years. Subjects' data were divided into 2 groups based on their clothing styles: covered (Muslim style clothing) and uncovered. Muslim style clothing, which covers the whole body but leaves the face and hands exposed, was worn by 40.0% of the undergraduate students. The mean BMI (in kilograms per meter squared) of the subjects was 23.0 ± 3.6. The BMI value for the covered students was 24.0 ± 4.0, and that for the uncovered students was 22.3 ± 3.1. Of the subjects, 28.0% had a BMI of at least 25 kg/m(2) (overweight). Serum 25-hydroxyvitamin D (in nanograms per milliliter), parathyroid hormone (in picograms per milliliter), alkaline phosphatase (in units per liter), and calcium levels (in milligrams per deciliter) were 21.1 ± 6.7, 27.5 ± 9.2, 65.9 ± 10.9, and 9.0 ± 0.2 for covered students, respectively, and 29.7 ± 3.1, 24.3 ± 6.1, 62.8 ± 13.2, and 9.0 ± 0.4, respectively, for uncovered students. The prevalence of vitamin D deficiencies was 55.0% for covered and 20.0% for uncovered students. The vitamin D status was found to be statistically significant and had a negative correlation with the

  7. Physical features of visual images affect macaque monkey’s preference for these images

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    Shintaro Funahashi

    2016-11-01

    Full Text Available Animals exhibit different degrees of preference toward various visual stimuli. In addition, it has been shown that strongly preferred stimuli can often act as a reward. The aim of the present study was to determine what features determine the strength of the preference for visual stimuli in order to examine neural mechanisms of preference judgment. We used 50 color photographs obtained from the Flickr Material Database as original stimuli. Four macaque monkeys performed a simple choice task, in which 2 stimuli selected randomly from among the 50 stimuli were simultaneously presented on a monitor and monkeys were required to choose either stimulus by eye movements. We considered that the monkeys preferred the chosen stimulus if it continued to look at the stimulus for an additional 6 s and calculated a choice ratio for each stimulus. Each monkey exhibited a different choice ratio for each of the original 50 stimuli. They tended to select clear, colorful, and in-focus stimuli. Complexity and clarity were stronger determinants of preference than colorfulness. Images that included greater amounts of spatial frequency components were selected more frequently. These results indicate that particular physical features of the stimulus can affect the strength of a monkey’s preference and that the complexity, clarity, and colorfulness of the stimulus are important determinants of this preference. Neurophysiological studies would be needed to examine whether these features of visual stimuli produce more activation in neurons that participate in this preference judgment.

  8. Physical Features of Visual Images Affect Macaque Monkey's Preference for These Images.

    Science.gov (United States)

    Funahashi, Shintaro

    2016-01-01

    Animals exhibit different degrees of preference toward various visual stimuli. In addition, it has been shown that strongly preferred stimuli can often act as a reward. The aim of the present study was to determine what features determine the strength of the preference for visual stimuli in order to examine neural mechanisms of preference judgment. We used 50 color photographs obtained from the Flickr Material Database (FMD) as original stimuli. Four macaque monkeys performed a simple choice task, in which two stimuli selected randomly from among the 50 stimuli were simultaneously presented on a monitor and monkeys were required to choose either stimulus by eye movements. We considered that the monkeys preferred the chosen stimulus if it continued to look at the stimulus for an additional 6 s and calculated a choice ratio for each stimulus. Each monkey exhibited a different choice ratio for each of the original 50 stimuli. They tended to select clear, colorful and in-focus stimuli. Complexity and clarity were stronger determinants of preference than colorfulness. Images that included greater amounts of spatial frequency components were selected more frequently. These results indicate that particular physical features of the stimulus can affect the strength of a monkey's preference and that the complexity, clarity and colorfulness of the stimulus are important determinants of this preference. Neurophysiological studies would be needed to examine whether these features of visual stimuli produce more activation in neurons that participate in this preference judgment.

  9. Physical Features of Visual Images Affect Macaque Monkey’s Preference for These Images

    Science.gov (United States)

    Funahashi, Shintaro

    2016-01-01

    Animals exhibit different degrees of preference toward various visual stimuli. In addition, it has been shown that strongly preferred stimuli can often act as a reward. The aim of the present study was to determine what features determine the strength of the preference for visual stimuli in order to examine neural mechanisms of preference judgment. We used 50 color photographs obtained from the Flickr Material Database (FMD) as original stimuli. Four macaque monkeys performed a simple choice task, in which two stimuli selected randomly from among the 50 stimuli were simultaneously presented on a monitor and monkeys were required to choose either stimulus by eye movements. We considered that the monkeys preferred the chosen stimulus if it continued to look at the stimulus for an additional 6 s and calculated a choice ratio for each stimulus. Each monkey exhibited a different choice ratio for each of the original 50 stimuli. They tended to select clear, colorful and in-focus stimuli. Complexity and clarity were stronger determinants of preference than colorfulness. Images that included greater amounts of spatial frequency components were selected more frequently. These results indicate that particular physical features of the stimulus can affect the strength of a monkey’s preference and that the complexity, clarity and colorfulness of the stimulus are important determinants of this preference. Neurophysiological studies would be needed to examine whether these features of visual stimuli produce more activation in neurons that participate in this preference judgment. PMID:27853424

  10. Do mature forest birds prefer early-successional habitat during the post-fledging period?

    Science.gov (United States)

    Carlin C. Chandler; David I. King; Richard B. Chandler

    2012-01-01

    Recent studies have highlighted the importance of the post-fledging period to bird populations, suggesting that the importance of this portion of the life cycle is equal to or greater than the nesting period. Nevertheless, few studies have compared abundance of forest nesting species between mature forest and early-successional habitats while controlling for...

  11. Coexistence and Habitat Preference of Two Honeyeaters and a Sunbird on Lombok, Indonesia

    DEFF Research Database (Denmark)

    Carstensen, Daniel Wisbech; Sweeny, Redmond; Ehlers, Bodil

    2011-01-01

    and aggressive interactions at rich and poor nectar resources in different habitats (forest and open areas) along an altitudinal gradient (800–1600masl). The two honeyeaters were partially segregated by altitude. In the zone of overlap, Lichmera limbata dominated the richest forest resources, while Lichmera...

  12. High Resolution Spatial Analysis of Habitat Preference of Aedes Albopictus (Diptera Culicidae) in an Urban Environment

    NARCIS (Netherlands)

    Cianci, Daniela; Hartemink, Nienke; Zeimes, Caroline B; Vanwambeke, Sophie O; Ienco, Annamaria; Caputo, Beniamino

    2015-01-01

    Over the past decades, the Asian tiger mosquito (Aedes albopictus (Skuse, 1895)) has emerged in many countries, and it has colonized new environments, including urban areas. The species is a nuisance and a potential vector of several human pathogens, and a better understanding of the habitat

  13. High Resolution Spatial Analysis of Habitat Preference of Aedes Albopictus (Diptera: Culicidae) in an Urban Environment

    NARCIS (Netherlands)

    Cianci, D.; Hartemink, N.; Zeimes, C.B.; Vanwambeke, S.O.; Ienco, A.; Caputo, B.

    2015-01-01

    Over the past decades, the Asian tiger mosquito (Aedes albopictus (Skuse, 1895)) has emerged in many countries, and it has colonized new environments, including urban areas. The species is a nuisance and a potential vector of several human pathogens, and a better understanding of the habitat

  14. Habitat quality affects early physiology and subsequent neuromotor development of juvenile black-capped chickadees.

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    Thibault Grava

    Full Text Available In songbirds, the ability to learn and render the species-specific song is influenced by the development of both the song nuclei in the brain and the syrinx (bird's vocal apparatus early in the bird's life. In black-capped chickadees (Poecille atricapillus, habitat quality is known to affect song structure, with birds in high-quality habitat (mature forest having a higher song consistency than birds in low-quality habitat (young forest. Although this difference is suspected to stem from differences in development, the developmental status of juvenile birds in either habitat remains unexplored. In this study, we used ptilochronology and feather corticosterone to compare the conditional state of juvenile chickadees in young and mature forest during two distinct periods of song learning - the sensory phase, which occurs prior to settlement, and the sensorimotor phase, which occurs post-settlement. A sample of juvenile males was captured and euthanized several weeks prior to their first breeding season to compare the development of song center nuclei and syrinx in both habitats. The corticosterone levels of natally-grown feathers were greater among birds that settled in mature than young forests - as these feathers were grown pre-settlement, they reflect differences in physiology during the sensory phase. This difference in conditional state is reflected by differences in syrinx and song center nuclei development later during the sensorimotor phase - birds in young forest have smaller syrinx, and moderately-larger RA, than birds in mature forest. Those differences could be responsible for the difference in consistency in song structure observed across habitats. The difference in physiological state across habitats, combined with potential compounding effect of differences in winter resources between habitats, could influence the difference in syrinx and neural development seen in juvenile males during the early spring, and influence the male

  15. Habitat edges affect patterns of artificial nest predation along a wetland-meadow boundary

    Science.gov (United States)

    Suvorov, Petr; Svobodová, Jana; Albrecht, Tomáš

    2014-08-01

    Wetland habitats are among the most endangered ecosystems in the world. However, little is known about factors affecting the nesting success of birds in pristine grass-dominated wetlands. During three breeding periods we conducted an experiment with artificial ground nests to test two basic mechanisms (the matrix and ecotonal effects) that may result in edge effects on nest predation in grass-dominated wetland habitats. Whereas the matrix effect model supposes that predator penetrate from habitat of higher predator density to habitat of lower predator density, thus causing an edge effect in the latter, according to the ecotonal effect model predators preferentially use edge habitats over habitat interiors. In addition, we tested the edge effect in a wetland habitat using artificial shrub nests that simulated the real nests of small open-cup nesting passerines. In our study area, the lowest predation rates on ground nests were found in wetland interiors and were substantially higher along the edges of both wetland and meadow habitat. However, predation was not significantly different between meadow and wetland interiors, indicating that both mechanisms can be responsible for the edge effect in wetland edges. An increased predation rate along wetland edges was also observed for shrub nests, and resembled the predation pattern of real shrub nests in the same study area. Though we are not able to distinguish between the two mechanisms of the edge effect found, our results demonstrate that species nesting in wetland edges bordering arable land may be exposed to higher predation. Therefore, an increase in the size of wetland patches that would lead to a reduced proportion of edge areas might be a suitable management practice to protect wetland bird species in cultural European landscapes.

  16. Cross-modal preference acquisition: Evaluative conditioning of pictures by affective olfactory and auditory cues.

    NARCIS (Netherlands)

    van Reekum, C.M.; van den Berg, H.; Frijda, N.H.

    1999-01-01

    A cross-modal paradigm was chosen to test the hypothesis that affective olfactory and auditory cues paired with neutral visual stimuli bearing no resemblance or logical connection to the affective cues can evoke preference shifts in those stimuli. Neutral visual stimuli of abstract paintings were

  17. [Relative abundance, population structure, habitat preferences and activity patterns of Tapirus bairdii (Perissodactyla: Tapiridae), in Chimalapas forest, Oaxaca, Mexico].

    Science.gov (United States)

    Lira-Torres, Iván; Briones-Salas, Miguel; Sánchez-Rojas, Gerardo

    2014-12-01

    Baird's tapir (Tapirus bairdii) is endangered primarily because of habitat loss and fragmentation, and overhunting throughout its distribution range. One of the priority land areas for the conservation of this species is the Northern part of its range in the Chimalapas forest, Oaxaca. The aim of this research was to determine the relative abundance, population struc- ture, habitat preferences and activity patterns of Baird's tapir (Tapirus bairdii) in the Chimalapas forest, Oaxaca, Mexico, through the non-invasive technique of camera-trap sampling. A total of five sampling sessions were undertaken among 2009-2013, and used a total of 30 camera-traps in each period. The determinant factor of the sampling design was the hunting between two study areas. A total sampling effort of 9000 trap-days allowed to estimate an index of relative abundance (IRA) of 6.77 tapir photographs/1,000 trap-days (n = 61). IRA varied significantly between sampling stations (Mann-Whitney, p habitats showed higher photo frequency than expected from random (χ2, p < 0.5). Considering population structure, a 95.08% of adult animals was obtained in photographic records (n = 58). Three types of activity pattern were observed, with more nocturnal records (88.33%; Kruskal-Wallis, p < 0.05). The Chimalapas forest appears to be the second most important terrestrial priority ecoregion, just after the Mayan Forest (Campeche, Chiapas, Quintana Roo), for the conservation of tapir populations, not only for Mexico but also for Central America.

  18. Poor transferability of species distribution models for a pelagic predator, the grey petrel, indicates contrasting habitat preferences across ocean basins.

    Directory of Open Access Journals (Sweden)

    Leigh G Torres

    Full Text Available Species distribution models (SDMs are increasingly applied in conservation management to predict suitable habitat for poorly known populations. High predictive performance of SDMs is evident in validations performed within the model calibration area (interpolation, but few studies have assessed SDM transferability to novel areas (extrapolation, particularly across large spatial scales or pelagic ecosystems. We performed rigorous SDM validation tests on distribution data from three populations of a long-ranging marine predator, the grey petrel Procellaria cinerea, to assess model transferability across the Southern Hemisphere (25-65°S. Oceanographic data were combined with tracks of grey petrels from two remote sub-Antarctic islands (Antipodes and Kerguelen using boosted regression trees to generate three SDMs: one for each island population, and a combined model. The predictive performance of these models was assessed using withheld tracking data from within the model calibration areas (interpolation, and from a third population, Marion Island (extrapolation. Predictive performance was assessed using k-fold cross validation and point biserial correlation. The two population-specific SDMs included the same predictor variables and suggested birds responded to the same broad-scale oceanographic influences. However, all model validation tests, including of the combined model, determined strong interpolation but weak extrapolation capabilities. These results indicate that habitat use reflects both its availability and bird preferences, such that the realized distribution patterns differ for each population. The spatial predictions by the three SDMs were compared with tracking data and fishing effort to demonstrate the conservation pitfalls of extrapolating SDMs outside calibration regions. This exercise revealed that SDM predictions would have led to an underestimate of overlap with fishing effort and potentially misinformed bycatch mitigation

  19. Food and oviposition preferences of Diabrotica v. virgifera in multiple-choice crop habitat situations

    Directory of Open Access Journals (Sweden)

    S. Toepfer

    2013-12-01

    Full Text Available Multiple-choice field cage experiments were used to clarify to what extent adults of one of the most destructive maize pest, the western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae, use non-maize crop habitats as alternative food sources or oviposition sites in situations of non-maize/maize rotations. Between 2009 and 2012, D. v. virgifera adults were released into large walk-in gauze cages each containing different combinations of three out of ten crop habitats in southern Hungary. Maize was planted the following year, allowing the development of larvae and the emergence of adults that were then captured in small cages. Results indicate that the polyphagous nature of D. v. virgifera adults is, under field situations, not as important as often stated. The generational, i.e. annual growth rate of populations, an indicator of crop habitat quality for food and oviposition, appeared highest when the entire multiple-choice cage had been planted with maize (populations nearly doubled. When Sudan grass and Sorghum millet were combined with maize, a slight population grow was still possible. When maize was combined with any other habitat type, populations decreased from year to year, suggesting that non-maize crop habitats are suboptimal, and their role as alternative food sources under field conditions might be overestimated. As for oviposition, also maize was found to be the most attractive. Of medium proportional attractiveness for oviposition were Sorghum millet, Sudan grass, and ploughed bare soil. Harvested and grubbed winter rape with some regrowth, harvested and grubbed or not grubbed winter-wheat with regrowth, and potatoes were comparatively less attractive for oviposition, suggesting that regrowth or volunteer crops play no role for D. v. virgifera. Least suitable were harvested and grubbed peas and soybean. The presence of particular weed species had no detectable influence on oviposition, but vegetation

  20. Sea-ice habitat preference of the Pacific walrus (Odobenus rosmarus divergens) in the Bering Sea: A multiscaled approach

    Science.gov (United States)

    Sacco, Alexander Edward

    fall and spring subsistence hunts, and sea-ice characteristics that walruses typically occupy. These observations are compared with ice-patch preferences analyzed from aerial imagery. Floe size was found to agree with remotely-sensed ice-patch analysis results, while floe shape was not distinguishable to informants during the hunt. Ice-patch arrangement descriptors concentration and density generally agreed with ice-patch analysis results. Results include possible preference of ice-patch descriptors at the ice-patch scale and fragmented pack ice preference at the seascape scale. Traditional knowledge suggests large ice ridges are preferential sea-ice features at the ice-patch scale, which are rapidly becoming less common during the fall and spring migration of sea ice through the Bering Sea. Traditional knowledge, combined with a scientific analysis and field work to study species habitat preferences and, ultimately, habitat partitioning, can stem from these results. Future work includes increased sophistication of the synthetic aperture radar classification algorithm, experimentation with various spatial scales to determine the optimal scale for walrus' life-cycle events, and incorporation of further traditional knowledge to investigate and interface cross-cultural sea-ice observations, knowledge and science to determine sea ice importance to marine mammals in a changing Arctic.

  1. Floral resources and habitat affect the composition of hummingbirds at the local scale in tropical mountaintops

    Directory of Open Access Journals (Sweden)

    LC Rodrigues

    Full Text Available Hummingbird communities tend to respond to variation in resources, having a positive relationship between abundance and diversity of food resources and the abundance and/or diversity of hummingbirds. Here we examined the influence of floral resource availability, as well as seasonality and type of habitat on the composition of hummingbird species. The study was carried out in two habitats of eastern Brazilian mountaintops. A gradient representative of the structure of hummingbird community, based on species composition, was obtained by the ordination of samples using the method of non-metric multidimensional scaling. The composition of hummingbird species was influenced by the type of habitat and floral resource availability, but not by seasonality. Hummingbird communities differ between habitats mainly due to the relative abundance of hummingbird species. The variation in composition of hummingbird species with the variation in floral resource availability may be related to differences in feeding habits of hummingbirds. Hummingbird species with the longest bills visited higher proportions of ornithophilous species, while hummingbirds with shorter bills visited higher proportions of non-ornithophilous species. The results demonstrate that at local-scale the composition of hummingbird species is affected by the type of habitat and floral resources availability, but not by seasonality.

  2. Floral resources and habitat affect the composition of hummingbirds at the local scale in tropical mountaintops.

    Science.gov (United States)

    Rodrigues, L C; Rodrigues, M

    2015-01-01

    Hummingbird communities tend to respond to variation in resources, having a positive relationship between abundance and diversity of food resources and the abundance and/or diversity of hummingbirds. Here we examined the influence of floral resource availability, as well as seasonality and type of habitat on the composition of hummingbird species. The study was carried out in two habitats of eastern Brazilian mountaintops. A gradient representative of the structure of hummingbird community, based on species composition, was obtained by the ordination of samples using the method of non-metric multidimensional scaling. The composition of hummingbird species was influenced by the type of habitat and floral resource availability, but not by seasonality. Hummingbird communities differ between habitats mainly due to the relative abundance of hummingbird species. The variation in composition of hummingbird species with the variation in floral resource availability may be related to differences in feeding habits of hummingbirds. Hummingbird species with the longest bills visited higher proportions of ornithophilous species, while hummingbirds with shorter bills visited higher proportions of non-ornithophilous species. The results demonstrate that at local-scale the composition of hummingbird species is affected by the type of habitat and floral resources availability, but not by seasonality.

  3. Rates of evolution in stress-related genes are associated with habitat preference in two Cardamine lineages

    Directory of Open Access Journals (Sweden)

    Ometto Lino

    2012-01-01

    Full Text Available Abstract Background Elucidating the selective and neutral forces underlying molecular evolution is fundamental to understanding the genetic basis of adaptation. Plants have evolved a suite of adaptive responses to cope with variable environmental conditions, but relatively little is known about which genes are involved in such responses. Here we studied molecular evolution on a genome-wide scale in two species of Cardamine with distinct habitat preferences: C. resedifolia, found at high altitudes, and C. impatiens, found at low altitudes. Our analyses focussed on genes that are involved in stress responses to two factors that differentiate the high- and low-altitude habitats, namely temperature and irradiation. Results High-throughput sequencing was used to obtain gene sequences from C. resedifolia and C. impatiens. Using the available A. thaliana gene sequences and annotation, we identified nearly 3,000 triplets of putative orthologues, including genes involved in cold response, photosynthesis or in general stress responses. By comparing estimated rates of molecular substitution, codon usage, and gene expression in these species with those of Arabidopsis, we were able to evaluate the role of positive and relaxed selection in driving the evolution of Cardamine genes. Our analyses revealed a statistically significant higher rate of molecular substitution in C. resedifolia than in C. impatiens, compatible with more efficient positive selection in the former. Conversely, the genome-wide level of selective pressure is compatible with more relaxed selection in C. impatiens. Moreover, levels of selective pressure were heterogeneous between functional classes and between species, with cold responsive genes evolving particularly fast in C. resedifolia, but not in C. impatiens. Conclusions Overall, our comparative genomic analyses revealed that differences in effective population size might contribute to the differences in the rate of protein evolution

  4. Noise affects the shape of female preference functions for acoustic signals.

    Science.gov (United States)

    Reichert, Michael S; Ronacher, Bernhard

    2015-02-01

    The shape of female mate preference functions influences the speed and direction of sexual signal evolution. However, the expression of female preferences is modulated by interactions between environmental conditions and the female's sensory processing system. Noise is an especially relevant environmental condition because it interferes directly with the neural processing of signals. Although noise is therefore likely a significant force in the evolution of communication systems, little is known about its effects on preference function shape. In the grasshopper Chorthippus biguttulus, female preferences for male calling song characteristics are likely to be affected by noise because its auditory system is sensitive to fine temporal details of songs. We measured female preference functions for variation in male song characteristics in several levels of masking noise and found strong effects of noise on preference function shape. The overall responsiveness to signals in noise generally decreased. Preference strength increased for some signal characteristics and decreased for others, largely corresponding to expectations based on neurophysiological studies of acoustic signal processing. These results suggest that different signal characteristics will be favored under different noise conditions, and thus that signal evolution may proceed differently depending on the extent and temporal patterning of environmental noise. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  5. Fertility affects asymmetry detection not symmetry preference in assessments of 3D facial attractiveness.

    Science.gov (United States)

    Lewis, Michael B

    2017-09-01

    Consistent with theories from evolutionary psychology, facial symmetry correlates with attractiveness. Further, the preference for symmetrical faces appears to be affected by fertility in women. One limitation of previous research is that faces are often symmetrically lit front-views and so symmetry can be assessed using 2D pictorial information. Another limitation is that two-alternative-forced-choice (2afc) tasks are often used to assess symmetry preference and these cannot distinguish between differences in preference for symmetry and differences in ability of asymmetry detection. The current study used three tasks to assess the effects of facial symmetry: attractiveness ratings, 2afc preference and asymmetry detection. To break the link between 2D pictorial symmetry and facial symmetry, 3D computer generated heads were used with asymmetrical lighting and yaw rotation. Facial symmetry correlated with attractiveness even under more naturalistic viewing conditions. Path analysis indicates that the link between fertility and 2afc symmetry preference is mediated by asymmetry detection not increased preference for symmetry. The existing literature on symmetry preference and attractiveness is reinterpreted in terms of differences in asymmetry detection. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Aquatic insects dealing with dehydration: do desiccation resistance traits differ in species with contrasting habitat preferences?

    Science.gov (United States)

    Pallarés, Susana; Velasco, Josefa; Millán, Andrés; Bilton, David T; Arribas, Paula

    2016-01-01

    Desiccation resistance shapes the distribution of terrestrial insects at multiple spatial scales. However, responses to drying stress have been poorly studied in aquatic groups, despite their potential role in constraining their distribution and diversification, particularly in arid and semi-arid regions. We examined desiccation resistance in adults of four congeneric water beetle species (Enochrus, family Hydrophilidae) with contrasting habitat specificity (lentic vs. lotic systems and different salinity optima from fresh- to hypersaline waters). We measured survival, recovery capacity and key traits related to desiccation resistance (fresh mass, % water content, % cuticle content and water loss rate) under controlled exposure to desiccation, and explored their variability within and between species. Meso- and hypersaline species were more resistant to desiccation than freshwater and hyposaline ones, showing significantly lower water loss rates and higher water content. No clear patterns in desiccation resistance traits were observed between lotic and lentic species. Intraspecifically, water loss rate was positively related to specimens' initial % water content, but not to fresh mass or % cuticle content, suggesting that the dynamic mechanism controlling water loss is mainly regulated by the amount of body water available. Our results support previous hypotheses suggesting that the evolution of desiccation resistance is associated with the colonization of saline habitats by aquatic beetles. The interespecific patterns observed in Enochrus also suggest that freshwater species may be more vulnerable than saline ones to drought intensification expected under climate change in semi-arid regions such as the Mediterranean Basin.

  7. Aquatic insects dealing with dehydration: do desiccation resistance traits differ in species with contrasting habitat preferences?

    Directory of Open Access Journals (Sweden)

    Susana Pallarés

    2016-08-01

    Full Text Available Background Desiccation resistance shapes the distribution of terrestrial insects at multiple spatial scales. However, responses to drying stress have been poorly studied in aquatic groups, despite their potential role in constraining their distribution and diversification, particularly in arid and semi-arid regions. Methods We examined desiccation resistance in adults of four congeneric water beetle species (Enochrus, family Hydrophilidae with contrasting habitat specificity (lentic vs. lotic systems and different salinity optima from fresh- to hypersaline waters. We measured survival, recovery capacity and key traits related to desiccation resistance (fresh mass, % water content, % cuticle content and water loss rate under controlled exposure to desiccation, and explored their variability within and between species. Results Meso- and hypersaline species were more resistant to desiccation than freshwater and hyposaline ones, showing significantly lower water loss rates and higher water content. No clear patterns in desiccation resistance traits were observed between lotic and lentic species. Intraspecifically, water loss rate was positively related to specimens’ initial % water content, but not to fresh mass or % cuticle content, suggesting that the dynamic mechanism controlling water loss is mainly regulated by the amount of body water available. Discussion Our results support previous hypotheses suggesting that the evolution of desiccation resistance is associated with the colonization of saline habitats by aquatic beetles. The interespecific patterns observed in Enochrus also suggest that freshwater species may be more vulnerable than saline ones to drought intensification expected under climate change in semi-arid regions such as the Mediterranean Basin.

  8. Habitat Preferences, Distribution Pattern, and Root Weight Estimation of Pasak Bumi (Eurycoma longifolia Jack.

    Directory of Open Access Journals (Sweden)

    Siti Masitoh Kartikawati

    2014-04-01

    Full Text Available Pasak bumi (Eurycoma longifolia Jack is one of non timber forest products with “indeterminate” conservation status and commercially traded in West Kalimantan. The research objective was to determine the potential of pasak bumi root per hectare and its ecological condition under natural habitat. Root weight of E. longifolia Jack was estimated using simple linear regression and exponential equation with stem diameter and height as independent variables. The results showed that the individual number of the population was 114 with the majority in seedling stage with 71 individuals (62.28%. The distribution was found in clumped pattern. Conditions of the habitat could be described as follows: daily average temperature of 25.6oC, daily average relative humidity of 73.6%, light intensity of 0.9 klx, and red-yellow podsolic soil with texture ranged from clay to sandy clay. The selected estimator model for E. longifolia Jack root weight used exponential equation with stem height as independent variable using the equation of Y= 21.99T0,010 and determination coefficient of 0.97. After height variable was added, the potential of E. longifolia Jack minimum root weight that could be harvested per hectare was 0.33 kg.

  9. Habitat variation and wing coloration affect wing shape evolution in dragonflies.

    Science.gov (United States)

    Outomuro, D; Dijkstra, K-D B; Johansson, F

    2013-09-01

    Habitats are spatially and temporally variable, and organisms must be able to track these changes. One potential mechanism for this is dispersal by flight. Therefore, we would expect flying animals to show adaptations in wing shape related to habitat variation. In this work, we explored variation in wing shape in relation to preferred water body (flowing water or standing water with tolerance for temporary conditions) and landscape (forested to open) using 32 species of dragonflies of the genus Trithemis (80% of the known species). We included a potential source of variation linked to sexual selection: the extent of wing coloration on hindwings. We used geometric morphometric methods for studying wing shape. We also explored the phenotypic correlation of wing shape between the sexes. We found that wing shape showed a phylogenetic structure and therefore also ran phylogenetic independent contrasts. After correcting for the phylogenetic effects, we found (i) no significant effect of water body on wing shape; (ii) male forewings and female hindwings differed with regard to landscape, being progressively broader from forested to open habitats; (iii) hindwings showed a wider base in wings with more coloration, especially in males; and (iv) evidence for phenotypic correlation of wing shape between the sexes across species. Hence, our results suggest that natural and sexual selection are acting partially independently on fore- and hindwings and with differences between the sexes, despite evidence for phenotypic correlation of wing shape between males and females. © 2013 The Authors. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

  10. Two widespread green Neottia species (Orchidaceae) show mycorrhizal preference for Sebacinales in various habitats and ontogenetic stages.

    Science.gov (United States)

    Těšitelová, Tamara; Kotilínek, Milan; Jersáková, Jana; Joly, François-Xavier; Košnar, Jiří; Tatarenko, Irina; Selosse, Marc-André

    2015-03-01

    Plant dependence on fungal carbon (mycoheterotrophy) evolved repeatedly. In orchids, it is connected with a mycorrhizal shift from rhizoctonia to ectomycorrhizal fungi and a high natural (13)C and (15)N abundance. Some green relatives of mycoheterotrophic species show identical trends, but most of these remain unstudied, blurring our understanding of evolution to mycoheterotrophy. We analysed mycorrhizal associations and (13)C and (15)N biomass content in two green species, Neottia ovata and N. cordata (tribe Neottieae), from a genus comprising green and nongreen (mycoheterotrophic) species. Our study covered 41 European sites, including different meadow and forest habitats and orchid developmental stages. Fungal ITS barcoding and electron microscopy showed that both Neottia species associated mainly with nonectomycorrhizal Sebacinales Clade B, a group of rhizoctonia symbionts of green orchids, regardless of the habitat or growth stage. Few additional rhizoctonias from Ceratobasidiaceae and Tulasnellaceae, and ectomycorrhizal fungi were detected. Isotope abundances did not detect carbon gain from the ectomycorrhizal fungi, suggesting a usual nutrition of rhizoctonia-associated green orchids. Considering associations of related partially or fully mycoheterotrophic species such as Neottia camtschatea or N. nidus-avis with ectomycorrhizal Sebacinales Clade A, we propose that the genus Neottia displays a mycorrhizal preference for Sebacinales and that the association with nonectomycorrhizal Sebacinales Clade B is likely ancestral. Such a change in preference for mycorrhizal associates differing in ecology within the same fungal taxon is rare among orchids. Moreover, the existence of rhizoctonia-associated Neottia spp. challenges the shift to ectomycorrhizal fungi as an ancestral pre-adaptation to mycoheterotrophy in the whole Neottieae. © 2015 John Wiley & Sons Ltd.

  11. Ranging behaviour and habitat preferences of the Martial Eagle: Implications for the conservation of a declining apex predator.

    Science.gov (United States)

    van Eeden, Rowen; Whitfield, D Philip; Botha, Andre; Amar, Arjun

    2017-01-01

    Understanding the ranging behaviours of species can be helpful in effective conservation planning. However, for many species that are rare, occur at low densities, or occupy challenging environments, this information is often lacking. The Martial Eagle (Polemaetus bellicosus) is a low density apex predator declining in both non-protected and protected areas in southern Africa, and little is known about its ranging behaviour. We use GPS tags fitted to Martial Eagles (n = 8) in Kruger National Park (KNP), South Africa to describe their ranging behaviour and habitat preference. This represents the first time that such movements have been quantified in adult Martial Eagles. Territorial eagles (n = 6) held home ranges averaging ca. 108 km2. Home range estimates were similar to expectations based on inter-nest distances, and these large home range sizes could constrain the carrying capacity of even the largest conservation areas. Two tagged individuals classed as adults on plumage apparently did not hold a territory, and accordingly ranged more widely (ca. 44,000 km2), and beyond KNP boundaries as floaters. Another two territorial individuals abandoned their territories and joined the 'floater' population, and so ranged widely after leaving their territories. These unexpected movements after territory abandonment could indicate underlying environmental degradation. Relatively high mortality of these wide-ranging 'floaters' due to anthropogenic causes (three of four) raises further concerns for the species' persistence. Habitat preference models suggested Martial Eagles used areas preferentially that were closer to rivers, had higher tree cover, and were classed as dense bush rather than open bush or grassland. These results can be used by conservation managers to help guide actions to preserve breeding Martial Eagles at an appropriate spatial scale.

  12. Factors affecting seasonal habitat use, and predicted range of two tropical deer in Indonesian rainforest

    Science.gov (United States)

    Rahman, Dede Aulia; Gonzalez, Georges; Haryono, Mohammad; Muhtarom, Aom; Firdaus, Asep Yayus; Aulagnier, Stéphane

    2017-07-01

    There is an urgent recognized need for conservation of tropical forest deer. In order to identify some environmental factors affecting conservation, we analyzed the seasonal habitat use of two Indonesian deer species, Axis kuhlii in Bawean Island and Muntiacus muntjak in south-western Java Island, in response to several physical, climatic, biological, and anthropogenic variables. Camera trapping was performed in different habitat types during both wet and dry season to record these elusive species. The highest number of photographs was recorded in secondary forest and during the dry season for both Bawean deer and red muntjac. In models, anthropogenic and climatic variables were the main predictors of habitat use. Distances to cultivated area and to settlement were the most important for A. kuhlii in the dry season. Distances to cultivated area and annual rainfall were significant for M. muntjak in both seasons. Then we modelled their predictive range using Maximum entropy modelling (Maxent). We concluded that forest landscape is the fundamental scale for deer management, and that secondary forests are potentially important landscape elements for deer conservation. Important areas for conservation were identified accounting of habitat transformation in both study areas.

  13. Delta-9-tetrahydrocannabinol (THC) history fails to affect THC's ability to induce place preferences in rats.

    Science.gov (United States)

    Hempel, Briana J; Wakeford, Alison G P; Clasen, Matthew M; Friar, Mary A; Riley, Anthony L

    2016-05-01

    In pre-clinical models of marijuana abuse, there is relatively limited evidence of delta-9-tetrahydrocannabinol's (THC) rewarding effects, as indexed by its general inability to induce a place preference. One explanation for this failure is that its rewarding effects are masked by its concurrently occurring aversive properties. Consistent with this explanation, THC pre-exposure, which presumably weakens its aversive effects, induces place preferences. Such demonstrations are limited to mice and given reported species differences in THC reactivity, it is unknown to what extent the same shift in affective properties would be evident in rats. The present experiment examined the effect of THC history (3.2mg/kg) on THC (1 or 3.2mg/kg) induced place preference conditioning in rats. An assessment of taste avoidance was also run to independently characterize THC's aversive effects and any changes that occurred with drug pre-exposure. These assessments were made in a combined taste avoidance/place preference procedure in which a novel saccharin solution and environment were paired with THC (0, 1 or 3.2mg/kg). THC did not induce place conditioning, and a history of THC was ineffective in increasing THC's ability to do so, despite the fact that this same history significantly attenuated the aversive effects of THC. The failure of THC to consistently induce place preferences has been argued to be a function of its concurrently occurring aversive effects masking its rewarding properties. The fact that pre-exposure to THC significantly reduced its aversive effects without impacting THC's ability to induce place preferences suggests that THC has weak rewarding effects and/or its residual aversive affects may have still masked its rewarding properties. An important area for future work will be characterizing under what conditions THC is rewarding and whether its overall reinforcing effects are impacted by the relationship between its affective properties. Copyright © 2016

  14. Spatial Models of Abundance and Habitat Preferences of Commerson's and Peale's Dolphin in Southern Patagonian Waters.

    Science.gov (United States)

    Dellabianca, Natalia A; Pierce, Graham J; Raya Rey, Andrea; Scioscia, Gabriela; Miller, David L; Torres, Mónica A; Paso Viola, M Natalia; Goodall, R Natalie P; Schiavini, Adrián C M

    2016-01-01

    Commerson's dolphins (Cephalorhynchus c. commersonii) and Peale's dolphins (Lagenorhynchus australis) are two of the most common species of cetaceans in the coastal waters of southwest South Atlantic Ocean. Both species are listed as Data Deficient by the IUCN, mainly due to the lack of information about population sizes and trends. The goal of this study was to build spatially explicit models for the abundance of both species in relation to environmental variables using data collected during eight scientific cruises along the Patagonian shelf. Spatial models were constructed using generalized additive models. In total, 88 schools (212 individuals) of Commerson's dolphin and 134 schools (465 individuals) of Peale's dolphin were recorded in 8,535 km surveyed. Commerson's dolphin was found less than 60 km from shore; whereas Peale's dolphins occurred over a wider range of distances from the coast, the number of animals sighted usually being larger near or far from the coast. Fitted models indicate overall abundances of approximately 22,000 Commerson's dolphins and 20,000 Peale's dolphins in the total area studied. This work provides the first large-scale abundance estimate for Peale's dolphin in the Atlantic Ocean and an update of population size for Commerson's dolphin. Additionally, our results contribute to baseline data on suitable habitat conditions for both species in southern Patagonia, which is essential for the implementation of adequate conservation measures.

  15. Functional diversity in a fragmented landscape — Habitat alterations affect functional trait composition of frog assemblages in Madagascar

    Directory of Open Access Journals (Sweden)

    Jana C. Riemann

    2017-04-01

    Full Text Available Anthropogenic habitat alterations cause biodiversity loss, which in turn negatively affects ecosystem functioning and services, and thus human well-being. To be able to consider ecosystem functioning in conservation actions, analyzing the effects of habitat alteration on functional diversity is essential. Some altered habitats can maintain a significant part of regional biodiversity, however, functional diversity information in altered habitats is so far mostly lacking. We compared functional richness and functional β-diversity based on resource-use traits of frogs between three land-use categories in a rainforest ecosystem in Madagascar. Land-use categories represent a habitat alteration gradient ranging from continuous forest over forest fragments to matrix habitats including different agricultures. Our study revealed distinct changes in resource-use trait composition and complex patterns in the relationship between species richness and functional richness. Thus, the functional structure of frog assemblages changed due to habitat alterations. However, altered habitats likely provide different, rather than fewer functions compared to intact forest. Streams in all land-use categories were the functionally richest habitats, and thus important for ecosystem functioning. Species richness was one, but not the only driver of functional richness in our system. Functional clustering, potentially due to environmental filters depending on resource availability, was caused by anthropogenic and natural drivers. Our study shows that, even in systems where fragmented landscapes still maintain high species diversity, functional diversity can be altered in human altered habitats, which may affect ecosystem processes like productivity, nutrient cycling, and energy flows.

  16. Fragmentation of nest and foraging habitat affects time budgets of solitary bees, their fitness and pollination services, depending on traits: Results from an individual-based model.

    Science.gov (United States)

    Everaars, Jeroen; Settele, Josef; Dormann, Carsten F

    2018-01-01

    Solitary bees are important but declining wild pollinators. During daily foraging in agricultural landscapes, they encounter a mosaic of patches with nest and foraging habitat and unsuitable matrix. It is insufficiently clear how spatial allocation of nesting and foraging resources and foraging traits of bees affect their daily foraging performance. We investigated potential brood cell construction (as proxy of fitness), number of visited flowers, foraging habitat visitation and foraging distance (pollination proxies) with the model SOLBEE (simulating pollen transport by solitary bees, tested and validated in an earlier study), for landscapes varying in landscape fragmentation and spatial allocation of nesting and foraging resources. Simulated bees varied in body size and nesting preference. We aimed to understand effects of landscape fragmentation and bee traits on bee fitness and the pollination services bees provide, as well as interactions between them, and the general consequences it has to our understanding of the system. This broad scope gives multiple key results. 1) Body size determines fitness more than landscape fragmentation, with large bees building fewer brood cells. High pollen requirements for large bees and the related high time budgets for visiting many flowers may not compensate for faster flight speeds and short handling times on flowers, giving them overall a disadvantage compared to small bees. 2) Nest preference does affect distribution of bees over the landscape, with cavity-nesting bees being restricted to nesting along field edges, which inevitably leads to performance reductions. Fragmentation mitigates this for cavity-nesting bees through increased edge habitat. 3) Landscape fragmentation alone had a relatively small effect on all responses. Instead, the local ratio of nest to foraging habitat affected bee fitness positively through reduced local competition. The spatial coverage of pollination increases steeply in response to this ratio

  17. Habitat and food preferences of the endangered Palila (Loxioides bailleui) on Mauna Kea, Hawai'i

    Science.gov (United States)

    Hess, Steven C.; Banko, Paul C.; Miller, Linda J.; Laniawe, Leona P.

    2014-01-01

    Seeds and flowers of the leguminous māmane (Sophora chrysophylla) tree are the primary food resource of the federally endangered Palila (Loxioides bailleui; Fringillidae: Drepanidinae), which is now restricted to dry subalpine woodland on Mauna Kea Volcano on the island of Hawai'i because of centuries of habitat degradation by non-native ungulates. Palila are morphologically and behaviorally adapted to consume māmane seeds by grasping seed pods with their feet and opening pods with stout bills and demonstrate limited ability to exploit alternative food resources. This degree of single species dependency is rare among birds and illustrates unique adaptations that also occurred in other Hawaiian species that are now extinct. In mixed-woodland with co-dominant naio (Myoporum sandwicense), Palila spent 1.7-3.9 times longer in māmane than in naio during foraging observations where naio was 1.3-4.6 times as dense as māmane. Naio fruit was readily available, but it comprised proportionally flowers were more abundant than māmane pods throughout this study except at one lower-elevation mixed-woodland site, Palila spent more time foraging on pods than flowers in both māmane woodland and mixed-woodland, but consumed more flowers than pods in mixed-woodland. Insects, which have been reported as an important component of the diet of Palila, were apparently taken rarely in this study. Protecting and restoring māmane in woodlands adjacent to the current range of Palila will benefit their recovery, allowing them to exploit increased food availability in areas of their former range.

  18. Winter density and habitat preferences of three declining granivorous farmland birds: The importance of the keeping of poultry and dairy farms

    Czech Academy of Sciences Publication Activity Database

    Šálek, Martin; Havlíček, J.; Riegert, J.; Nešpor, M.; Fuchs, R.; Kipson, M.

    2015-01-01

    Roč. 24, č. 1 (2015), s. 10-16 ISSN 1617-1381 Institutional support: RVO:68081766 Keywords : Central Europe * Dairy farms * Granivorous birds * Habitat preferences * Poultry keeping * Winter period Subject RIV: EH - Ecology, Behaviour Impact factor: 2.220, year: 2015

  19. Traditional ecological knowledge reveals the extent of sympatric lake trout diversity and habitat preferences

    Directory of Open Access Journals (Sweden)

    Kia Marin

    2017-06-01

    Full Text Available Multidisciplinary approaches to conservation have become increasingly important in northern regions. Because many First Nations communities have relied on freshwater fish populations for essential food over millennia, community members often possess traditional ecological knowledge (TEK. We consulted Cree First Nation fishers to collate TEK for one of Canada's most important subsistence fishes (lake trout in Québec's largest lake (Mistassini, 2335 km2. We further integrated TEK with what was regionally known scientifically about the species, toward effective fisheries conservation. Cree fishers described a richer diversity of sympatric lake trout forms than did scientific research that was conducted simultaneously, based on color, size, fin accent patterns, scale texture and depth, and spatial preferences. Traditional ecological knowledge also provided descriptions of lake trout seasonal movements, spawning locations, and reproductive timing that were not captured by scientific research, and highlighted several concerns or temporal changes of import to future management initiatives. Our study highlights the wealth of TEK on harvested species in First Nations communities. It further illustrates how TEK can reveal not only distinctions within species of relevance to natural resource management and taxonomy, but also informs upon the extent of such population differentiation, thereby providing important conservation benefits for remote and northern regions.

  20. The role of temporal abundance structure and habitat preferences in the survival of conodonts during the mid-early Silurian Ireviken mass extinction event.

    Directory of Open Access Journals (Sweden)

    Andrej Spiridonov

    Full Text Available The Ireviken event was one of the most intense extinction episodes that occurred during the mid-Paleozoic era. It had a strong global effect on a range of clades, with conodonts, graptolites and chitinozoans affected most. Using geophysical proxies and conodont species parameters of their temporal abundance structure we investigate how they affected the selectivity of conodont species survival during this calamity. After performing bivariate logistic analyses on 34 species of conodonts, we find three variables that were statistically significantly associated with their odds of survival. These namely include spectral exponents that describe degrees of autocorrelation in a time series, the skewness of species abundance distribution, and average environmental preferences, which are mostly determined by ancient water depths at sampling sites. Model selection of multivariate logistic models found the best model includes species local abundance skewness and substrate preference. A similar pattern is revealed through the regression tree analysis. The apparent extinction selectivity points to a possible causes of environmental deterioration during the Ireviken event. The significant positive relationship between extinction risk and preferential existence in deeper environments suggests the open ocean causal mechanisms of biotic stress that occurred during the Ireviken event. Marine regressions, which were previously suggested as a causal factor in this extinction episode, on theoretical grounds should have had higher impact on species living in near-shore environments, through the processes of habitat loss which are associated with decreases of shelfal areas. In addition, the significant positive correlations found between skewness of abundance distributions and spectral exponent values and the probability of species survival suggest that community and ecosystem processes (which controlled species abundance fluctuation patterns were significantly

  1. The role of temporal abundance structure and habitat preferences in the survival of conodonts during the mid-early Silurian Ireviken mass extinction event.

    Science.gov (United States)

    Spiridonov, Andrej; Brazauskas, Antanas; Radzevičius, Sigitas

    2015-01-01

    The Ireviken event was one of the most intense extinction episodes that occurred during the mid-Paleozoic era. It had a strong global effect on a range of clades, with conodonts, graptolites and chitinozoans affected most. Using geophysical proxies and conodont species parameters of their temporal abundance structure we investigate how they affected the selectivity of conodont species survival during this calamity. After performing bivariate logistic analyses on 34 species of conodonts, we find three variables that were statistically significantly associated with their odds of survival. These namely include spectral exponents that describe degrees of autocorrelation in a time series, the skewness of species abundance distribution, and average environmental preferences, which are mostly determined by ancient water depths at sampling sites. Model selection of multivariate logistic models found the best model includes species local abundance skewness and substrate preference. A similar pattern is revealed through the regression tree analysis. The apparent extinction selectivity points to a possible causes of environmental deterioration during the Ireviken event. The significant positive relationship between extinction risk and preferential existence in deeper environments suggests the open ocean causal mechanisms of biotic stress that occurred during the Ireviken event. Marine regressions, which were previously suggested as a causal factor in this extinction episode, on theoretical grounds should have had higher impact on species living in near-shore environments, through the processes of habitat loss which are associated with decreases of shelfal areas. In addition, the significant positive correlations found between skewness of abundance distributions and spectral exponent values and the probability of species survival suggest that community and ecosystem processes (which controlled species abundance fluctuation patterns) were significantly related to selectivity

  2. Which characteristic of Natto: appearance, odor, or taste most affects preference for Natto

    Directory of Open Access Journals (Sweden)

    Tsumura Yuki

    2012-05-01

    Full Text Available Abstract Background In Japan, consumption of Natto, a fermented bean dish, is recommended because of its high quality protein, digestibility in the gut and its preventive effect on blood clot formation due to high vitamin K content. However, consumption of Natto in Kansai and the Chugoku area (the western part of Honshu is less than that in the other areas of Japan probably because of a “food related cultural inhibition”. In this study, we determined which characteristic of Natto (appearance, odor or taste most affect subjects’ perception of sensory attributes by observation of brain hemodynamics in relation to subjects’ preference for Natto. Findings In this experiment, we defined each subject’s changes in brain hemodynamics as (+ or (− corresponding to an increase or a decrease in total hemoglobin concentration after stimuli compared to that before stimuli. As a result, there was no relation between preference for Natto and change in brain hemodynamics by the stimuli of “looking at” or “smelling”, while there was a significant relationship between preference and stimulus of “ingestion”; (+ : (− = 21:15 in the subjects of the “favorite” group and (+:(− = 30:7 in the subjects of the “non-favorite” group (P = 0.034. Conclusion This result indicated that characteristic “taste” of Natto most affects preference for Natto.

  3. Factors Affecting Call Center as a Job Preference among Employees in Davao City

    OpenAIRE

    Castro, Alyssa Mae; Deluna, Roperto Jr

    2013-01-01

    This study was conducted to determine the factors that influence employees in Davao City to work in call centers. The objective of the study is to determine the socio-economic and demographic profile of employees working in the call center sector andidentify the factors that affect the job preferences among employees. Employees of the call center sector composed the population of this study and other occupations such as engineers, human resources personnel, and teachers were included for comp...

  4. Factors Affecting High School Students’ Career Preference: A Basis for Career Planning Program

    OpenAIRE

    Nancy Talavera Pascual

    2014-01-01

    Unemployment rate in the country is commonly associated with the misfit graduates produced by universities and colleges and the workforce needed by different companies. The wrong choice of course taken by most of high school students adds to the unemployment and underemployment rate of newly graduate students. With this the study determined the factors affecting the fourth year high school students’ career preference of University of Rizal System’ Laboratory School in Morong Rizal. The rela...

  5. Pedogenic carbonate stable isotopic evidence for wooded habitat preference of early Pleistocene tool makers in the Turkana Basin.

    Science.gov (United States)

    Quinn, Rhonda L; Lepre, Christopher J; Feibel, Craig S; Wright, James D; Mortlock, Richard A; Harmand, Sonia; Brugal, Jean-Philip; Roche, Hélène

    2013-07-01

    The origin and evolution of early Pleistocene hominin lithic technologies in Africa occurred within the context of savanna grassland ecosystems. The Nachukui Formation of the Turkana Basin in northern Kenya, containing Oldowan and Acheulean tool assemblages and fossil evidence for early members of Homo and Paranthropus, provides an extensive spatial and temporal paleosol record of early Pleistocene savanna flora. Here we present new carbon isotopic (δ(13)CVPDB) values of pedogenic carbonates (68 nodules, 193 analyses) from the Nachukui Formation in order to characterize past vegetation structure and change through time. We compared three members (Kalochoro, Kaitio, and Natoo) at five locations spanning 2.4-1.4Ma and sampled in proximity to hominin archaeological and paleontological sites. Our results indicate diverse habitats showing a mosaic pattern of vegetation cover at each location yet demonstrate grassland expansion through time influenced by paleogeography. Kalochoro floodplains occurred adjacent to large river systems, and paleosols show evidence of C3 woodlands averaging 46-50% woody cover. Kaitio habitats were located along smaller rivers and lake margins. Paleosols yielded evidence for reduced portions of woody vegetation averaging 34-37% woody cover. Natoo environments had the highest percentage of grasslands averaging 21% woody cover near a diminishing Lake Turkana precursor. We also compared paleosol δ(13)CVPDB values of lithic archaeological sites with paleosol δ(13)CVPDB values of all environments available to hominins at 2.4-1.4Ma in the Nachukui and Koobi Fora Formations. Grassy environments became more widespread during this interval; woody canopy cover mean percentages steadily decreased by 12%. However, significantly more wooded savanna habitats were present in the vicinity of lithic archaeological sites and did not mirror the basin-wide trend of grassland spread. Hominin lithic archaeological sites consistently demonstrated woody cover

  6. Habitat restoration affects immature stages of a wetland butterfly through indirect effects on predation.

    Science.gov (United States)

    Aschehoug, Erik T; Sivakoff, F S; Cayton, H L; Morris, W F; Haddad, N M

    2015-07-01

    Habitat loss worldwide has led to the widespread use of restoration practices for the recovery of imperiled species. However, recovery success may be hampered by focusing on plant communities, rather than the complex suite of direct and indirect interactions among trophic levels that occur in natural systems. Through a factorial field experiment, we tested the effects of wetland restoration on egg and juvenile survival of a locally rare butterfly, Satyrodes appalachia, via tree removal and damming. Tree removal more than tripled S. appalachia host plant abundance, but neither restoration action directly affected S. appalachia egg and juvenile survival. Instead, we found strong indirect effects of habitat manipulation on S. appalachia egg and juvenile survival that were mediated through predation. The interaction of tree removal and damming significantly decreased predation of S. appalachia eggs relative to each treatment alone. Damming alone had a significant positive indirect effect on the survival of S. appalachia juveniles, likely because increases in standing water reduced predator access. Our results emphasize the need for experiments that evaluate the demographic responses of imperiled species to habitat restoration prior to management action and quantify potential indirect effects mediated through higher trophic levels.

  7. Habitat stability affects dispersal and the ability to track climate change

    DEFF Research Database (Denmark)

    Hof, Christian; Brändle, Martin; Dehling, D. Matthias

    2012-01-01

    than lotic species. Assuming that climate is an important determinant of species distributions, we hypothesize that lentic species should have distributions that are closer to equilibrium with current climate, and should more rapidly track climatic changes. We tested these hypotheses using datasets...... from 1988 and 2006 containing all European dragon- and damselfly species. Bioclimatic envelope models showed that lentic species were closer to climatic equilibrium than lotic species. Furthermore, the models over-predicted lotic species ranges more strongly than lentic species ranges, indicating...... that lentic species track climatic changes more rapidly than lotic species. These results are consistent with the proposed hypothesis that habitat persistence affects the evolution of dispersal....

  8. Habitat preference of geese is affected by livestock grazing : Seasonal variation in an experimental field evaluation

    NARCIS (Netherlands)

    Mandema, Freek S.; Tinbergen, Joost M.; Stahl, Julia; Esselink, Peter; Bakker, Jan P.

    The number of staging geese in northwestern Europe has increased dramatically. Growing goose numbers put strong grazing pressure on agricultural pastures. Damage to agricultural land may be mitigated by managing nature reserves in order to optimally accommodate large numbers of grazing geese.

  9. Evidences of adaptive traits to rocky substrates undermine paradigm of habitat preference of the Mediterranean seagrass Posidonia oceanica

    Science.gov (United States)

    Badalamenti, Fabio; Alagna, Adriana; Fici, Silvio

    2015-03-01

    Posidonia oceanica meadows are acknowledged as one of the most valuable ecosystems of the Mediterranean Sea. P. oceanica has been historically described as a species typically growing on mobile substrates whose development requires precursor communities. Here we document for the first time the extensive presence of sticky hairs covering P. oceanica seedling roots. Adhesive root hairs allow the seedlings to firmly anchor to rocky substrates with anchorage strength values up to 5.23 N, regardless of the presence of algal cover and to colonise bare rock without the need for precursor assemblages to facilitate settlement. Adhesive root hairs are a morphological trait common on plants living on rocks in high-energy habitats, such as the riverweed Podostemaceae and the seagrass Phyllospadix scouleri. The presence of adhesive root hairs in P. oceanica juveniles suggests a preference of this species for hard substrates. Such an adaptation leads to hypothesize a new microsite driven bottleneck in P. oceanica seedling survival linked to substrate features. The mechanism described can favour plant establishment on rocky substrates, in contrast with traditional paradigms. This feature may have strongly influenced P. oceanica pattern of colonisation through sexual propagules in both the past and present.

  10. Service design attributes affecting diabetic patient preferences of telemedicine in South Korea.

    Science.gov (United States)

    Park, Hayoung; Chon, Yucheong; Lee, Jongsu; Choi, Ie-Jung; Yoon, Kun-Ho

    2011-01-01

    Attempts to introduce telemedicine in South Korea have failed mostly, leaving critical questions for service developers and providers about whether patients would be willing to pay for the service and how the service should be designed to encourage patient buy-in. In this study, we explore patients' valuations and preferences for each attribute of telemedicine service for diabetes management and evaluate patient willingness to pay for specific service attributes. We conducted a conjoint survey to collect data on patients' stated preferences among telemedicine service alternatives. The alternatives for diabetes-related service differed in 10 attributes, including those related to price, type of service provider, and service scope. To estimate the relative importance of attributes, patients' willingness to pay for each attribute, and their probable choice of specific alternatives, we used a rank-ordered logit model. A total of 118 respondents participated in the survey. All 10 attributes significantly affected patients' valuations and preferences, and demographic and disease characteristics, such as existence of complications and comorbidities, significantly affected patients' valuations of the attributes. Price was the most important attribute, followed by comprehensive scope of service, the availability of mobile phone-based delivery, and large general-hospital provided services. The study findings have significant implications for adoption policy and strategy of telemedicine in diabetes management care. Further, the methodology presented in this study can be used to draw knowledge needed to formulate effective policy for adoption of the necessary technology and for the design of services that attract potential beneficiaries.

  11. Drought stress affects plant metabolites and herbivore preference but not host location by its parasitoids.

    Science.gov (United States)

    Weldegergis, Berhane T; Zhu, Feng; Poelman, Erik H; Dicke, Marcel

    2015-03-01

    One of the main abiotic stresses that strongly affects plant survival and the primary cause of crop loss around the world is drought. Drought stress leads to sequential morphological, physiological, biochemical and molecular changes that can have severe effects on plant growth, development and productivity. As a consequence of these changes, the interaction between plants and insects can be altered. Using cultivated Brassica oleracea plants, the parasitoid Microplitis mediator and its herbivorous host Mamestra brassicae, we studied the effect of drought stress on (1) the emission of plant volatile organic compounds (VOCs), (2) plant hormone titres, (3) preference and performance of the herbivore, and (4) preference of the parasitoid. Higher levels of jasmonic acid (JA) and abscisic acid (ABA) were recorded in response to herbivory, but no significant differences were observed for salicylic acid (SA) and indole-3-acetic acid (IAA). Drought significantly impacted SA level and showed a significant interactive effect with herbivory for IAA levels. A total of 55 VOCs were recorded and the difference among the treatments was influenced largely by herbivory, where the emission rate of fatty acid-derived volatiles, nitriles and (E)-4,8-dimethylnona-1,3,7-triene [(E)-DMNT] was enhanced. Mamestra brassicae moths preferred to lay eggs on drought-stressed over control plants; their offspring performed similarly on plants of both treatments. VOCs due to drought did not affect the choice of M. mediator parasitoids. Overall, our study reveals an influence of drought on plant chemistry and insect-plant interactions.

  12. How predictability of feeding patches affects home range and foraging habitat selection in avian social scavengers?

    Directory of Open Access Journals (Sweden)

    Sophie Monsarrat

    Full Text Available Feeding stations are commonly used to sustain conservation programs of scavengers but their impact on behaviour is still debated. They increase the temporal and spatial predictability of food resources while scavengers have supposedly evolved to search for unpredictable resources. In the Grands Causses (France, a reintroduced population of Griffon vultures Gyps fulvus can find carcasses at three types of sites: 1. "light feeding stations", where farmers can drop carcasses at their farm (spatially predictable, 2. "heavy feeding stations", where carcasses from nearby farms are concentrated (spatially and temporally predictable and 3. open grasslands, where resources are randomly distributed (unpredictable. The impact of feeding stations on vulture's foraging behaviour was investigated using 28 GPS-tracked vultures. The average home range size was maximal in spring (1272 ± 752 km(2 and minimal in winter (473 ± 237 km(2 and was highly variable among individuals. Analyses of home range characteristics and feeding habitat selection via compositional analysis showed that feeding stations were always preferred compared to the rest of the habitat where vultures can find unpredictable resources. Feeding stations were particularly used when resources were scarce (summer or when flight conditions were poor (winter, limiting long-ranging movements. However, when flight conditions were optimal, home ranges also encompassed large areas of grassland where vultures could find unpredictable resources, suggesting that vultures did not lose their natural ability to forage on unpredictable resources, even when feeding stations were available. However during seasons when food abundance and flight conditions were not limited, vultures seemed to favour light over heavy feeding stations, probably because of the reduced intraspecific competition and a pattern closer to the natural dispersion of resources in the landscape. Light feeding stations are interesting tools

  13. Life stage and species identity affect whether habitat subsidies enhance or simply redistribute consumer biomass.

    Science.gov (United States)

    Keller, Danielle A; Gittman, Rachel K; Bouchillon, Rachel K; Fodrie, F Joel

    2017-10-01

    Quantifying the response of mobile consumers to changes in habitat availability is essential for determining the degree to which population-level productivity is habitat limited rather than regulated by other, potentially density-independent factors. Over landscape scales, this can be explored by monitoring changes in density and foraging as habitat availability varies. As habitat availability increases, densities may: (1) decrease (unit-area production decreases; weak habitat limitation); (2) remain stable (unit-area production remains stable; habitat limitation) or (3) increase (unit-area production increases; strong habitat limitation). We tested the response of mobile estuarine consumers over 5 months to changes in habitat availability in situ by comparing densities and feeding rates on artificial reefs that were or were not adjacent to neighbouring artificial reefs or nearby natural reefs. Using either constructed or natural reefs to manipulate habitat availability, we documented threefold density decreases among juvenile stone crabs as habitat increased (i.e. weak habitat imitation). However, for adult stone crabs, density remained stable across treatments, demonstrating that habitat limitation presents a bottleneck in this species' later life history. Oyster toadfish densities also did not change with increasing habitat availability (i.e. habitat limitation), but densities of other cryptic fishes decreased as habitat availability increased (i.e. weak limitation). Feeding and abundance data suggested that some mobile fishes experience habitat limitation, or, potentially in one case, strong limitation across our habitat manipulations. These findings of significant, community-level habitat limitation provide insight into how global declines in structurally complex estuarine habitats may have reduced the fishery production of coastal ecosystems. © 2017 The Authors. Journal of Animal Ecology © 2017 British Ecological Society.

  14. Trophic disruption: a meta-analysis of how habitat fragmentation affects resource consumption in terrestrial arthropod systems.

    Science.gov (United States)

    Martinson, Holly M; Fagan, William F

    2014-09-01

    Habitat fragmentation is a complex process that affects ecological systems in diverse ways, altering everything from population persistence to ecosystem function. Despite widespread recognition that habitat fragmentation can influence food web interactions, consensus on the factors underlying variation in the impacts of fragmentation across systems remains elusive. In this study, we conduct a systematic review and meta-analysis to quantify the effects of habitat fragmentation and spatial habitat structure on resource consumption in terrestrial arthropod food webs. Across 419 studies, we found a negative overall effect of fragmentation on resource consumption. Variation in effect size was extensive but predictable. Specifically, resource consumption was reduced on small, isolated habitat fragments, higher at patch edges, and neutral with respect to landscape-scale spatial variables. In general, resource consumption increased in fragmented settings for habitat generalist consumers but decreased for specialist consumers. Our study demonstrates widespread disruption of trophic interactions in fragmented habitats and describes variation among studies that is largely predictable based on the ecological traits of the interacting species. We highlight future prospects for understanding how changes in spatial habitat structure may influence trophic modules and food webs. © 2014 John Wiley & Sons Ltd/CNRS.

  15. The Moderating Influence of Situational Motivation on the Relationship Between Preferred Exercise and Positive Affect

    Directory of Open Access Journals (Sweden)

    Eva Guérin

    2013-10-01

    Full Text Available Despite convincing evidence supporting the association between exercise and positive affect, this complex relationship requires further theoretical and person-centered explanation. The nature of one’s motivation for exercise, as postulated by Self-Determination Theory (SDT, may supply a missing and understudied link. The primary aim of this experimental study was to examine the moderating influence of situational motivation from SDT on the relationship between an acute bout of preferred exercise, namely running (vs. control, and changes in positive affect. Forty-one active women attended two sessions to engage in (a a 30-min moderate-intensity self-paced treadmill run and (b a 30-min quiet activity (i.e., newspaper reading. Participants with high introjection versus those with low introjection reported a greater increase in positive affect from pre- to postrunning and a greater decrease in positive affect from pre- to postcontrol. A “relief from guilt” effect was postulated to explain these results. Motivational variables accounted for 7% of variance in postrun positive affect. Consistent with SDT, running because one values this behavior and its benefits (i.e., identified regulation was significantly associated with postrun positive affect.

  16. Dawn simulation vs. bright light in seasonal affective disorder: Treatment effects and subjective preference.

    Science.gov (United States)

    Danilenko, K V; Ivanova, I A

    2015-07-15

    Studies comparing the efficacy of dawn simulation to conventional bright light for the treatment of seasonal affective disorder (in parallel groups) have yielded conflicting results. This crossover study investigated treatment outcomes and long-term treatment preference. Forty winter depressives were treated for a week with bright light (4.300lx for 30-45min shortly after awakening) or dawn simulation (gradually increasing light during the last 30min of sleep achieving 100lx before alarm beep, with the dawn simulator placed closer to the open eyes for a further 15min: 250lx). The depression level was self-rated using SIGH-SAD-SR. Depression scores reduced similarly following bright light and dawn simulation: for 43.8% and 42.2% (medians), respectively; efficacy ratio was 23:17. The preference was also similar (21:19). Among those who preferred bright light, the most common reason was that they perceived the bright light to be more effective (19/21; it was more effective, p=0.0096; this subgroup tended to have more severe depression) and ease of use (6/21). Among those who preferred the dawn simulator, the reasons were a more "natural" action (9/19), device compactness and/or time-saving (10/19) and in 4 cases where bright light caused eyestrain. Not overhead naturalistic light for dawn simulation, self-rating of depression. Dawn simulation is similarly effective to bright light in the treatment of winter depression. Patients with more severe depression tended to report greater improvement with bright light; in such cases, this would outweigh the non-clinical advantages of dawn simulation. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Water level affects availability of optimal feeding habitats for threatened migratory waterbirds

    DEFF Research Database (Denmark)

    Aharon-Rotman, Yaara; McEvoy, John; Zheng Zhaoju

    2017-01-01

    Extensive ephemeral wetlands at Poyang Lake, created by dramatic seasonal changes in water level, constitute the main wintering site for migratory Anatidae in China. Reductions in wetland area during the last 15years have led to proposals to build a Poyang Dam to retain high winter water levels...... within the lake. Changing the natural hydrological system will affect waterbirds dependent on water level changes for food availability and accessibility. We tracked two goose species with different feeding behaviors (greater white-fronted geese Anser albifrons [grazing species] and swan geese Anser...... cygnoides [tuber-feeding species]) during two winters with contrasting water levels (continuous recession in 2015; sustained high water in 2016, similar to those predicted post-Poyang Dam), investigating the effects of water level change on their habitat selection based on vegetation and elevation. In 2015...

  18. Like or dislike? Affective preference modulates neural response to others' gains and losses.

    Directory of Open Access Journals (Sweden)

    Yang Wang

    Full Text Available Previous studies have demonstrated that the brain responds differentially to others' gains and losses relative to one's own, moderated by social context factors such as competition and interpersonal relationships. In the current study, we tested the hypothesis that the neural response to others' outcomes could be modulated by a short-term induced affective preference. We engaged 17 men and 18 women in a social-exchange game, in which two confederates played fairly or unfairly. Both men and women rated the fair player as likable and the unfair players as unlikable. Afterwards, ERPs were recorded while participants observed each confederates playing a gambling game individually. This study examines feedback related negativity (FRN, an ERP component sensitive to negative feedback. ANOVA showed a significant interaction in which females but not males displayed stronger FRNs when observing likable players' outcomes compared to unlikable ones'. However, males did not respond differently under either circumstance. These findings suggest that, at least in females, the neural response is influenced by a short-term induced affective preference.

  19. Like or dislike? Affective preference modulates neural response to others' gains and losses.

    Science.gov (United States)

    Wang, Yang; Qu, Chen; Luo, Qiuling; Qu, Lulu; Li, Xuebing

    2014-01-01

    Previous studies have demonstrated that the brain responds differentially to others' gains and losses relative to one's own, moderated by social context factors such as competition and interpersonal relationships. In the current study, we tested the hypothesis that the neural response to others' outcomes could be modulated by a short-term induced affective preference. We engaged 17 men and 18 women in a social-exchange game, in which two confederates played fairly or unfairly. Both men and women rated the fair player as likable and the unfair players as unlikable. Afterwards, ERPs were recorded while participants observed each confederates playing a gambling game individually. This study examines feedback related negativity (FRN), an ERP component sensitive to negative feedback. ANOVA showed a significant interaction in which females but not males displayed stronger FRNs when observing likable players' outcomes compared to unlikable ones'. However, males did not respond differently under either circumstance. These findings suggest that, at least in females, the neural response is influenced by a short-term induced affective preference.

  20. Depth rotation and mirror-image reflection reduce affective preference as well as recognition memory for pictures of novel objects

    National Research Council Canada - National Science Library

    Lawson, Rebecca

    2004-01-01

    In two experiments, the identification of novel 3-D objects was worse for depth-rotated and mirrorreflected views, compared with the study view in an implicit affective preference memory task, as well...

  1. Tree holes as larval habitats for Aedes aegypti in urban, suburban and forest habitats in a dengue affected area.

    Science.gov (United States)

    Mangudo, C; Aparicio, J P; Gleiser, R M

    2015-12-01

    Aedes aegypti (L.) (Diptera: Culicidae), the main vector of dengue and urban yellow fever in the world, is highly adapted to the human environment. Artificial containers are the most common larval habitat for the species, but it may develop in tree holes and other phytotelmata. This study assessed whether tree holes in San Ramón de la Nueva Orán, a city located in subtropical montane moist forest where dengue outbreaks occur, are relevant as larval habitat for Ae. aegypti and if the species may be found in natural areas far from human habitations. Water holding tree holes were sampled during 3 years once a month along the rainy season using a siphon bottle, in urban and suburban sites within the city and in adjacent forested areas. Larvae and pupae were collected and the presence and volume of water in each tree hole were recorded. Finding Ae. aegypti in forested areas was an isolated event; however, the species was frequently collected from tree holes throughout the city and along the sampling period. Moreover, larvae were collected in considerably high numbers, stressing the importance of taking into account these natural cavities as potential reinfestation foci within dengue control framework.

  2. Determining Home Range and Preferred Habitat of Feral Horses on the Nevada National Security Site Using Geographic Information Systems

    Energy Technology Data Exchange (ETDEWEB)

    Burns, Ashley V. [Univ. of Denver, CO (United States)

    2014-05-30

    Feral horses (Equus caballus) are free-roaming descendants of domesticated horses and legally protected by the Wild and Free-Roaming Horses and Burros Act of 1971, which mandates how feral horses and burros should be managed and protected on federal lands. Using a geographic information system to determine the home range and suitable habitat of feral horses on the federally managed Nevada National Security Site can enable wildlife biologists in making best management practice recommendations. Home range was estimated at 88.1 square kilometers. Site suitability was calculated for elevation, forage, slope, water presence and horse observations. These variables were combined in successive iterations into one polygon. Suitability rankings established that 85 square kilometers are most suitable habitat, with 2,052 square kilometers of good habitat 1,252 square kilometers of fair habitat and 122 square kilometers of least suitable habitat.

  3. Do Soils affect Brown Hare (Lepus europaeus abundance in agricultural habitats?

    Directory of Open Access Journals (Sweden)

    Francesco Santilli

    2008-07-01

    Full Text Available Abstract In recent years, much research on brown hare (Lepus europaeus, Pallas 1778 ecology has been conducted in Europe to identify habitat-species relationships and the reasons for the decline in hare populations that have occurred since the 1960s. However, very few studies have considered the influence of soil texture on the abundance of this species in agricultural habitats. In this paper we examine the relationship between winter brown hare density in protected areas (game refuges in four provinces of the Tuscany region (central Italy and soil texture. Results show that hares reach higher densities in areas characterized by "loam" soils compared to areas where soils are richer in clay. Although this relationship is probably complex, soil texture may indirectly affect brown hare populations by influencing the temperature and moisture of the ground and influencing the timing of farming operations (tillage. Riassunto Il suolo influenza l’abbondanza della lepre Lepus europaeus negli ambienti agricoli? Negli ultimi anni sono state effettuate numerose ricerche sull’ecologia della lepre europea Lepus europaeus, al fine di evidenziare le relazioni fra questa specie ed il tipo di habitat e di comprendere i motivi del declino avvenuto a partire dagli anni ’60. Ciononostante pochi studi hanno preso in considerazione l’influenza del tipo di suolo sulla consistenza di questo lagomorfo negli ambienti agricoli. Nel presente lavoro viene esaminata la relazione fra la densità invernale della lepre all’interno delle zone di ripopolamento e cattura di quattro province toscane e la tessitura del suolo di queste aree. E’ stato riscontrato che le lepri raggiungono densità più elevate in aree dove predominano i suoli franchi rispetto ad aree dove risultano più argillosi. Sebbene questa relazione sia probabilmente complessa, la tessitura del suolo potrebbe influenzare

  4. Recent diversification of a marine genus (Tursiops spp.) Tracks habitat preference and environmental change

    DEFF Research Database (Denmark)

    Moura, Andre E.; Nielsen, Sandra Cathrine Abel; Mouatt, Julia Thidamarth Vilstrup

    2013-01-01

    Understanding the evolution of diversity and the resulting systematics in marine systems is confounded by the lack of clear boundaries in oceanic habitats, especially for highly mobile species like marine mammals. Dolphin populations and sibling species often show differentiation between coastal...... and offshore habitats, similar to the pelagic/littoral or benthic differentiation seen for some species of fish. Here we test the hypothesis that lineages within the polytypic genus Tursiops track past changes in the environment reflecting ecological drivers of evolution facilitated by habitat release. We used...

  5. Habitat simplification affects nuclear-follower foraging association among stream fishes

    Directory of Open Access Journals (Sweden)

    Fabrício Barreto Teresa

    Full Text Available Nuclear-follower interaction is a particular kind of interspecific foraging association that includes a nuclear species, which dig in or inspect the bottom, and follower species, which access the food items made available by the nuclear. In this study we examined the effect of habitat structure on nuclear-follower relationship in a stream of Bodoquena Plateau, Central-West Brazil. Foraging associations were registered while snorkeling in 24 observation sessions, totaling six hours in unaltered and altered sites. Overall, 272 nuclear-follower associations were registered, having four species acting as nuclear and seven as followers. The dominant nuclear species were different in each site. Prochilodus lineatus was the main nuclear species in the altered site and Leporinus macrocephalus in the unaltered site. The richness of follower species was similar between sites, however, follower species abundance per interaction were significantly higher in the unaltered site than in the altered site. These differences seem to be a consequence of the alterations in assemblage composition and feeding behavior of the nuclear species that presumably are affected by different substrate composition and food availability between the structurally distinct areas.

  6. Introduced goldfish affect amphibians through inhibition of sexual behaviour in risky habitats: an experimental approach.

    Science.gov (United States)

    Winandy, Laurane; Denoël, Mathieu

    2013-01-01

    The introduction of alien species is one of the major causes of current and global biodiversity loss. The introduction of fish can be a particular threat to native amphibian populations, which are declining worldwide. One way for amphibians to persist in such altered environments is to adopt anti-predator strategies especially at the behavioural level. However, although it has been shown that avoidance behaviour may decrease the probability of being detected by a potential predator, little is known on the consequences on sexual behaviour. In this study, we tested the hypothesis that adult Alpine newts (Ichthyosaura alpestris) use shelters more often and exhibit less sexual activity in the presence of goldfish (Carassius auratus) and that they reduce sexual activity more in risky micro-habitats than in safe environments. To this end, we assessed behavioural patterns of adult newts in a replicated laboratory design. Goldfish were present in direct contact with newts in half of the tanks. Consistently throughout the study period, significantly more newts used shelter in the presence of fish than in their absence. Newts also significantly decreased their sexual activity level overall, but specially outside the shelter when they were in direct contact with fish. These results show that fish presence can affect newts in complex ways, such as through inhibition of their reproduction. Our work highlights that integrating behaviour in conservation studies is essential to understanding the patterns of coexistence and exclusion between introduced fish and amphibians.

  7. Habitat Preference and Population Ecology of Limpets Cellana karachiensis (Winckworth and Siphonaria siphonaria (Sowerby at Veraval Coast of Kathiawar Peninsula, India

    Directory of Open Access Journals (Sweden)

    Julee Faladu

    2014-01-01

    Full Text Available Present study reports the habitat preference and spatiotemporal variations in the population abundance of limpets Cellana karachiensis and Siphonaria siphonaria inhabiting rocky intertidal zones of Veraval coast, Kathiawar Peninsula, India. The entire intertidal zone of the Veraval coast was divided into five microsampling sites based on their substratum type and assemblage structure. Extensive field surveys were conducted every month in these microsampling sites and the population abundance of two limpet species was analyzed using belt transect method. The results revealed that C. karachiensis was the dominating species at microsampling Site-1 (having rocky substratum possibly due to its ability to tolerate high desiccation, salinity, and temperature fluctuations, while the S. siphonaria was found to be the most dominating species at microsampling Site-2 (having rocky substratum with abundant algal population possibly due to their preference for the perpetual wet areas. The study also indicated that S. siphonaria preferred upper littoral zone where the green algae were abundant while C. karachiensis preferred the spray zone, where it faces almost no competition for space and food with other molluscs. The condition of the spray zone is very harsh for other species to survive.

  8. Factors Affecting Piping Plover Chick Survival In Different Brood-Rearing Habitats

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The published report for Piping Plover in Maryland discusses the current status of the species, habitat requirements and limiting factors, recovery objectives and...

  9. Population distribution, density and habitat preference of the Cerulean Warbler (Setophaga cerulea) in the Delaware Water Gap National Recreation Area

    Science.gov (United States)

    Shannon Curley; Terry Master; Gregory George

    2012-01-01

    The breeding range of the Cerulean Warbler has expanded into second-growth forest and converted agricultural land in the northeastern United States where, according to the North American Breeding Bird Survey, the population is increasing. Despite this expansion in one part of its range, the population as a whole is still in rapid decline implying that habitat quality...

  10. Habitat preferences, diet, feeding strategy and social organization of the black spider monkey (Ateles paniscus paniscus Linnaeus 1758) in Surinam

    NARCIS (Netherlands)

    Roosmalen, van M.G.M.

    1980-01-01

    This study describes habitat choice of the Surinam black spider monkey ( Atelespaniscuspaniscus ) and clarifies complex temporal and spatial effects of food sources on the behaviour of a group of spider monkeys in a 350 ha study area in

  11. Preferred habitat of breeding birds may be compromised by climate change: unexpected effects of an exceptionally cold, wet spring.

    Directory of Open Access Journals (Sweden)

    Michael J Whitehouse

    Full Text Available Previous studies of the consequences for breeding birds of climate change have explored how their populations may respond to increasing temperatures. However, few have considered the likely outcome of predicted extreme conditions and the relative vulnerability of populations in different habitats. Here, we compare phenology and breeding success in great tits and blue tits over a 10 year period, including the extremely harsh conditions during spring 2012, at three sites in eastern England--mixed deciduous woodland, riparian and urban habitat. Production, measured as brood biomass, was significantly lower in 2012 compared with the previous 9 years, with the decrease in productivity relatively greatest in woodland habitat. Production was related to hatch delay, i.e. birds not initiating incubation immediately after clutch completion, which was more common in 2012 than in previous years. The best predictor of hatch delay was daytime temperature (not nighttime minimum temperature and rainfall, which convincingly reflected low growth and activity of caterpillar prey. We found that birds breeding in riparian and urban habitats were less vulnerable to the extremes of weather than those breeding in mixed deciduous woodland.

  12. The effect of landscape heterogeneity on population density and habitat preferences of the European hare (Lepus europaeus) in contrasting farmlands

    Czech Academy of Sciences Publication Activity Database

    Pavliska, P. L.; Riegert, J.; Grill, S.; Šálek, Martin

    2018-01-01

    Roč. 88, January (2018), s. 8-15 ISSN 1616-5047 Institutional support: RVO:68081766 Keywords : Lepus europaeus * Field size * Agricultural policy * Conservation measures * Density-dependent habitat selection Subject RIV: EH - Ecology, Behaviour Impact factor: 1.429, year: 2016

  13. Habitat, food, and climate affecting leaf litter anuran assemblages in an Atlantic Forest remnant

    Science.gov (United States)

    Rievers, Camila Rabelo; Pires, Maria Rita Silvério; Eterovick, Paula Cabral

    2014-07-01

    Leaf litter anuran assemblages include both species that have terrestrial development and species that, during the breeding season, aggregate around bodies of water where their tadpoles develop. The resources used by these two groups in the leaf litter are likely to differ, as well as their sampled species richness, abundance and biomass as resource availability changes. We conducted a 12-month survey of leaf litter anuran assemblages at three forest areas in the largest Atlantic Forest remnant in the state of Minas Gerais in southeastern Brazil. Each month we estimated, based on capture rates, anuran species richness, abundance, and biomass as assemblage descriptors. We also measured variables that could potentially affect these descriptors in space and time: invertebrate litter fauna (abundance and richness of taxa), leaf litter biomass, and microclimatic conditions (air humidity, air and soil temperature, soil water content, and rainfall). We tested for differences in these variables among areas. We used general linear models to search for the variables that best explained variation in anuran abundance (based on capture rates) throughout the year. We analyzed species with terrestrial development (TD) and with aquatic larvae (AL) separately. We recorded 326 anurans of 15 species. Sampled anuran abundance (correlated to species richness and biomass) was explained by air humidity and/or invertebrate abundance for species with TD, and by soil water content or air humidity and leaf litter biomass for species with AL. The variability in the results of studies on leaf litter frogs that try to find variables to explain changes in community descriptors may be due to spatial variation of resources among areas and also to the fact that TD and AL species are frequently analyzed together, when in fact they are likely to show different responses to resources present in the leaf litter habitat, reflected on capture rates.

  14. Floral resources and habitat affect the composition of hummingbirds at the local scale in tropical mountaintops

    OpenAIRE

    Rodrigues, LC; M. Rodrigues

    2015-01-01

    Hummingbird communities tend to respond to variation in resources, having a positive relationship between abundance and diversity of food resources and the abundance and/or diversity of hummingbirds. Here we examined the influence of floral resource availability, as well as seasonality and type of habitat on the composition of hummingbird species. The study was carried out in two habitats of eastern Brazilian mountaintops. A gradient representative of the structure of hummingbird community, b...

  15. Does foraging habitat quality affect reproductive performance in the Little Egret, Egretta garzetta?

    Directory of Open Access Journals (Sweden)

    Tourenq, C.

    2001-06-01

    Full Text Available In order to understand the role of foraging habitat quality on fecundity parameters we measured habitat use, breeding parameters, and body condition of chicks in six colonies of Little Egrets in southern France. The foraging habitat available differed between colonies; it was mainly natural marshes around the Carrelet colony, agricultural lands (rice fields and dry crops around the Agon colony, a mix of agricultural and natural lands around the Redon and Fiélouse colonies, a mix of natural and urbanised/industrial lands around the Palissade colony, and mainly cultivated and urbanised lands around the Chaumont colony. The habitat attractiveness to adult Little Egret breeding was higher for natural marshes than for other habitat types. Agricultural marshes (rice fields came next. Other human¿made habitats came last. Clutch size and body condition index of chicks did not differ between colonies. Brood size was influenced by both the association of the proportion of natural marshes in the foraging area and clutch size, and the association of clutch size and the total number of heron pairs in the colony. The effect of the proportion of natural marshes could not be distinguished from the effects of the colony size. The potential influence of other parameters not taken into account in this study is discussed.

  16. Comparing habitat preferences of a set of waterbird species wintering in coastal wetlands of North Africa: implication for management

    Directory of Open Access Journals (Sweden)

    Elafri Ali

    2017-06-01

    Full Text Available Every year, the Coastal wetlands of North Africa support an important wintering waterbird population of many Palearctic and sub-Saharan species of various contrasting habitat requirements. In this study, we describe the habitat use by24 water-obligate species wintering in a coastal wetland of the Northeastern Algeria (the wetland of Lake Tonga, highlighting thereby the ecological mechanisms that support their coexistence and their resources partitioning. The analysis of resource exploitation (Relative frequency, Feinsinger niche breadth, Pianka niche overlap and Ivlev’s electivity indexes showed that waterbird species inhabiting the lake wetland have several similarities in using the different habitat categories, which lead us to cluster them into 5 guilds (G1: one rails, two grebes and eight ducks; G2: five wading species and one gull; G3: three herons; G4: cormorants, mallards, and on gull; finally, G5: only one species Cattle egret (Bubulcus ibis.Almost all the species were specialists in resource utilization patterns (narrow niche breadths, both under 0.3 and therefore, vulnerable to fluctuations in resources, particularly the feeding habitats. Mean niche overlaps for all the pairs of species ranged from 0.05 to 0.68. The overall pattern in the community was higher niche overlaps between the species of a particular guild than those between other species. According to Ivlev’s electivity index, we found that only three microhabitats from seven were the most important for the discussed species, open water body was the most attractive, followed by meadows, muddy areas and floating- leafed vegetation. Similarities on habitat requirements derived from our region can provide important and optimal wetland management at multi-species assemblage level for this wetland and similar area around the African coast.

  17. Evolution of habitat preference and nutrition mode in a cosmopolitan fungal genus with evidence of interkingdom host jumps and major shifts in ecology.

    Science.gov (United States)

    Chaverri, Priscila; Samuels, Gary J

    2013-10-01

    Host jumps by microbial symbionts are often associated with bursts of species diversification driven by the exploitation of new adaptive zones. The objective of this study was to infer the evolution of habitat preference (decaying plants, soil, living fungi, and living plants), and nutrition mode (saprotrophy and mycoparasitism) in the fungal genus Trichoderma to elucidate possible interkingdom host jumps and shifts in ecology. Host and ecological role shifts were inferred by phylogenetic analyses and ancestral character reconstructions. The results support several interkingdom host jumps and also show that the preference for a particular habitat was gained or lost multiple times. Diversification analysis revealed that mycoparasitism is associated with accelerated speciation rates, which then suggests that this trait may be linked to the high number of species in Trichoderma. In this study it was also possible to infer the cryptic roles that endophytes or soil inhabitants play in their hosts by evaluating their closest relatives and determining their most recent ancestors. Findings from this study may have implications for understanding certain evolutionary processes such as species radiations in some hyperdiverse groups of fungi, and for more applied fields such as the discovery and development of novel biological control strategies. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

  18. Using Ellenberg-Pignatti values to estimate habitat preferences of wild food and medicinal plants: an example from northeastern Istria (Croatia).

    Science.gov (United States)

    Vitasović Kosić, Ivana; Juračak, Josip; Łuczaj, Łukasz

    2017-06-02

    The paper presents the first ethnobotanical application of Ellenberg indicator values, which are widely used in European plant ecology. The aim of the study was to find out if Ellenberg values (indicating habitat preferences) differ for wild food and medicinal plants used in north-eastern Istria (Croatia). We used Ellenberg-Pignatti values (the version of Ellenberg values used in this part of Europe). Fifty semi-structured interviews were carried out among local key informants, asking which wild food and medicinal plants they used. The mean number of food and medicinal plants mentioned per interview was 30. Altogether, 121 species were recorded as food or medicine used or previously used in the study area. Thirty-one species are used exclusively as food or everyday drink, 50 species are used exclusively as medicine and 40 species are used for both food and medicine. There were no significant differences between Ellenberg values for food and medicinal plants, apart from the Nitrogen indicator value - the plants used exclusively as food had a significantly higher index than those used in medicine. This probably stems from the fact that plants with soft fleshy shoots are attractive as food and they are more likely to come from nitrogen-rich ruderal habitats. Food plants and medicinal plants are collected from a variety of habitats and no clear difference between the two categories of plants was detected, however further testing of Ellenberg values in ethnobotanical studies could be interesting.

  19. What do calves choose to eat and how do preferences affect calf behaviour and welfare?

    NARCIS (Netherlands)

    Webb, L.E.; Engel, B.; Berends, H.; Reenen, van C.G.; Gerrits, W.J.J.; Boer, de I.J.M.; Bokkers, E.A.M.

    2014-01-01

    Calves raised for milk or meat are fed diets that differ from feral-herd calf diets and are based on the nutritional requirements of the ‘average calf’. These diets may not meet the dietary preferences of each individual calf. This study explored diet preferences in calves with free dietary choice,

  20. Maternal habitat affects germination requirements of Anabasis setifera, a succulent shrub of the Arabian deserts

    Directory of Open Access Journals (Sweden)

    Ali El-Keblawy

    2016-03-01

    Full Text Available The effects of maternal habitat on light and temperature requirements during germination were assessed for the succulent desert shrub Anabasis setifera. Seeds were collected from the Mediterranean habitats of Egypt and the hyper-arid subtropical habitats of the United Arab Emirates (UAE. Seeds from the two populations were germinated in three temperature treatments in both a light/dark regime and continuous darkness. Seeds from the Egyptian population germinated significantly greater and faster than those of UAE. Seeds stored for four months at room temperatures have little dormancy and germinate at wide range of temperatures and light conditions, but seeds stored four months in the natural habitat lost their ability to germinate and rotted 10 days after incubation. The germination response to temperature depended on the habitat type. Seeds of the Egyptian population attained a significantly greater germination at lower temperatures, compared with seeds from the UAE population, but there was no difference in germination between the two populations at higher temperatures. Germination of A. setifera was very fast; most seeds germinated within four days. These results reflect the adaptive strategy of germination in both populations, and may help explain the wide distribution of this species in different climatic regions.

  1. Trophic relationships and habitat preferences of delphinids from the southeastern Brazilian coast determined by carbon and nitrogen stable isotope composition.

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    Tatiana Lemos Bisi

    Full Text Available To investigate the foraging habitats of delphinids in southeastern Brazil, we analyzed stable carbon (δ(13C and nitrogen (δ(15N isotopes in muscle samples of the following 10 delphinid species: Sotalia guianensis, Stenella frontalis, Tursiops truncatus, Steno bredanensis, Pseudorca crassidens, Delphinus sp., Lagenodelphis hosei, Stenella attenuata, Stenella longirostris and Grampus griseus. We also compared the δ(13C and δ(15N values among four populations of S. guianensis. Variation in carbon isotope results from coast to ocean indicated that there was a significant decrease in δ(13C values from estuarine dolphins to oceanic species. S. guianensis from Guanabara Bay had the highest mean δ(13C value, while oceanic species showed significantly lower δ(13C values. The highest δ(15N values were observed for P. crassidens and T. truncatus, suggesting that these species occupy the highest trophic position among the delphinids studied here. The oceanic species S. attenuata, G. griseus and L. hosei had the lowest δ(15N values. Stable isotope analysis showed that the three populations of S. guianensis in coastal bays had different δ(13C values, but similar δ(15N results. Guiana dolphins from Sepetiba and Ilha Grande bays had different foraging habitat, with specimens from Ilha Grande showing more negative δ(13C values. This study provides further information on the feeding ecology of delphinids occurring in southeastern Brazil, with evidence of distinctive foraging habitats and the occupation of different ecological niches by these species in the study area.

  2. Population status, demography and habitat preferences of the threatened lipstick palm Cyrtostachys renda Blume in Kerumutan Reserve, Sumatra

    Science.gov (United States)

    Widyatmoko, Didik; Burgman, Mark A.; Guhardja, Edi; Mogea, Johanis P.; Walujo, Eko B.; Setiadi, Dede

    2005-09-01

    Population status and demography of a population of the threatened lipstick palm Cyrtostachys renda in a peat swamp ecosystem of Kerumutan Reserve, Sumatra (one of the largest remaining populations) was documented at 16 different sites, covering a wide range of forest and habitat types, vegetation associations, and population sizes. Population sizes were dominated by suckers comprising 89% of the total population. Individuals with stem heights between 0 and 4 m (47.5%), stem diameters between 4 and 10 cm (82.0%), and leaf scar numbers between 0 and 60 (69.2%) dominated. Ages of individuals were estimated and used to fit a curvilinear relationship between age and stem height. Wild plants reach reproductive maturity within 25-30 years, or when they have stem heights in excess of 2.0 m, or when they have 15-25 leaf scars. They can survive more than 80 years. Cultivated plants appear to reproduce earlier and produce more seeds than wild plants. Individual growth was plant size-dependent with the adult stage being the most productive. Higher mortality was experienced by suckers, especially in continuously waterlogged conditions and locations with dense canopies. Sucker growth was faster than seedling growth, an adaptation that may allow the species to cope with periodically waterlogged conditions. Population abundances varied with habitat types; well-drained areas were the most suitable habitat. To conserve the most important remaining populations of the lipstick palm, it is crucial to protect well-drained sites in Kerumutan Reserve.

  3. Habitat degradation and seasonality affect physiological stress levels of Eulemur collaris in littoral forest fragments.

    Directory of Open Access Journals (Sweden)

    Michela Balestri

    Full Text Available The littoral forest on sandy soil is among the most threatened habitats in Madagascar and, as such, it represents a hot-spot within a conservation hot-spot. Assessing the health of the resident lemur fauna is not only critical for the long-term viability of these populations, but also necessary for the future re-habilitation of this unique habitat. Since the Endangered collared brown lemur, Eulemur collaris, is the largest seed disperser of the Malagasy south-eastern littoral forest its survival in this habitat is crucial. In this study we compared fecal glucocorticoid metabolite (fGCM levels, a measure of physiological stress and potential early indicator of population health, between groups of collared brown lemurs living in a degraded forest fragment and groups occurring in a more preserved area. For this, we analysed 279 fecal samples collected year-round from 4 groups of collared brown lemurs using a validated 11-oxoetiocholanolone enzyme immunoassay and tested if fGCM levels were influenced by reproductive stages, phenological seasons, sex, and habitat degradation. The lemurs living in the degraded forest had significantly higher fGCM levels than those living in the more preserved area. In particular, the highest fGCM levels were found during the mating season in all animals and in females during gestation in the degraded forest. Since mating and gestation are both occurring during the lean season in the littoral forest, these results likely reflect a combination of ecological and reproductive pressures. Our findings provide a clear indication that habitat degradation has additive effects to the challenges found in the natural habitat. Since increased stress hormone output may have long-term negative effects on population health and reproduction, our data emphasize the need for and may add to the development of effective conservation plans for the species.

  4. Habitat degradation and seasonality affect physiological stress levels of Eulemur collaris in littoral forest fragments.

    Science.gov (United States)

    Balestri, Michela; Barresi, Marta; Campera, Marco; Serra, Valentina; Ramanamanjato, Jean Baptiste; Heistermann, Michael; Donati, Giuseppe

    2014-01-01

    The littoral forest on sandy soil is among the most threatened habitats in Madagascar and, as such, it represents a hot-spot within a conservation hot-spot. Assessing the health of the resident lemur fauna is not only critical for the long-term viability of these populations, but also necessary for the future re-habilitation of this unique habitat. Since the Endangered collared brown lemur, Eulemur collaris, is the largest seed disperser of the Malagasy south-eastern littoral forest its survival in this habitat is crucial. In this study we compared fecal glucocorticoid metabolite (fGCM) levels, a measure of physiological stress and potential early indicator of population health, between groups of collared brown lemurs living in a degraded forest fragment and groups occurring in a more preserved area. For this, we analysed 279 fecal samples collected year-round from 4 groups of collared brown lemurs using a validated 11-oxoetiocholanolone enzyme immunoassay and tested if fGCM levels were influenced by reproductive stages, phenological seasons, sex, and habitat degradation. The lemurs living in the degraded forest had significantly higher fGCM levels than those living in the more preserved area. In particular, the highest fGCM levels were found during the mating season in all animals and in females during gestation in the degraded forest. Since mating and gestation are both occurring during the lean season in the littoral forest, these results likely reflect a combination of ecological and reproductive pressures. Our findings provide a clear indication that habitat degradation has additive effects to the challenges found in the natural habitat. Since increased stress hormone output may have long-term negative effects on population health and reproduction, our data emphasize the need for and may add to the development of effective conservation plans for the species.

  5. Metal toxicity differently affects the Iris pseudacorus-arbuscular mycorrhiza fungi symbiosis in terrestrial and semi-aquatic habitats.

    Science.gov (United States)

    Wężowicz, K; Turnau, K; Anielska, T; Zhebrak, I; Gołuszka, K; Błaszkowski, J; Rozpądek, P

    2015-12-01

    Phytoremediation offers an environmental friendly alternative to conventional cleanup techniques. In this study, mycorrhizal fungi isolated from the roots of Mentha longifolia grown in the basin of the Centuria River (S Poland) were used. Iris pseudacorus was grown in substratum from an industrial waste, enriched in Pb, Fe, Zn, and Cd in a terrestrial and water-logged habitat. Plant yield and photosynthetic performance was the highest in the aquatic environment; however, the presence of toxic metals (TM) negatively affected photosystem II (PSII) photochemistry as shown by the JIP test. Fungi colonization and Cd accumulation within plant tissues was decreased. In the terrestrial habitat, neither arbuscular mycorrhizal fungi (AMF) nor metal toxicity affected plant growth, although metal uptake, Cd in particular, as well as photosynthesis were affected. Inoculated plants accumulated significantly more Cd, and photosynthesis was downregulated. The results presented in this study clearly indicate that the I. pseudacorus-AMF symbiosis adapts itself to the presence of toxic metals in the environment, optimizing resource supply, energy fluxes, and possibly stress tolerance mechanisms. Plant/AMF consortia grown in terrestrial and water-logged habitats utilize different strategies to cope with metal toxicity. The use of AMF in improving the phytoremediation potential of I. pseudacorus needs, however, further research.

  6. Preferences for heat, cold, or contrast in patients with knee osteoarthritis affect treatment response

    Directory of Open Access Journals (Sweden)

    Craig R Denegar

    2010-07-01

    Full Text Available Craig R Denegar, Devon R Dougherty, Jacob E Friedman, Maureen E Schimizzi, James E Clark, Brett A Comstock, William J KraemerHuman Performance Laboratory and Physical Therapy Program, Department of Kinesiology, University of Connecticut, Storrs, CT, USAObjective: This investigation assessed preferences for, and effects of, 5 days of twice daily superficial heat, cold, or contrast therapy applied with a commercially available system ­permitting the circulation of water through a wrap-around garment, use of an electric heating pad, or rest for patients with level II–IV osteoarthritis (OA of the knee.Methods: We employed a within subject, randomized order design to study 34 patients ­receiving each treatment in 1-week blocks. A knee injury and osteoarthritis outcome score (KOOS questionnaire and visual analog pain scale was completed at baseline, and twice each week. Treatment preferences were assessed in the last week of the study.Results: Treatment with the device set to warm was preferred by 48% of subjects. Near equal preferences were observed for cold (24% and contrast (24%. Pain reduction and improvements in KOOS subscale measures were demonstrated for each treatment but responses were (P < 0.05 greater with preferred treatments. Most patients preferred treatment with the water circulating garment system over a heating pad.Conclusions: We recommend that when superficial heat or cold is considered in the management of knee OA that patients experiment to identify the intervention that offers them the greatest relief and that contrast is a treatment option.Keywords: pain scales, KOOS, therapeutic agents, knee, patient preferences

  7. Multidimensional Evaluation of Endogenous and Health Factors Affecting Food Preferences, Taste and Smell Perception.

    Science.gov (United States)

    Guido, D; Perna, S; Carrai, M; Barale, R; Grassi, M; Rondanelli, M

    2016-01-01

    This study, by taking a holistic approach, investigates the relationships between taste, smell sensitivity and food preference with prognostic (endogenous and health) factors including age, gender, genetic taste markers, body mass, cigarette smoking, and number of drugs used. Cross sectional study. Northern Italy. 203 healthy subjects (160 women/43 men; mean age: 58.2±19.8 years) were examined. Individual taste sensitivity was determined by saccharose, sodium chloride, acetic acid and caffeine solutions and by 6-n-propylthiouracil (PROP) responsiveness test. Olfactory sensitivity has been assessed by «Sniffin' Sticks». Four tag Single nucleotide polymorphisms (SNPs) in regions of interest were genotyped. Factor analysis and multivariate regression were performed for scaling food preferences and screening prognostic factors, respectively. Increasing age is associated with decreased responsiveness to NaCl (P=0.001), sweet solutions (P=0.044), and smell perception (Psmell perception (Psmell perception and food preferences.

  8. Offshore Habitat Preference of Overwintering Juvenile and Adult Black Sea Bass, Centropristis striata, and the Relationship to Year-Class Success.

    Directory of Open Access Journals (Sweden)

    Alicia S Miller

    Full Text Available Black sea bass (Centropristis striata migrations are believed to play a role in overwinter survival and connectivity between juvenile and adult populations. This study investigated oceanographic drivers of winter habitat choice and regional differences between populations of juvenile and adult black sea bass. Trends in cohort strength, as a result of juvenile survival, were also identified. Oceanographic and fisheries survey data were analyzed using generalized additive models. Among the oceanographic variables investigated, salinity was the main driver in habitat selection with an optimal range of 33-35 practical salinity units (PSU for both juveniles and adults. Preferred temperature ranges varied between juveniles and adults, but held a similar minimum preference of >8°C. Salinity and temperature ranges also differed by regions north and south of Hudson Canyon. Shelf water volume had less of an effect than temperature or salinity, but showed an overall negative relationship with survey catch. The effect of winter conditions on juvenile abundance was also observed across state and federal survey index trends. A lack of correlation observed among surveys in the fall paired with a strong correlation in the spring identifies the winter period as a factor determining year-class strength of new recruits to the population. A rank order analysis of spring indices identified three of the largest year classes occurring during years with reduced shelf water volumes, warmer winter shelf waters, and a 34 PSU isohaline aligned farther inshore. While greater catches of black sea bass in the northwest Atlantic Ocean remain south of Hudson Canyon, the species' range has expanded north in recent years.

  9. Climate change and Southern Ocean ecosystems I: how changes in physical habitats directly affect marine biota.

    Science.gov (United States)

    Constable, Andrew J; Melbourne-Thomas, Jessica; Corney, Stuart P; Arrigo, Kevin R; Barbraud, Christophe; Barnes, David K A; Bindoff, Nathaniel L; Boyd, Philip W; Brandt, Angelika; Costa, Daniel P; Davidson, Andrew T; Ducklow, Hugh W; Emmerson, Louise; Fukuchi, Mitsuo; Gutt, Julian; Hindell, Mark A; Hofmann, Eileen E; Hosie, Graham W; Iida, Takahiro; Jacob, Sarah; Johnston, Nadine M; Kawaguchi, So; Kokubun, Nobuo; Koubbi, Philippe; Lea, Mary-Anne; Makhado, Azwianewi; Massom, Rob A; Meiners, Klaus; Meredith, Michael P; Murphy, Eugene J; Nicol, Stephen; Reid, Keith; Richerson, Kate; Riddle, Martin J; Rintoul, Stephen R; Smith, Walker O; Southwell, Colin; Stark, Jonathon S; Sumner, Michael; Swadling, Kerrie M; Takahashi, Kunio T; Trathan, Phil N; Welsford, Dirk C; Weimerskirch, Henri; Westwood, Karen J; Wienecke, Barbara C; Wolf-Gladrow, Dieter; Wright, Simon W; Xavier, Jose C; Ziegler, Philippe

    2014-10-01

    Antarctic and Southern Ocean (ASO) marine ecosystems have been changing for at least the last 30 years, including in response to increasing ocean temperatures and changes in the extent and seasonality of sea ice; the magnitude and direction of these changes differ between regions around Antarctica that could see populations of the same species changing differently in different regions. This article reviews current and expected changes in ASO physical habitats in response to climate change. It then reviews how these changes may impact the autecology of marine biota of this polar region: microbes, zooplankton, salps, Antarctic krill, fish, cephalopods, marine mammals, seabirds, and benthos. The general prognosis for ASO marine habitats is for an overall warming and freshening, strengthening of westerly winds, with a potential pole-ward movement of those winds and the frontal systems, and an increase in ocean eddy activity. Many habitat parameters will have regionally specific changes, particularly relating to sea ice characteristics and seasonal dynamics. Lower trophic levels are expected to move south as the ocean conditions in which they are currently found move pole-ward. For Antarctic krill and finfish, the latitudinal breadth of their range will depend on their tolerance of warming oceans and changes to productivity. Ocean acidification is a concern not only for calcifying organisms but also for crustaceans such as Antarctic krill; it is also likely to be the most important change in benthic habitats over the coming century. For marine mammals and birds, the expected changes primarily relate to their flexibility in moving to alternative locations for food and the energetic cost of longer or more complex foraging trips for those that are bound to breeding colonies. Few species are sufficiently well studied to make comprehensive species-specific vulnerability assessments possible. Priorities for future work are discussed. © 2014 John Wiley & Sons Ltd.

  10. Season and landscape composition affect pollen foraging distances and habitat use of honey bees.

    Science.gov (United States)

    Danner, Nadja; Molitor, Anna Maria; Schiele, Susanne; Härtel, Stephan; Steffan-Dewenter, Ingolf

    2016-09-01

    Honey bees (Apis mellifera L.) show a large variation in foraging distances and use a broad range of plant species as pollen resources, even in regions with intensive agriculture. However, it is unknown how increasing areas of mass-flowering crops like oilseed rape (Brassica napus; OSR) or a decrease of seminatural habitats (SNH) change the temporal and spatial availability of pollen resources for honey bee colonies, and thus foraging distances and frequency in different habitat types. We studied pollen foraging of honey bee colonies in 16 agricultural landscapes with independent gradients of OSR and SNH area within 2 km and used waggle dances and digital geographic maps with major land cover types to reveal the distance and visited habitat type on a landscape level. Mean pollen foraging distance of 1347 decoded bee dances was 1015 m (± 26 m; SEM). In spring, increasing area of flowering OSR within 2 km reduced mean pollen foraging distances from 1324 m to only 435 m. In summer, increasing cover of SNH areas close to the colonies (within 200 m radius) reduced mean pollen foraging distances from 846 to 469 m. Frequency of pollen foragers per habitat type, measured as the number of dances per hour and hectare, was equally high for SNH, grassland, and OSR fields, but lower for other crops and forests. In landscapes with a small proportion of SNH a significantly higher density of pollen foragers on SNH was observed, indicating that pollen resources in such simple agricultural landscapes are more limited. Overall, we conclude that SNH and mass-flowering crops can reduce foraging distances of honey bee colonies at different scales and seasons with possible benefits for the performance of honey bee colonies. Further, mixed agricultural landscapes with a high proportion of SNH reduce foraging densities of honey bees in SNH and thus possible competition for pollen resources. © 2016 by the Ecological Society of America.

  11. Macroinvertebrate Taxonomic and Functional Trait Compositions within Lotic Habitats Affected By River Restoration Practices

    Science.gov (United States)

    White, J. C.; Hill, M. J.; Bickerton, M. A.; Wood, P. J.

    2017-09-01

    The widespread degradation of lotic ecosystems has prompted extensive river restoration efforts globally, but many studies have reported modest ecological responses to rehabilitation practices. The functional properties of biotic communities are rarely examined within post-project appraisals, which would provide more ecological information underpinning ecosystem responses to restoration practices and potentially pinpoint project limitations. This study examines macroinvertebrate community responses to three projects which aimed to physically restore channel morphologies. Taxonomic and functional trait compositions supported by widely occurring lotic habitats (biotopes) were examined across paired restored and non-restored (control) reaches. The multivariate location (average community composition) of taxonomic and functional trait compositions differed marginally between control and restored reaches. However, changes in the amount of multivariate dispersion were more robust and indicated greater ecological heterogeneity within restored reaches, particularly when considering functional trait compositions. Organic biotopes (macrophyte stands and macroalgae) occurred widely across all study sites and supported a high alpha (within-habitat) taxonomic diversity compared to mineralogical biotopes (sand and gravel patches), which were characteristic of restored reaches. However, mineralogical biotopes possessed a higher beta (between-habitat) functional diversity, although this was less pronounced for taxonomic compositions. This study demonstrates that examining the functional and structural properties of taxa across distinct biotopes can provide a greater understanding of biotic responses to river restoration works. Such information could be used to better understand the ecological implications of rehabilitation practices and guide more effective management strategies.

  12. Benthic non-indigenous species among indigenous species and their habitat preferences in Puck Bay (southern Baltic Sea

    Directory of Open Access Journals (Sweden)

    Urszula Janas

    2014-06-01

    Full Text Available To date 11 non-indigenous benthic taxa have been reported in Puck Bay (southern Baltic Sea. Five of the 34 taxa forming the soft bottom communities are regarded as non-indigenous to this area. They are Marenzelleria spp., Mya arenaria, Potamopyrgus antipodarum, Gammarus tigrinus and Amphibalanus improvisus. Non-indigenous species comprised up to 33% of the total number of identified macrofaunal taxa (mean 17%. The average proportion of aliens was 6% (max 46% in the total abundance of macrofauna, and 10% (max 65% in the biomass. A significant positive relationship was found between the numbers of native taxa and non-indigenous species. The number of native taxa was significantly higher on a sea bed covered with vascular plants than on an unvegetated one, but no such relationship was found for their abundance. No significant differences were found in the number and abundance of non-indigenous species between sea beds devoid of vegetation and those covered with vascular plants, Chara spp. or mats of filamentous algae. G. tigrinus preferred a sea bed with vegetation, whereas Marenzelleria spp. decidedly preferred one without vegetation.

  13. Does personal experience affect choice-based preferences for wildfire protection programs?

    Science.gov (United States)

    Armando González-Cabán; Thomas P. Holmes; John B. Loomis; José J. Sánchez

    2013-01-01

    In this paper, we investigate homeowner preferences and willingness to pay for wildfire protection programs using a choice experiment with three attributes: risk, loss, and cost. A phone-mail-phone survey was used to collect data from homeowners predominantly living in medium and high wildfire risk communities in Florida. We tested three hypotheses: (1) homeowner...

  14. Treatment Preferences Affect the Therapeutic Alliance: Implications for Randomized Controlled Trials

    Science.gov (United States)

    Iacoviello, Brian M.; McCarthy, Kevin Scott; Barrett, Marna S.; Rynn, Moira; Gallop, Robert; Barber, Jacques P.

    2007-01-01

    The influence of treatment preferences on the development of the therapeutic alliance was investigated. Seventy-five patients were followed while participating in a randomized controlled trial comparing supportive-expressive psychotherapy with sertraline or pill placebo in the treatment of major depressive disorder. Therapeutic alliance was…

  15. 13 CFR 107.1820 - Conditions affecting issuers of Preferred Securities and/or Participating Securities.

    Science.gov (United States)

    2010-01-01

    ... after April 25, 1994, or if you issue Participating Securities or have Earmarked Assets in your... Preferred Securities or guarantee of Participating Securities and for as long as you own Earmarked Assets... in paragraph (d) of this section: (1) Insolvency or extreme Capital Impairment. You become equitably...

  16. Territory quality affects female preference in a Lake Victoria cichlid fish

    NARCIS (Netherlands)

    Dijkstra, Peter; van der Zee, Elsbeth; Groothuis, Ton G.G.

    Mate preferences on male colour have been implicated in generating and maintaining species diversity among haplochromine cichlid fish. Their lek-like mating system suggests that not only male colour but also territory quality is instrumental inmate choice. We assessed the relative importance of

  17. Factors affecting consumers' preferences for and purchasing decisions regarding pasteurized and raw milk specialty cheeses.

    Science.gov (United States)

    Colonna, A; Durham, C; Meunier-Goddik, L

    2011-10-01

    Eight hundred ninety consumers at a local food festival were surveyed about their specialty cheese purchasing behavior and asked to taste and rate, through nonforced choice preference, 1 of 4 cheese pairs (Cheddar and Gouda) made from pasteurized and raw milks. The purpose of the survey was to examine consumers' responses to information on the safety of raw milk cheeses. The associated consumer test provided information about specialty cheese consumers' preferences and purchasing behavior. Half of the consumers tested were provided with cheese pairs that were identified as being made from unpasteurized and pasteurized milk. The other half evaluated samples that were identified only with random 3-digit codes. Overall, more consumers preferred the raw milk cheeses than the pasteurized milk cheeses. A larger portion of consumers indicated preferences for the raw milk cheese when the cheeses were labeled and thus they knew which samples were made from raw milk. Most of the consumers tested considered the raw milk cheeses to be less safe or did not know if raw milk cheeses were less safe. After being informed that the raw milk cheeses were produced by a process approved by the FDA (i.e., 60-d ripening), most consumers with concerns stated that they believed raw milk cheeses to be safe. When marketing cheese made from raw milk, producers should inform consumers that raw milk cheese is produced by an FDA-approved process. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  18. Habitat Fragmentation Differentially Affects Genetic Variation, Phenotypic Plasticity and Survival in Populations of a Gypsum Endemic.

    Science.gov (United States)

    Matesanz, Silvia; Rubio Teso, María Luisa; García-Fernández, Alfredo; Escudero, Adrián

    2017-01-01

    Habitat fragmentation, i.e., fragment size and isolation, can differentially alter patterns of neutral and quantitative genetic variation, fitness and phenotypic plasticity of plant populations, but their effects have rarely been tested simultaneously. We assessed the combined effects of size and connectivity on these aspects of genetic and phenotypic variation in populations of Centaurea hyssopifolia , a narrow endemic gypsophile that previously showed performance differences associated with fragmentation. We grew 111 maternal families sampled from 10 populations that differed in their fragment size and connectivity in a common garden, and characterized quantitative genetic variation, phenotypic plasticity to drought for key functional traits, and plant survival, as a measure of population fitness. We also assessed neutral genetic variation within and among populations using eight microsatellite markers. Although C. hyssopifolia is a narrow endemic gypsophile, we found substantial neutral genetic variation and quantitative variation for key functional traits. The partition of genetic variance indicated that a higher proportion of variation was found within populations, which is also consistent with low population differentiation in molecular markers, functional traits and their plasticity. This, combined with the generally small effect of habitat fragmentation suggests that gene flow among populations is not restricted, despite large differences in fragment size and isolation. Importantly, population's similarities in genetic variation and plasticity did not reflect the lower survival observed in isolated populations. Overall, our results indicate that, although the species consists of genetically variable populations able to express functional plasticity, such aspects of adaptive potential may not always reflect populations' survival. Given the differential effects of habitat connectivity on functional traits, genetic variation and fitness, our study highlights

  19. Habitat Fragmentation Differentially Affects Genetic Variation, Phenotypic Plasticity and Survival in Populations of a Gypsum Endemic

    Directory of Open Access Journals (Sweden)

    Silvia Matesanz

    2017-05-01

    Full Text Available Habitat fragmentation, i.e., fragment size and isolation, can differentially alter patterns of neutral and quantitative genetic variation, fitness and phenotypic plasticity of plant populations, but their effects have rarely been tested simultaneously. We assessed the combined effects of size and connectivity on these aspects of genetic and phenotypic variation in populations of Centaurea hyssopifolia, a narrow endemic gypsophile that previously showed performance differences associated with fragmentation. We grew 111 maternal families sampled from 10 populations that differed in their fragment size and connectivity in a common garden, and characterized quantitative genetic variation, phenotypic plasticity to drought for key functional traits, and plant survival, as a measure of population fitness. We also assessed neutral genetic variation within and among populations using eight microsatellite markers. Although C. hyssopifolia is a narrow endemic gypsophile, we found substantial neutral genetic variation and quantitative variation for key functional traits. The partition of genetic variance indicated that a higher proportion of variation was found within populations, which is also consistent with low population differentiation in molecular markers, functional traits and their plasticity. This, combined with the generally small effect of habitat fragmentation suggests that gene flow among populations is not restricted, despite large differences in fragment size and isolation. Importantly, population’s similarities in genetic variation and plasticity did not reflect the lower survival observed in isolated populations. Overall, our results indicate that, although the species consists of genetically variable populations able to express functional plasticity, such aspects of adaptive potential may not always reflect populations’ survival. Given the differential effects of habitat connectivity on functional traits, genetic variation and fitness

  20. How climate, migration ability and habitat fragmentation affect the projected future distribution of European beech.

    Science.gov (United States)

    Saltré, Frédérik; Duputié, Anne; Gaucherel, Cédric; Chuine, Isabelle

    2015-02-01

    Recent efforts to incorporate migration processes into species distribution models (SDMs) are allowing assessments of whether species are likely to be able to track their future climate optimum and the possible causes of failing to do so. Here, we projected the range shift of European beech over the 21st century using a process-based SDM coupled to a phenomenological migration model accounting for population dynamics, according to two climate change scenarios and one land use change scenario. Our model predicts that the climatically suitable habitat for European beech will shift north-eastward and upward mainly because (i) higher temperature and precipitation, at the northern range margins, will increase survival and fruit maturation success, while (ii) lower precipitations and higher winter temperature, at the southern range margins, will increase drought mortality and prevent bud dormancy breaking. Beech colonization rate of newly climatically suitable habitats in 2100 is projected to be very low (1-2% of the newly suitable habitats colonised). Unexpectedly, the projected realized contraction rate was higher than the projected potential contraction rate. As a result, the realized distribution of beech is projected to strongly contract by 2100 (by 36-61%) mainly due to a substantial increase in climate variability after 2050, which generates local extinctions, even at the core of the distribution, the frequency of which prevents beech recolonization during more favourable years. Although European beech will be able to persist in some parts of the trailing edge of its distribution, the combined effects of climate and land use changes, limited migration ability, and a slow life-history are likely to increase its threat status in the near future. © 2014 John Wiley & Sons Ltd.

  1. Spatial Models of Abundance and Habitat Preferences of Commerson’s and Peale’s Dolphin in Southern Patagonian Waters

    Science.gov (United States)

    Dellabianca, Natalia A.; Pierce, Graham J.; Raya Rey, Andrea; Scioscia, Gabriela; Miller, David L.; Torres, Mónica A.; Paso Viola, M. Natalia; Schiavini, Adrián C. M.

    2016-01-01

    Commerson’s dolphins (Cephalorhynchus c. commersonii) and Peale’s dolphins (Lagenorhynchus australis) are two of the most common species of cetaceans in the coastal waters of southwest South Atlantic Ocean. Both species are listed as Data Deficient by the IUCN, mainly due to the lack of information about population sizes and trends. The goal of this study was to build spatially explicit models for the abundance of both species in relation to environmental variables using data collected during eight scientific cruises along the Patagonian shelf. Spatial models were constructed using generalized additive models. In total, 88 schools (212 individuals) of Commerson’s dolphin and 134 schools (465 individuals) of Peale’s dolphin were recorded in 8,535 km surveyed. Commerson’s dolphin was found less than 60 km from shore; whereas Peale’s dolphins occurred over a wider range of distances from the coast, the number of animals sighted usually being larger near or far from the coast. Fitted models indicate overall abundances of approximately 22,000 Commerson’s dolphins and 20,000 Peale’s dolphins in the total area studied. This work provides the first large-scale abundance estimate for Peale’s dolphin in the Atlantic Ocean and an update of population size for Commerson’s dolphin. Additionally, our results contribute to baseline data on suitable habitat conditions for both species in southern Patagonia, which is essential for the implementation of adequate conservation measures. PMID:27783627

  2. Channel morphodynamics and habitat recovery in a river reach affected by gravel-mining (River Ésera, Ebro basin)

    Science.gov (United States)

    Lopez-Tarazon, J. A.; Lobera, G.; Andrés-Doménech, I.; Martínez-Capel, F.; Muñoz-Mas, R.; Vallés, F.; Tena, A.; Vericat, D.; Batalla, R. J.

    2012-04-01

    Physical processes in rivers are the result of the interaction between flow regime and hydraulics, morphology, sedimentology and sediment transport. The frequency and magnitude of physical disturbance (i.e. bed stability) control habitat integrity and, consequently, ecological diversity of a particular fluvial system. Most rivers experience human-induced perturbations that alter such hydrosedimentary equilibrium, thus affecting the habitat of aquatic species. A dynamic balance may take long time to be newly attained. Within this context, gravel mining is well known to affect channel characteristics mostly at the local scale, but its effect may also propagate downstream and upstream. Sedimentary forms are modified during extraction and habitat features are reduced or even eliminated. Effects tend to be most acute in contrasted climatic environments, such as the Mediterranean areas, in which climatic and hydrological variability maximises effects of impacts and precludes short regeneration periods. Present research focuses on the evolution of a river reach, which has experienced an intense gravel extraction. The selected area is located in the River Ésera (Ebro basin), where interactions between morphodynamics and habitat recovery are examined. Emphasis is put on monitoring sedimentary, morphological and hydraulic variables to later compare pre (t0) and post (t1, t2... tn) extraction situations. Methodology for all time monitoring steps (i.e. ti) includes: i) characterization of grain size distribution at all of the different hydromorphological units within the reach; ii) description of channel morphology (together with changes before and after floods) by means of close-range aerial photographs, which are taken with a digital camera attached to a 1m3 helium balloon (i.e. BLIMP); and iii) determination of flow parameters from 2D hydraulic modelling that is based on detailed topographical data obtained from Leica® GNSS/GPS and robotic total station, and River

  3. Jasmonic acid-induced changes in Brassica oleracea affect oviposition preference of two specialist herbivores

    OpenAIRE

    Bruinsma, M; Dam, van, J.T.P.; Loon, van, C.D.; Dicke, M

    2007-01-01

    Jasmonic acid (JA) is a key hormone involved in plant defense responses. The effect of JA treatment of cabbage plants on their acceptability for oviposition by two species of cabbage white butterflies, Pieris rapae and P. brassicae, was investigated. Both butterfly species laid fewer eggs on leaves of JA-treated plants compared to control plants. We show that this is due to processes in the plant after JA treatment rather than an effect of JA itself. The oviposition preference for control pla...

  4. High-predation habitats affect the social dynamics of collective exploration in a shoaling fish.

    Science.gov (United States)

    Ioannou, Christos C; Ramnarine, Indar W; Torney, Colin J

    2017-05-01

    Collective decisions play a major role in the benefits that animals gain from living in groups. Although the mechanisms of how groups collectively make decisions have been extensively researched, the response of within-group dynamics to ecological conditions is virtually unknown, despite adaptation to the environment being a cornerstone in biology. We investigate how within-group interactions during exploration of a novel environment are shaped by predation, a major influence on the behavior of prey species. We tested guppies (Poecilia reticulata) from rivers varying in predation risk under controlled laboratory conditions and find the first evidence of differences in group interactions between animals adapted to different levels of predation. Fish from high-predation habitats showed the strongest negative relationship between initiating movements and following others, which resulted in less variability in the total number of movements made between individuals. This relationship between initiating movements and following others was associated with differentiation into initiators and followers, which was only observed in fish from high-predation rivers. The differentiation occurred rapidly, as trials lasted 5 min, and was related to shoal cohesion, where more diverse groups from high-predation habitats were more cohesive. Our results show that even within a single species over a small geographical range, decision-making in a social context can vary with local ecological factors.

  5. Habitat quality affects stress responses and survival in a bird wintering under extremely low ambient temperatures

    Science.gov (United States)

    Cīrule, Dina; Krama, Tatjana; Krams, Ronalds; Elferts, Didzis; Kaasik, Ants; Rantala, Markus J.; Mierauskas, Pranas; Luoto, Severi; Krams, Indrikis A.

    2017-12-01

    Animals normally respond to stressful environmental stimuli by releasing glucocorticoid hormones. We investigated whether baseline corticosterone (CORT), handling-induced corticosterone concentration(s), and body condition indices of members of willow tit ( Poecile montanus) groups differed while wintering in old growth forests and managed young forests in mild weather conditions and during cold spells. Willow tits spend the winter season in non-kin groups in which dominant individuals typically claim their priority to access resources, while subordinate individuals may experience greater levels of stress and higher mortality, especially during cold spells. We captured birds to measure baseline CORT and levels of handling-induced CORT secretion after 20 min of capture. Willow tits in the young forests had higher baseline CORT and a smaller increase in CORT in response to capture than individuals in the old forests. Baseline CORT was higher in females and juvenile birds compared to adult males, whereas handling-induced CORT secretion did not differ between birds of different ages. During cold spells, baseline CORT of willow tits increased and handling-induced CORT secretion decreased, especially in birds in young forests. Willow tits' survival was higher in the old forests, with dominant individuals surviving better than subordinates. Our results show that changes in CORT secretion reflect responses to habitat quality and climate harshness, indicating young managed coniferous forests as a suboptimal habitat for the willow tit.

  6. The Analysis of the Factors Affecting Fruit Mineral Water Preferences By Logit Model: The Case of Beypazarı

    Directory of Open Access Journals (Sweden)

    Rüveyda Kızıloğlu

    2014-02-01

    Full Text Available This study aimed to determine the factors affecting the consumption of fruit mineral water by households living in the urban areas in Beypazari. The main material of the study consisted of data collected through a questionnaire from 240 households. The study also aimed to reveal the features of the households and the preferences, tastes and thoughts of the households affecting the consumption. Binary Logit Regression method was employed to determine the factors affecting the fruit mineral water consumption. Seven variables affecting the likelihood of fruit mineral water consumption were identified based on the regression analysis employed. The companies in food industry are expected to increase the number of their consumers while they are determining their strategies to raise income rates or while they are increasing the current potential through studies aiming women and young people.

  7. Logging impacts on avian species richness and composition differ across latitudes and foraging and breeding habitat preferences.

    Science.gov (United States)

    LaManna, Joseph A; Martin, Thomas E

    2017-08-01

    Understanding the causes underlying changes in species diversity is a fundamental pursuit of ecology. Animal species richness and composition often change with decreased forest structural complexity associated with logging. Yet differences in latitude and forest type may strongly influence how species diversity responds to logging. We performed a meta-analysis of logging effects on local species richness and composition of birds across the world and assessed responses by different guilds (nesting strata, foraging strata, diet, and body size). This approach allowed identification of species attributes that might underlie responses to this anthropogenic disturbance. We only examined studies that allowed forests to regrow naturally following logging, and accounted for logging intensity, spatial extent, successional regrowth after logging, and the change in species composition expected due to random assembly from regional species pools. Selective logging in the tropics and clearcut logging in temperate latitudes caused loss of species from nearly all forest strata (ground to canopy), leading to substantial declines in species richness (up to 27% of species). Few species were lost or gained following any intensity of logging in lower-latitude temperate forests, but the relative abundances of these species changed substantially. Selective logging at higher-temperate latitudes generally replaced late-successional specialists with early-successional specialists, leading to no net changes in species richness but large changes in species composition. Removing less basal area during logging mitigated the loss of avian species from all forests and, in some cases, increased diversity in temperate forests. This meta-analysis provides insights into the important role of habitat specialization in determining differential responses of animal communities to logging across tropical and temperate latitudes. © 2016 Cambridge Philosophical Society.

  8. Logging impacts on avian species richness and composition differ across latitudes relative to foraging and breeding habitat preferences

    Science.gov (United States)

    LaManna, Joseph A.; Martin, Thomas E.

    2017-01-01

    Understanding the causes underlying changes in species diversity is a fundamental pursuit of ecology. Animal species richness and composition often change with decreased forest structural complexity associated with logging. Yet differences in latitude and forest type may strongly influence how species diversity responds to logging. We performed a meta-analysis of logging effects on local species richness and composition of birds across the world and assessed responses by different guilds (nesting strata, foraging strata, diet, and body size). This approach allowed identification of species attributes that might underlie responses to this anthropogenic disturbance. We only examined studies that allowed forests to regrow naturally following logging, and accounted for logging intensity, spatial extent, successional regrowth after logging, and the change in species composition expected due to random assembly from regional species pools. Selective logging in the tropics and clearcut logging in temperate latitudes caused loss of species from nearly all forest strata (ground to canopy), leading to substantial declines in species richness (up to 27% of species). Few species were lost or gained following any intensity of logging in lower-latitude temperate forests, but the relative abundances of these species changed substantially. Selective logging at higher-temperate latitudes generally replaced late-successional specialists with early-successional specialists, leading to no net changes in species richness but large changes in species composition. Removing less basal area during logging mitigated the loss of avian species from all forests and, in some cases, increased diversity in temperate forests. This meta-analysis provides insights into the important role of habitat specialization in determining differential responses of animal communities to logging across tropical and temperate latitudes.

  9. Social variables affecting mate preferences, copulation and reproductive outcome in a pack of free-ranging dogs.

    Directory of Open Access Journals (Sweden)

    Simona Cafazzo

    Full Text Available Mating and reproductive outcome is often determined by the simultaneous operation of different mechanisms like intra-sexual competition, mating preferences and sexual coercion. The present study investigated how social variables affected mating outcome in a pack of free-ranging dogs, a species supposed to have lost most features of the social system of wolves during domestication. We found that, although the pack comprised multiple breeding individuals, both male copulation success and female reproductive success were positively influenced by a linear combination of dominance rank, age and leadership. Our results also suggest that mate preferences affect mating outcome by reinforcing the success of most dominant individuals. In particular, during their oestrous period bitches clearly searched for the proximity of high-ranking males who displayed affiliative behaviour towards them, while they were more likely to reject the males who intimidated them. At the same time, male courting effort and male-male competition for receptive females appeared to be stronger in the presence of higher-ranking females, suggesting a male preference for dominant females. To our knowledge, these results provide the first clear evidence of social regulation of reproductive activities in domestic dogs, and suggest that some common organizing mechanisms may contribute to shape the social organization of both dogs and wolves.

  10. Uncertainty management and communication preferences related to genetic relativism among families affected by down syndrome, Marfan syndrome, and neurofibromatosis.

    Science.gov (United States)

    Parrott, Roxanne; Peters, Kathryn F; Traeder, Tara

    2012-01-01

    Genes hold opportunities for us to look backward and forward in family health and disease incidence. Our beliefs about genes' roles in health form around frameworks relating to personal control, and the influence of social networks and/or religious faith on genetic expression in health. These genetic relativistic frameworks were found to predict levels of illness uncertainty among 541 diagnosed adults and family members affected by neurofibromatosis, Down syndrome, and Marfan syndrome. Participants were recruited and surveyed about their expectations and preferences for communicating about their respective disorder, with illness uncertainty found to predict the desire to communicate about the condition and to manage related uncertainty. The desire to manage uncertainty in ways that foster control and hope partially mediated the relationship between illness uncertainty and communication preferences. Negative feelings about the condition, which were stronger for affected participants than for family members, related to illness uncertainty, the desire to manage uncertainty, and communication preferences, mediating the relationship between illness uncertainty and uncertainty management. Findings contribute to research in illness uncertainty management and have pragmatic implications for the design of counseling and educational materials associated with the genetic conditions considered in this research.

  11. How Can Interdisciplinarity Of food, Design, Architecture, Engineering And Pedagogy Affect Children's Eating Habits And Food Preferences?

    DEFF Research Database (Denmark)

    Fisker, Anna Marie; Hermanssdottir, Sunna; Rasmussen, Mai

    not to miss out any relevant angles and opportunities regarding the task to be solved (Fisker et al., 2011). This leads to the purpose of this study, which is to explore if and how interdisciplinary approach involving the disciplines of food, design, engineering, architecture and pedagogy can create solutions...... to create a positive and strong relationship to the carrot, and therefore the activities were all based on sensory and playfulness, as results show, that sensory education has positive effect on children’s food preferences (Reverdy et al, 2010) and positive reinforcement retrains the brain to learn new...... by drawing face and clothes on it. To strengthen the case and to research if physical architecture affects the children's eating habits and food preferences, we looked into the possibility, if the physical room for the activities had any relation to this effect. A 10 x 10 meter carrot pavilion with “walls...

  12. FACTORS THAT AFFECT TRANSPORT MODE PREFERENCE FOR GRADUATE STUDENTS IN THE NATIONAL UNIVERSITY OF MALAYSIA BY LOGIT METHOD

    Directory of Open Access Journals (Sweden)

    ALI AHMED MOHAMMED

    2013-06-01

    Full Text Available A study was carried out to examine the perceptions and preferences of students on choosing the type of transportation for their travels in university campus. This study focused on providing personal transport users road transport alternatives as a countermeasure aimed at shifting car users to other modes of transportation. Overall 456 questionnaires were conducted to develop a choice of transportation mode preferences. Consequently, Logit model and SPSS were used to identify the factors that affect the determination of the choice of transportation mode. Results indicated that by reducing travel time by 70% the amount of private cars users will be reduced by 84%, while reduction the travel cost was found to be highly improving the public modes of utilization. This study revealed positive aspects is needed to shift travellers from private modes to public. The positive aspect contributes to travel time and travel cost reduction, hence improving the services, whereby contributing to sustainability.

  13. Jasmonic acid-induced changes in Brassica oleracea affect oviposition preference of two specialist herbivores.

    Science.gov (United States)

    Bruinsma, Maaike; Van Dam, Nicole M; Van Loon, Joop J A; Dicke, Marcel

    2007-04-01

    Jasmonic acid (JA) is a key hormone involved in plant defense responses. The effect of JA treatment of cabbage plants on their acceptability for oviposition by two species of cabbage white butterflies, Pieris rapae and P. brassicae, was investigated. Both butterfly species laid fewer eggs on leaves of JA-treated plants compared to control plants. We show that this is due to processes in the plant after JA treatment rather than an effect of JA itself. The oviposition preference for control plants is adaptive, as development time from larval hatch until pupation of P. rapae caterpillars was longer on JA-treated plants. Total glucosinolate content in leaf surface extracts was similar for control and treated plants; however, two of the five glucosinolates were present in lower amounts in leaf surface extracts of JA-treated plants. When the butterflies were offered a choice between the purified glucosinolate fraction isolated from leaf surface extracts of JA-treated plants and that from control plants, they did not discriminate. Changes in leaf surface glucosinolate profile, therefore, do not seem to explain the change in oviposition preference of the butterflies after JA treatment, suggesting that as yet unknown infochemicals are involved.

  14. How to deal with ground truthing affected by human-induced habitat change?: Identifying high-quality habitats for the Critically Endangered Red Siskin.

    Science.gov (United States)

    Sánchez-Mercado, Ada; Rodríguez-Clark, Kathryn M; Miranda, Jhonathan; Ferrer-Paris, José Rafael; Coyle, Brian; Toro, Samuel; Cardozo-Urdaneta, Arlene; Braun, Michael J

    2018-01-01

    Species distribution models (SDM) can be valuable for identifying key habitats for conservation management of threatened taxa, but anthropogenic habitat change can undermine SDM accuracy. We used data for the Red Siskin ( Spinus cucullatus ), a critically endangered bird and ground truthing to examine anthropogenic habitat change as a source of SDM inaccuracy. We aimed to estimate: (1) the Red Siskin's historic distribution in Venezuela; (2) the portion of this historic distribution lost to vegetation degradation; and (3) the location of key habitats or areas with both, a high probability of historic occurrence and a low probability of vegetation degradation. We ground-truthed 191 locations and used expert opinion as well as landscape characteristics to classify species' habitat suitability as excellent, good, acceptable, or poor. We fit a Random Forest model (RF) and Enhanced Vegetation Index (EVI) time series to evaluate the accuracy and precision of the expert categorization of habitat suitability. We estimated the probability of historic occurrence by fitting a MaxLike model using 88 presence records (1960-2013) and data on forest cover and aridity index. Of the entire study area, 23% (20,696 km 2 ) had a historic probability of Red Siskin occurrence over 0.743. Furthermore, 85% of ground-truthed locations had substantial reductions in mean EVI, resulting in key habitats totaling just 976 km 2 , in small blocks in the western and central regions. Decline in Area of Occupancy over 15 years was between 40% and 95%, corresponding to an extinction risk category between Vulnerable and Critically Endangered. Relating key habitats with other landscape features revealed significant risks and opportunities for proposed conservation interventions, including the fact that ongoing vegetation degradation could limit the establishment of reintroduced populations in eastern areas, while the conservation of remaining key habitats on private lands could be improved with

  15. Modeling habitat and environmental factors affecting mosquito abundance in Chesapeake, Virginia

    Science.gov (United States)

    Bellows, Alan Scott

    The models I present in this dissertation were designed to enable mosquito control agencies in the mid-Atlantic region that oversee large jurisdictions to rapidly track the spatial and temporal distributions of mosquito species, especially those species known to be vectors of eastern equine encephalitis and West Nile virus. I was able to keep these models streamlined, user-friendly, and not cost-prohibitive using empirically based digital data to analyze mosquito-abundance patterns in real landscapes. This research is presented in three major chapters: (II) a series of semi-static habitat suitability indices (HSI) grounded on well-documented associations between mosquito abundance and environmental variables, (III) a dynamic model for predicting both spatial and temporal mosquito abundance based on a topographic soil moisture index and recent weather patterns, and (IV) a set of protocols laid out to aid mosquito control agencies for the use of these models. The HSIs (Chapter II) were based on relationships of mosquitoes to digital surrogates of soil moisture and vegetation characteristics. These models grouped mosquitoes species derived from similarities in habitat requirements, life-cycle type, and vector competence. Quantification of relationships was determined using multiple linear regression models. As in Chapter II, relationships between mosquito abundance and environmental factors in Chapter III were quantified using regression models. However, because this model was, in part, a function of changes in weather patterns, it enables the prediction of both 'where' and 'when' mosquito outbreaks are likely to occur. This model is distinctive among similar studies in the literature because of my use of NOAA's NEXRAD Doppler radar (3-hr precipitation accumulation data) to quantify the spatial and temporal distributions in precipitation accumulation. \\ Chapter IV is unique among the chapters in this dissertation because in lieu of presenting new research, it

  16. Cuticular Hydrocarbon Content that Affects Male Mate Preference of Drosophila melanogaster from West Africa

    Directory of Open Access Journals (Sweden)

    Aya Takahashi

    2012-01-01

    Full Text Available Intraspecific variation in mating signals and preferences can be a potential source of incipient speciation. Variable crossability between Drosophila melanogaster and D. simulans among different strains suggested the abundance of such variations. A particular focus on one combination of D. melanogaster strains, TW1(G23 and Mel6(G59, that showed different crossabilities to D. simulans, revealed that the mating between females from the former and males from the latter occurs at low frequency. The cuticular hydrocarbon transfer experiment indicated that cuticular hydrocarbons of TW1 females have an inhibitory effect on courtship by Mel6 males. A candidate component, a C25 diene, was inferred from the gas chromatography analyses. The intensity of male refusal of TW1 females was variable among different strains of D. melanogaster, which suggested the presence of variation in sensitivity to different chemicals on the cuticle. Such variation could be a potential factor for the establishment of premating isolation under some conditions.

  17. Eww she sneezed! Contamination context affects children's food preferences and consumption.

    Science.gov (United States)

    DeJesus, Jasmine M; Shutts, Kristin; Kinzler, Katherine D

    2015-04-01

    Does contextual information about disgust influence children's food consumption and subjective experience of taste? Three- to eight-year-old children (N = 60) were presented with two identical foods, yet children were led to believe that one food had been contaminated by sneezing and licking, while the other was clean. When given the opportunity to eat the foods, 5- to 8-year-old children consumed more clean food and rated the clean food's taste more positively; younger children did not distinguish between the foods. The relation between contamination and subjective taste held even among children who ate both foods and had direct evidence that they were identical. These data indicate that children's consumption behavior and food preferences are influenced by information external to foods themselves. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Factors affecting oviposition site preference by Toxorhynchites splendens in the laboratory.

    Science.gov (United States)

    Benzon, G L; Apperson, C S; Clay, W

    1988-03-01

    In a series of laboratory oviposition assays, gravid Toxorhynchites splendens exhibited a preference for cups containing Aedes aegypti larval rearing water, but not for cups containing liquid cultures of bacteria, live Ae. aegypti in distilled water, Ae. aegypti larval holding water with reduced bacterial contamination, or methyl propionate at 0.1, 0.2 and 0.3% in distilled water. Preoviposition flight behavior was elicited by dark-colored containers, but few eggs were deposited if they contained no water. An invisible source of humidity placed in cups enhanced oviposition, but a reflective surface placed in dry cups did not. It is concluded that this species is strongly influenced by humidity and visual stimuli in the acceptance of a site for oviposition.

  19. A highly diverse molluscan assemblage associated with eelgrass beds (Zostera marina L. in the Alboran Sea: Micro-habitat preference, feeding guilds and biogeographical distribution

    Directory of Open Access Journals (Sweden)

    José L. Rueda

    2009-12-01

    Full Text Available The fauna of molluscs associated with deep subtidal Zostera marina beds (12-16 m in southern Spain (Alboran Sea has been characterised in terms of micro-habitat preference, feeding guilds and biogeographical affinity. The species list (162 taxa is based on sampling completed before the strong eelgrass decline experienced in 2005-2006, using different methods (small Agassiz trawl covering 222 m2 and quadrates covering 0.06 m2 and different temporal scales (months, day/night. Dominant epifaunal species are Jujubinus striatus, Rissoa spp. and Smaragdia viridis in the leaf stratum and Nassarius pygmaeus, Bittium reticulatum and Calliostoma planatum on the sediment. Nevertheless, the infauna dominated the epifauna in terms of number of individuals, including mainly bivalves (Tellina distorta, T. fabula, Dosinia lupinus. The epifauna of both the sediment and leaf strata included high numbers of species, probably due to the soft transition between vegetated and unvegetated areas. The dominant feeding guilds were deposit feeders, filter feeders and peryphiton grazers, but ectoparasites (eulimids, seagrass grazers (Smaragdia viridis and an egg feeder (Mitrella minor also occurred, unlike in other eelgrass beds of Europe. The molluscan fauna of these Z. marina beds is essentially derived from the local fauna, which includes many widely distributed species along European coasts, with a low representation of strictly Mediterranean or strictly Atlantic species. This fauna is richer than that found in other eelgrass beds of Europe, and deserves important attention for conservation.

  20. When and why do ideal partner preferences affect the process of initiating and maintaining romantic relationships?

    Science.gov (United States)

    Eastwick, Paul W; Finkel, Eli J; Eagly, Alice H

    2011-11-01

    Three studies explored how the traits that people ideally desire in a romantic partner, or ideal partner preferences, intersect with the process of romantic relationship initiation and maintenance. Two attraction experiments in the laboratory found that, when participants evaluated a potential romantic partner's written profile, they expressed more romantic interest in a partner whose traits were manipulated to match (vs. mismatch) their idiosyncratic ideals. However, after a live interaction with the partner, the match vs. mismatch manipulation was no longer associated with romantic interest. This pattern appeared to have emerged because participants reinterpreted the meaning of the traits as they applied to the partner, a context effect predicted by classic models of person perception (S. E. Asch, 1946). Finally, a longitudinal study of middle-aged adults demonstrated that participants evaluated a current romantic partner (but not a partner who was merely desired) more positively to the extent that the partner matched their overall pattern of ideals across several traits; the match in level of ideals (i.e., high vs. low ratings) was not relevant to participants' evaluations. In general, the match between ideals and a partner's traits may predict relational outcomes when participants are learning about a partner in the abstract and when they are actually in a relationship with the partner, but not when considering potential dating partners they have met in person.

  1. Factors affecting career preferences of medical students at the College of Medicine, Malawi.

    Science.gov (United States)

    Yeganeh-Arani, Erfan; Chandratilake, Mudawa; Muula, Adamson S

    2012-03-07

    The shortage of doctors in all specialties in Malawi is particularly severe in rural areas. Contributory factors are the low number of students graduating each year, migration of doctors, and the preference of new graduates for practising in urban areas. Attempts to increase the output from Malawi's only medical school are insufficient to meet the country's healthcare needs. We studied the factors influencing career choices of medical undergraduates of the College of Medicine in Blantyre, Malawi, who were surveyed by means of a self-administered questionnaire (N=205) and individual interviews (N=17). Most respondents (89.4%) indicated that they intend to specialise abroad, predominantly to study in 'better institutions' and to get the 'experience' of a different country; 87.0% indicated that they intend to live in Malawi long term. Although, in general, the rural lifestyle was unattractive to medical students, respondents from rural areas and small towns, and whose parents were 'non-professionals', were more likely to intend working in rural areas and small towns, and to settle in Malawi, than students from urban and professional families. The College of Medicine should consider increasing its intake of students with lower socio-economic backgrounds and from rural areas/small towns to increase the number of doctors working in rural areas and settling in Malawi. However, the Ministry of Health may need a multipronged approach to reduce the mismatch between doctors' career expectations and the country's healthcare needs.

  2. Factors Affecting the Consumer Purchasing Decisions of Perishable Foods: Exploring the Attitudes and the Preferences

    Directory of Open Access Journals (Sweden)

    Muhammad Rehan MASOOM

    2015-09-01

    Full Text Available The present study is designed to make a comprehensive understanding of the attitude of the urban consumers and explore the factors involved in dealing with the perishable food of certain kinds. The rise of the middle class stipulates the enhancement of the shopping environment; hence witnessing a substantial increase of the number of the supermarkets in developing countries like Bangladesh will not be surprising. A number of urban supermarkets in recent times start selling perishable foods that were once available in Bangladesh only in flea markets (Kaccha Bazaar. However, due to the lack of proper infrastructure, agro-based perishable food reaches the urban market via a long process of chain mediations and raises concerns about quality and price for both retailers and consumers. Very often the attitudes of consumers regarding perishable foods are unknown and their preferences remain unidentified. This high level of uncertainty regarding the attitude of consumers and the unpopularity regarding overall food quality need to be resolved to ensure the continuity of the business and guarantee the quality of the products. This has made the study of the consumers’ attitude towards perishable food, especially relevant for emerging economies like Bangladesh. The data is collected from one hundred (100 consumers, who buy food regularly from both super-shops and flea markets in Dhaka city. The collected data are analyzed in terms of factors like importance, expectation and perceived actual level of value to show the gap in terms of perishable foods involved.

  3. Pregnancy planning preferences among people and couples affected by human immunodeficiency virus: Piloting a discrete choice experiment.

    Science.gov (United States)

    Loutfy, Mona; Kennedy, V Logan; Sanandaji, Morvarid; Barry, Fatimatou; Ongoiba, Fanta; Muchenje, Marvelous; Tharao, Wangari; Regier, Dean A

    2017-01-01

    Decision-making related to pregnancy planning is complex and human immunodeficiency virus (HIV) may further complicate the process. With increasing rates of pregnancy among individuals affected by HIV, the need to understand decision-making is imperative. The primary objectives of this pilot study were to confirm the feasibility of using discrete choice experimentation (DCE) to elicit an understanding of this process and to determine the acceptability of the choice factors that were included in two novel DCEs, while gathering a preliminary understanding of preference. The choice attributes were risk of vertical HIV transmission, risk of horizontal HIV transmission, cost, probability of conception, method of conception, and travel time. Thirteen respondents completed a DCE for serodiscordant couples in which the female partner was HIV-positive, and 12 respondents completed a DCE for seroconcordant couples. All respondents' utility for an increased chance of a successful pregnancy was positive and statistically significant. In the serodiscordant dyads, the attributes of risk of horizontal transmission, risk of vertical transmission, a 5-h travel time to clinic, and cost were significantly associated with decreased utility. In the seroconcordant dyads, only the attributes of chance of risk of vertical transmission and cost were significantly associated with decreased utility. The serodiscordant dyads preferred home insemination with a syringe and the seroconcordant couples preferred conception methods within fertility clinics, over condomless sex with timed ovulation. On average, participants were willing to pay more for greater chance of conception and less willing to pay for increased risk of transmission. Couples affected by HIV are willing to participate in a DCE and the attributes that were included all seem relevant except risk of vertical transmission. There are various real-life trade-offs that are made during pregnancy planning with HIV and better

  4. Affective sensory tests and internal analysis of preference in acceptability assessment of Brazilian varietal white wines

    OpenAIRE

    BEHRENS, Jorge H.; SILVA, Maria Aparecida A. P. da; WAKELING, Ian N.

    1999-01-01

    The acceptability of nine commercial brazilian varietal white table wines (Riesling, Chardonnay and Gewürztraminer) was evaluated using sensory affective tests. The samples were assessed by 43 consumers of brazilian white wines using he nine-point structured hedonic scale. Judges were recruited based on their responses to a questionnary about consumer?s behavior towards white wines consumption. Subsequently, Analysis of Variance (ANOVA) with means comparision (Tukey test) and Internal Analysi...

  5. How does the job applicants' ethnicity affect the selection process? : Norms, Preferred competencies and expected fit

    OpenAIRE

    Wolgast, Sima

    2017-01-01

    The present thesis aimed to study different factors influencing recruiters when recruiting from an applicant pool with applicants from an ethnic ingroup and outgroup. Ethnicity was predicted to influence recruiters’ perception and behaviour in different phases during recruitment. Study I demonstrated that company norms affect recruiters’ perception of what an employee should be like. Company norms, either emphasizing cohesion (employees should “fit in”) or fairness (everybody should be treate...

  6. The Factors affecting Preference to select foreign universities for studying view points of graduated students from abroad universities, 2014

    Directory of Open Access Journals (Sweden)

    MA Hosseini

    2015-12-01

    Full Text Available Introduction: The aim of the study was to determine the effective factors on choosing universities and countries abroad for studying by graduated students. Method: It was a descriptive-analytical study. This study was performed on 160 graduates who referred to the Center for Educational Services, Ministry of Health and Medical Education and International Conference Center of Iran during the year 2013. The data were gathered through the questionnaire prepared by the researcher. The internal consistency of the questionnaire in all of the subscales was confirmed using Cronbach alpha and it was more than 7%. To determine the main factors affecting on preferences in studying abroad, single-sample T-test and to determine the priority of each factor Friedman test was used. Results: Most of the participants (%64.3 were males. The average impact of science and technology factors was 2.91 and the average impact of factors related to admitting students was 1.83. The impact of factors related to student admission, social and cultural factors, science and technology and economic factors on the preference of studying in universities abroad on the perspective of graduates were meaningful (P-value 0.001. Conclusion: The findings of this study revealed that among main factors of preferences of graduates about studying abroad, science and technology factors had the highest impact and the student admission factor had the lowest impact. Among the science and technology factors, the factors related to more facilities on the Internet access and lack of restriction on accessing to sites were the most important factors for studying abroad. .

  7. Looking is buying. How visual attention and choice are affected by consumer preferences and properties of the supermarket shelf.

    Science.gov (United States)

    Gidlöf, Kerstin; Anikin, Andrey; Lingonblad, Martin; Wallin, Annika

    2017-09-01

    There is a battle in the supermarket isle, a battle between what the consumer wants and what the retailer and others want her to see, and subsequently to buy. Product packages and displays contain a number of features and attributes tailored to catch consumers' attention. These are what we call external factors comprising the visual saliency, the number of facings, and the placement of each product. But a consumer also brings with her a number of goals and interests related to the products and their attributes. These are important internal factors, including brand preferences, price sensitivity, and dietary inclinations. We fit mobile eye trackers to consumers visiting real-life supermarkets in order to investigate to what extent external and internal factors affect consumers' visual attention and purchases. Both external and internal factors influenced what products consumers looked at, with a strong positive interaction between visual saliency and consumer preferences. Consumers appear to take advantage of visual saliency in their decision making, using their knowledge about products' appearance to guide their visual attention towards those that fit their preferences. When it comes to actual purchases, however, visual attention was by far the most important predictor, even after controlling for all other internal and external factors. In other words, the very act of looking longer or repeatedly at a package, for any reason, makes it more likely that this product will be bought. Visual attention is thus crucial for understanding consumer behaviour, even in the cluttered supermarket environment, but it cannot be captured by measurements of visual saliency alone. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Do positive affectivity and boundary preferences matter for work-family enrichment? A study of human service workers.

    Science.gov (United States)

    McNall, Laurel A; Scott, Lindsay D; Nicklin, Jessica M

    2015-01-01

    More individuals than ever are managing work and family roles, but relatively little research has been done exploring whether boundary preferences help individuals benefit from multiple role memberships. Drawing on Greenhaus and Powell's (2006) work-family enrichment theory, along with Boundary Theory (Ashforth, Kreiner, & Fugate, 2000) and Conservation of Resources Theory (Hobfoll, 2002), we explore the impact of personal characteristics as enablers of work-family enrichment, and in turn, work outcomes relevant to human service workers: turnover intentions and emotional exhaustion. In a 2-wave study of 161 human service employees, we found that individuals high in positive affectivity were more likely to experience both work-to-family and family to-work enrichment, whereas those with preferences toward integration were more likely to experience work-to-family enrichment (but not family to-work enrichment). In turn, work-to-family enrichment (but not family to-work enrichment) was related to lower turnover intentions and emotional exhaustion. Enrichment served as a mediating mechanism for only some of the hypothesized relationships. Implications for theory and practice are discussed. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  9. Ecological and social factors affecting the local habitat distribution of western sandpipers wintering at Bah?Santa Mar? Northwest Mexico

    OpenAIRE

    Fernᮤez Aceves, Guillermo Juan

    2005-01-01

    The process of habitat selection often requires individuals to choose among habitats that differ in foraging profitability and predation danger. The local habitat distribution of Western Sandpipers (Calidris maur~] was studied at Bahia Santa Maria, northwest Mexico, for three non-breeding seasons (1 999-2002). Western Sandpipers are highly sexually dimorphic, males being lighter and smaller-billed than females, and thus males may use visual foraging more often, be more susceptible to interfer...

  10. Does the scale of our observational window affect our conclusions about correlations between endangered salmon populations and their habitat?

    Science.gov (United States)

    Blake E. Feist; E. Ashley Steel; David W. Jensen; Damon N.D. Sather

    2010-01-01

    Differences in the strength of species-habitat relationships across scales provide insights into the mechanisms that drive these relationships and guidance for designing in situ monitoring programs, conservation efforts and mechanistic studies. The scale of our observation can also impact the strength of perceived relationships between animals and habitat conditions....

  11. The Development of Automated Detection Techniques for Passive Acoustic Monitoring as a Tool for Studying Beaked Whale Distribution and Habitat Preferences in the California Current Ecosystem

    Science.gov (United States)

    Yack, Tina M.

    California Bight (SCB). The preliminary measurement of the visually validated Baird's beaked whale echolocation signals recorded from the ship-based towed array were used as a basis for identifying Baird's signals in the seafloor-mounted autonomous recorder data. The passive acoustic detection algorithms for beaked whales developed using data from Chapters 2 and 3 were field tested during a three year period to test the reliability of acoustic beaked whale monitoring techniques and to use these methods to describe beaked whale habitat in the SCB. In 2009 and 2010, PAM methods using towed hydrophone arrays were tested. These methods proved highly effective for real-time detection of beaked whales in the SCB and were subsequently implemented in 2011 to successfully detect and track beaked whales during the ongoing Southern California Behavioral Response Study (SOCAL-BRS). The final step in this research was to utilize the passive acoustic detection techniques developed herin to predictively model beaked whale habitat use and preferences in the CCE. This chapter uses a multifaceted approach to model beaked whale encounter rates in the CCE. Beaked whale acoustic encounters are utilized to inform Generalized Additive Models (GAMs) of encounter rate for beaked whales in the CCE and compare these to visual based models. Acoustic and visual based models were independently developed for a small beaked whale group and Baird's beaked whales. Two models were evaluated for visual and acoustic encounters, one that also included Beaufort sea state as a predictor variable in addition to those listed and one that did not include Beaufort sea state. (Abstract shortened by UMI.)

  12. HOW ARE PLANT SPECIES IN CENTRAL EUROPEAN BEECH (FAGUS SYLVATICA L. FORESTS AFFECTED BY TEMPERATURE CHANGES? SHIFT OF POTENTIAL SUITABLE HABITATS UNDER GLOBAL WARMING

    Directory of Open Access Journals (Sweden)

    M. C. Jantsch

    2013-10-01

    Full Text Available This study reveals which temperature range is favoured or avoided by 156 forest plant species and how the distribution of potential suitable habitats of species in beech forests may change in the future. We performed 140 phytosociological relevés along a temperature gradient (4.1 to 9.8 °C in Bavaria, southern Germany, on south exposed slopes. One half of the plots were located on acidic substrate, the other half on base-rich substrate. Generalized linear models (GLM were used to analyse species occurrence along the temperature gradient and to model habitats for species in beech forests under a present (1971-2000 and a future climate (2071-2100 scenario assuming a temperature increase of 1.8 °C. Herb species of beech forests are more adapted to lower temperatures and tree species more to higher temperatures. Current habitats will clearly change under increasing temperatures. We found large habitat losses for Luzula sylvatica (Huds. Gaudin, Maianthemum bifolium (L. F. W. Schmidt, Picea abies (L. H. Karst., Prenanthes purpurea L. and large habitat gains for Carpinus betulus L., Impatiens parviflora DC., Prunus avium (L. L. and Quercus petraea (Matt. Liebl. on both substrates. Forestry will be affected positively as well as negatively with a change in tree cultivation. Losses in biodiversity might be strong for mountainous forests and must also be considered in future conservation plans.

  13. Interplay between habitat fragmentation and climate change : inbreeding affects the response to thermal stress in Drosophila melanogaster

    NARCIS (Netherlands)

    Joubert, D.; Bijlsma, R.

    2010-01-01

    Climate change, exerting thermal stress, and habitat destruction and fragmentation, resulting in genetic drift and inbreeding, are amongst the most disturbing human activities that endanger global biodiversity. We studied the interplay between these 2 processes using Drosophila melanogaster as a

  14. Aggression and prosocial behaviors in social conflicts mediating the influence of cold social intelligence and affective empathy on children's social preference.

    Science.gov (United States)

    Carreras, M R; Braza, P; Muñoz, J M; Braza, F; Azurmendi, A; Pascual-Sagastizabal, E; Cardas, J; Sánchez-Martín, J R

    2014-08-01

    This study proposes a model in which aggressive and prosocial behaviors exhibited in social conflicts mediate the influence of empathy and social intelligence to children's social preference by same-sex peers. Data were obtained from kindergarten to the end of the first grade. The sample yielded 117 Spanish children (64 girls and 53 boys) with a mean age of 62.8 months (SD = 3.3) at the beginning of the study. For boys, affective empathy contributed to boys' social preference through a decrease in physical aggression as responses to social conflict. For girls, affective empathy had an indirect effect on girls' preference by increasing assistance to others in their conflicts. No mediating effect in the contribution of social intelligence on girls' social preference was detected. Our results suggest that, only for girls, cold social intelligence can promote both indirect aggression (coercive strategic that do not leave social preference, at least at these ages) and behaviors that lead social preference (such as prosocial behaviors). © 2014 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

  15. Does coastal lagoon habitat quality affect fish growth rate and their recruitment? Insights from fishing and acoustic surveys

    Science.gov (United States)

    Brehmer, P.; Laugier, T.; Kantoussan, J.; Galgani, F.; Mouillot, D.

    2013-07-01

    Ensuring the sustainability of fish resources necessitates understanding their interaction with coastal habitats, which is becoming ever more challenging in the context of ever increasing anthropogenic pressures. The ability of coastal lagoons, exposed to major sources of disturbance, to provide resources and suitable habitats for growth and survival of juvenile fish is especially important. We analysed three lagoons with different ecological statuses and habitat quality on the basis of their eutrophication and ecotoxicity (Trix test) levels. Fish abundances were sampled using fishing and horizontal beaming acoustic surveys with the same protocols in the same year. The relative abundance of Anguilla anguilla, Dicentrarchus labrax or the Mugilidae group was not an indicator of habitat quality, whereas Atherina boyeri and Sparus aurata appeared to be more sensitive to habitat quality. Fish abundance was higher in the two lagoons with high eutrophication and ecotoxicity levels than in the less impacted lagoon, while fish sizes were significantly higher in the two most severely impacted lagoons. This leads us to suggest low habitat quality may increase fish growth rate (by the mean of a cascading effect), but may reduce lagoon juvenile abundance by increasing larval mortality. Such a hypothesis needs to be further validated using greater investigations which take into account more influences on fish growth and recruitment in such variable environments under complex multi-stressor conditions.

  16. Photocatalytic properties of titanium dioxide nanoparticles affect habitat selection of and food quality for a key species in the leaf litter decomposition process.

    Science.gov (United States)

    Feckler, Alexander; Rosenfeldt, Ricki R; Seitz, Frank; Schulz, Ralf; Bundschuh, Mirco

    2015-01-01

    Interactions with environmental parameters may alter the ecotoxicity of nanoparticles. The present study therefore assessed the (in)direct effects of nanoparticulate titanium dioxide (nano-TiO(2)) towards Gammarus fossarum, considering nano-TiO(2)'s photocatalytic properties at ambient UV-intensities. Gammarids' habitat selection was investigated using its feeding preference on leaf discs either exposed to or protected from UV-irradiation in presence of nano-TiO(2) as proxy (n = 49). UV-irradiational one induced a significant preference for UV-protected habitats, which was more pronounced in simultaneous presence of nano-TiO(2). This behaviour may be mainly explained by the UV-induced formation of reactive oxygen species (ROS) by nano-TiO(2). Besides their direct toxicity, ROS may have lowered the leaf-quality in UV-exposed areas contributing (approximately 30%) to the observed behavioural pattern. Since the predicted no effect concentration of nano-TiO(2) in combination with UV irradiation falls below the predicted environmental concentration this study underpins the importance of considering environmental parameters during the risk assessment of nanoparticles.

  17. Habitat Preference of Great-Spotted Woodpecker (Dendrocopos major Linnaeus, 1758 and Lesser-Spotted Woodpecker (Dendrocopos minor Linnaeus, 1758 in the Presence of Invasive Plant Species - Preliminary Study

    Directory of Open Access Journals (Sweden)

    Ónodi Gábor

    2015-02-01

    Full Text Available This study was carried out in Hungary, in an old, unmanaged, riparian poplar-willow forest, where two invasive tree species, the green ash and the boxelder maple are presented and reproduce more effectively therefore are more abundant than the native species in the study area. There are also invasive hybrid wild grapes to be found. These invasive plants cause widespread problems in floodplain forests in Central Europe. We studied Great-spotted and Lesser-spotted Woodpeckers. We investigated the following questions: Which tree species are preferred by the foraging birds? How are the foraging birds distributed spatially between the microhabitats? Are there any differences in terms of foraging niche utilization between the two studied species? We gathered our data through weekly standard observations throughout two whole years. Based on our findings we could determine that both species preferred the less abundant native trees rather than the invasive ash and maple trees, though Lesser-spotted Woodpeckers preferred hybrid wild grapes the most. Great-spotted Woodpeckers preferred the middle heights of the trees, they also moved mainly on trunks. Lesser-spotted Woodpeckers used the thinnest branches in the canopy. Based on our results we predict that the decrease of the native tree species may create a suboptimal habitat compared to the current situation. As the studied species are the major cavity excavators, the above mentioned changes will probably have significant effects on numerous cavity dependent species.

  18. Economic considerations and patients' preferences affect treatment selection for patients with rheumatoid arthritis: a discrete choice experiment among European rheumatologists

    NARCIS (Netherlands)

    Hifinger, M.; Hiligsmann, M.; Ramiro, S.; Watson, V.; Severens, J. L.; Fautrel, B.; Uhlig, T.; van Vollenhoven, R.; Jacques, P.; Detert, J.; Canas da Silva, J.; Scirè, C. A.; Berghea, F.; Carmona, L.; Péntek, M.; Keat, A.; Boonen, A.

    2017-01-01

    To compare the value that rheumatologists across Europe attach to patients' preferences and economic aspects when choosing treatments for patients with rheumatoid arthritis. In a discrete choice experiment, European rheumatologists chose between two hypothetical drug treatments for a patient with

  19. FACTORS THAT AFFECT TRANSPORT MODE PREFERENCE FOR GRADUATE STUDENTS IN THE NATIONAL UNIVERSITY OF MALAYSIA BY LOGIT METHOD

    OpenAIRE

    ALI AHMED MOHAMMED; ALAA A. SHAKIR

    2013-01-01

    A study was carried out to examine the perceptions and preferences of students on choosing the type of transportation for their travels in university campus. This study focused on providing personal transport users road transport alternatives as a countermeasure aimed at shifting car users to other modes of transportation. Overall 456 questionnaires were conducted to develop a choice of transportation mode preferences. Consequently, Logit model and SPSS were used to identify the factors that ...

  20. Diversity and Composition of the Leaf Mycobiome of Beech (Fagus sylvatica) Are Affected by Local Habitat Conditions and Leaf Biochemistry.

    Science.gov (United States)

    Unterseher, Martin; Siddique, Abu Bakar; Brachmann, Andreas; Peršoh, Derek

    2016-01-01

    Comparative investigations of plant-associated fungal communities (mycobiomes) in distinct habitats and under distinct climate regimes have been rarely conducted in the past. Nowadays, high-throughput sequencing allows routine examination of mycobiome responses to environmental changes and results at an unprecedented level of detail. In the present study, we analysed Illumina-generated fungal ITS1 sequences from European beech (Fagus sylvatica) originating from natural habitats at two different altitudes in the German Alps and from a managed tree nursery in northern Germany. In general, leaf-inhabiting mycobiome diversity and composition correlated significantly with the origin of the trees. Under natural condition the mycobiome was more diverse at lower than at higher elevation, whereas fungal diversity was lowest in the artificial habitat of the tree nursery. We further identified significant correlation of leaf chlorophylls and flavonoids with both habitat parameters and mycobiome biodiversity. The present results clearly point towards a pronounced importance of local stand conditions for the structure of beech leaf mycobiomes and for a close interrelation of phyllosphere fungi and leaf physiology.

  1. The research of the factors affecting the trade mark preferences of the students attending Higher School of Physical Education and Sports

    Directory of Open Access Journals (Sweden)

    Hüseyin ÖZTÜRK

    2014-07-01

    Full Text Available This study was made to identify the factors affecting the trade mark preferences of the stud ents attending Higher School of Physical Education and Sports. In this study survey technique was used as data collecting tool and the surveys were applied by the searcher. The questionnaire was applied to 88 males and 122 females who are the students of Higher School of Physical Education and Sports. By the investigating thefactors affecting sports products’ trade mark preferences, the scale was subjected reliability test with Cronbach Alpha technique and it was found valid with the rate of %85. For th is study, the scale of which reliability and validity test has been made before by Tozoğlu (2009 was used. The data collected was evaluated through the SPSS programme. While evaluting, the percentage and frequency test results were used. The objective of this study is to determine how often the students attending Higher School of Physical Education and Sports does sports and whatkind of sports and recreation activities they do and whatkind of clothes and what trade mark clothes they prefer while doing the se activities and what affects these preferences. It is also considered that this study will provide infomation to companies producing sports products about the expectations and needs of market and which communication tools are effective on the consumers.

  2. Nest-site selection and reproductive success of greater sage-grouse in a fire-affected habitat of northwestern Nevada

    Science.gov (United States)

    Lockyer, Zachary B.; Coates, Peter S.; Casazza, Michael L.; Espinosa, Shawn; Delehanty, David J.

    2015-01-01

    Identifying links between micro-habitat selection and wildlife reproduction is imperative to population persistence and recovery. This information is particularly important for landscape species such as greater sage-grouse (Centrocercus urophasianus; sage-grouse). Although this species has been widely studied, because environmental factors can affect sage-grouse populations, local and regional studies are crucial for developing viable conservation strategies. We studied the habitat-use patterns of 71 radio-marked sage-grouse inhabiting an area affected by wildfire in the Virginia Mountains of northwestern Nevada during 2009–2011 to determine the effect of micro-habitat attributes on reproductive success. We measured standard vegetation parameters at nest and random sites using a multi-scale approach (range = 0.01–15,527 ha). We used an information-theoretic modeling approach to identify environmental factors influencing nest-site selection and survival, and determine whether nest survival was a function of resource selection. Sage-grouse selected micro-sites with greater shrub canopy cover and less cheatgrass (Bromus tectorum) cover than random sites. Total shrub canopy, including sagebrush (Artemisia spp.) and other shrub species, at small spatial scales (0.8 ha and 3.1 ha) was the single contributing selection factor to higher nest survival. These results indicate that reducing the risk of wildfire to maintain important sagebrush habitats could be emphasized in sage-grouse conservation strategies in Nevada. Managers may seek to mitigate the influx of annual grass invasion by preserving large intact sagebrush-dominated stands with a mixture of other shrub species. For this area of Nevada, the results suggest that ≥40% total shrub canopy cover in sage-grouse nesting areas could yield improved reproductive success. 

  3. "Do positive affectivity and boundary preferences matter for work-family enrichment? A study of human service workers": Correction to McNall, Scott, and Nicklin (2015).

    Science.gov (United States)

    2016-07-01

    Reports an error in "Do positive affectivity and boundary preferences matter for work-family enrichment? A study of human service workers" by Laurel A. McNall, Lindsay D. Scott and Jessica M. Nicklin (Journal of Occupational Health Psychology, 2015[Jan], Vol 20[1], 93-104). In the article there was an error in Figure 1. The lower left bubble should read "Boundary Preference Toward Segmentation" instead of "Boundary Preference Toward Integration." (The following abstract of the original article appeared in record 2014-44477-001.) More individuals than ever are managing work and family roles, but relatively little research has been done exploring whether boundary preferences help individuals benefit from multiple role memberships. Drawing on Greenhaus and Powell's (2006) work-family enrichment theory, along with Boundary Theory (Ashforth, Kreiner, & Fugate, 2000) and Conservation of Resources Theory (Hobfoll, 2002), we explore the impact of personal characteristics as enablers of work-family enrichment, and in turn, work outcomes relevant to human service workers: turnover intentions and emotional exhaustion. In a 2-wave study of 161 human service employees, we found that individuals high in positive affectivity were more likely to experience both work-to-family and family to-work enrichment, whereas those with preferences toward integration were more likely to experience work-to-family enrichment (but not family to-work enrichment). In turn, work-to-family enrichment (but not family to-work enrichment) was related to lower turnover intentions and emotional exhaustion. Enrichment served as a mediating mechanism for only some of the hypothesized relationships. Implications for theory and practice are discussed. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  4. SDN-POA volume, sexual behavior, and partner preference of male rats affected by perinatal treatment with ATD.

    Science.gov (United States)

    Houtsmuller, E J; Brand, T; de Jonge, F H; Joosten, R N; van de Poll, N E; Slob, A K

    1994-09-01

    The present study investigated 1) the importance of the aromatization process during the perinatal period for the development of the sexually dimorphic nucleus in the preoptic area of the hypothalamus (SDN-POA) of male rats, and 2) the relationship between SDN-POA volume and parameters of masculinization in male rats that were treated perinatally with the aromatase-inhibitor ATD. Males were treated with ATD either prenatally or pre- and neonatally, or with the vehicle. Masculine sexual behavior and partner preference were investigated in adulthood. Thereafter, animals were sacrificed and SDN-POA volume was measured. The SDN-POA volume was reduced in both the prenatally and the pre- and neonatally treated group, with a larger reduction in the latter than in the former group. Combined pre- and neonatal ATD treatment resulted in reduced frequency of mounts, intromissions, and ejaculations, as well as a reduced preference for a female over a male. The SDN-POA size was significantly and positively correlated with frequency of masculine sexual behavior, as well as preference for a female over a male.

  5. Specialization in habitat use by coral reef damselfishes and their susceptibility to habitat loss.

    Science.gov (United States)

    Pratchett, Morgan S; Coker, Darren J; Jones, Geoffrey P; Munday, Philip L

    2012-09-01

    While it is generally assumed that specialist species are more vulnerable to disturbance compared with generalist counterparts, this has rarely been tested in coastal marine ecosystems, which are increasingly subject to a wide range of natural and anthropogenic disturbances. Habitat specialists are expected to be more vulnerable to habitat loss because habitat availability exerts a greater limitation on population size, but it is also possible that specialist species may escape effects of disturbance if they use habitats that are generally resilient to disturbance. This study quantified specificity in use of different coral species by six coral-dwelling damselfishes (Chromis viridis, C. atripectoralis, Dascyllus aruanus, D. reticulatus, Pomacentrus moluccensis, and P. amboinensis) and related habitat specialization to proportional declines in their abundance following habitat degradation caused by outbreaks of the coral eating starfish, Acanthaster planci. The coral species preferred by most coral-dwelling damselfishes (e.g., Pocillopora damicornis) were frequently consumed by coral eating crown-of-thorns starfish, such that highly specialized damselfishes were disproportionately affected by coral depletion, despite using a narrower range of different coral species. Vulnerability of damselfishes to this disturbance was strongly correlated with both their reliance on corals and their degree of habitat specialization. Ongoing disturbances to coral reef ecosystems are expected, therefore, to lead to fundamental shifts in the community structure of fish communities where generalists are favored over highly specialist species.

  6. Análise da aceitação de aguardentes de cana por testes afetivos e mapa de preferência interno Acceptance evaluation of sugar cane brandy by sensorial affective tests and internal preference map

    Directory of Open Access Journals (Sweden)

    Helena Maria André Bolini CARDELLO

    2000-04-01

    ência dos provadores pelas amostras de aguardentes envelhecidas. Os resultados sugerem também que aguardentes envelhecidas por mais de 24 meses em tonel de carvalho de 200L são preferidas pelos consumidores, em detrimento das comerciais não envelhecidas e mesmo das comerciais envelhecidas, que podem ser adicionadas de aguardente não envelhecida (processo denominado corte e também ter correção da cor, conforme permite a Legislação Brasileira. O conteúdo de polifenóis totais e a intensidade de cor também foram determinados, e ambos apresentaram correlação linear positiva significativa (pIn order to compare distincts statistical treatments used in sensorial analysis, the acceptance of 11 sugar cane brandy samples were evaluated by sensorial affective tests, treated by two distints statistical analysis: univariate variance analysis (ANOVA and the multivariate internal preference map (MDPREF. It were analyzed samples stored in a 200 l oak casks during zero, 12, 24, 36 and 48 months and six commercial brands, three of then having the denomination stored and the other three not stored. The samples were evaluated by 100 judges, selected based in a questionary that evaluated affectivity for the product. The sensorial tests conducted in individual cabins were based in a hedonic scale of nine centimeters. The ANOVA and Tukey test and the Internal preference Map (MDPREF, were used to evaluate the obtained data. The ANOVA results showed that the samples stored during 48, 36 and 24 months in the oak cask, presented the higher acceptance scores (scores near 8.0 in the hedonic scale, one commercial brand not stored showed the lowest score, and the others samples showed intermediate acceptance scores. The MDPREF analysis generated in a multidimensional space where the preference data variations were presented in orthogonal axes values, based in the consumers response for each sample. Based on the acceptance data of individual consumers and the vectors of preference, it was

  7. Assessment of Habitat Suitability Is Affected by Plant-Soil Feedback: Comparison of Field and Garden Experiment.

    Science.gov (United States)

    Hemrová, Lucie; Knappová, Jana; Münzbergová, Zuzana

    2016-01-01

    Field translocation experiments (i.e., the introduction of seeds or seedlings of different species into different localities) are commonly used to study habitat associations of species, as well as factors limiting species distributions and local abundances. Species planted or sown in sites where they naturally occur are expected to perform better or equally well compared to sites at which they do not occur or are rare. This, however, contrasts with the predictions of the Janzen-Connell hypothesis and commonly reported intraspecific negative plant-soil feedback. The few previous studies indicating poorer performance of plants at sites where they naturally occur did not explore the mechanisms behind this pattern. In this study, we used field translocation experiments established using both seeds and seedlings to study the determinants of local abundance of four dominant species in grasslands. To explore the possible effects of intraspecific negative plant-soil feedback on our results, we tested the effect of local species abundance on the performance of the plants in the field experiment. In addition, we set up a garden experiment to explore the intensity of intraspecific as well as interspecific feedback between the dominants used in the experiment. In some cases, the distribution and local abundances of the species were partly driven by habitat conditions at the sites, and species performed better at their own sites. However, the prevailing pattern was that the local dominants performed worse at sites where they naturally occur than at any other sites. Moreover, the success of plants in the field experiment was lower in the case of higher intraspecific abundance prior to experimental setup. In the garden feedback experiment, two of the species performed significantly worse in soils conditioned by their species than in soils conditioned by the other species. In addition, the performance of the plants was significantly correlated between the two experiments

  8. Assessment of Habitat Suitability Is Affected by Plant-Soil Feedback: Comparison of Field and Garden Experiment.

    Directory of Open Access Journals (Sweden)

    Lucie Hemrová

    Full Text Available Field translocation experiments (i.e., the introduction of seeds or seedlings of different species into different localities are commonly used to study habitat associations of species, as well as factors limiting species distributions and local abundances. Species planted or sown in sites where they naturally occur are expected to perform better or equally well compared to sites at which they do not occur or are rare. This, however, contrasts with the predictions of the Janzen-Connell hypothesis and commonly reported intraspecific negative plant-soil feedback. The few previous studies indicating poorer performance of plants at sites where they naturally occur did not explore the mechanisms behind this pattern.In this study, we used field translocation experiments established using both seeds and seedlings to study the determinants of local abundance of four dominant species in grasslands. To explore the possible effects of intraspecific negative plant-soil feedback on our results, we tested the effect of local species abundance on the performance of the plants in the field experiment. In addition, we set up a garden experiment to explore the intensity of intraspecific as well as interspecific feedback between the dominants used in the experiment.In some cases, the distribution and local abundances of the species were partly driven by habitat conditions at the sites, and species performed better at their own sites. However, the prevailing pattern was that the local dominants performed worse at sites where they naturally occur than at any other sites. Moreover, the success of plants in the field experiment was lower in the case of higher intraspecific abundance prior to experimental setup. In the garden feedback experiment, two of the species performed significantly worse in soils conditioned by their species than in soils conditioned by the other species. In addition, the performance of the plants was significantly correlated between the two

  9. Varying congruence among spatial patterns of vascular plants and vertebrates based on habitat groups

    OpenAIRE

    Xu, Haigen; Cao, Yun; Cao, Mingchang; Wu, Jun; Wu, Yi; Le, Zhifang; Cui, Peng; Li, Jiaqi; Ma, Fangzhou; Liu, Li; Hu, Feilong; Chen, Mengmeng; Tong, Wenjun

    2017-01-01

    Abstract Proxies are adopted to represent biodiversity patterns due to inadequate information for all taxa. Despite the wide use of proxies, their efficacy remains unclear. Previous analyses focused on overall species richness for fewer groups, affecting the generality and depth of inference. Biological taxa often exhibit very different habitat preferences. Habitat groupings may be an appropriate approach to advancing the study of richness patterns. Diverse geographical patterns of species ri...

  10. Identifying community healthcare supports for the elderly and the factors affecting their aging care model preference: evidence from three districts of Beijing

    Directory of Open Access Journals (Sweden)

    Tianyang Liu

    2016-11-01

    Full Text Available Abstract Background The Chinese tradition of filial piety, which prioritized family-based care for the elderly, is transitioning and elders can no longer necessarily rely on their children. The purpose of this study was to identify community support for the elderly, and analyze the factors that affect which model of old-age care elderly people dwelling in communities prefer. Methods We used the database “Health and Social Support of Elderly Population in Community”. Questionnaires were issued in 2013, covering 3 districts in Beijing. A group of 1036 people over 60 years in age were included in the study. The respondents’ profile variables were organized in Andersen’s Model and community healthcare resource factors were added. A multinomial logistic model was applied to analyze the factors associated with the desired aging care models. Results Cohabiting with children and relying on care from family was still the primary desired aging care model for seniors (78 %, followed by living in institutions (14.8 % and living at home independently while relying on community resources (7.2 %. The regression result indicated that predisposing, enabling and community factors were significantly associated with the aging care model preference. Specifically, compared with those who preferred to cohabit with children, those having higher education, fewer available family and friend helpers, and shorter distance to healthcare center were more likely to prefer to live independently and rely on community support. And compared with choosing to live in institutions, those having fewer available family and friend helpers and those living alone were more likely to prefer to live independently and rely on community. Need factors (health and disability condition were not significantly associated with desired aging care models, indicating that desired aging care models were passive choices resulted from the balancing of family and social caring resources

  11. Wildlife habitat considerations

    Science.gov (United States)

    Helen Y. Smith

    2000-01-01

    Fire, insects, disease, harvesting, and precommercial thinning all create mosaics on Northern Rocky Mountain landscapes. These mosaics are important for faunal habitat. Consequently, changes such as created openings or an increase in heavily stocked areas affect the water, cover, and food of forest habitats. The “no action” alternative in ecosystem management of low...

  12. [Study of the dietary preferences and the social-psychological factors that affect the dietary behaviors of high school and university students].

    Science.gov (United States)

    Kasamaki, Junichi

    2013-01-01

    This study was conducted to elucidate the correlation among dietary intake, dietary preferences, and social-psychological factors in the youth and to examine the factors that affect such dietary behaviors as snacking, skipping breakfast, and taking a biased nutrition. A survey was carried out using a questionnaire with closed questions on multiple items such as dietary behaviors, psychosocial stress, dietary externalization, information and consciousness about health. The survey was conducted on 1,056 high school students and 1,323 university students in Japan. As a result of the factor analysis among the groups of male/female and high school/university students, relationships were found between the items of "preferences for snacking" and "snack food intakes" among all these groups. Those who like sweets and snacks tended to snack between lunch and dinner or after dinner by themselves more often than those who do not. In contrast to men, intermediate correlations were found between the item of "a meal as a diversion" and each of the items of "snack food intake," "preferences for fried foods/sautéed foods/meat dishes," and "preferences for snacking," among women who do not live alone, regardless of their being high school or university students. The item of "stress over human relationships/academic performance" was shown to have similarly weak correlations with the items of "reasons for skipping breakfast" and "nutrition intake" in the groups of male and female high school students. The less they value nutrition intake, the more they tend to be conscious of stress over human relationships/academic performance.

  13. Linking functional traits and species preferences to species’ abundance and occupancy trends through time to identify habitat changes in coastal ecosystems

    DEFF Research Database (Denmark)

    Pakeman, Robin J.; Hewison, Richard; Lewis, Robert John

    2017-01-01

    characteristic of nutrient-rich conditions exemplified by Arrhenatherum elatius. Coastal heathlands have been particularly affected by the increase in species such as Betula spp. and Pteridium aquilinum which can dominate and exclude other heathland species. On average, increasing species were both more common...

  14. Harvesting interacts with climate change to affect future habitat quality of a focal species in eastern Canada's boreal forest.

    Science.gov (United States)

    Tremblay, Junior A; Boulanger, Yan; Cyr, Dominic; Taylor, Anthony R; Price, David T; St-Laurent, Martin-Hugues

    2018-01-01

    Many studies project future bird ranges by relying on correlative species distribution models. Such models do not usually represent important processes explicitly related to climate change and harvesting, which limits their potential for predicting and understanding the future of boreal bird assemblages at the landscape scale. In this study, we attempted to assess the cumulative and specific impacts of both harvesting and climate-induced changes on wildfires and stand-level processes (e.g., reproduction, growth) in the boreal forest of eastern Canada. The projected changes in these landscape- and stand-scale processes (referred to as "drivers of change") were then assessed for their impacts on future habitats and potential productivity of black-backed woodpecker (BBWO; Picoides arcticus), a focal species representative of deadwood and old-growth biodiversity in eastern Canada. Forest attributes were simulated using a forest landscape model, LANDIS-II, and were used to infer future landscape suitability to BBWO under three anthropogenic climate forcing scenarios (RCP 2.6, RCP 4.5 and RCP 8.5), compared to the historical baseline. We found climate change is likely to be detrimental for BBWO, with up to 92% decline in potential productivity under the worst-case climate forcing scenario (RCP 8.5). However, large declines were also projected under baseline climate, underlining the importance of harvest in determining future BBWO productivity. Present-day harvesting practices were the single most important cause of declining areas of old-growth coniferous forest, and hence appeared as the single most important driver of future BBWO productivity, regardless of the climate scenario. Climate-induced increases in fire activity would further promote young, deciduous stands at the expense of old-growth coniferous stands. This suggests that the biodiversity associated with deadwood and old-growth boreal forests may be greatly altered by the cumulative impacts of natural and

  15. The effects of preferred natural stimuli on humans' affective states, physiological stress and mental health, and the potential implications for well-being in captive animals.

    Science.gov (United States)

    Ross, Misha; Mason, Georgia J

    2017-09-12

    Exposure to certain natural stimuli improves people's moods, reduces stress, enhances stress resilience, and promotes mental and physical health. Laboratory studies and real estate prices also reveal that humans prefer environments containing a broad range of natural stimuli. Potential mediators of these outcomes include: 1) therapeutic effects of specific natural products; 2) positive affective responses to stimuli that signalled safety and resources to our evolutionary ancestors; 3) attraction to environments that satisfy innate needs to explore and understand; and 4) ease of sensory processing, due to the stimuli's "evolutionary familiarity" and/or their fractal, self-repeating properties. These processes, and the benefits humans gain from natural stimuli, seem to be largely innate. They thus have strong implications for other species (including laboratory, farm and zoo animals living in environments devoid of natural stimuli), suggesting that they too may have nature-related "sensory needs". By promoting positive affect and stress resilience, preferred natural stimuli (including views, sounds and odours) could therefore potentially provide effective and efficient ways to improve captive animal well-being. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Male Kirtland's Warblers' patch-level response to landscape structure during periods of varying population size and habitat amounts

    Science.gov (United States)

    Donner, D.M.; Ribic, C.A.; Probst, J.R.

    2009-01-01

    Forest planners must evaluate how spatiotemporal changes in habitat amount and configuration across the landscape as a result of timber management will affect species' persistence. However, there are few long-term programs available for evaluation. We investigated the response of male Kirtland's Warbler (Dendroica kirtlandii) to 26 years of changing patch and landscape structure during a large, 26-year forestry-habitat restoration program within the warbler's primary breeding range. We found that the average density of male Kirtland's Warblers was related to a different combination of patch and landscape attributes depending on the species' regional population level and habitat amounts on the landscape (early succession jack pine (Pinus banksiana) forests; 15-42% habitat cover). Specifically, patch age and habitat regeneration type were important at low male population and total habitat amounts, while patch age and distance to an occupied patch were important at relatively high population and habitat amounts. Patch age and size were more important at increasing population levels and an intermediate amount of habitat. The importance of patch age to average male density during all periods reflects the temporal buildup and decline of male numbers as habitat suitability within the patch changed with succession. Habitat selection (i.e., preference for wildfire-regenerated habitat) and availability may explain the importance of habitat type and patch size during lower population and habitat levels. The relationship between male density and distance when there was the most habitat on the landscape and the male population was large and still increasing may be explained by the widening spatial dispersion of the increasing male population at the regional scale. Because creating or preserving habitat is not a random process, management efforts would benefit from more investigations of managed population responses to changes in spatial structure that occur through habitat gain

  17. Preferred modes of travel among older adults: what factors affect the choice to walk instead of drive?

    Science.gov (United States)

    Naumann, Rebecca B; Dellinger, Ann M; Anderson, Melissa L; Bonomi, Amy E; Rivara, Frederick P; Thompson, Robert S

    2009-10-01

    There are many factors that influence older adults' travel choices. This paper explores the associations between mode of travel choice for a short trip and older adults' personal characteristics. This study included 406 drivers over the age of 64 who were enrolled in a large integrated health plan in the United States between 1991 and 2001. Bivariate analyses and generalized linear modeling were used to examine associations between choosing to walk or drive and respondents' self-reported general health, physical and functional abilities, and confidence in walking and driving. Having more confidence in their ability to walk versus drive increased an older adult's likelihood of walking to make a short trip by about 20% (PR=1.22; 95% CI: 1.06-1.40), and walking for exercise increased the likelihood by about 50% (PR=1.53; 95% CI=1.22-1.91). Reporting fair or poor health decreased the likelihood of walking, as did cutting down on the amount of driving due to a physical problem. Factors affecting a person's decision to walk for exercise may not be the same as those that influence their decision to walk as a mode of travel. It is important to understand the barriers to walking for exercise and walking for travel to develop strategies to help older adults meet both their exercise and mobility needs. Increasing walking over driving among older adults may require programs that increase confidence in walking and encourage walking for exercise.

  18. Habitat selection of juvenile sole (Solea solea L.): Consequences for shoreface nourishment

    Science.gov (United States)

    Post, Marjolein H. M.; Blom, Ewout; Chen, Chun; Bolle, Loes J.; Baptist, Martin J.

    2017-04-01

    The shallow coastal zone is an essential nursery habitat for juvenile flatfish species such as sole (Solea solea L.). The increased frequency of shoreface nourishments along the coast is likely to affect this nursery function by altering important habitat conditions, including sediment grain size. Sediment preference of juvenile sole (41-91 mm) was studied in a circular preference chamber in order to understand the relationship between grain size and sole distribution. The preference tests were carried out at 11 °C and 20 °C to reflect seasonal influences. The juveniles showed a significant preference for finer sediments. This preference was not length dependent (within the length range tested) nor affected by either temperatures. Juvenile sole have a small home range and are not expected to move in response to unfavourable conditions. As a result, habitat alterations may have consequences for juvenile survival and subsequently for recruitment to adult populations. It is therefore important to carefully consider nourishment grain size characteristics to safeguard suitable nursery habitats for juvenile sole.

  19. Forested habitat preferences by Chilean citizens: Implications for biodiversity conservation in Pinus radiata plantations Preferencia por hábitats forestales por ciudadanos chilenos: Implicancias para la conservación de biodiversidad en plantaciones de Pinus radiata

    Directory of Open Access Journals (Sweden)

    NICOLE PÜSCHEL-HOENEISEN

    2012-06-01

    Full Text Available The need for conservation outside protected areas has prompted the modification of productive practices to allow the maintenance of wild biota in productive landscapes such as those associated to timber production. Forest plantations could cooperate in conserving biodiversity outside protected areas if they have a developed understory. However, the success of the production changes depends on the social support they receive. Therefore, we evaluate Chilean citizens' preference for five habitats of different types of forest management. In addition, we assessed perceptions regarding the relationship between pine plantations and native wildlife through surveys administered in Chillán, Santiago and six rural localities in the VII and VIII region. Despite there is not a unanimous opinion regarding pine plantations as a threat to biodiversity, people prefer pine plantations that serve as habitat for endangered fauna. In fact, they agree on paying more for forest products to contribute to conservation in forest plantations, and actually prefer plantations with a developed understory better than those without it. This would suggest that measures aimed at conservation in forest plantations could be supported by the Chilean society.La necesidad de la conservación fuera de áreas protegidas ha llevado a la modificación de las prácticas productivas para permitir el mantenimiento de la biota silvestre en paisajes productivos tales como los asociados a la producción de madera. Las plantaciones forestales podrían cooperar en la conservación de la biodiversidad fuera de áreas protegidas si tienen un sotobosque desarrollado. Sin embargo, el éxito de los cambios en la producción depende del apoyo social que estos reciben. Así, evaluamos la preferencia por cinco paisajes con diferentes tipos de manejo forestal. Además, se evaluó la percepción acerca de la relación entre las plantaciones de pino y la fauna nativa a través de encuestas realizadas en

  20. The Effects of Habitat Type and Volcanic Eruptions on the Breeding Demography of Icelandic Whimbrels Numenius phaeopus.

    Science.gov (United States)

    Katrínardóttir, Borgný; Alves, José A; Sigurjónsdóttir, Hrefna; Hersteinsson, Páll; Gunnarsson, Tómas G

    2015-01-01

    Distinct preference of species for habitats is most often driven by long term differences in demographic rates between habitats. Estimating variation in those rates is key for developing successful conservation strategies. Stochastic events can interact with underlying variation in habitat quality in regulating demography but the opportunities to explore such interactions are rare. Whimbrels in Iceland show a strong preference for sparsely vegetated riverplains. Such habitats in Iceland face various threats, e.g., climate change, river regulation and spread of alien plant species. In this study we compared demographic parameters of breeding Whimbrels between riverplains and other habitats before, during and after volcanic eruption events to estimate the importance of the habitats for the species and the effect of ash deposit on breeding success. We found that an estimated minimum of 23% of the Icelandic population of Whimbrels and c. 10% of the world population of the species breed in riverplain habitats in Iceland. Whimbrels bred consistently at much higher densities in riverplain habitats than in other habitats and riverplains also had higher densities of pairs with fledglings although the proportion of successful breeders was similar between habitats. Predation by livestock may have had a considerable negative effect on breeding success on our study sites. Breeding was negatively affected by the volcanic activity, probably through the effects of ash on the invertebrate food supply, with breeding success being gradually worse closer to the eruption. Breeding success was equally affected by volcanism across habitats which differed in underlying habitat quality. This study gives an example of how populations can be regulated by factors which operate at different spatial scales, such as local variation in habitat quality and stochastic events which impact larger areas.

  1. The Effects of Habitat Type and Volcanic Eruptions on the Breeding Demography of Icelandic Whimbrels Numenius phaeopus.

    Directory of Open Access Journals (Sweden)

    Borgný Katrínardóttir

    Full Text Available Distinct preference of species for habitats is most often driven by long term differences in demographic rates between habitats. Estimating variation in those rates is key for developing successful conservation strategies. Stochastic events can interact with underlying variation in habitat quality in regulating demography but the opportunities to explore such interactions are rare. Whimbrels in Iceland show a strong preference for sparsely vegetated riverplains. Such habitats in Iceland face various threats, e.g., climate change, river regulation and spread of alien plant species. In this study we compared demographic parameters of breeding Whimbrels between riverplains and other habitats before, during and after volcanic eruption events to estimate the importance of the habitats for the species and the effect of ash deposit on breeding success. We found that an estimated minimum of 23% of the Icelandic population of Whimbrels and c. 10% of the world population of the species breed in riverplain habitats in Iceland. Whimbrels bred consistently at much higher densities in riverplain habitats than in other habitats and riverplains also had higher densities of pairs with fledglings although the proportion of successful breeders was similar between habitats. Predation by livestock may have had a considerable negative effect on breeding success on our study sites. Breeding was negatively affected by the volcanic activity, probably through the effects of ash on the invertebrate food supply, with breeding success being gradually worse closer to the eruption. Breeding success was equally affected by volcanism across habitats which differed in underlying habitat quality. This study gives an example of how populations can be regulated by factors which operate at different spatial scales, such as local variation in habitat quality and stochastic events which impact larger areas.

  2. Do agents' characteristics affect their valuation of 'common pool' resources? A full-preference ranking analysis for the value of sustainable river basin management.

    Science.gov (United States)

    González Dávila, Osiel; Koundouri, Phoebe; Pantelidis, Theologos; Papandreou, Andreas

    2017-01-01

    In this paper we develop a full-preference ranking Choice Experiment (CE) designed to investigate how respondents evaluate a set of proposed improvements towards sustainable river basin management, as per the prescriptions of the European Union-Water Framework Directive (2000). The CE is applied in the Asopos River Basin (ARB) in Greece. Our interest is to test whether residency in the river basin, or otherwise, affects the preferences of the relevant agents. We first estimate a rank-ordered logistic regression based on a full set of choices in order to calculate the willingness to pay (WTP) of respondents for each one of the three attributes considered in the CE (i.e., environmental conditions, impact on the local economy and changes in the potential uses of water). The model is initially estimated for the full sample and then re-estimated twice for two sub-samples: the first one only includes the residents of Athens and the second only includes the residents of Asopos. Afterwards, we examine the effect of various demographic and socio-economic factors (such as income, gender, age, employment and education) on the estimates of our model in order to reveal any differences among respondents with different characteristics, mainly focusing on whether they reside or have personal experience of the RB under valuation. Thus, our analysis simultaneously provides a robustness check on previous findings in the literature and additional information about how various demographic and socio-economic characteristics affect the evaluation of the selected attributes. Copyright © 2016. Published by Elsevier B.V.

  3. Specialty preferences of 1(st) year medical students in a Saudi Medical School - Factors affecting these choices and the influence of gender.

    Science.gov (United States)

    Kaliyadan, Feroze; Amin, Tarek Tawfik; Qureshi, Habib; Al Wadani, Fahad

    2015-01-01

    In recent years there has been a growing appreciation of the issues of career preference in medicine as it affects student learning and academic performance. Various factors influence the specialty choices of medical students. Some specialties tend to attract students more than others. One possible consequence of this would be a mismatch between health needs and specialist numbers in the region. This study investigated the career preferences of 1(st) year medical students in a Saudi medical school and to assess factors affecting these choices. The study was a cross-sectional survey carried out on the 1(st) year undergraduate students in the college of medicine, King Faisal University, Saudi Arabia. A total of 109 students (57 female and 52 males) responded to the questionnaire which was initially administered to all the students of the 1(st) year - A total of 120 students (response rate was 90.8%). A mixed method approach was used and qualitative data from open-ended questions were analyzed based on thematic analysis. The top choices were general surgery, internal medicine, and pediatrics. Among female students; the top specialty choices were: General surgery (23%), pediatrics (18%), and dermatology (15%). Among the male students; the top choices were: General surgery (54%) and internal medicine (23%). Of the total, 57% of the students agreed or strongly agreed that primary aptitude was the main factor affecting the choice. Only 31% felt that there was a significant influence of role model, 48% felt that the advice of others - peers and family, would be a factor influencing their choices, and 53% agreed that specialty choice would influence their future learning patterns. Males were more likely to choose a specialty based on actual aptitude for the specialty, financial rewards, and scope for research; and this gender difference was statistically significant. Surgery was the top-choice in both genders. Other popular choices included internal medicine, pediatrics

  4. The Rationality behind Immigration Preferences

    NARCIS (Netherlands)

    H.P. van Dalen (Hendrik); K. Henkens

    2003-01-01

    textabstractWhat drives stated preferences about the number of foreigners? Is it self-interest as stressed by the political economy of immigration? Does social interaction affect this preference or is the immigration preference completely in line with the preference for the aggregate population

  5. Macroalgas varadas sobre la superficie de una playa arenosa del sur de Chile: preferencias alimentarias y de habitat de juveniles y adultos de Orchestoidea tuberculata (Nicolet, (Amphipoda, Talitridae Stranded algal wracks on a sandy beach of south central Chile: feeding and habitat preferences of juveniles and adults of Orchestoidea tuberculata (Nicolet, (Amphipoda, Talitridae

    Directory of Open Access Journals (Sweden)

    CRISTIAN DUARTE

    2008-03-01

    temes alimentarios diferentes, los juveniles pueden evitar el canibalismo de los adultos, interacción biológica previamente demostrada para O. tuberculata. La diferencia notoria en los patrones de preferencia de juveniles y adultos de este anfípodo demuestra la importancia de considerar la variabilidad intraespecífica en este tipo de estudiosThe amphipod Orchestoidea tuberculata, is the numerically dominant scavenger in the upper intertidal levels of sandy beaches from south central Chile. The main food source for juveniles and adults of this amphipod are the macroalgae stranded on the beach. Experiments of food preferences were carried out to analyze the eventual partition on the most common macroalgae on that beaches {Durvillaea antárctica, Macrocystis pyrifera y Lessonia nigrescens by .juveniles and adults of this amphipod. While juveniles preferred to consume L. nigrescens, adults showed a significant preference for D. antárctica. Similar to the laboratory results, that of field studies shows that juveniles of O. tubercula ta did not show significant preferences between D. antárctica and M. pyrifera, while adults preferred to consume D. antárctica instead of M. pyrifera. That suggest that D. antárctica is an important source of food (and habitat, for adult amphipods. Due to the fact that L. nigrescens could not be included in the field experiments, the possibility that juveniles also prefer this macroalgae in those conditions remains as an open question. Although the reasons underlying the differences in the food preferences of juveniles and adults are unknown, two possibilities can be proposed: ontogenetic changes in the morphology of mouth structures used for feeding and/or ontogenetic changes in nutritional requirements. However, the fact that juveniles preferred to consume the macroalgae with the lowest nutritional content (L. nigrescens among the three species offered as food, suggest another explanation to the observed differences. This refers to the fact, that by

  6. Driving with Central Visual Field Loss II: How Scotomas above or below the Preferred Retinal Locus (PRL) Affect Hazard Detection in a Driving Simulator

    Science.gov (United States)

    Bowers, Alex R.; Goldstein, Robert; Peli, Eli

    2015-01-01

    We determined whether binocular central scotomas above or below the preferred retinal locus affect detection of hazards (pedestrians) approaching from the side. Seven participants with central field loss (CFL), and seven age-and sex-matched controls with normal vision (NV), each completed two sessions of 5 test drives (each approximately 10 minutes long) in a driving simulator. Participants pressed the horn when detecting pedestrians that appeared at one of four eccentricities (-14°, -4°, left, 4°, or 14°, right, relative to car heading). Pedestrians walked or ran towards the travel lane on a collision course with the participant’s vehicle, thus remaining in the same area of the visual field, assuming participant's steady forward gaze down the travel lane. Detection rates were nearly 100% for all participants. CFL participant reaction times were longer (median 2.27s, 95% CI 2.13 to 2.47) than NVs (median 1.17s, 95%CI 1.10 to 2.13; difference p<0.01), and CFL participants would have been unable to stop for 21% of pedestrians, compared with 3% for NV, p<0.001. Although the scotomas were not expected to obscure pedestrian hazards, gaze tracking revealed that scotomas did sometimes interfere with detection; late reactions usually occurred when pedestrians were entirely or partially obscured by the scotoma (time obscured correlated with reaction times, r = 0.57, p<0.001). We previously showed that scotomas lateral to the preferred retinal locus delay reaction times to a greater extent; however, taken together, the results of our studies suggest that any binocular CFL might negatively impact timely hazard detection while driving and should be a consideration when evaluating vision for driving. PMID:26332315

  7. Greater shrub dominance alters breeding habitat and food resources for migratory songbirds in Alaskan arctic tundra.

    Science.gov (United States)

    Boelman, Natalie T; Gough, Laura; Wingfield, John; Goetz, Scott; Asmus, Ashley; Chmura, Helen E; Krause, Jesse S; Perez, Jonathan H; Sweet, Shannan K; Guay, Kevin C

    2015-04-01

    Climate warming is affecting the Arctic in multiple ways, including via increased dominance of deciduous shrubs. Although many studies have focused on how this vegetation shift is altering nutrient cycling and energy balance, few have explicitly considered effects on tundra fauna, such as the millions of migratory songbirds that breed in northern regions every year. To understand how increasing deciduous shrub dominance may alter breeding songbird habitat, we quantified vegetation and arthropod community characteristics in both graminoid and shrub dominated tundra. We combined measurements of preferred nest site characteristics for Lapland longspurs (Calcarius lapponicus) and Gambel's White-crowned sparrows (Zonotrichia leucophrys gambelii) with modeled predictions for the distribution of plant community types in the Alaskan arctic foothills region for the year 2050. Lapland longspur nests were found in sedge-dominated tussock tundra where shrub height does not exceed 20 cm, whereas White-crowned sparrows nested only under shrubs between 20 cm and 1 m in height, with no preference for shrub species. Shrub canopies had higher canopy-dwelling arthropod availability (i.e. small flies and spiders) but lower ground-dwelling arthropod availability (i.e. large spiders and beetles). Since flies are the birds' preferred prey, increasing shrubs may result in a net enhancement in preferred prey availability. Acknowledging the coarse resolution of existing tundra vegetation models, we predict that by 2050 there will be a northward shift in current White-crowned sparrow habitat range and a 20-60% increase in their preferred habitat extent, while Lapland longspur habitat extent will be equivalently reduced. Our findings can be used to make first approximations of future habitat change for species with similar nesting requirements. However, we contend that as exemplified by this study's findings, existing tundra modeling tools cannot yet simulate the fine-scale habitat

  8. Habitat management affects soil chemistry and allochthonous organic inputs mediating microbial structure and exo-enzyme activity in Wadden Sea salt-marsh soils

    Science.gov (United States)

    Mueller, Peter; Granse, Dirk; Thi Do, Hai; Weingartner, Magdalena; Nolte, Stefanie; Hoth, Stefan; Jensen, Kai

    2016-04-01

    The Wadden Sea (WS) region is Europe's largest wetland and home to approximately 20% of its salt marsh area. Mainland salt marshes of the WS are anthropogenically influenced systems and have traditionally been used for livestock grazing in wide parts. After foundation of WS National Parks in the late 1980s and early 1990s, artificial drainage has been abandoned; however, livestock grazing is still common in many areas of the National Parks and is under ongoing discussion as a habitat-management practice. While studies so far focused on effects of livestock grazing on biodiversity, little is known about how biogeochemical processes, element cycling, and particularly carbon sequestration are affected. Here, we present data from a recent field study focusing on grazing effects on soil properties, microbial exo-enzyme activity, microbial abundance and structure. Exo-enzyme activity was studied conducting digestive enzyme assays for various enzymes involved in C- and N cycling. Microbial abundance and structure was assessed measuring specific gene abundance of fungi and bacteria using quantitative PCR. Soil compaction induced by grazing led to higher bulk density and decreases in soil redox (Δ >100 mV). Soil pH was significantly lower in grazed parts. Further, the proportion of allochthonous organic matter (marine input) was significantly smaller in grazed vs. ungrazed sites, likely caused by a higher sediment trapping capacity of the taller vegetation in the ungrazed sites. Grazing induced changes in bulk density, pH and redox resulted in reduced activity of enzymes involved in microbial C acquisition; however, there was no grazing effect on enzymes involved in N acquisition. While changes in pH, bulk density or redox did not affect microbial abundance and structure, the relative amount of marine organic matter significantly reduced the relative abundance of fungi (F:B ratio). We conclude that livestock grazing directly affects microbial exo-enzyme activity, thus

  9. Varying congruence among spatial patterns of vascular plants and vertebrates based on habitat groups.

    Science.gov (United States)

    Xu, Haigen; Cao, Yun; Cao, Mingchang; Wu, Jun; Wu, Yi; Le, Zhifang; Cui, Peng; Li, Jiaqi; Ma, Fangzhou; Liu, Li; Hu, Feilong; Chen, Mengmeng; Tong, Wenjun

    2017-11-01

    Proxies are adopted to represent biodiversity patterns due to inadequate information for all taxa. Despite the wide use of proxies, their efficacy remains unclear. Previous analyses focused on overall species richness for fewer groups, affecting the generality and depth of inference. Biological taxa often exhibit very different habitat preferences. Habitat groupings may be an appropriate approach to advancing the study of richness patterns. Diverse geographical patterns of species richness and their potential mechanisms were then examined for habitat groups. We used a database of the spatial distribution of 32,824 species of mammals, birds, reptiles, amphibians and plants from 2,376 counties across China, divided the five taxa into 30 habitat groups, calculated Spearman correlations of species richness among taxa and habitat groups, and tested five hypotheses about richness patterns using multivariate models. We identified one major group [i.e., forest- and shrub-dependent (FS) groups], and some minor groups such as grassland-dependent vertebrates and desert-dependent vertebrates. There were mostly high or moderate correlations among FS groups, but mostly low or moderate correlations among other habitat groups. The prominent variables differed among habitat groups of the same taxon, such as birds and reptiles. The sets of predictors were also different within the same habitat, such as forests, grasslands, and deserts. Average correlations among the same habitat groups of vertebrates and among habitat groups of a single taxon were low or moderate, except correlations among FS groups. The sets of prominent variables of species richness differed strongly among habitat groups, although elevation range was the most important variable for most FS groups. The ecological and evolutionary processes that underpin richness patterns might be disparate among different habitat groups. Appropriate groupings based on habitats could reveal important patterns of richness gradients

  10. Predicting freshwater habitat integrity using land-use surrogates

    CSIR Research Space (South Africa)

    Amis, MA

    2007-04-01

    Full Text Available intolerance of fish occurring in a given river segment, and four components were taken into consideration in estimating intolerance namely, habitat prefer- ences and specialization, food preference and specialization, requirements for flowing water during...

  11. Dispersal limitation at the expanding range margin of an evergreen tree in urban habitats?

    DEFF Research Database (Denmark)

    Møller, Linda Agerbo; Skou, Anne-Marie Thonning; Kollmann, Johannes Christian

    2012-01-01

    Dispersal limitations contribute to shaping plant distribution patterns and thus are significant for biodiversity conservation and urban ecology. In fleshy-fruited plants, for example, any preference of frugivorous birds affects dispersal capacities of certain fruit species. We conducted a removal...... cultivars were offered to birds at the expanding range margin in urban habitats in eastern Denmark. The four fruit types were removed at different rates and red fruits were preferred over a yellow cultivar. Small fruit diameter was positively related to fruit removal, and removal was faster under tree...... canopies compared with open habitats. The preference for red cultivars compared with native I. aquifolium may contribute to naturalization and potential invasion of garden escapes. Preferential foraging under closed canopies indicates trees and shrubs as recruitment foci for fleshy-fruited plants in urban...

  12. The Moderating Influence of Situational Motivation on the Relationship Between Preferred Exercise and Positive Affect: An Experimental Study With Active Women

    National Research Council Canada - National Science Library

    Guérin, Eva; Fortier, Michelle S

    2013-01-01

    .... The primary aim of this experimental study was to examine the moderating influence of situational motivation from SDT on the relationship between an acute bout of preferred exercise, namely running (vs. control...

  13. Habitat Observations

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These data provide information on the relationship between California red-legged frogs and their habitat in a unique ecosystem to better conserve this threatened...

  14. Movement behaviour of the carabid beetle Pterostichus melanarius in crops and at a habitat interface explains patterns of population redistribution in the field.

    Directory of Open Access Journals (Sweden)

    Bas Allema

    Full Text Available Animals may respond to habitat quality and habitat edges and these responses may affect their distribution between habitats. We studied the movement behaviour of a ground-dwelling generalist predator, the carabid beetle Pterostichus melanarius (Illiger. We performed a mark-recapture experiment in two adjacent habitats; a large plot with oilseed radish (Raphanus sativus and a plot with rye (Secale cereale. We used model selection to identify a minimal model representing the mark-recapture data, and determine whether habitat-specific motility and boundary behaviour affected population redistribution. We determined movement characteristics of P. melanarius in laboratory arenas with the same plant species using video recording. Both the field and arena results showed preference behaviour of P. melanarius at the habitat interface. In the field, significantly more beetles moved from rye to oilseed radish than from radish to rye. In the arena, habitat entry was more frequent into oilseed radish than into rye. In the field, movement was best described by a Fokker-Planck diffusion model that contained preference behaviour at the interface and did not account for habitat specific motility. Likewise, motility calculated from movement data using the Patlak model was not different between habitats in the arena studies. Motility (m2 d-1 calculated from behavioural data resulted in estimates that were similar to those determined in the field. Thus individual behaviour explained population redistribution in the field qualitatively as well as quantitatively. The findings provide a basis for evaluating movement within and across habitats in complex agricultural landscapes with multiple habitats and habitat interfaces.

  15. Independent preferences

    DEFF Research Database (Denmark)

    Vind, Karl

    1991-01-01

    A simple mathematical result characterizing a subset of a product set is proved and used to obtain additive representations of preferences. The additivity consequences of independence assumptions are obtained for preferences which are not total or transitive. This means that most of the economic...

  16. Substantial CT radiation dose reduction does not affect the preference for CT over direct digital radiography to diagnose isolated zygomatic fractures: a study in human cadavers

    NARCIS (Netherlands)

    S. van der Duim; Dr. Martijn de Groot; W.P. Krijnen; B. van Minnen; A. Meijer; R. Hartman; R. Rozema

    2016-01-01

    Introduction: Zygomatic fractures can be diagnosed with either computed tomography (CT) or direct digital radiography (DR). The aim of the present study was to assess the effect of CT dose reduction on the preference for facial CT versus DR for accurate diagnosis of isolated zygomatic

  17. Roux-En-Y gastric bypass and sleeve gastrectomy does not affect food preferences when assessed by an ad libitum buffet meal

    DEFF Research Database (Denmark)

    Nielsen, Mette Søndergaard; Christensen, Bodil Just; Ritz, Christian

    2017-01-01

    BACKGROUND: Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) lead to a reduction in energy intake. It is uncertain whether this reduction is simply due to eating smaller portions or if surgery changes food preferences towards less energy-dense food. Previous results rely on verbal...

  18. Habitat selection and reproductive success of Ortolan Buntings Emberiza hortulana on farmland in central Sweden – the importance of habitat heterogeneity

    National Research Council Canada - National Science Library

    BERG, ÅKE

    2008-01-01

    .... The aim of the present study was to analyse habitat preferences and reproductive success of one such species, the Ortolan Bunting Emberiza hortulana , in different farmland habitats in south‐central Sweden...

  19. Fuzzy modelling of Atlantic salmon physical habitat

    Science.gov (United States)

    St-Hilaire, André; Mocq, Julien; Cunjak, Richard

    2015-04-01

    Fish habitat models typically attempt to quantify the amount of available river habitat for a given fish species for various flow and hydraulic conditions. To achieve this, information on the preferred range of values of key physical habitat variables (e.g. water level, velocity, substrate diameter) for the targeted fishs pecies need to be modelled. In this context, we developed several habitat suitability indices sets for three Atlantic salmon life stages (young-of-the-year (YOY), parr, spawning adults) with the help of fuzzy logic modeling. Using the knowledge of twenty-seven experts, from both sides of the Atlantic Ocean, we defined fuzzy sets of four variables (depth, substrate size, velocity and Habitat Suitability Index, or HSI) and associated fuzzy rules. When applied to the Romaine River (Canada), median curves of standardized Weighted Usable Area (WUA) were calculated and a confidence interval was obtained by bootstrap resampling. Despite the large range of WUA covered by the expert WUA curves, confidence intervals were relatively narrow: an average width of 0.095 (on a scale of 0 to 1) for spawning habitat, 0.155 for parr rearing habitat and 0.160 for YOY rearing habitat. When considering an environmental flow value corresponding to 90% of the maximum reached by WUA curve, results seem acceptable for the Romaine River. Generally, this proposed fuzzy logic method seems suitable to model habitat availability for the three life stages, while also providing an estimate of uncertainty in salmon preferences.

  20. Social preferences

    DEFF Research Database (Denmark)

    Gulløv, Eva

    2014-01-01

    The focus of this article is social divisions among preschool children in daycare centers. Based on ethnographic fieldwork in three daycare centers in Denmark, the analysis concerns young children’s social preferences. The ethnographic material shows that despite an explicit political ambition of...

  1. Habitat suitability index model of the sea cucumber Apostichopus japonicus (Selenka): A case study of Shandong Peninsula, China.

    Science.gov (United States)

    Zhang, Zhipeng; Zhou, Jian; Song, Jingjing; Wang, Qixiang; Liu, Hongjun; Tang, Xuexi

    2017-09-15

    A habitat suitability index (HSI) model for the sea cucumber Apostichopus japonicus (Selenka) was established in the present study. Based on geographic information systems, the HSI model was used to identify potential sites around the Shandong Peninsula suitable for restoration of immature (25g) A. japonicus. Six habitat factors were used as input variables for the HSI model: sediment classification, water temperature, salinity, water depth, pH and dissolved oxygen. The weighting of each habitat factor was defined through the Delphi method. Sediment classification was the most important condition affecting the HSI of A. japonicus in the different study areas, while water temperature was the most important condition in different seasons. The HSI of Western Laizhou Bay was relatively low, meaning the site was not suitable for aquaculture-based restoration of A. japonicus. In contrast, Xiaoheishan Island, Rongcheng Bay and Qingdao were preferable sites, suitable as habitats for restoration efforts. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Cultural legacies and political preferences

    DEFF Research Database (Denmark)

    Siroky, David S.; Mueller, Sean; Hechter, Michael

    2017-01-01

    that cultural identities matter for explaining secessionism, but not because of primordial attachments. Rather, religious and linguistic groups matter because their members are imbued with cultural legacies that lead to distinct political preferences – in this case preferences over welfare statism. Further......, ecological constraints such as geography and topography affect social interaction with like-minded individuals. On the basis of both these political preferences and ecological constraints, individuals then make rational choices about the desirability of secession. Instrumental considerations are therefore...

  3. Cooperation preferences and framing effects

    NARCIS (Netherlands)

    Petit Dit Dariel, A.C.

    2013-01-01

    This paper presents the results from an experiment investigating whether framing affects the elicitation and predictive power of preferences for cooperation, i.e., the willingness to cooperate with others. Cooperation preferences are elicited in three treatments using the method of Fischbacher,

  4. Lesions of cholinergic pedunculopontine tegmental nucleus neurons fail to affect cocaine or heroin self-administration or conditioned place preference in rats.

    Directory of Open Access Journals (Sweden)

    Stephan Steidl

    Full Text Available Cholinergic input to the ventral tegmental area (VTA is known to contribute to reward. Although it is known that the pedunculopontine tegmental nucleus (PPTg provides an important source of excitatory input to the dopamine system, the specific role of PPTg cholinergic input to the VTA in cocaine reward has not been previously determined. We used a diphtheria toxin conjugated to urotensin-II (Dtx::UII, the endogenous ligand for urotensin-II receptors expressed by PPTg cholinergic but not glutamatergic or GABAergic cells, to lesion cholinergic PPTg neurons. Dtx::UII toxin infusion resulted in the loss of 95.78 (±0.65% of PPTg cholinergic cells but did not significantly alter either cocaine or heroin self-administration or the development of cocaine or heroin conditioned place preferences. Thus, cholinergic cells originating in PPTg do not appear to be critical for the rewarding effects of cocaine or of heroin.

  5. Dietary Whey and Casein Differentially Affect Energy Balance, Gut Hormones, Glucose Metabolism, and Taste Preference in Diet-Induced Obese Rats.

    Science.gov (United States)

    Pezeshki, Adel; Fahim, Andrew; Chelikani, Prasanth K

    2015-10-01

    Dietary whey and casein proteins decrease food intake and body weight and improve glycemic control; however, little is known about the underlying mechanisms. We determined the effects of dietary whey, casein, and a combination of the 2 on energy balance, hormones, glucose metabolism, and taste preference in rats. In Expt. 1, Obesity Prone CD (OP-CD) rats were fed a high-fat control diet (33% fat energy) for 8 wk, and then randomly assigned to 4 isocaloric dietary treatments (n = 12/group): the control treatment (CO; 14% protein energy from egg white), the whey treatment (WH; 26% whey + 14% egg white), the casein treatment (CA; 26% casein + 14% egg white), or the whey plus casein treatment (WHCA; 13% whey + 13% casein + 14% egg white) for 28 d. Measurements included food intake, energy expenditure, body composition, metabolic hormones, glucose tolerance and key tissue markers of glucose and energy metabolism. In Expt. 2, naïve OP-CD rats were randomly assigned to 3 groups (n = 8/group). During an 8 d conditioning period, each group received on alternate days either the CO or WH, CO or CA, or CO or WHCA. Subsequently, preferences for the test diets were assessed on 2 consecutive days with food intake measurements at regular intervals. In Expt. 1, food intake was decreased by 17-37% for the first 14 d in the WH and CA rats, and by 18-34% only for the first 4 d in the WHCA compared with the CO rats. Fat mass decreased by 21-28% for the WH rats and 17-33% for the CA rats from day 14 onward, but by 30% only on day 28 in WHCA rats, relative to CO rats. Thus, food intake, body weight, and fat mass decreased more rapidly in WH and CA rats than in WHCA rats. Energy expenditure in WH rats decreased for the first 4 d compared with CA and WHCA rats, and for the first 7 d compared with the CO rats. Circulating leptin, glucose-dependent insulinotropic polypeptide, interleukin 6, and glucose concentrations were lower in WH, CA, and WHCA rats than in CO rats. Plasma glucagon

  6. The Effect of Emotion on Color Preferences

    National Research Council Canada - National Science Library

    Chan Jean Lee; Eduardo Andrade

    2010-01-01

    .... However, little is known about which colors consumers prefer, and why. Given the strong associations between colors and feelings, we investigate how the emotional state of an individual affects his/her color preferences...

  7. Reef fishes can recognize bleached habitat during settlement: sea anemone bleaching alters anemonefish host selection.

    Science.gov (United States)

    Scott, Anna; Dixson, Danielle L

    2016-05-25

    Understanding how bleaching impacts the settlement of symbiotic habitat specialists and whether there is flexibility in settlement choices with regard to habitat quality is essential given our changing climate. We used five anemonefishes (Amphiprion clarkii, Amphiprion latezonatus, Amphiprion ocellaris, Amphiprion percula and Premnas biaculeatus) and three host sea anemones (Entacmaea quadricolor, Heteractis crispa and Heteractis magnifica) in paired-choice flume experiments to determine whether habitat naive juveniles have the olfactory capabilities to distinguish between unbleached and bleached hosts, and how this may affect settlement decisions. All anemonefishes were able to distinguish between bleached and unbleached hosts, and responded only to chemical cues from species-specific host anemones irrespective of health status, indicating a lack of flexibility in host use. While bleached hosts were selected as habitat, this occurred only when unbleached options were unavailable, with the exception of A. latezonatus, which showed strong preferences for H. crispa regardless of health. This study highlights the potential deleterious indirect impacts of declining habitat quality during larval settlement in habitat specialists, which could be important in the field, given that bleaching events are becoming increasingly common. © 2016 The Author(s).

  8. Will the Three Gorges Dam affect the underwater light climate of Vallisneria spiralis L. and food habitat of Siberian crane in Poyang Lake?

    NARCIS (Netherlands)

    Wu, G.; Leeuw, de J.; Skidmore, A.K.; Prins, H.H.T.; Best, E.P.H.; Liu, Y.

    2009-01-01

    Almost 95% of the entire population of the Siberian crane (Grus leucogeranus) winter in Poyang Lake, China, where they forage on the tubers of the submerged aquatic macrophyte Vallisneria spiralis. The Three Gorges Dam on the Yangtze River may possibly affect this food source of the Siberian crane

  9. Residues at a Single Site Differentiate Animal Cryptochromes from Cyclobutane Pyrimidine Dimer Photolyases by Affecting the Proteins' Preferences for Reduced FAD.

    Science.gov (United States)

    Xu, Lei; Wen, Bin; Wang, Yuan; Tian, Changqing; Wu, Mingcai; Zhu, Guoping

    2017-06-19

    Cryptochromes (CRYs) and photolyases belong to the cryptochrome/photolyase family (CPF). Reduced FAD is essential for photolyases to photorepair UV-induced cyclobutane pyrimidine dimers (CPDs) or 6-4 photoproducts in DNA. In Drosophila CRY (dCRY, a type I animal CRY), FAD is converted to the anionic radical but not to the reduced state upon illumination, which might induce a conformational change in the protein to relay the light signal downstream. To explore the foundation of these differences, multiple sequence alignment of 650 CPF protein sequences was performed. We identified a site facing FAD (Ala377 in Escherichia coli CPD photolyase and Val415 in dCRY), hereafter referred to as "site 377", that was distinctly conserved across these sequences: CPD photolyases often had Ala, Ser, or Asn at this site, whereas animal CRYs had Ile, Leu, or Val. The binding affinity for reduced FAD, but not the photorepair activity of E. coli photolyase, was dramatically impaired when replacing Ala377 with any of the three CRY residues. Conversely, in V415S and V415N mutants of dCRY, FAD was photoreduced to its fully reduced state after prolonged illumination, and light-dependent conformational changes of these mutants were severely inhibited. We speculate that the residues at site 377 play a key role in the different preferences of CPF proteins for reduced FAD, which differentiate animal CRYs from CPD photolyases. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Odorant-binding proteins OBP57d and OBP57e affect taste perception and host-plant preference in Drosophila sechellia.

    Directory of Open Access Journals (Sweden)

    Takashi Matsuo

    2007-05-01

    Full Text Available Despite its morphological similarity to the other species in the Drosophila melanogaster species complex, D. sechellia has evolved distinct physiological and behavioral adaptations to its host plant Morinda citrifolia, commonly known as Tahitian Noni. The odor of the ripe fruit of M. citrifolia originates from hexanoic and octanoic acid. D. sechellia is attracted to these two fatty acids, whereas the other species in the complex are repelled. Here, using interspecies hybrids between D. melanogaster deficiency mutants and D. sechellia, we showed that the Odorant-binding protein 57e (Obp57e gene is involved in the behavioral difference between the species. D. melanogaster knock-out flies for Obp57e and Obp57d showed altered behavioral responses to hexanoic acid and octanoic acid. Furthermore, the introduction of Obp57d and Obp57e from D. simulans and D. sechellia shifted the oviposition site preference of D. melanogaster Obp57d/e(KO flies to that of the original species, confirming the contribution of these genes to D. sechellia's specialization to M. citrifolia. Our finding of the genes involved in host-plant determination may lead to further understanding of mechanisms underlying taste perception, evolution of plant-herbivore interactions, and speciation.

  11. Habitat correlates of the Eurasian otter Lutra lutra recolonizing Central Poland.

    Science.gov (United States)

    Romanowski, Jerzy; Brzeziński, Marcin; Zmihorski, Michał

    2013-04-01

    The increase in Eurasian otter Lutra lutra populations in their natural range and recolonization processes are recently observed in several European countries. We address the process of otter recolonization and habitat utilization in Central Poland over 14 years. Field surveys in 1998 and 2007 documented increase in occurrence of the species. The frequency of positive sites denoted 15 % in 1993, 38 % in 1998, and 89 % in 2007. Otter occurrence at study sites was positively affected by river width while negatively affected by presence of buildings at the site and river regulation. During the most intensive colonization process in the 1990s, the habitat preferences of the otter did not change. However, the sites inhabited by otters after 1998 were characterized by lower river width and tree cover and were more often located on regulated river sections, suggesting change in habitat tolerance during expansion. The otter abundance in transformed habitats is a result of increasing population numbers and the necessity to inhabit suboptimal sections of watercourses. Thus, it seems that presence-absence data for otter populations cannot be considered a reliable indicator of habitat quality, being depended of the population density.

  12. Harvesting interacts with climate change to affect future habitat quality of a focal species in eastern Canada’s boreal forest

    Science.gov (United States)

    Boulanger, Yan; Cyr, Dominic; Taylor, Anthony R.; Price, David T.; St-Laurent, Martin-Hugues

    2018-01-01

    Many studies project future bird ranges by relying on correlative species distribution models. Such models do not usually represent important processes explicitly related to climate change and harvesting, which limits their potential for predicting and understanding the future of boreal bird assemblages at the landscape scale. In this study, we attempted to assess the cumulative and specific impacts of both harvesting and climate-induced changes on wildfires and stand-level processes (e.g., reproduction, growth) in the boreal forest of eastern Canada. The projected changes in these landscape- and stand-scale processes (referred to as “drivers of change”) were then assessed for their impacts on future habitats and potential productivity of black-backed woodpecker (BBWO; Picoides arcticus), a focal species representative of deadwood and old-growth biodiversity in eastern Canada. Forest attributes were simulated using a forest landscape model, LANDIS-II, and were used to infer future landscape suitability to BBWO under three anthropogenic climate forcing scenarios (RCP 2.6, RCP 4.5 and RCP 8.5), compared to the historical baseline. We found climate change is likely to be detrimental for BBWO, with up to 92% decline in potential productivity under the worst-case climate forcing scenario (RCP 8.5). However, large declines were also projected under baseline climate, underlining the importance of harvest in determining future BBWO productivity. Present-day harvesting practices were the single most important cause of declining areas of old-growth coniferous forest, and hence appeared as the single most important driver of future BBWO productivity, regardless of the climate scenario. Climate-induced increases in fire activity would further promote young, deciduous stands at the expense of old-growth coniferous stands. This suggests that the biodiversity associated with deadwood and old-growth boreal forests may be greatly altered by the cumulative impacts of natural and

  13. Simulating Spawning and Juvenile Rainbow Trout (Oncorhynchus mykiss Habitat in Colorado River Based on High-Flow Effects

    Directory of Open Access Journals (Sweden)

    Weiwei Yao

    2017-02-01

    Full Text Available High flow generates significant alterations in downstream river reaches, resulting in physical condition changes in the downstream regions of the river such as water depth, flow velocity, water temperature and river bed. These alterations will lead to change in fish habitat configuration in the river. This paper proposes a model system to evaluate the high flow effects on river velocity, water depth, substrates changes, temperature distribution and consequently assess the change in spawning and juvenile rainbow trout (Oncorhynchus mykiss habitats in the downstream region of the Glen Canyon Dam. Firstly, based on the 2 dimensional (2D depth-averaged CFD (Computational Fluid Dynamics model and heat transfer equation applied for simulation, three indices were simulated, namely depth, flow velocity and temperature distribution. Then, the spawning and juvenile fish preference curves were obtained based on these three indices and substrates distribution. After that, the habitat model was proposed and used to simulate the high flow effects on juvenile and spawning rainbow trout habitat structure. Finally, the weighted usable area (WUA and overall suitability index (OSI of the spawning and juvenile fish species were quantitatively simulated to estimate the habitat sensitivity. The results illustrate that the high flow effect (HFE increased the juvenile rainbow trout habitat quality but decreased the spawning rainbow trout habitat quality. The juvenile trout were mainly affected by the water depth while the spawning rainbow trout were dominated by the bed elevation.

  14. Distribution and habitats of Melanoides tuberculata (Müller, 1774 ...

    African Journals Online (AJOL)

    The conservation status of these 2 species and the possible influence of global warming and climatic changes on their geographical distribution are briefly discussed. Keywords: Melanoides tuberculata, Melanoides victoriae, geographical distribution, habitat preferences, biological control, Trematoda, freshwater Mollusca, ...

  15. Testing the Role of Habitat Isolation among Ecologically Divergent Gall Wasp Populations

    Directory of Open Access Journals (Sweden)

    Scott P. Egan

    2012-01-01

    Full Text Available Habitat isolation occurs when habitat preferences lower the probability of mating between individuals associated with differing habitats. While a potential barrier to gene flow during ecological speciation, the effect of habitat isolation on reproductive isolation has rarely been directly tested. Herein, we first estimated habitat preference for each of six populations of the gall wasp Belonocnema treatae inhabiting either Quercus virginiana or Q. geminata. We then estimated the importance of habitat isolation in generating reproductive isolation between B. treatae populations that were host specific to either Q. virginiana or Q. geminata by measuring mate preference in the presence and absence of the respective host plants. All populations exhibited host preference for their native plant, and assortative mating increased significantly in the presence of the respective host plants. This host-plant-mediated assortative mating demonstrates that habitat isolation likely plays an important role in promoting reproductive isolation among populations of this host-specific gall former.

  16. Changing land use and its impact on the habitat suitability for wintering Anseriformes in China's Poyang Lake region.

    Science.gov (United States)

    Tang, Xuguang; Li, Hengpeng; Xu, Xibao; Yang, Guishan; Liu, Guihua; Li, Xinyan; Chen, Dongqiang

    2016-07-01

    As an internationally important wetland for migratory waterbirds, China's Poyang Lake region has experienced substantial changes in land use during the past two decades owing to climate change and anthropogenic disturbances. Recent dam constructions on the Yangtze River and its tributaries for agriculture and hydroelectric power exert strong effects on the hydrological regimes of this lake. However, few studies have investigated how the land-use changes through time affect the habitat suitability for wintering Anseriformes-the largest community in this region. Thus, it is necessary to timely monitor changes in the habitat quality and understand the potential factors that alter it. In this study, three periods (1995, 2005 and 2014) of typical environmental indicators that have direct impacts on foraging and resting for the Anserformes, including proximity to water (density of lakes, rivers and ponds), human disturbances (density of residences and various road networks), preferred land cover types and food availability (NDVI), are integrated to develop a habitat suitability index model for habitat mapping. The results indicate that long-term lake shrinkage in low-water periods led to greatly expanded wetlands in these years, which provided more suitable habitat for migratory waterfowl. The amount of highly suitable habitat in 2014 was nearly twice as much as in 1995. Recent survey data from 1997 to 2013 also revealed an increase in the population size, and confirmed the improvement of habitat suitability in the Poyang Lake region. Spatial analysis revealed that land use changes contributed most to the improved habitat coverage between 1995 and 2014. However, the relative significances of these transformations for highly suitable and moderately suitable habitats are strikingly different. Increases in wetland and paddy field area are the main reasons for explaining these improvements, respectively. The framework model proposed in this study will help governments to

  17. Habitat Loss, Not Fragmentation, Drives Occurrence Patterns of Canada Lynx at the Southern Range Periphery

    OpenAIRE

    Hornseth, Megan L.; Walpole, Aaron A.; Walton, Lyle R.; Bowman, Jeff; Ray, Justina C.; Fortin, Marie-Josée; Murray, Dennis L.

    2014-01-01

    Peripheral populations often experience more extreme environmental conditions than those in the centre of a species' range. Such extreme conditions include habitat loss, defined as a reduction in the amount of suitable habitat, as well as habitat fragmentation, which involves the breaking apart of habitat independent of habitat loss. The 'threshold hypothesis' predicts that organisms will be more affected by habitat fragmentation when the amount of habitat on the landscape is scarce (i.e., le...

  18. Habitat and food selection by herbivorous amphipods associated with macroalgal beds on the southeast coast of Brazil

    Directory of Open Access Journals (Sweden)

    Mauro Rezende Tavares

    Full Text Available The factors that influence the selection of marine macrophytes by meso-herbivores are complex, and may include the nutritional quality of algae, the value of the habitat as a shelter, and the availability of algae in the environment. Here we investigated the existence of differential use of Sargassum filipendula C. Agardh, 1824 (Phaeophyta and Galaxaura stupocaulon Kjellman, 1900 (Rhodophyta as habitats and feeding resources by species of Hyalidae and Ampithoidae, in laboratory manipulation experiments and in an algal bed on the northern coast of the state of São Paulo, Brazil. In the field, 19 fronds were collected from each alga and the associated amphipods were identified and counted. To evaluate food preference and habitat selection by amphipods, we conducted laboratory experiments using containers containing fragments of algae and individuals of Cymadusa filosa Savigny, 1816 or Hyale nigra (Haswell, 1879. In natural conditions, the density of C. filosa was significantly higher on G. stupocaulon, while in the feeding and habitat preference experiment we found a higher density on S. filipendula. The densities of H. nigra did not differ between the algae in both experiments, probably as a result of the variety of food items in its diet, and its high mobility and wide distribution on different substrates. The different results for C. filosa suggest that the pattern of feeding and habitat selection can be affected by external characteristics of the algae; probably, refuge from predation is an important selective force acting on the use of algae by these animals.

  19. South Carolina Superintendents' Change Style Preferences

    Science.gov (United States)

    Melton, Annette Ghent; Cox, Edward P.

    2010-01-01

    Little is known about the change style preferences of superintendents, and how they differ from school principals and from business leaders and whether a superintendent's change-style preference affects student achievement. The purpose of this study was to explore the change-style preferences of South Carolina superintendents, compare them with…

  20. The grasses of the Suikerbosrand Nature Reserve: Their habitat ...

    African Journals Online (AJOL)

    A classification is presented of the vegetation of the Suikerbosrand Nature Reserve, based on the habitat preferences of the grass species, and processed according to the Braun-Blanquet method. Habitat factors correlated with the grasses include geological formation, altitude, aspect, slope, stoniness, soil depth, soil pH ...

  1. Quantifying the effect of habitat availability on species distributions

    NARCIS (Netherlands)

    Aarts, G.M.; Fieberg, J.; Brasseur, S.M.J.M.; Matthiopoulos, J.

    2013-01-01

    1.If animals moved randomly in space, the use of different habitats would be proportional to their availability. Hence, deviations from proportionality between use and availability are considered the tell-tale sign of preference. This principle forms the basis for most habitat selection and species

  2. Separating the effects of habitat area, fragmentation and matrix resistance on genetic differentiation in complex landscapes

    Science.gov (United States)

    Samuel A. Cushman; Andrew J. Shirk; Erin L. Landguth

    2012-01-01

    Little is known about how variation in landscape mosaics affects genetic differentiation. The goal of this paper is to quantify the relative importance of habitat area and configuration, as well as the contrast in resistance between habitat and non-habitat, on genetic differentiation. We hypothesized that habitat configuration would be more influential than habitat...

  3. Predicting 21st-century polar bear habitat distribution from global climate models

    Science.gov (United States)

    Durner, G.M.; Douglas, D.C.; Nielson, R.M.; Amstrup, Steven C.; McDonald, T.L.; Stirling, I.; Mauritzen, Mette; Born, E.W.; Wiig, O.; Deweaver, E.; Serreze, M.C.; Belikov, Stanislav; Holland, M.M.; Maslanik, J.; Aars, Jon; Bailey, D.A.; Derocher, A.E.

    2009-01-01

    Projections of polar bear (Ursus maritimus) sea ice habitat distribution in the polar basin during the 21st century were developed to understand the consequences of anticipated sea ice reductions on polar bear populations. We used location data from satellitecollared polar bears and environmental data (e.g., bathymetry, distance to coastlines, and sea ice) collected from 1985 to 1995 to build resource selection functions (RSFs). RSFs described habitats that polar bears preferred in summer, autumn, winter, and spring. When applied to independent data from 1996 to 2006, the RSFs consistently identified habitats most frequently used by polar bears. We applied the RSFs to monthly maps of 21st-century sea ice concentration projected by 10 general circulation models (GCMs) used in the Intergovernmental Panel of Climate Change Fourth Assessment Report, under the A1B greenhouse gas forcing scenario. Despite variation in their projections, all GCMs indicated habitat losses in the polar basin during the 21st century. Losses in the highest-valued RSF habitat (optimal habitat) were greatest in the southern seas of the polar basin, especially the Chukchi and Barents seas, and least along the Arctic Ocean shores of Banks Island to northern Greenland. Mean loss of optimal polar bear habitat was greatest during summer; from an observed 1.0 million km2 in 1985-1995 (baseline) to a projected multi-model mean of 0.32 million km2 in 2090-2099 (-68% change). Projected winter losses of polar bear habitat were less: from 1.7 million km2 in 1985-1995 to 1.4 million km2 in 2090-2099 (-17% change). Habitat losses based on GCM multi-model means may be conservative; simulated rates of habitat loss during 1985-2006 from many GCMs were less than the actual observed rates of loss. Although a reduction in the total amount of optimal habitat will likely reduce polar bear populations, exact relationships between habitat losses and population demographics remain unknown. Density and energetic

  4. Stream habitat structure influences macroinvertebrate response to pesticides

    DEFF Research Database (Denmark)

    Rasmussen, Jes; Wiberg-Larsen, Peter; Baattrup-Pedersen, Annette

    2012-01-01

    Agricultural pesticide contamination in surface waters is increasingly threatening to impair the surface water ecosystems. Agricultural streams are furthermore often heavily maintained to optimise the transport of water away from fields. The physical habitat degradation that result from heavy...... of species with specific preferences for habitats with hard substrate. Our findings highlight the importance of considering physical habitat degradation in the assessment and mitigation of risk in agricultural streams....

  5. Pollen and gene flow in fragmented habitats

    NARCIS (Netherlands)

    Kwak, Manja M.; Velterop, Odilia; van Andel, Jelte

    . Habitat fragmentation affects both plants and pollinators. Habitat fragmentation leads to changes in species richness, population number and size, density, and shape, thus to changes in the spatial arrangement of flowers. These changes influence the amount of food for flower-visiting insects and

  6. Expressing an (E)-β-farnesene synthase in the chloroplast of tobacco affects the preference of green peach aphid and its parasitoid.

    Science.gov (United States)

    Wang, Gen-Ping; Yu, Xiu-Dao; Fan, Jia; Wang, Cheng-She; Xia, Lan-Qin

    2015-09-01

    (E)-β-Farnesene (EβF) synthase catalyses the production of EβF, which for many aphids is the main or only component of the alarm pheromone causing the repellence of aphids and also functions as a kairomone for aphids' natural enemies. Many plants possess EβF synthase genes and can release EβF to repel aphids. In order to effectively recruit the plant-derived EβF synthase genes for aphid control, by using chloroplast transit peptide (CTP) of the small subunit of Rubisco (rbcS) from wheat (Triticum aestivum L.), we targeted AaβFS1, an EβF synthase gene from sweet wormwood (Artemisia annua L.), to the chloroplast of tobacco to generate CTP + AaβFS1 transgenic lines. The CTP + AaβFS1 transgenic tobacco plants could emit EβF at a level up to 19.25 ng/day per g fresh tissues, 4-12 fold higher than the AaβFS1 transgenic lines without chloroplast targeting. Furthermore, aphid/parasitoid behavioral bioassays demonstrated that the CTP + AaβFS1 transgenic tobacco showed enhanced repellence to green peach aphid (Myzus persicae) and attracted response of its parasitoid Diaeretiella rapae, thus affecting aphid infestation at two trophic levels. These data suggest that the chloroplast is an ideal subcellular compartment for metabolic engineering of plant-derived EβF synthase genes to generate a novel type of transgenic plant emitting an alarm pheromone for aphid control. © 2014 Institute of Botany, Chinese Academy of Sciences.

  7. Genetic damage in Rhinella marina populations in habitats affected by agriculture in the middle region of the Sinú River, Colombia.

    Science.gov (United States)

    Cruz-Esquivel, Ángel; Viloria-Rivas, Jose; Marrugo-Negrete, Jose

    2017-10-03

    Contamination with pesticide residues affects the environmental health of agroecosystems, especially the amphibian fauna that lives in these environments. The objective of the present study was to determine pesticides concentrations in sediments of agroecosystems and to evaluate genetic damage in Rhinella marina populations living in these zones. A total of 91 individuals were collected, 51 in the group exposed in different areas of the middle region of the Sinú River (Irrigation District of Mocari 16, Irrigation District of Aguas Negras 21, Irrigation District of Cerete 14) and 40 in a control group; at the same time, 36 subsamples of sediments were taken at each sampled station to determine pesticides organochlorine by means of chromatography coupled with ISQ Thermo Scientific mass spectrometer. The micronucleus test was applied in erythrocytes of the individuals collected. Results showed the presence of persistent organochlorine pesticides (POPs) in the sediment samples (p,p'-DDT, p,p'-DDE, and p,p'-DDD) of agricultural soils. Two individuals were registered with abnormalities in their limbs at the Mocari station, representing 12.5% of the morphological malformations to this sector. Micronucleus analysis revealed statistically significant genetic damage in exposed individuals (Mocari 9.87 ± 5.1, Cerete 7.7 ± 1.7, Aguas Negras 5.6 ± 3.6) with respect to the control group (2.4 ± 1.9) (p < 0.05). Spearman correlation analysis revealed a positive association between genetic damage and POP concentrations (p < 0.05). In addition, cellular alterations such as nuclear buds, and pyknosis (cell death), were statistically significant in the exposed group compared to the control group (p < 0.05). This study suggests that there is evidence for morphological and genotoxic effects in R. marina populations inhabiting areas influenced by agriculture, possibly associated with the presence of p,p'-DDT, p,p'-DDD, and p,p'-DDE.

  8. Predictive habitat suitability models to aid conservation of elasmobranch diversity in the central Mediterranean Sea

    Science.gov (United States)

    Lauria, V.; Gristina, M.; Attrill, M. J.; Fiorentino, F.; Garofalo, G.

    2015-08-01

    Commercial fisheries have dramatically impacted elasmobranch populations worldwide. With high capture and bycatch rates, the abundance of many species is rapidly declining and around a quarter of the world’s sharks and rays are threatened with extinction. At a regional scale this negative trend has also been evidenced in the central Mediterranean Sea, where bottom-trawl fisheries have affected the biomass of certain rays (e.g. Raja clavata) and sharks (e.g. Mustelus spp.). Detailed knowledge of elasmobranch habitat requirements is essential for biodiversity conservation and fisheries management, but this is often hampered by a poor understanding of their spatial ecology. Habitat suitability models were used to investigate the habitat preference of nine elasmobranch species and their overall diversity (number of species) in relation to five environmental predictors (i.e. depth, sea surface temperature, surface salinity, slope and rugosity) in the central Mediterranean Sea. Results showed that depth, seafloor morphology and sea surface temperature were the main drivers for elasmobranch habitat suitability. Predictive distribution maps revealed different species-specific patterns of suitable habitat while high assemblage diversity was predicted in deeper offshore waters (400-800 m depth). This study helps to identify priority conservation areas and diversity hot-spots for rare and endangered elasmobranchs in the Mediterranean Sea.

  9. Growth trajectory influences temperature preference in fish through an effect on metabolic rate.

    Science.gov (United States)

    Killen, Shaun S

    2014-11-01

    Most animals experience temperature variations as they move through the environment. For ectotherms, in particular, temperature has a strong influence on habitat choice. While well studied at the species level, less is known about factors affecting the preferred temperature of individuals; especially lacking is information on how physiological traits are linked to thermal preference and whether such relationships are affected by factors such feeding history and growth trajectory. This study examined these issues in the common minnow Phoxinus phoxinus, to determine the extent to which feeding history, standard metabolic rate (SMR) and aerobic scope (AS), interact to affect temperature preference. Individuals were either: 1) food deprived (FD) for 21 days, then fed ad libitum for the next 74 days; or 2) fed ad libitum throughout the entire period. All animals were then allowed to select preferred temperatures using a shuttle-box, and then measured for SMR and AS at 10 °C, estimated by rates of oxygen uptake. Activity within the shuttle-box under a constant temperature regime was also measured. In both FD and control fish, SMR was negatively correlated with preferred temperature. The SMR of the FD fish was increased compared with the controls, probably due to the effects of compensatory growth, and so these growth-compensated fish preferred temperatures that were on average 2.85 °C cooler than controls fed a maintenance ration throughout the study. Fish experiencing compensatory growth also displayed a large reduction in activity. In growth-compensated fish and controls, activity measured at 10 °C was positively correlated with preferred temperature. Individual fish prefer temperatures that vary predictably with SMR and activity level, which are both plastic in response to feeding history and growth trajectories. Cooler temperatures probably allow individuals to reduce maintenance costs and divert more energy towards growth. A reduction in SMR at cooler

  10. Quantitative recommendations for amphibian terrestrial habitat conservation derived from habitat selection behavior.

    Science.gov (United States)

    Indermaur, Lukas; Schmidt, Benedikt R

    2011-10-01

    Conservation scientists have noted that conservation managers rarely use scientific information when making decisions. One of the reasons why managers rarely use scientific information may be that conservation scientists rarely provide their knowledge in a way that can directly be used by conservation practitioners. Here we show how quantitative recommendations for conservation can be derived. Previous research on terrestrial habitat selection behavior of toads (Bufo bufo and Bufo viridis) showed that wood deposits are a key resource in the terrestrial habitat. We used habitat-dependence analysis to estimate the amount of this key resource, wood deposits, that individual toads require. Based on these estimates we then quantify the requirements for wood deposits for a population. Additionally, we quantified the area that a population requires. Although wood deposits vary strongly in size, we found little evidence for size preferences: only one species preferred smallest sizes of wood deposits. We report all the estimates in a way that can be directly used by conservation managers. Habitat-dependence analysis is a simple and useful tool to quantify habitat requirements. Provisioning of wood deposits may improve the quality of terrestrial habitat for amphibians. Thereby, managers may increase the carrying capacity of terrestrial habitats and support elevated population densities.

  11. Ecosystem services Linking People to Coastal Habitats.

    Science.gov (United States)

    Given the growing desire to incorporate ecosystem goods and services (EGS) considerations into coastal planning efforts, it is imperative that stakeholders understand how coastal habitats affect the availability and delivery of those EGS. Nonetheless, methods requiring long-term ...

  12. Daytime habitat selection for juvenile parr brown trout (Salmo trutta) in small lowland streams

    DEFF Research Database (Denmark)

    Conallin, J.; Boegh, E.; Olsen, M.

    2014-01-01

    Physical habitat is important in determining the carrying capacity of juvenile brown trout, and within freshwater management. Summer daytime physical habitat selection for the parr lifestage (7-20 cm) juvenile brown trout (Salmo trutta) was assessed in 6 small lowland streams. Habitat preference ...

  13. Loss and modification of habitat

    Science.gov (United States)

    Lemckert, Francis; Hecnar, Stephen; Pilliod, David S.; Wilkinson, John W.; Heatwole, Harold

    2012-01-01

    water balance (Thorson and Svihla 1943; Brattstrom 1963; Tracy 1976). Hence, individuals require and seek specific microhabitats that maintain their preferred body temperature while at the same time reducing water loss or allowing individuals to re-hydrate. Amphibians also possess relatively few physical attributes that protect them from predators. Although they may avoid predators behaviourally or deter them by skin toxins, amphibians lack defensive shells or hardened cuticles, do not have protective teeth or claws, and most are insufficiently fast to escape predators. Hence, they are relatively dependent on sites that conceal or protect them from predation. Most amphibians also differ significantly from other vertebrates in possessing a complex two-phase life cycle: the pre-metamorphic larval (tadpole) stage and the post-metamorphic juvenile and adult stage (Wilbur 1980, 1984). Most amphibian species have two distinct econes (Heatwole 1989), each with different habitat requirements, the larvae being aquatic and the post-metamorphic animals more terrestrial. The habitats required by the two phases can differ greatly, but both are essential to the survival of a species. However, amphibian diversity is great and exceptions to this general pattern exist. For example, some species have direct development without going through a larval stage and are fully terrestrial, whereas the larvae of other species can reach sexual maturity without going through metamorphosis (i.e., neoteny) and are fully aquatic.

  14. Habitat specialization and climate affect arthropod fitness

    DEFF Research Database (Denmark)

    Ameline, Camille; Puzin, Charlene; Bowden, Joseph J.

    2017-01-01

    Life history trade-offs are a key notion in evolutionary biology, notably for understanding how selection shapes the diversity of traits among species. Despite the frequent study of such trade-offs, few studies synchronously investigate the effects of multiple factors, such as niche specializatio...... emphasize the need to test the role of plasticity and environmentally mediated effects of competition on arthropod fitness....

  15. ORIGINAL ARTICLES Factors affecting career preferences of ...

    African Journals Online (AJOL)

    population was the 294 medical students at the College of Medicine in Malawi. The questionnaires were .... with those settings – 8; they have knowledge of the problems and needs – 5; city life can be difficult – 3; .... and underserved areas, and giving them more financial aid than other students. Our findings support these ...

  16. Multi-scale habitat selection of the endangered Hawaiian Goose

    Science.gov (United States)

    Leopold, Christina R.; Hess, Steven C.

    2013-01-01

    After a severe population reduction during the mid-20th century, the endangered Hawaiian Goose (Branta sandvicensis), or Nēnē, has only recently re-established its seasonal movement patterns on Hawai‘i Island. Little is currently understood about its movements and habitat use during the nonbreeding season. The objectives of this research were to identify habitats preferred by two subpopulations of the Nēnē and how preferences shift seasonally at both meso-and fine scales. From 2009 to 2011, ten Nēnē ganders were outfitted with 40-to 45-g satellite transmitters with GPS capability. We used binary logistic regression to compare habitat use versus availability and an information-theoretic approach for model selection. Meso-scale habitat modeling revealed that Nēnē preferred exotic grass and human-modified landscapes during the breeding and molting seasons and native subalpine shrubland during the nonbreeding season. Fine-scale habitat modeling further indicated preference for exotic grass, bunch grass, and absence of trees. Proximity to water was important during molt, suggesting that the presence of water may provide escape from introduced mammalian predators while Nēnē are flightless. Finescale species-composition data added relatively little to understanding of Nēnē habitat preferences modeled at the meso scale, suggesting that the meso-scale is appropriate for management planning. Habitat selection during our study was consistent with historical records, although dissimilar from more recent studies of other subpopulations. Nēnē make pronounced seasonal movements between existing reserves and use distinct habitat types; understanding annual patterns has implications for the protection and restoration of important seasonal habitats.

  17. The Behavioural and Emotional Effects of Unconscious Brand Exposure on Fashion Preference

    DEFF Research Database (Denmark)

    Bagdziunaite, Dalia; Ramsøy, Thomas Z.

    Can subliminal brands affect preference? Here we show that subliminally presented fashion brands affect rating of fashion items. Individual brand preference demonstrates the positive bias for the direction and strength of fashion preference. Pupillometry data show the implicit emotional reactions...

  18. Beyond the border: effects of an expanding algal habitat on the fauna of neighbouring habitats.

    Science.gov (United States)

    Lanham, Brendan S; Gribben, Paul E; Poore, Alistair G B

    2015-05-01

    The impacts of novel habitat-forming organisms on associated fauna have been difficult to predict, and may affect the fauna of neighbouring habitats due to changes in the spatial configuration of habitat patches of differing quality. Here, we test whether the localised expansion of a native habitat-forming macroalga, Caulerpa filiformis, on subtidal reefs can affect the abundance of fauna associated with a neighbouring macroalgal habitat. C. filiformis was a functionally distinct habitat for fauna, and the total abundance of epifauna associated with the resident alga, Sargassum linearifolium, was reduced at some sites when in close proximity to or surrounded by C. filiformis. Experimental manipulation of habitat configuration demonstrated that the low abundance of gastropods on S. linearifolium when surrounded by C. filiformis was likely explained by C. filiformis acting as a physical dispersal barrier for mobile fauna. Changes to the spatial configuration of novel and resident habitats can thus affect the abundance of fauna in addition to the direct replacement of habitats by species undergoing range expansions or increasing in abundance. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. VIERS- User Preference Service

    Data.gov (United States)

    Department of Veterans Affairs — The Preferences service provides a means to store, retrieve, and manage user preferences. The service supports definition of enterprise wide preferences, as well as...

  20. Elicitation of ostomy pouch preferences

    DEFF Research Database (Denmark)

    Bonnichsen, Ole

    2011-01-01

    Background: Previous studies about patients who have undergone ostomy surgery commonly address the issues of the surgery, complications, preoperative counseling, quality of life, and psychosocial changes following surgery. Only a limited number of studies deal with how technical improvements...... in stoma care would affect patients and, to the author's knowledge, the present study is the first to elicit preferences for potential improvements in ostomy pouches in the form of monetary values. Objective: This article examines and measures Swedish patients' preferences for potential improvements...... in ostomy pouch attributes. The theory, study design, elicitation procedure, and resulting preference structure of the sample is described. Methods: A discrete-choice experiment (DCE) was used to elicit preferences. Respondents were asked to choose between alternatives in choice sets, in which each...

  1. Coastal Critical Habitat Designations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Endangered Species Act (ESA) requires the Federal government to designate critical habitat, areas of habitat essential to the species' conservation, for ESA...

  2. California Condor Critical Habitat

    Data.gov (United States)

    California Department of Resources — These Data identify (in general) the areas where critical habitat for the California Condor occur. Critical habitat for the species consists of the following 10...

  3. Abundance and Distribution Patterns of Thunnus albacares in Isla del Coco National Park through Predictive Habitat Suitability Models.

    Directory of Open Access Journals (Sweden)

    Cristina Gonzáles-Andrés

    Full Text Available Information on the distribution and habitat preferences of ecologically and commercially important species is essential for their management and protection. This is especially important as climate change, pollution, and overfishing change the structure and functioning of pelagic ecosystems. In this study, we used Bayesian hierarchical spatial-temporal models to map the Essential Fish Habitats of the Yellowfin tuna (Thunnus albacares in the waters around Isla del Coco National Park, Pacific Costa Rica, based on independent underwater observations from 1993 to 2013. We assessed if observed changes in the distribution and abundance of this species are related with habitat characteristics, fishing intensity or more extreme climatic events, including the El Niño Southern Oscillation, and changes on the average sea surface temperature. Yellowfin tuna showed a decreasing abundance trend in the sampled period, whereas higher abundances were found in shallow and warmer waters, with high concentration of chlorophyll-a, and in surrounding seamounts. In addition, El Niño Southern Oscillation events did not seem to affect Yellowfin tuna distribution and abundance. Understanding the habitat preferences of this species, using approaches as the one developed here, may help design integrated programs for more efficient management of vulnerable species.

  4. Color preference in red–green dichromats

    Science.gov (United States)

    Álvaro, Leticia; Moreira, Humberto; Lillo, Julio; Franklin, Anna

    2015-01-01

    Around 2% of males have red–green dichromacy, which is a genetic disorder of color vision where one type of cone photoreceptor is missing. Here we investigate the color preferences of dichromats. We aim (i) to establish whether the systematic and reliable color preferences of normal trichromatic observers (e.g., preference maximum at blue, minimum at yellow-green) are affected by dichromacy and (ii) to test theories of color preference with a dichromatic sample. Dichromat and normal trichromat observers named and rated how much they liked saturated, light, dark, and focal colors twice. Trichromats had the expected pattern of preference. Dichromats had a reliable pattern of preference that was different to trichromats, with a preference maximum rather than minimum at yellow and a much weaker preference for blue than trichromats. Color preference was more affected in observers who lacked the cone type sensitive to long wavelengths (protanopes) than in those who lacked the cone type sensitive to medium wavelengths (deuteranopes). Trichromats’ preferences were summarized effectively in terms of cone-contrast between color and background, and yellow-blue cone-contrast could account for dichromats’ pattern of preference, with some evidence for residual red–green activity in deuteranopes’ preference. Dichromats’ color naming also could account for their color preferences, with colors named more accurately and quickly being more preferred. This relationship between color naming and preference also was present for trichromat males but not females. Overall, the findings provide novel evidence on how dichromats experience color, advance the understanding of why humans like some colors more than others, and have implications for general theories of aesthetics. PMID:26170287

  5. The airspace is habitat

    Science.gov (United States)

    Diehl, Robert H.

    2013-01-01

    A preconception concerning habitat persists and has gone unrecognized since use of the term first entered the lexicon of ecological and evolutionary biology many decades ago. Specifically, land and water are considered habitats, while the airspace is not. This might at first seem a reasonable, if unintended, demarcation, since years of education and personal experience as well as limits to perception predispose a traditional view of habitat. Nevertheless, the airspace satisfies the definition and functional role of a habitat, and its recognition as habitat may have implications for policy where expanding anthropogenic development of airspace could impact the conservation of species and subject parts of the airspace to formalized legal protection.

  6. Keanekaragaman serangga dan struktur vegetasi pada habitat burung insektivora Lanius schach Linn. di Tanjungsari, Yogyakarta

    Directory of Open Access Journals (Sweden)

    Fredy Lala

    2015-09-01

    Full Text Available Insect diversity and vegetation structure are two aspects that affect the reproduction of insectivorous birds. The objective of this study was to investigate the characteristics of the original habitat Lanius schach in Tanjungsari of particularly the type, composition of vegetation, and preference to insect sprey. Observation of vegetation and insects were conduct using a combination methods of the track and checkered line on the transect along the 10 km (ten observation points. Insect and tree species were counted on plot (20 m x 20 m, shrub (10 m x 10 m, bush (5 m x 5 m, and grass (2 m x 2 m. Vegetation analysis was used to calculate the structure and composition of vegetation, whereas Shannon diversity index was used for insect diversity. Prey test was conducted to determine the preferences of insectivore birds on insects. The composition of the vegetation species consists of 7 grasses, 20 bushes, 5 shrubs and 18 trees. The dominant species of vegetation based on highest important value index was Tectona grandis, Ipomoea sp., I. cylindrica, and Panicum brevifolium respectively. The highest diversity index of vegetation group were bush (2.430, tree (1.696, grass (1,680, and shrubs (1.364, respectively. Insect diversity index was 2.572 and grasshoppers (Orthoptera was the most preferred prey by L. schach. Overall, the habitat of insectivore birds L. schach are dominated by T. grandis, and has high diversity of bush.

  7. Seasonal use of shallow water habitat in the Lower Snake River reservoirs by juvenile fall Chinook salmon

    Science.gov (United States)

    Tiffan, Kenneth F.; Connor, William P.

    2012-01-01

    The U.S. Army Corps of Engineers (COE) is preparing a long term management plan for sediments that affect the authorized project purposes of the Lower Granite, Little Goose, Lower Monumental, and Ice Harbor reservoirs (hereafter, the lower Snake River reservoirs), and the area from the mouth of the Snake River to Ice Harbor Dam. We conducted a study from spring 2010 through winter 2011 to describe the habitat use by juvenile Chinook salmon within a selected group of shallow water habitat complexes (deep) in the lower Snake River reservoirs to help inform the long-term plan. Natural fry and parr were present within all four shallow water habitat complexes that we studied from early spring through early summer, and parr ( = 40,345 ± 18,800 [error bound]) were more abundant than fry ( = 24,615 ± 5,701). Water deep was highly used for rearing by natural fall Chinook salmon subyearlings (fry and parr combined; hereafter natural subyearlings) based on duration of use and relative group abundances during spring and summer, whereas the 2–6 m depth interval was more highly used by migratory hatchery fall Chinook salmon subyearlings and spring, summer, and fall Chinook salmon yearlings. Overall mean spring-summer apparent density of natural subyearlings was 15.5 times higher within the use of shallow water habitat by reservoir-type juveniles was limited during our study. We only collected 38 reservoir-type juveniles in shallow water habitat sites in beach and lampara seines during the fall. Radiotelemetry data revealed that though many tagged fish passed shallow water habitat sites, relatively few fish entered them and the median time fish spent within a given site was less than 1.4 h. Fish located by mobile tracking away from study sites were pelagically oriented, and generally not found over shallow water or close to shore. The findings in this report: (1) support the selection of natural fall Chinook subyearlings as the indicator group for determining the potential

  8. Seasonal variation in coastal marine habitat use by the European shag: Insights from fine scale habitat selection modeling and diet

    Science.gov (United States)

    Michelot, Candice; Pinaud, David; Fortin, Matthieu; Maes, Philippe; Callard, Benjamin; Leicher, Marine; Barbraud, Christophe

    2017-07-01

    Studies of habitat selection by higher trophic level species are necessary for using top predator species as indicators of ecosystem functioning. However, contrary to terrestrial ecosystems, few habitat selection studies have been conducted at a fine scale for coastal marine top predator species, and fewer have coupled diet data with habitat selection modeling to highlight a link between prey selection and habitat use. The aim of this study was to characterize spatially and oceanographically, at a fine scale, the habitats used by the European Shag Phalacrocorax aristotelis in the Special Protection Area (SPA) of Houat-Hœdic in the Mor Braz Bay during its foraging activity. Habitat selection models were built using in situ observation data of foraging shags (transect sampling) and spatially explicit environmental data to characterize marine benthic habitats. Observations were first adjusted for detectability biases and shag abundance was subsequently spatialized. The influence of habitat variables on shag abundance was tested using Generalized Linear Models (GLMs). Diet data were finally confronted to habitat selection models. Results showed that European shags breeding in the Mor Braz Bay changed foraging habitats according to the season and to the different environmental and energetic constraints. The proportion of the main preys also varied seasonally. Rocky and coarse sand habitats were clearly preferred compared to fine or muddy sand habitats. Shags appeared to be more selective in their foraging habitats during the breeding period and the rearing of chicks, using essentially rocky areas close to the colony and consuming preferentially fish from the Labridae family and three other fish families in lower proportions. During the post-breeding period shags used a broader range of habitats and mainly consumed Gadidae. Thus, European shags seem to adjust their feeding strategy to minimize energetic costs, to avoid intra-specific competition and to maximize access

  9. Human preference for individual colors

    Science.gov (United States)

    Palmer, Stephen E.; Schloss, Karen B.

    2010-02-01

    Color preference is an important aspect of human behavior, but little is known about why people like some colors more than others. Recent results from the Berkeley Color Project (BCP) provide detailed measurements of preferences among 32 chromatic colors as well as other relevant aspects of color perception. We describe the fit of several color preference models, including ones based on cone outputs, color-emotion associations, and Palmer and Schloss's ecological valence theory. The ecological valence theory postulates that color serves an adaptive "steering' function, analogous to taste preferences, biasing organisms to approach advantageous objects and avoid disadvantageous ones. It predicts that people will tend to like colors to the extent that they like the objects that are characteristically that color, averaged over all such objects. The ecological valence theory predicts 80% of the variance in average color preference ratings from the Weighted Affective Valence Estimates (WAVEs) of correspondingly colored objects, much more variance than any of the other models. We also describe how hue preferences for single colors differ as a function of gender, expertise, culture, social institutions, and perceptual experience.

  10. Patient preferences prompt a peek at priorities.

    Science.gov (United States)

    Blankenship, James C

    2017-09-01

    Patients rate the downsides of bare metal stents (higher restenosis rates) as being of similar magnitude to the downsides of drug eluting stents (longer dual anti-platelet therapy). Patient preferences regarding choice of bare metal versus drug eluting stents should be elicited before coronary stenting. This article does not study actual patient preferences for stent type. Future studies should assess how personalized discussions of trade-offs of stent types affect patient preferences. © 2017 Wiley Periodicals, Inc.

  11. Habitat preferences of coral-associated wentletrap snails (Gastropoda: Epitoniidae)

    NARCIS (Netherlands)

    Gittenberger, A.; Hoeksema, B.W.

    2013-01-01

    Examination of about 60,000 scleractinian corals of the families Dendrophylliidae, Euphylliidae and Fungiidae for the presence of associated wentletrap snails (Gastropoda: Epitoniidae) revealed various ectoparasitic life history strategies. Twenty Indo-Pacific wentletrap species were found, which

  12. Habitat preferences and abundance relations of small mammals in ...

    African Journals Online (AJOL)

    Natal Parks Board, Pietermaritzburg, and Department of Biological Sciences, University of Natal, Durban. Small mammals were studied ... D.T. Rowe-Rowe". Natal Parks Board, P.O. Box 662, Pietermaritzburg 3200, Republic of South. Africa ... Giant's Castle Game Reserve (GCGR), 29°08' to 29°23'S and 29°23' to 29°37'E, ...

  13. Population density and habitat preferences of forest duikers in ...

    African Journals Online (AJOL)

    Doudou National Park, Gabon. ... in the African rainforest. Our results indicate that quick surveys may be an effective approach to estimate the densities of rare species. Key words: Cephalophus, density, distance sampling, forest antelope, rainforest.

  14. Habitat selection by postbreeding female diving ducks: Influence of habitat attributes and conspecifics

    Science.gov (United States)

    Austin, Jane E.; O'Neil, Shawn T.; Warren, Jeffrey M.

    2017-01-01

    Habitat selection studies of postbreeding waterfowl have rarely focused on within-wetland attributes such as water depth, escape cover, and food availability. Flightless waterfowl must balance habitat selection between avoiding predation risks and feeding. Reproductively successful female ducks face the greatest challenges because they begin the definitive prebasic molt at or near the end of brood rearing, when their body condition is at a low point. We assessed the relative importance of habitat attributes and group effects in habitat selection by postbreeding female lesser scaup Aythya affinis on a 2332-ha montane wetland complex during the peak flightless period (August) over seven years. Hypothesis-based habitat attributes included percent open water, open water:emergent edge density, water depth, percent flooded bare substrate, fetch (distance wind can travel unobstructed), group size, and several interactions representing functional responses to interannual variation in water levels. Surveys of uniquely marked females were conducted within randomly ordered survey blocks. We fitted two-part generalized linear mixed-effects models to counts of marked females within survey blocks, which allowed us to relate habitat attributes to relative probability of occurrence and, given the presence of a marked female, abundance of marked individuals. Postbreeding female scaup selected areas with water depths > 40 cm, large open areas, and intermediate edge densities but showed no relation to flooded bare substrate, suggesting their habitat preferences were more influenced by avoiding predation risks and disturbances than in meeting foraging needs. Grouping behavior by postbreeding scaup suggests habitat selection is influenced in part by behavioral components and/or social information, conferring energetic and survival benefits (predation and disturbance risks) but potentially also contributing to competition for food resources. This study demonstrates the importance of

  15. Preference at First Sight

    Directory of Open Access Journals (Sweden)

    Chanjuan Liu

    2016-06-01

    Full Text Available We consider decision-making and game scenarios in which an agent is limited by his/her computational ability to foresee all the available moves towards the future – that is, we study scenarios with short sight. We focus on how short sight affects the logical properties of decision making in multi-agent settings. We start with single-agent sequential decision making (SSDM processes, modeling them by a new structure of 'preference-sight trees'. Using this model, we first explore the relation between a new natural solution concept of Sight-Compatible Backward Induction (SCBI and the histories produced by classical Backward Induction (BI. In particular, we find necessary and sufficient conditions for the two analyses to be equivalent. Next, we study whether larger sight always contributes to better outcomes. Then we develop a simple logical special-purpose language to formally express some key properties of our preference-sight models. Lastly, we show how short-sight SSDM scenarios call for substantial enrichments of existing fixed-point logics that have been developed for the classical BI solution concept. We also discuss changes in earlier modal logics expressing 'surface reasoning' about best actions in the presence of short sight. Our analysis may point the way to logical and computational analysis of more realistic game models.

  16. Does knowledge about antiretroviral therapy and mother-to-child transmission affect the relationships between HIV status and fertility preferences and contraceptive use? New evidence from Nigeria and Zambia.

    Science.gov (United States)

    Bankole, Akinrinola; Biddlecom, Ann E; Dzekedzeke, Kumbutso; Akinyemi, Joshua O; Awolude, Olutosin; Adewole, Isaac F

    2014-09-01

    The increasing availability of antiretroviral therapy (ART) and drug regimens to prevent mother-to-child transmission (PMTCT) has probably changed the context of childbearing for people living with HIV. Using data from 2009-2010 community-based surveys in Nigeria and Zambia, this study explores whether women's knowledge about ART and PMTCT influences the relationship between HIV status and fertility preferences and contraceptive behaviour. The findings show that women living with HIV are more likely to want more children in Nigeria and to want to limit childbearing in Zambia compared with HIV-negative women. While there is no significant difference in contraceptive use by women's HIV status in the two countries, women who did not know their HIV status are less likely to use contraceptives relative to women who are HIV-negative. Knowledge about ART reduces the childbearing desires of HIV-positive women in Nigeria and knowledge about PMTCT increases desire for more children among HIV-positive women in Zambia, as well as contraceptive use among women who do not know their HIV status. The findings indicate that knowledge about HIV prevention and treatment services changes how living with HIV affects childbearing desires and, at least in Zambia, pregnancy prevention, and highlight the importance of access to accurate knowledge about ART and PMTCT services to assist women and men to make informed childbearing decisions. Knowledge about ART and PMTCT should be promoted not only through HIV treatment and maternal and newborn care facilities but also through family planning centres and the mass media.

  17. Scale-dependent habitat selection of nesting Great Egrets and Snowy Egrets

    Science.gov (United States)

    Stolen, Eric D.; Collazo, J.A.; Percival, H.F.

    2007-01-01

    Foraging habitat selection of nesting Great Egrets (Ardea alba) and Snowy Egrets (Egretta thula) was investigated within an estuary with extensive impounded salt marsh habitat. Using a geographic information system, available habitat was partitioned into concentric bands at five, ten, and 15 km radius from nesting colonies to assess the relative effects of habitat composition and distance on habitat selection. Snowy Egrets were more likely than Great Egrets to depart colonies and travel to foraging sites in groups, but both species usually arrived at sites that were occupied by other wading birds. Mean flight distances were 6.2 km (SE = 0.4, N = 28, range 1.8-10.7 km) for Great Egrets and 4.7 km (SE = 0.48, N = 31, range 0.7-12.5 km) for Snowy Egrets. At the broadest spatial scale both species used impounded (mostly salt marsh) and estuarine edge habitat more than expected based on availability while avoiding unimpounded (mostly fresh water wetland) habitat. At more local scales habitat use matched availability. Interpretation of habitat preference differed with the types of habitat that were included and the maximum distance that habitat was considered available. These results illustrate that caution is needed when interpreting the results of habitat preference studies when individuals are constrained in their choice of habitats, such as for central place foragers.

  18. Trends on Habitat Management

    OpenAIRE

    Raluca Giuşcă

    2008-01-01

    According to traditional image, human habitat constitution is the result of natural inter-relations, the fundamental premise of the existence of natural resources, the climate, and the access to more developed proximities for commercial trading. Human habitat represents a complex system, with environmental values, having live and natural components that are inter-related. The dwelling is the fundamental component of the habitat and by relationship with the other components determines the leve...

  19. Trends on Habitat Management

    Directory of Open Access Journals (Sweden)

    Raluca Giuşcă

    2008-01-01

    Full Text Available According to traditional image, human habitat constitution is the result of natural inter-relations, the fundamental premise of the existence of natural resources, the climate, and the access to more developed proximities for commercial trading. Human habitat represents a complex system, with environmental values, having live and natural components that are inter-related. The dwelling is the fundamental component of the habitat and by relationship with the other components determines the level of habitation.

  20. Profiling crop pollinators: life history traits predict habitat use and crop visitation by Mediterranean wild bees.

    Science.gov (United States)

    Pisanty, Gideon; Mandelik, Yael

    2015-04-01

    Wild pollinators, bees in particular, may greatly contribute to crop pollination and provide a safety net against declines in commercial pollinators. However, the identity, life history traits, and environmental sensitivities of main crop pollinator species.have received limited attention. These are crucial for predicting pollination services of different communities and for developing management practices that enhance crop pollinators. We sampled wild bees in three crop systems (almond, confection sunflower, and seed watermelon) in a mosaic Israeli Mediterranean landscape. Bees were sampled in field/orchard edges and interiors, and in seminatural scrub surrounding the fields/orchards. We also analyzed land cover at 50-2500 m radii around fields/orchards. We used this data to distinguish crop from non-crop pollinators based on a set of life history traits (nesting, lecty, sociality, body size) linked to habitat preference and crop visitation. Bee abundance and species richness decreased from the surrounding seminatural habitat to the field/orchard interior, especially across the seminatural habitat-field edge ecotone. Thus, although rich bee communities were found near fields, only small fractions crossed the ecotone and visited crop flowers in substantial numbers. The bee assemblage in agricultural fields/orchards and on crop flowers was dominated by ground-nesting bees of the tribe Halictini, which tend to nest within fields. Bees' habitat preferences were determined mainly by nesting guild, whereas crop visitation was determined mainly by sociality. Lecty and body size also affected both measures. The percentage of surrounding seminatural habitat at 250-2500 m radii had a positive effect on wild bee diversity in field edges, for all bee guilds, while at 50-100 m radii, only aboveground nesters were positively affected. In sum, we found that crop and non-crop pollinators are distinguished by behavioral and morphological traits. Hence, analysis of life

  1. Stratification of habitats for identifying habitat selection by Merriam's turkeys

    Science.gov (United States)

    Mark A. Rumble; Stanley H. Anderson

    1992-01-01

    Habitat selection patterns of Merriam’s Turkeys were compared in hierarchical analyses of three levels of habitat stratification. Habitat descriptions in first-level analyses were based on dominant species of vegetation. Habitat descriptions in second-level analyses were based on dominant species of vegetation and overstory canopy cover. Habitat descriptions in third-...

  2. Habitat and forage associations of a naturally colonising insect pollinator, the tree bumblebee Bombus hypnorum.

    Directory of Open Access Journals (Sweden)

    Liam P Crowther

    Full Text Available Bumblebees (Bombus species are major pollinators of commercial crops and wildflowers but factors affecting their abundance, including causes of recent population declines, remain unclear. Investigating the ecology of species with expanding ranges provides a potentially powerful means of elucidating these factors. Such species may also bring novel pollination services to their new ranges. We therefore investigated landscape-scale habitat use and foraging preferences of the Tree Bumblebee, B. hypnorum, a recent natural colonist that has rapidly expanded its range in the UK over the past decade. Counts of B. hypnorum and six other Bombus species were made in March-June 2012 within a mixed landscape in south-eastern Norfolk, UK. The extent of different landscape elements around each transect was quantified at three scales (250 m, 500 m and 1500 m. We then identified the landscape elements that best predicted the density of B. hypnorum and other Bombus species. At the best fitting scale (250 m, B. hypnorum density was significantly positively associated with extent of both urban and woodland cover and significantly negatively associated with extent of oilseed rape cover. This combination of landscape predictors was unique to B. hypnorum. Urban and woodland cover were associated with B. hypnorum density at three and two, respectively, of the three scales studied. Relative to other Bombus species, B. hypnorum exhibited a significantly higher foraging preference for two flowering trees, Crataegus monogyna and Prunus spinosa, and significantly lower preferences for Brassica napus, Glechoma hederacea and Lamium album. Our study provides novel, quantitative support for an association of B. hypnorum with urban and woodland landscape elements. Range expansion in B. hypnorum appears to depend, on exploitation of widespread habitats underutilised by native Bombus species, suggesting B. hypnorum will readily co-exist with these species. These findings suggest

  3. Habitat loss, not fragmentation, drives occurrence patterns of Canada lynx at the southern range periphery.

    Directory of Open Access Journals (Sweden)

    Megan L Hornseth

    Full Text Available Peripheral populations often experience more extreme environmental conditions than those in the centre of a species' range. Such extreme conditions include habitat loss, defined as a reduction in the amount of suitable habitat, as well as habitat fragmentation, which involves the breaking apart of habitat independent of habitat loss. The 'threshold hypothesis' predicts that organisms will be more affected by habitat fragmentation when the amount of habitat on the landscape is scarce (i.e., less than 30% than when habitat is abundant, implying that habitat fragmentation may compound habitat loss through changes in patch size and configuration. Alternatively, the 'flexibility hypothesis' predicts that individuals may respond to increased habitat disturbance by altering their selection patterns and thereby reducing sensitivity to habitat loss and fragmentation. While the range of Canada lynx (Lynx canadensis has contracted during recent decades, the relative importance of habitat loss and habitat fragmentation on this phenomenon is poorly understood. We used a habitat suitability model for lynx to identify suitable land cover in Ontario, and contrasted occupancy patterns across landscapes differing in cover, to test the 'threshold hypothesis' and 'flexibility hypothesis'. When suitable land cover was widely available, lynx avoided areas with less than 30% habitat and were unaffected by habitat fragmentation. However, on landscapes with minimal suitable land cover, lynx occurrence was not related to either habitat loss or habitat fragmentation, indicating support for the 'flexibility hypothesis'. We conclude that lynx are broadly affected by habitat loss, and not specifically by habitat fragmentation, although occurrence patterns are flexible and dependent on landscape condition. We suggest that lynx may alter their habitat selection patterns depending on local conditions, thereby reducing their sensitivity to anthropogenically-driven habitat

  4. Habitat loss, not fragmentation, drives occurrence patterns of Canada lynx at the southern range periphery.

    Science.gov (United States)

    Hornseth, Megan L; Walpole, Aaron A; Walton, Lyle R; Bowman, Jeff; Ray, Justina C; Fortin, Marie-Josée; Murray, Dennis L

    2014-01-01

    Peripheral populations often experience more extreme environmental conditions than those in the centre of a species' range. Such extreme conditions include habitat loss, defined as a reduction in the amount of suitable habitat, as well as habitat fragmentation, which involves the breaking apart of habitat independent of habitat loss. The 'threshold hypothesis' predicts that organisms will be more affected by habitat fragmentation when the amount of habitat on the landscape is scarce (i.e., less than 30%) than when habitat is abundant, implying that habitat fragmentation may compound habitat loss through changes in patch size and configuration. Alternatively, the 'flexibility hypothesis' predicts that individuals may respond to increased habitat disturbance by altering their selection patterns and thereby reducing sensitivity to habitat loss and fragmentation. While the range of Canada lynx (Lynx canadensis) has contracted during recent decades, the relative importance of habitat loss and habitat fragmentation on this phenomenon is poorly understood. We used a habitat suitability model for lynx to identify suitable land cover in Ontario, and contrasted occupancy patterns across landscapes differing in cover, to test the 'threshold hypothesis' and 'flexibility hypothesis'. When suitable land cover was widely available, lynx avoided areas with less than 30% habitat and were unaffected by habitat fragmentation. However, on landscapes with minimal suitable land cover, lynx occurrence was not related to either habitat loss or habitat fragmentation, indicating support for the 'flexibility hypothesis'. We conclude that lynx are broadly affected by habitat loss, and not specifically by habitat fragmentation, although occurrence patterns are flexible and dependent on landscape condition. We suggest that lynx may alter their habitat selection patterns depending on local conditions, thereby reducing their sensitivity to anthropogenically-driven habitat alteration.

  5. Rotational Preference in Gymnastics

    National Research Council Canada - National Science Library

    Heinen, Thomas; Jeraj, Damian; Vinken, Pia M; Velentzas, Konstantinos

    2012-01-01

    In gymnastics, most skills incorporate rotations about one or more body axes. At present, the question remains open if factors such as lateral preference and/or vestibulo-spinal asymmetry are related to gymnast's rotational preference...

  6. Habitat selection by breeding red-winged blackbirds

    Science.gov (United States)

    Albers, P.H.

    1978-01-01

    Habitat preferences of breeding Red-winged Blackbirds in an agricultural area were determined by comparing population density, landscape characteristics, and vegetational descriptions. Observations were made throughout the breeding season. Preferred breeding habitats of Red-wings, in order of preference, were wetlands, hayfields, old fields, and pastures. Males and females occupied old fields and wetlands first, then hayfields, and finally, pastures. Cutting of hayfields caused territorial abandonment by both sexes within 48 h. The apparent movement of displaced females from cut hayfields to uncut hayfields suggests that habitat fidelity of females is strong after the breeding effort has begun. Breeding Red-wings exhibited general preferences for trees, large amounts of habitat edge, erect old vegetation, and sturdy, tall, and dense vegetation. Vegetative forms and species, such as upland grasses, broad- and narrow-leafed monocots in wetlands, and forbs were important to the Red-wing at various times during the breeding season. Landscape and vegetational preferences of breeding adults were easier to observe early in the breeding season (March through May) than later. Vegetational growth and increases in the size of the breeding population probably make these preferences more difficult to detect. Territory size was poorly correlated with landscape and vegetational characteristics in uplands but strongly correlated with broad- and narrow-leafed mono cots and vegetative height in wetlands. Wetland territories were smaller than upland territories. Territories increased in size during the middle and late portions of the breedi g season. Habitat selection by the Red-winged Blackbird can best be studied by evaluating vegetative preferences throughout the breeding season.

  7. Developmental effects of visual environment on species-assortative mating preferences in Lake Victoria cichlid fish.

    Science.gov (United States)

    Wright, D S; Demandt, N; Alkema, J T; Seehausen, O; Groothuis, T G G; Maan, M E

    2017-02-01

    Local adaptation can be a potent force in speciation, with environmental heterogeneity leading to niche specialization and population divergence. However, local adaption often requires nonrandom mating to generate reproductive isolation. Population divergence in sensory properties can be particularly consequential in speciation, affecting both ecological adaptation and sexual communication. Pundamilia pundamila and Pundamilia nyererei are two closely related African cichlid species that differ in male coloration, blue vs. red. They co-occur at rocky islands in southern Lake Victoria, but inhabit different depth ranges with different light environments. The species differ in colour vision properties, and females exert species-specific preferences for blue vs. red males. Here, we investigated the mechanistic link between colour vision and preference, which could provide a rapid route to reproductive isolation. We tested the behavioural components of this link by experimentally manipulating colour perception - we raised both species and their hybrids under light conditions mimicking shallow and deep habitats - and tested female preference for blue and red males under both conditions. We found that rearing light significantly affected female preference: shallow-reared females responded more strongly to P. pundamilia males and deep-reared females favoured P. nyererei males - implying that visual development causally affects mate choice. These results are consistent with sensory drive predictions, suggesting that the visual environment is key to behavioural isolation of these species. However, the observed plasticity could also make the species barrier vulnerable to environmental change: species-assortative preferences were weaker in females that were reared in the other species' light condition. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

  8. A preference for migration

    OpenAIRE

    Stark, Oded

    2007-01-01

    At least to some extent migration behavior is the outcome of a preference for migration. The pattern of migration as an outcome of a preference for migration depends on two key factors: imitation technology and migration feasibility. We show that these factors jointly determine the outcome of a preference for migration and we provide examples that illustrate how the prevalence and transmission of a migration-forming preference yield distinct migration patterns. In particular, the imitation of...

  9. Preferences for distributional impacts of climate policy

    DEFF Research Database (Denmark)

    Svenningsen, Lea Skræp; Thorsen, Bo Jellesmark

    What role do people think distributional aspects should play in design of climate policy? The literature assessing climate policies has shown that assumptions regarding peoples’ distributional preferences for climate change policy impacts are central for policy assessment, but empirical evidence...... for such preferences is lacking. We design a discrete choice experiment that varies how climate policies affect the income of people living in the future in three geographical regions. The experiment is implemented on a representative sample of the Danish population and preferences are modelled in a latent class model...... expresses some form of distributional preferences, but shows positive preferences for costs, suggesting that responses could be influenced by strategic behaviour and over-signalling of commitment. Our results provide support for the inclusion of social preferences regarding distributional effects of climate...

  10. Habitats, activities, and signs

    DEFF Research Database (Denmark)

    Andersen, Peter Bøgh; Brynskov, Martin

    2004-01-01

    Digital habitats is a framework for designing and modeling environments for activities that involve mobile and embedded computing systems. This paper 1) introduces the basic concepts of the framework, i.e. activity, thematic role, and the three ‘dimensions’ of a habitat: physical, informational, ...

  11. Advanced Plant Habitat (APH)

    Science.gov (United States)

    Richards, Stephanie E. (Compiler); Levine, Howard G.; Reed, David W.

    2016-01-01

    The Advanced Plant Habitat (APH) hardware will be a large growth volume plant habitat, capable of hosting multigenerational studies, in which environmental variables (e.g., temperature, relative humidity, carbon dioxide level light intensity and spectral quality) can be tracked and controlled in support of whole plant physiological testing and Bio-regenerative Life Support System investigations.

  12. Exploring Habitat Selection by Wildlife with adehabitat

    Directory of Open Access Journals (Sweden)

    Clément Calenge

    2007-07-01

    Full Text Available Knowledge of the environmental features affecting habitat selection by animals is important for designing wildlife management and conservation policies. The package adehabitat for the R software is designed to provide a computing environment for the analysis and modelling of such relationships. This paper focuses on the preliminary steps of data exploration and analysis, performed prior to a more formal modelling of habitat selection. In this context, I illustrate the use of a factorial analysis, the K-select analysis. This method is a factorial decomposition of marginality, one measure of habitat selection. This method was chosen to present the package because it illustrates clearly many of its features (home range estimation, spatial analyses, graphical possibilities, etc.. I strongly stress the powerful capabilities of factorial methods for data analysis, using as an example the analysis of habitat selection by the wild boar (Sus scrofa L. in a Mediterranean environment.

  13. Calcareous Bio-Concretions in the Northern Adriatic Sea: Habitat Types, Environmental Factors that Influence Habitat Distributions, and Predictive Modeling.

    Directory of Open Access Journals (Sweden)

    Annalisa Falace

    Full Text Available Habitat classifications provide guidelines for mapping and comparing marine resources across geographic regions. Calcareous bio-concretions and their associated biota have not been exhaustively categorized. Furthermore, for management and conservation purposes, species and habitat mapping is critical. Recently, several developments have occurred in the field of predictive habitat modeling, and multiple methods are available. In this study, we defined the habitats constituting northern Adriatic biogenic reefs and created a predictive habitat distribution model. We used an updated dataset of the epibenthic assemblages to define the habitats, which we verified using the fuzzy k-means (FKM clustering method. Redundancy analysis was employed to model the relationships between the environmental descriptors and the FKM membership grades. Predictive modelling was carried out to map habitats across the basin. Habitat A (opportunistic macroalgae, encrusting Porifera, bioeroders characterizes reefs closest to the coastline, which are affected by coastal currents and river inputs. Habitat B is distinguished by massive Porifera, erect Tunicata, and non-calcareous encrusting algae (Peyssonnelia spp.. Habitat C (non-articulated coralline, Polycitor adriaticus is predicted in deeper areas. The onshore-offshore gradient explains the variability of the assemblages because of the influence of coastal freshwater, which is the main driver of nutrient dynamics. This model supports the interpretation of Habitat A and C as the extremes of a gradient that characterizes the epibenthic assemblages, while Habitat B demonstrates intermediate characteristics. Areas of transition are a natural feature of the marine environment and may include a mixture of habitats and species. The habitats proposed are easy to identify in the field, are related to different environmental features, and may be suitable for application in studies focused on other geographic areas. The habitat

  14. Preferences over Social Risk

    DEFF Research Database (Denmark)

    Harrison, Glenn W.; Lau, Morten; Rutström, E. Elisabet

    2013-01-01

    We elicit individual preferences over social risk. We identify the extent to which these preferences are correlated with preferences over individual risk and the well-being of others. We examine these preferences in the context of laboratory experiments over small, anonymous groups, although...... the methodological issues extend to larger groups that form endogenously (e.g., families, committees, communities). Preferences over social risk can be closely approximated by individual risk attitudes when subjects have no information about the risk preferences of other group members. We find no evidence...... that subjects systematically reveal different risk attitudes in a social setting with no prior knowledge about the risk preferences of others compared to when they solely bear the consequences of the decision. However, we also find that subjects are significantly more risk averse when they know the risk...

  15. Ocean acidification alters temperature and salinity preferences in larval fish.

    Science.gov (United States)

    Pistevos, Jennifer C A; Nagelkerken, Ivan; Rossi, Tullio; Connell, Sean D

    2017-02-01

    Ocean acidification alters the way in which animals perceive and respond to their world by affecting a variety of senses such as audition, olfaction, vision and pH sensing. Marine species rely on other senses as well, but we know little of how these might be affected by ocean acidification. We tested whether ocean acidification can alter the preference for physicochemical cues used for dispersal between ocean and estuarine environments. We experimentally assessed the behavioural response of a larval fish (Lates calcarifer) to elevated temperature and reduced salinity, including estuarine water of multiple cues for detecting settlement habitat. Larval fish raised under elevated CO 2 concentrations were attracted by warmer water, but temperature had no effect on fish raised in contemporary CO 2 concentrations. In contrast, contemporary larvae were deterred by lower salinity water, where CO 2 -treated fish showed no such response. Natural estuarine water-of higher temperature, lower salinity, and containing estuarine olfactory cues-was only preferred by fish treated under forecasted high CO 2 conditions. We show for the first time that attraction by larval fish towards physicochemical cues can be altered by ocean acidification. Such alterations to perception and evaluation of environmental cues during the critical process of dispersal can potentially have implications for ensuing recruitment and population replenishment. Our study not only shows that freshwater species that spend part of their life cycle in the ocean might also be affected by ocean acidification, but that behavioural responses towards key physicochemical cues can also be negated through elevated CO 2 from human emissions.

  16. Habitat Blocks and Wildlife Corridors

    Data.gov (United States)

    Vermont Center for Geographic Information — Habitat blocks are areas of contiguous forest and other natural habitats that are unfragmented by roads, development, or agriculture. Vermonts habitat blocks are...

  17. Hantavirus seropositivity in rodents in relation to habitat heterogeneity in human-shaped landscapes of Southeast Asia.

    Science.gov (United States)

    Blasdell, Kim; Morand, Serge; Henttonen, Heikki; Tran, Annelise; Buchy, Philippe

    2016-05-01

    To establish how the conversion of natural habitats for agricultural purposes may impact the distribution of hantaviruses in Southeast Asia, we tested how habitat structure affects hantavirus infection prevalence of common murine rodents that inhabit human-dominated landscapes in this region. For this, we used geo-referenced data of rodents analysed for hantavirus infection and land cover maps produced for the seven study sites in Thailand, Cambodia and Lao PDR where they were collected. Rodents were tested by serological methods that detect several hantaviruses, including pathogenic ones. Rodents with a seropositive status were more likely to be found near to agriculture on steep land, and also in environments with a high proportion of agriculture on steep land. These results suggest that in Southeast Asia, hantaviruses, which are often associated with generalist rodent species with a preference for agricultural land, may benefit from land conversion to agriculture. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Investigating Targets of Avian Habitat Management to Eliminate an Ecological Trap

    Directory of Open Access Journals (Sweden)

    Bruce A. Robertson

    2012-12-01

    trees. Both sexes preferred standing dead perch trees (snags and these preferences were most obvious in harvested forest where snags are rarer. Because previous research shows that snag density is linked to habitat preference and spruce/fir trees are preferred nest substrate, my results suggest these two habitat components are focal habitat selection cues. I suggest alternative and complementary strategies for eliminating the ecological trap for Olive-sided Flycatchers including: (1 reduced retention and creation of snags, (2 avoiding selective harvest in spruce, fir, and larch stands, (3 avoiding retention of these tree species, and (4 selecting only even-aged canopy height trees for retention so as to reduce perch availability for female flycatchers. Because these strategies also have potential to negatively impact habitat suitability for other forest species or even create new ecological traps, we urge caution in the application of our management recommendations.

  19. Weather, habitat composition, and female behavior interact to modify offspring survival in Greater Sage-Grouse.

    Science.gov (United States)

    Gibson, Daniel; Blomberg, Erik J; Atamian, Michael T; Sedinger, James S

    2017-01-01

    Weather is a source of environmental variation that can affect population vital rates. However, the influence of weather on individual fitness is spatially heterogeneous and can be driven by other environmental factors, such as habitat composition. Therefore, individuals can experience reduced fitness (e.g., decreased reproductive success) during poor environmental conditions through poor decisions regarding habitat selection. This requires, however, that habitat selection is adaptive and that the organism can correctly interpret the environmental cues to modify habitat use. Greater Sage-Grouse (Centrocercus urophasianus) are an obligate of the sagebrush ecosystems of western North America, relying on sagebrush for food and cover. Greater Sage-Grouse chicks, however, require foods with high nutrient content (i.e., forbs and insects), the abundance of which is both temporally and spatially dynamic and related primarily to water availability. Our goal was to assess whether nest site selection and movements of broods by females reduced the negative effect of drought on offspring survival. As predicted, chick survival was negatively influenced by drought severity. We found that sage-grouse females generally preferred to nest and raise their young in locations where their chicks would experience higher survival. We also found that use of habitats positively associated with chick survival were also positively associated with drought severity, which suggests that females reduced drought impacts on their dependent young by selecting more favorable environments during drought years. Although our findings suggest that female nest site selection and brood movement rates can reduce the negative effects of drought on early offspring survival, the influence of severe drought conditions was not completely mitigated by female behavior, and that drought conditions should be considered a threat to Greater Sage-Grouse population persistence. © 2016 by the Ecological Society of

  20. Low habitat overlap at landscape scale between wild camelids and feral donkeys in the Chilean desert

    Science.gov (United States)

    Malo, Juan E.; González, Benito A.; Mata, Cristina; Vielma, André; Donoso, Denise S.; Fuentes, Nicolás; Estades, Cristián F.

    2016-01-01

    Feral domestic ungulates may compete with the populations of wild herbivores with which they coexist, particularly so in arid regions. The potential competition between wild camelids and feral donkeys at the eastern sector of the Atacama Desert is evaluated in terms of their coincidence or segregation in habitat use and complemented with a comparison of reproductive output (yearling/adult ratio) of vicuña family groups in the proximity vs. distant from donkey observations. Habitat use of wild camelids and donkeys was sampled driving some 1250 km of roads and tracks at the dry and wet seasons. There were 221 vicuñas (Vicugna vicugna) sightings, 77 for donkeys (Equus asinus), 25 for guanacos (Lama guanicoe) and 8 for hybrids between guanacos and domestic llamas (Lama glama), as well as 174 randomly selected control locations. By means of Generalised Discriminant Analysis and Analysis of Variance we show that all ungulates actively select their habitat, with significant differences between use and availability in the area. Donkeys are relatively abundant in comparison with camelids and coincide broadly with both of them across the altitudinal gradient, but they fall between them in local scale habitat selection and do not seem to force their displacement from their preferred habitats. Thus donkeys occur preferentially on slopes with a high cover of tall shrubs, whereas vicuñas use valley bottoms with grass and guanacos the upper slope zones with grass. The potential for competition between donkeys and wild camelids is thus limited and it does not affect the reproductive output of vicuña in this region. Therefore, with the present knowledge we suggest that population control is not currently merited for feral donkeys.

  1. Sex- and habitat-specific movement of an omnivorous semi-terrestrial crab controls habitat connectivity and subsidies: a multi-parameter approach.

    Science.gov (United States)

    Hübner, Lena; Pennings, Steven C; Zimmer, Martin

    2015-08-01

    Distinct habitats are often linked through fluxes of matter and migration of organisms. In particular, intertidal ecotones are prone to being influenced from both the marine and the terrestrial realms, but whether or not small-scale migration for feeding, sheltering or reproducing is detectable may depend on the parameter studied. Within the ecotone of an upper saltmarsh in the United States, we investigated the sex-specific movement of the semi-terrestrial crab Armases cinereum using an approach of determining multiple measures of across-ecotone migration. To this end, we determined food preference, digestive abilities (enzyme activities), bacterial hindgut communities (genetic fingerprint), and the trophic position of Armases and potential food sources (stable isotopes) of males versus females of different sub-habitats, namely high saltmarsh and coastal forest. Daily observations showed that Armases moved frequently between high-intertidal (saltmarsh) and terrestrial (forest) habitats. Males were encountered more often in the forest habitat, whilst gravid females tended to be more abundant in the marsh habitat but moved more frequently. Food preference was driven by both sex and habitat. The needlerush Juncus was preferred over three other high-marsh detrital food sources, and the periwinkle Littoraria was the preferred prey of male (but not female) crabs from the forest habitats; both male and female crabs from marsh habitat preferred the fiddler crab Uca over three other prey items. In the field, the major food sources were clearly vegetal, but males have a higher trophic position than females. In contrast to food preference, isotope data excluded Uca and Littoraria as major food sources, except for males from the forest, and suggested that Armases consumes a mix of C4 and C3 plants along with animal prey. Digestive enzyme activities differed significantly between sexes and habitats and were higher in females and in marsh crabs. The bacterial hindgut community

  2. Not equal in the face of habitat change: closely related fishes differ in their ability to use predation-related information in degraded coral.

    Science.gov (United States)

    Ferrari, Maud C O; McCormick, Mark I; Allan, Bridie J M; Chivers, Douglas P

    2017-04-12

    Coral reefs are biodiversity hotpots that are under significant threat due to the degradation and death of hard corals. When obligate coral-dwelling species die, the remaining species must either move or adjust to the altered conditions. Our goal was to investigate the effect of coral degradation on the ability of coral reef fishes to assess their risk of predation using alarm cues from injured conspecifics. Here, we tested the ability of six closely related species of juvenile damselfish (Pomacentridae) to respond to risk cues in both live coral or dead-degraded coral environments. Of those six species, two are exclusively associated with live coral habitats, two are found mostly on dead-degraded coral rubble, while the last two are found in both habitat types. We found that the two live coral associates failed to respond appropriately to the cues in water from degraded habitats. In contrast, the cue response of the two rubble associates was unaffected in the same degraded habitat. Interestingly, we observed a mixed response from the species found in both habitat types, with one species displaying an appropriate cue response while the other did not. Our second experiment suggested that the lack of responses stemmed from deactivation of the alarm cues, rather than the inability of the species to smell. Habitat preference (live coral versus dead coral associates) and phylogeny are good candidates for future work aimed at predicting which species are affected by coral degradation. Our results point towards a surprising level of variation in the ability of congeneric species to fare in altered habitats and hence underscores the difficulty of predicting community change in degraded habitats. © 2017 The Authors.

  3. Home-range use patterns and movements of the Siberian flying squirrel in urban forests: Effects of habitat composition and connectivity.

    Science.gov (United States)

    Mäkeläinen, Sanna; de Knegt, Henrik J; Ovaskainen, Otso; Hanski, Ilpo K

    2016-01-01

    Urbanization causes modification, fragmentation and loss of native habitats. Such landscape changes threaten many arboreal and gliding mammals by limiting their movements through treeless parts of a landscape and by making the landscape surrounding suitable habitat patches more inhospitable. Here, we investigate the effects of landscape structure and habitat availability on the home-range use and movement patterns of the Siberian flying squirrel (Pteromys volans) at different spatial and temporal scales. We followed radio-tagged individuals in a partly urbanized study area in Eastern Finland, and analysed how landscape composition and connectivity affected the length and speed of movement bursts, distances moved during one night, and habitat and nest-site use. The presence of urban habitat on movement paths increased both movement lengths and speed whereas nightly distances travelled by males decreased with increasing amount of urban habitat within the home range. The probability of switching from the present nest site to another nest site decreased with increasing distance among the nest sites, but whether the nest sites were connected or unconnected by forests did not have a clear effect on nest switching. Flying squirrels preferred to use mature forests for their movements at night. Our results suggest that the proximity to urban habitats modifies animal movements, possibly because animals try to avoid such habitats by moving faster through them. Urbanization at the scale of an entire home range can restrict their movements. Thus, maintaining a large enough amount of mature forests around inhabited landscape fragments will help protect forest specialists in urban landscapes. The effect of forested connections remains unclear, highlighting the difficulty of measuring and preserving connectivity in a species-specific way.

  4. Quantifying the effect of habitat availability on species distributions.

    Science.gov (United States)

    Aarts, Geert; Fieberg, John; Brasseur, Sophie; Matthiopoulos, Jason

    2013-11-01

    1. If animals moved randomly in space, the use of different habitats would be proportional to their availability. Hence, deviations from proportionality between use and availability are considered the tell-tale sign of preference. This principle forms the basis for most habitat selection and species distribution models fitted to use-availability or count data (e.g. MaxEnt and Resource Selection Functions). 2. Yet, once an essential habitat type is sufficiently abundant to meet an individual's needs, increased availability of this habitat type may lead to a decrease in the use/availability ratio. Accordingly, habitat selection functions may estimate negative coefficients when habitats are superabundant, incorrectly suggesting an apparent avoidance. Furthermore, not accounting for the effects of availability on habitat use may lead to poor predictions, particularly when applied to habitats that differ considerably from those for which data have been collected. 3. Using simulations, we show that habitat use varies non-linearly with habitat availability, even when individuals follow simple movement rules to acquire food and avoid risk. The results show that the impact of availability strongly depends on the type of habitat (e.g. whether it is essential or substitutable) and how it interacts with the distribution and availability of other habitats. 4. We demonstrate the utility of a variety of existing and new methods that enable the influence of habitat availability to be explicitly estimated. Models that allow for non-linear effects (using b-spline smoothers) and interactions between environmental covariates defining habitats and measures of their availability were best able to capture simulated patterns of habitat use across a range of environments. 5. An appealing aspect of some of the methods we discuss is that the relative influence of availability is not defined a priori, but directly estimated by the model. This feature is likely to improve model prediction

  5. The Effect of High Versus Low Teacher Affect and Passive Versus Active Student Activity During Music Listening on Preschool Children's Attention, Piece Preference, Time Spent Listening, and Piece Recognition.

    Science.gov (United States)

    Sims, Wendy L.

    1986-01-01

    Small-group listening lessons and subsequent individual posttests were used to judge 94 three- through five-year-old subjects' attention, paired-comparison piece preference, time spent listening, and piece recognition. Research procedures included a modified multiple baseline design and split-screen video taping of instructional sessions.…

  6. Factors influencing Consumer Preference for Fresh Beef in Sokoto ...

    African Journals Online (AJOL)

    SH

    selected and interviewed to identify factors that affect preference for fresh beef and to determine the nature of the .... preference for beef, the negative sign here ... of respondents according to problems with beef preference. Problem. Frequency. Percentage (%). Price. 26. 28.89. Availability. 8. 8.89. Health effect. 8. 8.89.

  7. Millennial Instructional Preferences in Post-Secondary Business Programs

    Science.gov (United States)

    West, Cynthia Elaine

    2017-01-01

    The purpose of this mixed method study was to examine the instructional preferences of millennial learners and how their instructional preferences affect their choice in post-secondary business programs. The instructional preferences of millennial learners are an important question for post-secondary business programs enrolling learners from…

  8. Suboptimal Larval Habitats Modulate Oviposition of the Malaria Vector Mosquito Anopheles coluzzii.

    Directory of Open Access Journals (Sweden)

    Eunho Suh

    Full Text Available Selection of oviposition sites by gravid females is a critical behavioral step in the reproductive cycle of Anopheles coluzzii, which is one of the principal Afrotropical malaria vector mosquitoes. Several studies suggest this decision is mediated by semiochemicals associated with potential oviposition sites. To better understand the chemosensory basis of this behavior and identify compounds that can modulate oviposition, we examined the generally held hypothesis that suboptimal larval habitats give rise to semiochemicals that negatively influence the oviposition preference of gravid females. Dual-choice bioassays indicated that oviposition sites conditioned in this manner do indeed foster significant and concentration dependent aversive effects on the oviposition site selection of gravid females. Headspace analyses derived from aversive habitats consistently noted the presence of dimethyl disulfide (DMDS, dimethyl trisulfide (DMTS and 6-methyl-5-hepten-2-one (sulcatone each of which unitarily affected An. coluzzii oviposition preference. Electrophysiological assays across the antennae, maxillary palp, and labellum of gravid An. coluzzii revealed differential responses to these semiochemicals. Taken together, these findings validate the hypothesis in question and suggest that suboptimal environments for An. coluzzii larval development results in the release of DMDS, DMTS and sulcatone that impact the response valence of gravid females.

  9. Seasonal Variations in Color Preference.

    Science.gov (United States)

    Schloss, Karen B; Nelson, Rolf; Parker, Laura; Heck, Isobel A; Palmer, Stephen E

    2017-08-01

    We investigated how color preferences vary according to season and whether those changes could be explained by the ecological valence theory (EVT). To do so, we assessed the same participants' preferences for the same colors during fall, winter, spring, and summer in the northeastern United States, where there are large seasonal changes in environmental colors. Seasonal differences were most pronounced between fall and the other three seasons. Participants liked fall-associated dark-warm colors-for example, dark-red, dark-orange (brown), dark-yellow (olive), and dark-chartreuse-more during fall than other seasons. The EVT could explain these changes with a modified version of Palmer and Schloss' (2010) weighted affective valence estimate (WAVE) procedure that added an activation term to the WAVE equation. The results indicate that color preferences change according to season, as color-associated objects become more/less activated in the observer. These seasonal changes in color preferences could not be characterized by overall shifts in weights along cone-contrast axes. Copyright © 2016 Cognitive Science Society, Inc.

  10. Predicting potential European bison habitat across its former range.

    Science.gov (United States)

    Kuemmerle, Tobias; Radeloff, Volker C; Perzanowski, Kajetan; Kozlo, Piotr; Sipko, Taras; Khoyetskyy, Pavlo; Bashta, Andriy-Taras; Chikurova, Evgenia; Parnikoza, Ivan; Baskin, Leonid; Angelstam, Per; Waller, Donald M

    2011-04-01

    Habitat loss threatens large mammals worldwide, and their survival will depend on habitat in human-dominated landscapes. Conservation planners thus face the challenge to identify areas of least conflict with land use, yet broadscale species distribution models rarely incorporate real landscape patterns nor do they identify potential conservation conflicts. An excellent example of such conservation challenges is provided by European bison (Bison bonasus). Almost extinct by the early 20th century, bison can only survive in the wild if large metapopulations are established, but it is unclear where new herds can be reintroduced. Using European bison as an example we conducted a continental-scale habitat assessment based on real landscape patterns. Our specific aims here were to (1) map European bison habitat throughout the species' former range, (2) examine whether broadscale habitat suitability factors differ from previously reported fine-scale factors, and (3) assess where suitable habitat occurs in areas with low potential for conflict with land use. We assessed habitat suitability using herd range maps for all 36 free-ranging European bison herds as habitat use data. Habitat suitability maps were compared with maps of land cover, livestock density, agricultural constraints, and protected areas to assess potential conservation conflicts. Our models had high goodness of fit (AUC = 0.941), and we found abundant potential bison habitat. European bison prefer mosaic-type landscapes, with a preference for broad-leaved and mixed forests. European bison metapopulations do not appear to be limited by habitat availability. However, most potential habitat occurred outside protected areas and has substantial potential for conservation conflicts. The most promising areas for establishing large bison metapopulations all occur in Eastern Europe (i.e., the Carpathians, the Belarus-Ukraine borderlands, and several regions in European Russia). The future of European bison and that

  11. Critical Habitat Designations

    Data.gov (United States)

    Department of Homeland Security — The Endangered Species Act (ESA) requires the Federal government to designate 'critical habitat' for any species it lists under the ESA. This dataset combines both...

  12. Green Turtle Critical Habitat

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These data represent the critical habitat for green turtle as designated by Federal Register Vol. 63, No. 46701, September 2, 1998, Rules and Regulations.

  13. Majuro_Benthic_Habitats

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Benthic habitat maps of the nearshore marine environment of Majuro, Republic of the Marshall Islands were created by visual interpretation of remotely sensed...

  14. VT Wildlife Linkage Habitat

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The Wildlife Linkage Habitat Analysis uses landscape scale data to identify or predict the location of potentially significant wildlife linkage...

  15. Habitat Mapping Camera (HABCAM)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset entails imagery collected using the HabCam towed underwater vehicle and annotated data on objects or habitats in the images and notes on image...

  16. Johnsons Seagrass Critical Habitat

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data represent the critical habitat for Johnson's Seagrass as designated by Federal Register Vol. 65, No. 66, Wednesday, April 5, 2000, Rules and Regulations.

  17. Designated Critical Habitat

    Data.gov (United States)

    Kansas Data Access and Support Center — Critical habitats include those areas documented as currently supporting self-sustaining populations of any threatened or endangered species of wildlife as well as...

  18. Right Whale Critical Habitat

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data represent the critical habitat for Right Whale as designated by Federal Register Vol. 59, No. 28805, May 19, 1993, Rules and Regulations.

  19. Smalltooth Sawfish Critical Habitat

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data represent the critical habitat for smalltooth sawfish (Pristis pectinatat) as designated by 74 FR 45353, September 2, 2009, Rules and Regulations.

  20. Green Turtle Critical Habitat

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data represent the critical habitat for green turtle as designated by Federal Register Vol. 63, No. 46701, September 2, 1998, Rules and Regulations.

  1. Habitat planning, maintenance and management working group

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    The Gulf of Mexico (GOM), called {open_quotes}America`s Sea,{close_quotes} is actually a small ocean basin covering over 1.5 million square kilometers. Because of the multiple uses, diversity, and size of the Gulf`s resources, management is shared by a number of governmental agencies including the Minerals Management Service, the Gulf of Mexico Fishery Management Council, the Gulf States Marine Fisheries Commission, National Marine Fisheries Service, the US Coast Guard, the US Army Corps of Engineers, and the five Gulf states fisheries agencies. All of these entities share a common goal of achieving optimum sustainable yield to maximize geological, biological, social, and economic benefits from these resources. These entities also share a common theme that the successful management of the northern GOM requires maintenance and enhancement of both the quantity and quality of habitats. A closer look at the GOM shows the sediment to be clearly dominated by vast sand and mud plains. These soft bottom habitats are preferred by many groundfish and shrimp species and, thus, have given rise to large commercial fisheries on these stocks. Hard bottom and reef habitats, on the other hand, are limited to approximately 1.6% of the total area of the Gulf, so that, while there are high demands by commercial and recreational fishermen for reef associated species, the availability of habitat for these stocks is limited. The thousands of oil and gas structures placed in the Gulf have added significant amounts of new hard substrate. The rigs-to-reefs concept was a common sense idea with support from environmental user groups and the petroleum industry for preserving a limited but valuable habitat type. As long as maximizing long-term benefits from the Gulf s resources for the greatest number of users remains the goal, then programs such as Rigs-to-Reefs will remain an important tool for fisheries and habitat managers in the Gulf.

  2. Effects of habitat fragmentation on abundance, larval food and parasitism of a spider-hunting wasp.

    Science.gov (United States)

    Coudrain, Valérie; Herzog, Felix; Entling, Martin H

    2013-01-01

    Habitat fragmentation strongly affects species distribution and abundance. However, mechanisms underlying fragmentation effects often remain unresolved. Potential mechanisms are (1) reduced dispersal of a species or (2) altered species interactions in fragmented landscapes. We studied if abundance of the spider-hunting and cavity-nesting wasp Trypoxylon figulus Linnaeus (Hymenoptera: Crabronidae) is affected by fragmentation, and then tested for any effect of larval food (bottom up regulation) and parasitism (top down regulation). Trap nests of T. figulus were studied in 30 agricultural landscapes of the Swiss Plateau. The sites varied in the level of isolation from forest (adjacent, in the open landscape but connected, isolated) and in the amount of woody habitat (from 4% to 74%). We recorded wasp abundance (number of occupied reed tubes), determined parasitism of brood cells and analysed the diversity and abundance of spiders that were deposited as larval food. Abundances of T. figulus were negatively related to forest cover in the landscape. In addition, T. figulus abundances were highest at forest edges, reduced by 33.1% in connected sites and by 79.4% in isolated sites. The mean number of spiders per brood cell was lowest in isolated sites. Nevertheless, structural equation modelling revealed that this did not directly determine wasp abundance. Parasitism was neither related to the amount of woody habitat nor to isolation and did not change with host density. Therefore, our study showed that the abundance of T. figulus cannot be fully explained by the studied trophic interactions. Further factors, such as dispersal and habitat preference, seem to play a role in the population dynamics of this widespread secondary carnivore in agricultural landscapes.

  3. The influence of food abundance, food dispersion and habitat ...

    African Journals Online (AJOL)

    Most tropical insectivorous birds, unlike their temperate counterparts, hold and defend a feeding and breeding territory year-around. However, our understanding of ... We believe the most likely explanation for the Usambara Thrush's preference for open understorey and closed overstorey habitat relates to foraging behavior.

  4. Modifications and influences of tactual preferences for shape and texture.

    Science.gov (United States)

    Margolin, C R

    1976-12-01

    The effects of pretraining on tactual preferences for shape and texture and the effects of the preferences on discrimination learning were investigated in three experiments using kindergarten and third grade children. The pretraining experience significantly affected the dimensional preferences in both age groups, while an unexpected significant sex difference indicated a stronger texture preference in girls. Children tended to learn faster when the dimension they preferred was relevant to the task, but girls were affected more strongly than boys. In all experiments, the girls' behavior closely resembled that predicted for younger children.

  5. The Importance of Providing Multiple-Channel Sections in Dredging Activities to Improve Fish Habitat Environments

    Directory of Open Access Journals (Sweden)

    Hung-Pin Chiu

    2016-01-01

    Full Text Available After Typhoon Morakot, dredging engineering was conducted while taking the safety of humans and structures into consideration, but partial stream reaches were formed in the multiple-channel sections in Cishan Stream because of anthropogenic and natural influences. This study mainly explores the distribution of each fish species in both the multiple- and single-channel sections in the Cishan Stream. Parts of the environments did not exhibit significant differences according to a one-way ANOVA comparing the multiple- and single-channel sections, but certain areas of the multiple-channel sections had more diverse habitats. Each fish species was widely distributed by non-metric multidimensional scaling in the multiple-channel sections as compared to those in the single-channel sections. In addition, according to the principal component analysis, each fish species has a preferred environment, and all of them have a wide choice of habitat environments in the multiple-channel sections. Finally, the existence of multiple-channel sections could significantly affect the existence of the fish species under consideration in this study. However, no environmental factors were found to have an influence on fish species in the single-channel sections, with the exception of Rhinogobius nantaiensis. The results show that providing multiple-channel sections in dredging activities could improve fish habitat environments.

  6. Abundance of birds in six selected habitats | Ogunsusi | Journal of ...

    African Journals Online (AJOL)

    Data collected were subjected to t-test of independent variables with LSD in ANOVA for birds' use of habitats and linear regression for the dependence of birds' abundance on habitats' variables.88 bird species belonging to 31 families were associated with the study area. The abundance of birds was significantly affected ...

  7. Songbird use of regenerating forest, glade, and edge habitat types

    Science.gov (United States)

    Alix D. Fink; Frank R., III Thompson; April A. Tudor

    2006-01-01

    Population numbers of many bird species associated with early-successional or disturbance-dependent habitat types are declining. We used an information-theoretic approach to evaluate hypotheses concerning factors affecting breeding bird densities in different early-successional habitat types. We studied shrubland bird communities in 3- to 5-year-old regenerating forest...

  8. Seasonal differences in foraging dynamics, habitat use and home ...

    African Journals Online (AJOL)

    Urbanization through the process of habitat loss and fragmentation affects ecosystems. Many species are no longer able to survive in these urban areas; however, there are some that have been able to persist and even thrive in these habitats. One such species is Wahlberg's epauletted fruit bat (Epomophorus wahlbergi).

  9. Characterisation of juvenile flatfish habitats in the Baltic Sea

    Science.gov (United States)

    Florin, Ann-Britt; Sundblad, Göran; Bergström, Ulf

    2009-04-01

    Survival and growth of the earliest life-stages is considered a key factor in determining the abundance of many marine fish species. For flatfishes, the availability of high quality nursery areas is essential for successful recruitment. Regarding the Baltic Sea, there are large gaps in knowledge on factors that influence the distribution of flatfishes during this sensitive stage. To identify the characteristics of important nursery areas in the Baltic for flounder ( Platichthys flesus) and turbot ( Psetta maxima), a field survey with push net sampling was conducted in the northern Baltic proper during autumn 2006. The sampling stations were stratified to cover several different habitat types defined by substrate and wave exposure. Apart from density of young-of-the-year (YOY) flatfishes, a number of ecological characteristics of the habitat were recorded. Physical habitat variables included substrate type, salinity, depth, turbidity, vegetation and habitat structure. Variables describing biotic processes, such as prey availability and abundance of competitors, were also sampled. The relationships between the spatial distribution of species and these ecological characteristics were fitted to presence/absence data of juvenile flatfish using generalized additive models (GAM). The best habitat descriptors for flounder in order of contribution were: substrate, habitat structure, salinity, wave exposure and occurrence of filamentous algae. Positive effects of increasing wave exposure, salinity and structure were detected while a high cover of filamentous algae had a negative effect. Sand and gravel were preferred over soft and stony substrates. For turbot the best habitat descriptors in order of contribution were: occurrence of filamentous algae, substrate and turbidity. Turbot showed a preference for areas with a low cover of filamentous algae, high turbidity and sandy substrate. Prey availability and abundance of competitors were not included in the models, indicating

  10. Seasonal narwhal habitat associations in the high Arctic

    DEFF Research Database (Denmark)

    Laidre, K.L.; Heide-Jørgensen, M.P.; Logdson, M.L.

    2004-01-01

    Movements and behavior of top marine predators are often closely linked with productive oceanic fronts or regional prey aggregations. Consequently, it is of interest to quantify habitat needs and preferences, which can facilitate predictions of conditions favoring persistence and success. Multiva......Movements and behavior of top marine predators are often closely linked with productive oceanic fronts or regional prey aggregations. Consequently, it is of interest to quantify habitat needs and preferences, which can facilitate predictions of conditions favoring persistence and success...... grounds often coincided with areas of concurrent high density of Greenland halibut (Reinhardtius hippoglossoides, Walbaum) and predictable open water in winter pack ice in Baffin Bay. These quantitative habitat models made it possible to reconcile the behavioral traits of narwhals with dynamic...

  11. Short- and long-term effects of habitat fragmentation differ but are predicted by response to the matrix.

    Science.gov (United States)

    Evans, Maldwyn J; Banks, Sam C; Driscoll, Don A; Hicks, Andrew J; Melbourne, Brett A; Davies, Kendi F

    2017-03-01

    Habitat loss and fragmentation are major threats to biodiversity and ecosystem processes. Our current understanding of the impacts of habitat loss and fragmentation is based largely on studies that focus on either short-term or long-term responses. Short-term responses are often used to predict long-term responses and make management decisions. The lack of studies comparing short- and long-term responses to fragmentation means we do not adequately understand when and how well short-term responses can be extrapolated to predict long-term responses, and when or why they cannot. To address this gap, we used data from one of the world's longest-running fragmentation experiments, The Wog Wog Habitat Fragmentation Experiment. Using data for carabid beetles, we found that responses in the long term (more than 22 yr post-fragmentation ≈22 generations) often contrasted markedly with those in the short term (5 yr post-fragmentation). The total abundance of all carabids, species richness and the occurrence of six species declined in the short term in the fragments but increased over the long term. The occurrence of three species declined initially and continued to decline, whilst another species was positively affected initially but decreased in the long term. Species' responses to the matrix that surrounds the fragments strongly predicted both the direction (increase/decline in occurrence) and magnitude of their responses to fragmentation. Additionally, species' responses to the matrix were somewhat predicted by their preferences for different types of native habitat (open vs. shaded). Our study highlights the degree of the matrix's influence in fragmented landscapes, and how this influence can change over time. We urge caution in using short-term responses to forecast long-term responses in cases where the matrix (1) impacts species' responses to fragmentation (by isolating them, creating new habitat or altering fragment habitat) and (2) is likely to change through time

  12. Landscape habitat suitability index software

    Science.gov (United States)

    William D. Dijak; Chadwick D. Rittenhouse; Michael A. Larson; Frank R. III Thompson; Joshua J. Millspaugh

    2007-01-01

    Habitat suitability index (HSI) models are traditionally used to evaluate habitat quality for wildlife at a local scale. Rarely have such models incorporated spatial relationships of habitat components. We introduce Landscape HSImodels, a new Microsoft Windowst (Microsoft, Redmond, WA)-based program that incorporates local habitat as well as landscape-scale attributes...

  13. Naloxone treatment alters gene expression in the mesolimbic reward system in 'junk food' exposed offspring in a sex-specific manner but does not affect food preferences in adulthood.

    Science.gov (United States)

    Gugusheff, J R; Ong, Z Y; Muhlhausler, B S

    2014-06-22

    We have previously reported that the opioid receptor blocker, naloxone, is less effective in reducing palatable food intake in offspring exposed to a maternal cafeteria diet during the perinatal period, implicating a desensitization of the central opioid pathway in the programming of food preferences. The present study aimed to investigate the effect of a maternal cafeteria diet and naloxone treatment on the development of the mesolimbic reward pathway and food choices in adulthood. We measured mRNA expression of key components of the reward pathway (mu-opioid receptor, proenkephalin, tyrosine hydroxylase, D1 and D2 receptors and the dopamine active transporter (DAT)) in the nucleus accumbens (NAc) and ventral tegmental area (VTA) of the offspring of control and cafeteria fed (JF) dams at weaning and after a 10-day naloxone treatment post-weaning and determined food preferences in adulthood in the remaining offspring. Naloxone treatment decreased the expression of DAT by 8.2 fold in female control offspring but increased it by 4.3 fold in female offspring of JF dams relative to the saline-injected reference groups. Proenkephalin mRNA expression was higher in the NAc of female JF offspring compared to controls, independent of naloxone treatment (Pfood preferences in adulthood in either control or JF offspring. These data indicate that prenatal exposure to a cafeteria diet alters the impact of opioid signaling blockade in the early post-weaning period on gene expression in the central reward pathway in a sex specific manner, but that these changes in gene expression do not appear to have any persistent impact on food preferences in adulthood. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Eye tracking social preferences

    NARCIS (Netherlands)

    Jiang, Ting; Potters, Jan; Funaki, Yukihiko

    We hypothesize that if people are motivated by a particular social preference, then choosing in accordance with this preference will lead to an identifiable pattern of eye movements. We track eye movements while subjects make choices in simple three-person distribution experiments. We characterize

  15. Consumer Preferences of Travel Web Content

    OpenAIRE

    Yang, Mari

    2015-01-01

    The purpose of this Bachelor’s Thesis was to study the web content preferences of users in online travel. The research was done for the commissioning party, TripAhead, a start-up online travel organizer, in order to help get insight into the consumer opinions and preferences. Moreover, the thesis researches which web content features affect the consumer the most into choosing a holiday destination, and essentially purchasing a service or product from a travel website. Additionally, the travel...

  16. Consumers’ preferences for bread

    DEFF Research Database (Denmark)

    Edenbrandt, Anna Kristina; Gamborg, Christian; Thorsen, Bo Jellesmark

    2018-01-01

    Consumers are apprehensive about transgenic technologies, so cisgenics, which limit gene transfers to sexually compatible organisms, have been suggested to address consumer concerns. We study consumer preferences for rye bread alternatives based on transgenic or cisgenic rye, grown conventionally...... pesticide-free production methods, and that while cisgenics is preferred over transgenics, the majority of respondents favour traditional breeding methods. The distribution in preferences suggests that some respondents prefer bread from cisgenic crops produced without pesticides over traditional crops...... produced using pesticides. Preferences for organic bread are stronger than for pesticide-free products. From a policy perspective results suggest that excluding cisgenics from mandatory labeling in the EU, or including it in the voluntary non-GM labelling in the US, would cause welfare losses for consumers....

  17. Geomorphic Framework to assess changes to aquatic habitat due to flow regulation and channel and floodplain alteration, Cedar River, Washington

    Science.gov (United States)

    Gendaszek, Andrew S.; Magirl, Christopher S.; Czuba, Christiana R.; Konrad, Christopher P.; Little, Rand

    2010-01-01

    Flow regulation, bank armoring, and floodplain alteration since the early 20th century have contributed to significant changes in the hydrologic regime and geomorphic processes of the Cedar River in Washington State. The Cedar River originates in the Cascade Range, provides drinking water to the Seattle metropolitan area, and supports several populations of anadromous salmonids. Flow regulation currently has limited influence on the magnitude, duration, and timing of high-flow events, which affect the incubation of salmonids as well as the production and maintenance of their habitat. Unlike structural changes to the channel and floodplain, flow regulation may be modified in the short-term to improve the viability of salmon populations. An understanding of the effects of flow regulation on those populations must be discerned over a range of scales from individual floods that affect the size of individual year classes to decadal high flow regime that influences the amount and quality of channel and off-channel habitat available for spawning and rearing. We present estimates of reach-scale sediment budgets and changes to channel morphology derived from historical orthoimagery, specific gage analyses at four long-term streamflow-gaging stations to quantify trends in aggradation, and hydrologic statistics of the magnitude and duration of peak streamflows. These data suggest a gradient of channel types from unconfined, sediment-rich segments to confined, sediment-poor segments that are likely to have distinct responses to high flows. Particle-size distribution data and longitudinal water surface and streambed profiles for the 56 km downstream of Chester Morse Lake measured in 2010 show the spatial extent of preferred salmonid habitat along the Cedar River. These historical and current data constitute a geomorphic framework to help assess different river management scenarios for salmonid habitat and population viability. PDF version of a presentation on changes to aquatic

  18. Preference SQL - Design, Implementation, Experiences

    OpenAIRE

    Kießling, Werner; Köstler, Gerhard

    2006-01-01

    Current search engines can hardly cope adequately with complex preferences. The biggest problem of search engines directly implemented with standard SQL is that SQL does not directly understand the notion of preferences. Preference SQL extends standard SQL by a preference model based on strict partial orders, where preference queries behave like soft selection constraints. A variety of built-in base preference types and the powerful Pareto accumulation operator to construct complex preference...

  19. Modified habitats influence kelp epibiota via direct and indirect effects.

    Science.gov (United States)

    Marzinelli, Ezequiel M; Underwood, Antony J; Coleman, Ross A

    2011-01-01

    Addition of man-made structures alters abiotic and biotic characteristics of natural habitats, which can influence abundances of biota directly and/or indirectly, by altering the ecology of competitors or predators. Marine epibiota in modified habitats were used to test hypotheses to distinguish between direct and indirect processes. In Sydney Harbour, kelps on pier-pilings supported greater covers of bryozoans, particularly of the non-indigenous species Membranipora membranacea, than found on natural reefs. Pilings influenced these patterns and processes directly due to the provision of shade and indirectly by altering abundances of sea-urchins which, in turn, affected covers of bryozoans. Indirect effects were more important than direct effects. This indicates that artificial structures affect organisms living on secondary substrata in complex ways, altering the biodiversity and indirectly affecting abundances of epibiota. Understanding how these components of habitats affect ecological processes is necessary to allow sensible prediction of the effects of modifying habitats on the ecology of organisms.

  20. Assessing juvenile salmon rearing habitat and associated predation risk in a lower Snake River reservoir

    Science.gov (United States)

    Tiffan, Kenneth F.; Hatten, James R.; Trachtenbarg, David A

    2015-01-01

    Subyearling fall Chinook salmon (Oncorhynchus tshawytscha) in the Columbia River basin exhibit a transient rearing strategy and depend on connected shoreline habitats during freshwater rearing. Impoundment has greatly reduced the amount of shallow-water rearing habitat that is exacerbated by the steep topography of reservoirs. Periodic dredging creates opportunities to strategically place spoils to increase the amount of shallow-water habitat for subyearlings while at the same time reducing the amount of unsuitable area that is often preferred by predators. We assessed the amount and spatial arrangement of subyearling rearing habitat in Lower Granite Reservoir on the Snake River to guide future habitat improvement efforts. A spatially explicit habitat assessment was conducted using physical habitat data, two-dimensional hydrodynamic modelling and a statistical habitat model in a geographic information system framework. We used field collections of subyearlings and a common predator [smallmouth bass (Micropterus dolomieu)] to draw inferences about predation risk within specific habitat types. Most of the high-probability rearing habitat was located in the upper half of the reservoir where gently sloping landforms created low lateral bed slopes and shallow-water habitats. Only 29% of shorelines were predicted to be suitable (probability >0.5) for subyearlings, and the occurrence of these shorelines decreased in a downstream direction. The remaining, less suitable areas were composed of low-probability habitats in unmodified (25%) and riprapped shorelines (46%). As expected, most subyearlings were found in high-probability habitat, while most smallmouth bass were found in low-probability locations. However, some subyearlings were found in low-probability habitats, such as riprap, where predation risk could be high. Given their transient rearing strategy and dependence on shoreline habitats, subyearlings could benefit from habitat creation efforts in the lower

  1. Effects of spatial habitat heterogeneity on habitat selection and annual fecundity for a migratory forest songbird

    Science.gov (United States)

    Cornell, K.L.; Donovan, T.M.

    2010-01-01

    Understanding how spatial habitat patterns influence abundance and dynamics of animal populations is a primary goal in landscape ecology. We used an information-theoretic approach to investigate the association between habitat patterns at multiple spatial scales and demographic patterns for black-throated blue warblers (Dendroica caerulescens) at 20 study sites in west-central Vermont, USA from 2002 to 2005. Sites were characterized by: (1) territory-scale shrub density, (2) patch-scale shrub density occurring within 25 ha of territories, and (3) landscape-scale habitat patterns occurring within 5 km radius extents of territories. We considered multiple population parameters including abundance, age ratios, and annual fecundity. Territory-scale shrub density was most important for determining abundance and age ratios, but landscape-scale habitat structure strongly influenced reproductive output. Sites with higher territory-scale shrub density had higher abundance, and were more likely to be occupied by older, more experienced individuals compared to sites with lower shrub density. However, annual fecundity was higher on sites located in contiguously forested landscapes where shrub density was lower than the fragmented sites. Further, effects of habitat pattern at one spatial scale depended on habitat conditions at different scales. For example, abundance increased with increasing territory-scale shrub density, but this effect was much stronger in fragmented landscapes than in contiguously forested landscapes. These results suggest that habitat pattern at different spatial scales affect demographic parameters in different ways, and that effects of habitat patterns at one spatial scale depends on habitat conditions at other scales. ?? Springer Science+Business Media B.V. 2009.

  2. Habitat fragmentation and reproductive success: a structural equation modelling approach.

    Science.gov (United States)

    Le Tortorec, Eric; Helle, Samuli; Käyhkö, Niina; Suorsa, Petri; Huhta, Esa; Hakkarainen, Harri

    2013-09-01

    1. There is great interest on the effects of habitat fragmentation, whereby habitat is lost and the spatial configuration of remaining habitat patches is altered, on individual breeding performance. However, we still lack consensus of how this important process affects reproductive success, and whether its effects are mainly due to reduced fecundity or nestling survival. 2. The main reason for this may be the way that habitat fragmentation has been previously modelled. Studies have treated habitat loss and altered spatial configuration as two independent processes instead of as one hierarchical and interdependent process, and therefore have not been able to consider the relative direct and indirect effects of habitat loss and altered spatial configuration. 3. We investigated how habitat (i.e. old forest) fragmentation, caused by intense forest harvesting at the territory and landscape scales, is associated with the number of fledged offspring of an area-sensitive passerine, the Eurasian treecreeper (Certhia familiaris). We used structural equation modelling (SEM) to examine the complex hierarchical associations between habitat loss and altered spatial configuration on the number of fledged offspring, by controlling for individual condition and weather conditions during incubation. 4. Against generally held expectations, treecreeper reproductive success did not show a significant association with habitat fragmentation measured at the territory scale. Instead, our analyses suggested that an increasing amount of habitat at the landscape scale caused a significant increase in nest predation rates, leading to reduced reproductive success. This effect operated directly on nest predation rates, instead of acting indirectly through altered spatial configuration. 5. Because habitat amount and configuration are inherently strongly collinear, particularly when multiple scales are considered, our study demonstrates the usefulness of a SEM approach for hierarchical partitioning

  3. Applying factor analyses of statistics to evaluate habitat biodiversity index in dry-season creeks.

    Science.gov (United States)

    Su, Tzu-Chieh; Wong, Mu-Han; Huang, Hung-Pin

    2014-02-01

    The purpose of this study is to analyze the habitat factors (environmental variables) affecting dry-season creek fish, and evaluate habitat biodiversity index (HBI) in dry-season creeks. This research determined HBI formula by 133 study sites in the creek flows in seven rivers in Taiwan from 2007 to 2008. This research considered 10 habitat factors: water depth, width, length, pH, electrical conductivity, temperature, current velocity, rainfall, elevation, and substrate diversity. Using the principal component analysis (PCA), varimax rotated factor analysis (FA), and the simultaneous regression in product-exponential model (PEM), fish total numbers and HBI were formulated by these 10 habitat factors. Pearson's correlation coefficient matrix and three-factor loading plots reported that current flow velocity, rainfall, and elevation affected on fish numbers similarly; besides, water length (logarithmic) and width (logarithmic) had the positive and similar influences in fish numbers. Habitat evaluation levels were classified six groups, namely, excellent habitat, very good habitat, good habitat, fair habitat, poor habitat, and then very poor habitat. In brief, HBI was reasonable and calculated simply by 10 environmental variables of fish habitats. The results of this study can be applied extensively to evaluate the conditions of fish habitats in dry-season creeks for habitat recovery projects.

  4. Habitat selection and risk of predation: re-colonization by lynx had limited impact on habitat selection by roe deer.

    Science.gov (United States)

    Samelius, Gustaf; Andrén, Henrik; Kjellander, Petter; Liberg, Olof

    2013-01-01

    Risk of predation is an evolutionary force that affects behaviors of virtually all animals. In this study, we examined how habitat selection by roe deer was affected by risk of predation by Eurasian lynx - the main predator of roe deer in Scandinavia. Specifically, we compared how habitat selection by roe deer varied (1) before and after lynx re-established in the study area and (2) in relation to habitat-specific risk of predation by lynx. All analyses were conducted at the spatial and temporal scales of home ranges and seasons. We did not find any evidence that roe deer avoided habitats in which the risk of predation by lynx was greatest and information-theoretic model selection showed that re-colonization by lynx had limited impact on habitat selection by roe deer despite lynx predation causing 65% of known mortalities after lynx re-colonized the area. Instead we found that habitat selection decreased when habitat availability increased for 2 of 5 habitat types (a pattern referred to as functional response in habitat selection). Limited impact of re-colonization by lynx on habitat selection by roe deer in this study differs from elk in North America altering both daily and seasonal patterns in habitat selection at the spatial scales of habitat patches and home ranges when wolves were reintroduced to Yellowstone National Park. Our study thus provides further evidence of the complexity by which animals respond to risk of predation and suggest that it may vary between ecosystems and predator-prey constellations.

  5. Habitat selection and risk of predation: re-colonization by lynx had limited impact on habitat selection by roe deer.

    Directory of Open Access Journals (Sweden)

    Gustaf Samelius

    Full Text Available Risk of predation is an evolutionary force that affects behaviors of virtually all animals. In this study, we examined how habitat selection by roe deer was affected by risk of predation by Eurasian lynx - the main predator of roe deer in Scandinavia. Specifically, we compared how habitat selection by roe deer varied (1 before and after lynx re-established in the study area and (2 in relation to habitat-specific risk of predation by lynx. All analyses were conducted at the spatial and temporal scales of home ranges and seasons. We did not find any evidence that roe deer avoided habitats in which the risk of predation by lynx was greatest and information-theoretic model selection showed that re-colonization by lynx had limited impact on habitat selection by roe deer despite lynx predation causing 65% of known mortalities after lynx re-colonized the area. Instead we found that habitat selection decreased when habitat availability increased for 2 of 5 habitat types (a pattern referred to as functional response in habitat selection. Limited impact of re-colonization by lynx on habitat selection by roe deer in this study differs from elk in North America altering both daily and seasonal patterns in habitat selection at the spatial scales of habitat patches and home ranges when wolves were reintroduced to Yellowstone National Park. Our study thus provides further evidence of the complexity by which animals respond to risk of predation and suggest that it may vary between ecosystems and predator-prey constellations.

  6. Managing harvest and habitat as integrated components

    Science.gov (United States)

    Osnas, Erik; Runge, Michael C.; Mattsson, Brady J.; Austin, Jane E.; Boomer, G. S.; Clark, R. G.; Devers, P.; Eadie, J. M.; Lonsdorf, E. V.; Tavernia, Brian G.

    2014-01-01

    In 2007, several important initiatives in the North American waterfowl management community called for an integrated approach to habitat and harvest management. The essence of the call for integration is that harvest and habitat management affect the same resources, yet exist as separate endeavours with very different regulatory contexts. A common modelling framework could help these management streams to better understand their mutual effects. Particularly, how does successful habitat management increase harvest potential? Also, how do regional habitat programmes and large-scale harvest strategies affect continental population sizes (a metric used to express habitat goals)? In the ensuing five years, several projects took on different aspects of these challenges. While all of these projects are still on-going, and are not yet sufficiently developed to produce guidance for management decisions, they have been influential in expanding the dialogue and producing some important emerging lessons. The first lesson has been that one of the more difficult aspects of integration is not the integration across decision contexts, but the integration across spatial and temporal scales. Habitat management occurs at local and regional scales. Harvest management decisions are made at a continental scale. How do these actions, taken at different scales, combine to influence waterfowl population dynamics at all scales? The second lesson has been that consideration of the interface of habitat and harvest management can generate important insights into the objectives underlying the decision context. Often the objectives are very complex and trade-off against one another. The third lesson follows from the second – if an understanding of the fundamental objectives is paramount, there is no escaping the need for a better understanding of human dimensions, specifically the desires of hunters and nonhunters and the role they play in conservation. In the end, the compelling question is

  7. Loss and modification of habitat: Chapter 1

    Science.gov (United States)

    Lemckert, Francis; Hecnar, Stephen; Pilliod, David S.

    2012-01-01

    water balance (Thorson and Svihla 1943; Brattstrom 1963; Tracy 1976). Hence, individuals require and seek specific microhabitats that maintain their preferred body temperature while at the same time reducing water loss or allowing individuals to re-hydrate. Amphibians also possess relatively few physical attributes that protect them from predators. Although they may avoid predators behaviourally or deter them by skin toxins, amphibians lack defensive shells or hardened cuticles, do not have protective teeth or claws, and most are insufficiently fast to escape predators. Hence, they are relatively dependent on sites that conceal or protect them from predation. Most amphibians also differ significantly from other vertebrates in possessing a complex two-phase life cycle: the pre-metamorphic larval (tadpole) stage and the post-metamorphic juvenile and adult stage (Wilbur 1980, 1984). Most amphibian species have two distinct econes (Heatwole 1989), each with different habitat requirements, the larvae being aquatic and the post-metamorphic animals more terrestrial. The habitats required by the two phases can differ greatly, but both are essential to the survival of a species. However, amphibian diversity is great and exceptions to this general pattern exist. For example, some species have direct development without going through a larval stage and are fully terrestrial, whereas the larvae of other species can reach sexual maturity without going through metamorphosis (i.e., neoteny) and are fully aquatic.

  8. Smartphone technologies and Bayesian networks to assess shorebird habitat selection

    Science.gov (United States)

    Zeigler, Sara; Thieler, E. Robert; Gutierrez, Ben; Plant, Nathaniel G.; Hines, Megan K.; Fraser, James D.; Catlin, Daniel H.; Karpanty, Sarah M.

    2017-01-01

    Understanding patterns of habitat selection across a species’ geographic distribution can be critical for adequately managing populations and planning for habitat loss and related threats. However, studies of habitat selection can be time consuming and expensive over broad spatial scales, and a lack of standardized monitoring targets or methods can impede the generalization of site-based studies. Our objective was to collaborate with natural resource managers to define available nesting habitat for piping plovers (Charadrius melodus) throughout their U.S. Atlantic coast distribution from Maine to North Carolina, with a goal of providing science that could inform habitat management in response to sea-level rise. We characterized a data collection and analysis approach as being effective if it provided low-cost collection of standardized habitat-selection data across the species’ breeding range within 1–2 nesting seasons and accurate nesting location predictions. In the method developed, >30 managers and conservation practitioners from government agencies and private organizations used a smartphone application, “iPlover,” to collect data on landcover characteristics at piping plover nest locations and random points on 83 beaches and barrier islands in 2014 and 2015. We analyzed these data with a Bayesian network that predicted the probability a specific combination of landcover variables would be associated with a nesting site. Although we focused on a shorebird, our approach can be modified for other taxa. Results showed that the Bayesian network performed well in predicting habitat availability and confirmed predicted habitat preferences across the Atlantic coast breeding range of the piping plover. We used the Bayesian network to map areas with a high probability of containing nesting habitat on the Rockaway Peninsula in New York, USA, as an example application. Our approach facilitated the collation of evidence-based information on habitat selection

  9. Global rates of habitat loss and implications for amphibian conservation

    Science.gov (United States)

    Gallant, A.L.; Klaver, R.W.; Casper, G.S.; Lannoo, M.J.

    2007-01-01

    A large number of factors are known to affect amphibian population viability, but most authors agree that the principal causes of amphibian declines are habitat loss, alteration, and fragmentation. We provide a global assessment of land use dynamics in the context of amphibian distributions. We accomplished this by compiling global maps of amphibian species richness and recent rates of change in land cover, land use, and human population growth. The amphibian map was developed using a combination of published literature and digital databases. We used an ecoregion framework to help interpret species distributions across environmental, rather than political, boundaries. We mapped rates of land cover and use change with statistics from the World Resources Institute, refined with a global digital dataset on land cover derived from satellite data. Temporal maps of human population were developed from the World Resources Institute database and other published sources. Our resultant map of amphibian species richness illustrates that amphibians are distributed in an uneven pattern around the globe, preferring terrestrial and freshwater habitats in ecoregions that are warm and moist. Spatiotemporal patterns of human population show that, prior to the 20th century, population growth and spread was slower, most extensive in the temperate ecoregions, and largely exclusive of major regions of high amphibian richness. Since the beginning of the 20th century, human population growth has been exponential and has occurred largely in the subtropical and tropical ecoregions favored by amphibians. Population growth has been accompanied by broad-scale changes in land cover and land use, typically in support of agriculture. We merged information on land cover, land use, and human population growth to generate a composite map showing the rates at which humans have been changing the world. When compared with the map of amphibian species richness, we found that many of the regions of the

  10. Ratio Bias and Policy Preferences

    DEFF Research Database (Denmark)

    Pedersen, Rasmus Tue

    2016-01-01

    Numbers permeate modern political communication. While current scholarship on framing effects has focused on the persuasive effects of words and arguments, this article shows that framing of numbers can also substantially affect policy preferences. Such effects are caused by ratio bias, which...... regarding salient political issues such as education and taxes. Furthermore, the effects of numerical framing are found across most groups of the population, largely regardless of their political predisposition and their general ability to understand and use numerical information. These findings have...

  11. Habitat shifts in the evolutionary history of a Neotropical flycatcher lineage from forest and open landscapes

    Directory of Open Access Journals (Sweden)

    Christidis Les

    2008-07-01

    Full Text Available Abstract Background Little is known about the role ecological shifts play in the evolution of Neotropical radiations that have colonized a variety of environments. We here examine habitat shifts in the evolutionary history of Elaenia flycatchers, a Neotropical bird lineage that lives in a range of forest and open habitats. We evaluate phylogenetic relationships within the genus based on mitochondrial and nuclear DNA sequence data, and then employ parsimony-based and Bayesian methods to reconstruct preferences for a number of habitat types and migratory behaviour throughout the evolutionary history of the genus. Using a molecular clock approach, we date the most important habitat shifts. Results Our analyses resolve phylogenetic relationships among Elaenia species and confirm several species associations predicted by morphology while furnishing support for other taxon placements that are in conflict with traditional classification, such as the elevation of various Elaenia taxa to species level. While savannah specialism is restricted to one basal clade within the genus, montane forest was invaded from open habitat only on a limited number of occasions. Riparian growth may have been favoured early on in the evolution of the main Elaenia clade and subsequently been deserted on several occasions. Austral long-distance migratory behaviour evolved on several occasions. Conclusion Ancestral reconstructions of habitat preferences reveal pronounced differences not only in the timing of the emergence of certain habitat preferences, but also in the frequency of habitat shifts. The early origin of savannah specialism in Elaenia highlights the importance of this habitat in Neotropical Pliocene and late Miocene biogeography. While forest in old mountain ranges such as the Tepuis and the Brazilian Shield was colonized early on, the most important colonization event of montane forest was in conjunction with Pliocene Andean uplift. Riparian habitats may have

  12. Bioenergy and biodiversity: Intensified biomass extraction from hedges impairs habitat conditions for birds.

    Science.gov (United States)

    Sauerbrei, Ralf; Aue, Birgit; Krippes, Christian; Diehl, Eva; Wolters, Volkmar

    2017-02-01

    Biomass is increasingly used as an alternative source for energy in Europe. Woody material cut from hedges is considered to provide a suitable complement to maize and oilseed rape, which are currently the dominant biomass sources. Since shrubs and trees are also important habitats for birds, however, coppicing of hedges at the landscape scale may adversely affect the diversity of the avifauna. To evaluate this risk, we estimated the response of hedge birds to three management scenarios differing in cutting intensity and hedge selection. The analysis was done using hedge data of the Lautertal municipality (n = 339 hedges; Vogelsberg area, Hesse, Germany). It focused on 25 bird species, which are all listed in the hedge programme of the German Ornithological Stations. Information on the preferences of these birds for certain hedge features such as height or width was gathered by an extensive literature review. A cluster analysis on the consolidated literature data allowed us to identify three groups of birds according to their preference for certain hedge attributes. Two groups, which included Yellowhammer (Emberiza citrinella L.) (i) and Blackbird (Turdus merula L.) (ii), favoured trees located in hedges, but differed in their preference for hedge shape, with (i) being attracted by long and broad hedges and (ii) by high hedges. The third group, which included the Whitethroat (Sylvia communis L.), preferred small hedges with gaps and medium vegetation density. Spatially explicit suitability models based on these data allowed us to predict the status quo of hedge suitability for these species groups. Field surveys proved the accuracy of the predictions to be sufficient, since the hedge suitability predicted was significantly and positively correlated to the occurrence of 9 out of the 12 testable focal species. Our models predicted biomass extraction to almost always reduce hedge suitability for the three bird groups. Concerning the Yellowhammer and the Blackbird

  13. Aceitação de sobremesas lácteas dietéticas e formuladas com açúcar: teste afetivo e mapa de preferência interno Acceptability of sweetened and low calorie dairy desserts: affective tests and internal preference mapping

    Directory of Open Access Journals (Sweden)

    Ana Paula Vital de Oliveira

    2004-12-01

    Full Text Available A aceitação de sobremesas lácteas de chocolate (três pudins com açúcar, cinco pudins dietéticos e dois flans comerciais foi avaliada por 56 consumidores utilizando delineamento de blocos completos balanceados e empregando-se uma escala hedônica estruturada de nove pontos. Os provadores foram caracterizados através de um questionário para coleta de informações pessoais e hábitos de consumo de produtos dietéticos e pudins. Os dados de aceitação foram analisados por ANOVA e teste de médias. Empregou-se, também, a metodologia de Mapa de Preferência Interno utilizando diferentes técnicas estatísticas (Análise de Componentes Principais e Escala Multidimensional associadas à Análise de Agrupamentos, para segmentação dos consumidores. Considerando-se as notas médias, observou-se que os pudins dietéticos se destacaram pela boa aceitação. O emprego da técnica de Escala Multidimensional proporcionou uma avaliação mais abrangente do comportamento dos provadores do que a Análise de Componentes Principais, permitindo identificar dois grandes grupos de consumidores: os que preferiam os produtos (pudins e flan de uma determinada marca e os que preferiam os pudins dietéticos. Os resultados demonstram a eficiência do emprego do mapa na identificação e caracterização de preferências e de grupos de consumidores.The acceptance of commercial chocolate dairy desserts (three regular puddings, five dietetic puddings and two regular flans was evaluated by 56 consumers in a balanced-block design, using a nine-point structured hedonic scale. Panelists were characterized using a questionnaire asking for personal information and consumer's behavior towards dietary products and puddings consumption. The acceptance data were analyzed by ANOVA with means comparison and using the technique of Internal Preference Mapping (MDPREF applying different statistical methods (Principal Components Analysis and Muldimensional Scale associated to

  14. Social preferences for the design of biodiversity offsets for shorebirds in Australia.

    Science.gov (United States)

    Rogers, Abbie A; Burton, Michael P

    2017-08-01

    Understanding the social acceptability of biodiversity offsets is important to the design of offset policy. We used a discrete choice experiment to quantify preferences of Australians for a migratory shorebird offset in the context of an oil and gas development project. We surveyed a nationally representative sample of 1371 respondents on their preferences for current and prospective offset-policy characteristics via an online questionnaire to inform policy design of the social dimensions related to offset acceptability. The majority of respondents accepted offsetting as a means to allow economic development; the option to reject development (and an offset) was selected in 13% of possible offset scenarios. Substituting protection of a species affected by the development with protection of a more endangered species was a desirable policy characteristic, as was having the offset implemented by a third party or the government rather than the company responsible for the development. Direct offset activities (e.g., improving degraded habitat) were preferred over indirect activities (e.g., a research program), and respondents were strongly against locating the offset at a site other than where the impact occurred. Positive and negative characteristics of offsets could be traded off by changing the number of birds protected by the offset. Our results show that Australians are likely to support increased flexibility in biodiversity-offset policies, particularly when undesirable policy characteristics are compensated for. © 2016 Society for Conservation Biology.

  15. Bridging gaps: On the performance of airborne LiDAR to model wood mouse-habitat structure relationships in pine forests.

    Science.gov (United States)

    Jaime-González, Carlos; Acebes, Pablo; Mateos, Ana; Mezquida, Eduardo T

    2017-01-01

    LiDAR technology has firmly contributed to strengthen the knowledge of habitat structure-wildlife relationships, though there is an evident bias towards flying vertebrates. To bridge this gap, we investigated and compared the performance of LiDAR and field data to model habitat preferences of wood mouse (Apodemus sylvaticus) in a Mediterranean high mountain pine forest (Pinus sylvestris). We recorded nine field and 13 LiDAR variables that were summarized by means of Principal Component Analyses (PCA). We then analyzed wood mouse's habitat preferences using three different models based on: (i) field PCs predictors, (ii) LiDAR PCs predictors; and (iii) both set of predictors in a combined model, including a variance partitioning analysis. Elevation was also included as a predictor in the three models. Our results indicate that LiDAR derived variables were better predictors than field-based variables. The model combining both data sets slightly improved the predictive power of the model. Field derived variables indicated that wood mouse was positively influenced by the gradient of increasing shrub cover and negatively affected by elevation. Regarding LiDAR data, two LiDAR PCs, i.e. gradients in canopy openness and complexity in forest vertical structure positively influenced wood mouse, although elevation interacted negatively with the complexity in vertical structure, indicating wood mouse's preferences for plots with lower elevations but with complex forest vertical structure. The combined model was similar to the LiDAR-based model and included the gradient of shrub cover measured in the field. Variance partitioning showed that LiDAR-based variables, together with elevation, were the most important predictors and that part of the variation explained by shrub cover was shared. LiDAR derived variables were good surrogates of environmental characteristics explaining habitat preferences by the wood mouse. Our LiDAR metrics represented structural features of the forest

  16. Preferred Dance Tempo

    DEFF Research Database (Denmark)

    Dahl, Sofia; Huron, David; Brod, Garvin

    2014-01-01

    predictors of preferred dance tempo in Experiment 1. A second experiment, where males and females were matched in terms of height, resulted in no significant correlation between sex and preferred dance tempo. In the matched sample, height was found to be the single best predictor but with a relatively small...... effect size. These results are consistent with a biomechanical “resonance” model of dancing....

  17. Saproxylic Hemiptera Habitat Associations

    Science.gov (United States)

    Michael D. Ulyshen; James L. Hanula; Robert L. Blinn; Gene. Kritsky

    2012-01-01

    Understanding the habitat requirements of organisms associated with dead wood is important in order to conserve them in managed forests. Unfortunately, many of the less diverse saproxylic taxa, including Hemiptera, remain largely unstudied. An effort to rear insects from dead wood taken from two forest types (an upland pine-dominated and a bottomland mixed hardwood),...

  18. Wildlife habitat fragmentation.

    Science.gov (United States)

    John. Lehmkuhl

    2005-01-01

    A primary issue in forest wildlife management is habitat fragmentation and its effects on viability, which is the "bottom line" for plant and animal species of conservation concern. Population viability is the likelihood that a population will be able to maintain itself (remain viable) over a long period of time-usually 100 years or more. Though it is true...

  19. Children's gender and parents' color preferences.

    Science.gov (United States)

    Cohen, Philip N

    2013-04-01

    Gender differences in color preferences have been found in adults and children, but they remain unexplained. This study asks whether the gendered social environment in adulthood affects parents' color preferences. The analysis used the gender of children to represent one aspect of the gendered social environment. Because having male versus female children in the U.S. is generally randomly distributed, it provides something of a natural experiment, offering evidence about the social construction of gender in adulthood. The participants were 749 adults with children who responded to an online survey invitation, asking "What's your favorite color?" Men were more likely to prefer blue, while women were more likely to prefer red, purple, and pink, consistent with long-standing U.S. patterns. The effect of having only sons was to widen the existing gender differences between men and women, increasing the odds that men prefer blue while reducing the odds that women do; and a marginally significant effect showed women having higher odds of preferring pink when they have sons only. The results suggest that, in addition to any genetic, biological or child-socialization effects shaping adults' tendency to segregate their color preferences by gender, the gender context of adulthood matters as well.

  20. The influence of habitat on the evolution of plants: a case study across Saxifragales.

    Science.gov (United States)

    de Casas, Rafael Rubio; Mort, Mark E; Soltis, Douglas E

    2016-12-01

    Organismal evolution tends to be closely associated with ecological conditions. However, the extent to which this association constrains adaptation or diversification into new habitats remains unclear. We studied habitat evolution in the hyper-diverse angiosperm clade Saxifragales. We used species-level phylogenies for approx. 950 species to analyse the evolution of habitat shifts as well as their influence on plant diversification. We combined habitat characterization based on floristic assignments and state-of-the art phylogenetic comparative methods to estimate within- and across-habitat diversification patterns. Our analyses showed that Saxifragales diversified into multiple habitats from a forest-inhabiting ancestor and that this diversification is governed by relatively rare habitat shifts. Lineages are likely to stay within inferred ancestral ecological conditions. Adaptation to some habitat types (e.g. aquatic, desert) may be canalizing events that lineages do not escape. Although associations between increased diversification rates and shifts in habitat preferences are occasionally observed, extreme macroevolutionary rates are closely associated with specific habitats. Lineages occurring in shrubland, and especially tundra and rock cliffs, exhibit comparatively high diversification, whereas forest, grassland, desert and aquatic habitats are associated with low diversification. The likelihood of occupation of new habitats appears to be asymmetric. Shifts to aquatic and desert habitats may be canalizing events. Other habitats, such as tundra, might act as evolutionary sources, while forests provide the only habitat seemingly colonized easily by lineages originating elsewhere. However, habitat shifts are very rare, and any major environmental alteration is expected to have dramatic evolutionary consequences. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company.

  1. Preference Handling for Artificial Intelligence

    OpenAIRE

    Goldsmith, Judy; University of Kentucky; Junker, Ulrich; ILOG

    2009-01-01

    This article explains the benefits of preferences for AI systems and draws a picture of current AI research on preference handling. It thus provides an introduction to the topics covered by this special issue on preference handling.

  2. Earth is a Marine Habitat. Habitat Conservation Program.

    Science.gov (United States)

    National Oceanic and Atmospheric Administration (DOC), Rockville, MD.

    This brochure is intended to educate the public about the need to conserve and preserve the earth's environment (man's habitat). It contains an introduction to the ocean world and threats to coastal habitat. Photos and narrative revolve around the theme "Earth is a Marine Habitat." Sections include: "The Web of…

  3. Hunting or habitat? Drivers of waterbird abundance and community structure in agricultural wetlands of southern India.

    Science.gov (United States)

    Ramachandran, Ramesh; Kumar, Ajith; Gopi Sundar, Kolla S; Bhalla, Ravinder Singh

    2017-09-01

    The relative impacts of hunting and habitat on waterbird community were studied in agricultural wetlands of southern India. We surveyed wetlands to document waterbird community, and interviewed hunters to document hunting intensity, targeted species, and the motivations for hunting. Our results show that hunting leads to drastic declines in waterbird diversity and numbers, and skew the community towards smaller species. Hunting intensity, water spread, and vegetation cover were the three most important determinants of waterbird abundance and community structure. Species richness, density of piscivorous species, and medium-sized species (31-65 cm) were most affected by hunting. Out of 53 species recorded, 47 were hunted, with a preference for larger birds. Although illegal, hunting has increased in recent years and is driven by market demand. This challenges the widely held belief that waterbird hunting in India is a low intensity, subsistence activity, and undermines the importance of agricultural wetlands in waterbird conservation.

  4. Demographic consequences of disease in a habitat-forming seaweed and impacts on interactions between natural enemies.

    Science.gov (United States)

    Campbell, Alexandra H; Vergés, Adriana; Steinberg, Peter D

    2014-01-01

    Diseases affecting natural ecosystems are increasing in frequency and severity, but unless obviously catastrophic, the consequences of disease outbreaks are often overlooked, relative to other ecological processes (e.g., predation, competition). Disease can have profound effects on individuals and can also strongly influence interactions between infected hosts and their natural enemies. We investigated whether a novel bleaching disease affected the survival or performance of a habitat-forming red seaweed, Delisea pulchra. In addition, we investigated bidirectional, multipartite interactions between this seaweed host, its pathogens, and consumers. Although we found no negative impacts of disease on survival of D. pulchra, bleaching had substantial, negative consequences for affected individuals, including a dramatic drop in fecundity and a significant decrease in size. In the first direct demonstration of bacterial disease-mediated herbivory of seaweeds, herbivores generally preferred to consume bleached tissue in feeding trials, and we also found higher densities of herbivores on bleached than co-occurring, healthy algae at sites where herbivores were abundant. In a conceptually reciprocal test of the effects of herbivores on infection, we showed that simulated herbivory increased susceptibility to bleaching when algae were also exposed to cultures of a bacterial pathogen. Given the high proportions of D. pulchra affected by bleaching during peak periods, the impacts of this disease are likely to have important implications at the population level. This work highlights complex interactions between habitat-forming organisms and their natural enemies and further emphasizes the need to consider disease in ecological research.

  5. NEPR Benthic Habitat Map 2015

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This benthic habitat map was created from a semi-automated habitat mapping process, using a combination of bathymetry, satellite imagery, aerial imagery and...

  6. NORTHWOODS Wildlife Habitat Data Base

    Science.gov (United States)

    Mark D. Nelson; Janine M. Benyus; Richard R. Buech

    1992-01-01

    Wildlife habitat data from seven Great Lakes National Forests were combined into a wildlife-habitat matrix named NORTHWOODS. Several electronic file formats of NORTHWOODS data base and documentation are available on floppy disks for microcomputers.

  7. Carpinteria Salt Marsh Habitat Polygons

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — We identified five common habitat types in Carpinteria Salt Marsh: channels, pans (flats), marsh, salt flat and upland. We then drew polygons around each habitat...

  8. TURKISH CONSUMER DECISIONS AFFECTING ICE CREAM CONSUMPTION

    National Research Council Canada - National Science Library

    Yavuz Topcu

    2015-01-01

    The aim of the study is to determine the main factors affecting the national-branded ice cream preferences of Turkish consumers, and to analyze the relationships between their preferences and consumption amounts...

  9. Diversity and activity patterns of sympatric animals among four types of forest habitat in Guanyinshan Nature Reserve in the Qinling Mountains, China.

    Science.gov (United States)

    Liu, Xuehua; Wu, Pengfeng; Shao, Xiaoming; Songer, Melissa; Cai, Qiong; He, Xiangbo; Zhu, Yun

    2017-07-01

    Environmental heterogeneity contributes to various habitats and may influence the diversity and activity patterns of wildlife among habitats. We used camera traps to assess wildlife habitat use in Guanyinshan Nature Reserve from 2009 to 2012. We focused on four types of habitat including open areas with gentle slope (<15°) (Type1), low elevation areas (about 1500-1700 m) with high bamboo coverage (Type2), high elevation areas (about 2100-2300 m) with high canopy coverage (Type3), and wildlife migration passages (Type4). We analyzed the differences in species richness, relative abundance index (RAI), species diversity, and animals' activity pattern among habitats. Total six species were analyzed on activity pattern, which are Takin (Budorcas taxicolor), tufted deer (Elaphodus cephalophus), Himalayan goral (Naemorhedus goral), wild boar (Sus scrofa), golden pheasant (Chrysolophus pictus), and porcupine (Hystrix hodgsoni). The results are (1) that there were significant differences in richness and RAI t among habitats; (2) Type4 habitat had the highest richness and RAI t while Type2 had the highest species diversity; giant pandas were found in these two habitats; (3) there were significant differences in species' activity during daytime and nighttime; and (4) differences appeared in habitat preference of the most abundant species. Takin and tufted deer preferred Type1, Himalayan goral preferred Type2, and golden pheasant preferred Type3. Type4 habitat was used by most animals. All these revealed that habitat heterogeneity plays an important role in species diversity and the importance for conservation.

  10. Spatial distribution & physicochemical characterization of the breeding habitats of Aedes aegypti in & around Kolkata, West Bengal, India.

    Science.gov (United States)

    Chatterjee, Soumendranath; Chakraborty, Arunima; Sinha, Shuvra Kanti

    2015-12-01

    Dengue infection is endemic in several areas and the dengue virus is transmitted by Aedes mosquitoes. Thus, it becomes important to understand the breeding ecology of dengue vector and characterize the physicochemical parameters of its breeding habitat. The objective of this study was to analyze the physicochemical parameters of the breeding habitat of the dengue vector and to find out the nutrient composition of the habitat in and around Kolkata, West Bengal. In addition, a geographic information system (GIS) was used to map the disease prone areas for its effective management and prevention. Water samples were collected from various breeding habitats of Aedes mosquitoes of Kolkata and adjoining areas and were analysed for various physicochemical properties like acidity, alkalinity, hardness, electrical conductivity, total dissolved solids, concentration of chloride (Cl - ), sodium (Na + ), potassium (K + ), fluoride (F - ) in relation to larval prevalence. Parameters like water pH, total dissolved solids, total hardness, electrical conductivity, concentration of chloride, sodium and potassium were seen to vary throughout the year. Certain parameters were found to be dependent on container type, like concentration of fluoride. Significant positive correlations were seen between per dip larval density and total dissolved solids (TDS) and electrical conductivity. Water pH, electrical conductivity, total dissolved solids were seen to play a major role in the ovipositional preferences. Container type did not seem to affect TDS. Tyres had the highest TDS in most of the cases. Nutrient composition like sodium concentration was mostly found in the coconut shells, potassium concentration also showed the same. Thus, container type and various parameters and nutrients play a major role in determining where a gravid female mosquito will lay its eggs. It was observed that by altering various chemical and physical properties of breeding habitats it was possible to control the

  11. Sound solutions for habitat monitoring

    Science.gov (United States)

    Mary M. Rowland; Lowell H. Suring; Christina D. Vojta

    2015-01-01

    For agencies and organizations to effectively manage wildlife, knowledge about the status and trend of wildlife habitat is critical. Traditional wildlife monitoring, however, has focused on populations rather than habitat, because ultimately population status drives long-term species viability. Still, habitat loss has contributed to the decline of nearly all at-risk...

  12. On Spatial Resolution in Habitat Models: Can Small-scale Forest Structure Explain Capercaillie Numbers?

    Directory of Open Access Journals (Sweden)

    Ilse Storch

    2002-06-01

    Full Text Available This paper explores the effects of spatial resolution on the performance and applicability of habitat models in wildlife management and conservation. A Habitat Suitability Index (HSI model for the Capercaillie (Tetrao urogallus in the Bavarian Alps, Germany, is presented. The model was exclusively built on non-spatial, small-scale variables of forest structure and without any consideration of landscape patterns. The main goal was to assess whether a HSI model developed from small-scale habitat preferences can explain differences in population abundance at larger scales. To validate the model, habitat variables and indirect sign of Capercaillie use (such as feathers or feces were mapped in six study areas based on a total of 2901 20 m radius (for habitat variables and 5 m radius sample plots (for Capercaillie sign. First, the model's representation of Capercaillie habitat preferences was assessed. Habitat selection, as expressed by Ivlev's electivity index, was closely related to HSI scores, increased from poor to excellent habitat suitability, and was consistent across all study areas. Then, habitat use was related to HSI scores at different spatial scales. Capercaillie use was best predicted from HSI scores at the small scale. Lowering the spatial resolution of the model stepwise to 36-ha, 100-ha, 400-ha, and 2000-ha areas and relating Capercaillie use to aggregated HSI scores resulted in a deterioration of fit at larger scales. Most importantly, there were pronounced differences in Capercaillie abundance at the scale of study areas, which could not be explained by the HSI model. The results illustrate that even if a habitat model correctly reflects a species' smaller scale habitat preferences, its potential to predict population abundance at larger scales may remain limited.

  13. Habitat Use Database - Groundfish Essential Fish Habitat (EFH) Habitat Use Database (HUD)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Habitat Use Database (HUD) was specifically designed to address the need for habitat-use analyses in support of groundfish EFH, HAPCs, and fishing and nonfishing...

  14. Measuring children's food preferences

    DEFF Research Database (Denmark)

    Olsen, Annemarie; Kildegaard, Heidi; Gabrielsen, Gorm

    2012-01-01

    The aim of this study is to investigate if children’s food preferences can be reliable measured by using pictures of foods presented on a computer screen in a conjoint layout.We investigate reproducibility (test–retest) and infer validity by comparison with traditional hedonic evaluations...... juices (tangible products), chosen to span the preference spectrum, were hedonically evaluated for appearance and taste. Finally, an actual product choice was performed by having the children choose between two buns and two juices.Results showed that the computer evaluationswith pictures of foods...... provided reproducible information about the children’s visual food preferences, which were in concordance with both hedonic measures and products choices, and can thus be considered valid....

  15. Habitats of Life

    Science.gov (United States)

    Dirk, Schulze-Makuch; Irwin, Louis N.

    There are four principal habitats in which life may exist - the surface of a planetary body, its subsurface, its atmosphere and space. From our own experience we know that life does exist on the surface of a planet, in its subsurface, and transiently at least in the atmosphere. Where it is present, it exists in a surprising diversity and in a variety of microhabitats, from deep caverns (Hose et al. 2000, Melim et al. 2001) to hydrothermal fluids and hot springs of various chemistries (Jannasch 1995, Rzonca and Schulze-Makuch 2002), to the frozen deserts of Antarctica (Friedmann 1982, Sun and Friedmann 1999). In this chapter we will elaborate on the principal habitats, the constraints they impose on life, and the possibilities they provide.

  16. Habitat monitoring needs for Arapaho NWR

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is the refuge's ideas on what level of monitoring is needed for each habitat objective. Habitat objectives include riparian habitat, wetland habitat,...

  17. Measuring acoustic habitats.

    Science.gov (United States)

    Merchant, Nathan D; Fristrup, Kurt M; Johnson, Mark P; Tyack, Peter L; Witt, Matthew J; Blondel, Philippe; Parks, Susan E

    2015-03-01

    1. Many organisms depend on sound for communication, predator/prey detection and navigation. The acoustic environment can therefore play an important role in ecosystem dynamics and evolution. A growing number of studies are documenting acoustic habitats and their influences on animal development, behaviour, physiology and spatial ecology, which has led to increasing demand for passive acoustic monitoring (PAM) expertise in the life sciences. However, as yet, there has been no synthesis of data processing methods for acoustic habitat monitoring, which presents an unnecessary obstacle to would-be PAM analysts. 2. Here, we review the signal processing techniques needed to produce calibrated measurements of terrestrial and aquatic acoustic habitats. We include a supplemental tutorial and template computer codes in matlab and r, which give detailed guidance on how to produce calibrated spectrograms and statistical analyses of sound levels. Key metrics and terminology for the characterisation of biotic, abiotic and anthropogenic sound are covered, and their application to relevant monitoring scenarios is illustrated through example data sets. To inform study design and hardware selection, we also include an up-to-date overview of terrestrial and aquatic PAM instruments. 3. Monitoring of acoustic habitats at large spatiotemporal scales is becoming possible through recent advances in PAM technology. This will enhance our understanding of the role of sound in the spatial ecology of acoustically sensitive species and inform spatial planning to mitigate the rising influence of anthropogenic noise in these ecosystems. As we demonstrate in this work, progress in these areas will depend upon the application of consistent and appropriate PAM methodologies.

  18. Enterprise Mac Managed Preferences

    CERN Document Server

    Marczak, Edward

    2010-01-01

    Many systems administrators on the Mac need a way to manage machine configuration after initial setup and deployment. Apple's Managed Preferences system (also known as MCX) is under-documented, often misunderstood, and sometimes outright unknown by sys admins. MCX is usually deployed in conjunction with an OS X server, but it can also be used in Windows environments or where no dedicated server exists at all. Enterprise Mac Managed Preferences is the definitive guide to Apple's Managed Client technology. With this book, you'll get the following: * An example-driven guide to Mac OS X Managed Pr

  19. Preferred provider organizations.

    Science.gov (United States)

    Davy, J D

    1984-05-01

    The 1980s has marked the beginning of a new alternative health care delivery system: the preferred provider organization ( PPO ). This system has developed from the health maintenance organization model and is predominant in California and Colorado. A PPO is a group of providers, usually hospitals and doctors, who agree to provide health care to subscribers for a negotiated fee that is usually discounted. Preferred provider organizations are subject to peer review and strict use controls in exchange for a consistent volume of patients and speedy turnaround on claims payments. This article describes the factors leading to the development of PPOs and the implications for occupational therapy.

  20. Habitat association and conservation implications of endangered Francois' langur (Trachypithecus francoisi.

    Directory of Open Access Journals (Sweden)

    Yajie Zeng

    Full Text Available Francois' langur (Trachypithecus francoisi is an endangered primate and endemic to the limestone forests of the tropical and subtropical zone of northern Vietnam and South-west China with a population of about 2,000 individuals. Conservation efforts are hampered by limited knowledge of habitat preference in its main distribution area. We surveyed the distribution of Francois' langur and modeled the relationship between the probability of use and habitat features in Mayanghe National Nature Reserve, Guizhou, China. The main objectives of this study were to provide quantitative information on habitat preference, estimating the availability of suitable habitat, and providing management guidelines for the effective conservation of this species. By comparing 92 used locations with habitat available in the reserve, we found that Francois' langur was mainly distributed along valleys and proportionally, used bamboo forests and mixed conifer-broadleaf forests more than their availability, whereas they tended to avoid shrubby areas and coniferous forests. The langur tended to occur at sites with lower elevation, steeper slope, higher tree canopy density, and a close distance to roads and water. The habitat occupancy probability was best modeled by vegetation type, vegetation coverage, elevation, slope degree, distances to nearest water, paved road, and farmland edge. The suitable habitat in this reserve concentrated in valleys and accounted for about 25% of the total reserve area. Our results showed that Francois' langur was not only restricted at the landscapes level at the regions with karst topography, limestone cliffs, and caves, but it also showed habitat preference at the local scale. Therefore, the protection and restoration of the langur preferred habitats such as mixed conifer-broadleaf forests are important and urgent for the conservation of this declining species.

  1. Armed Forces Food Preferences

    Science.gov (United States)

    1974-12-01

    PINEAPPLE CHEESE SALAD PINEAPPLE CREAM PIE PINEAPPLE JUICE PINEAPPLE PIE PINEAPPLE SUNDAE PINEAPPLE UPSIDE DOWN CAKE PIZZA PIZZA PLAIN MUFFINS...fruit and vegetable juices, orange, apple and grape flavors are preferred, with grapefruit, pineapple , tomato, and vegetable falling lower, and...include many popular items Oasagna, pizza , beef stew). Overall, entrees do not contribute heavily to the bottom ranking items. This is especially

  2. Patterns of Environmental Preference

    Science.gov (United States)

    Kaplan, Rachel

    1977-01-01

    This study sought to evaluate components of the Environmental Preference Questionnaire (EPQ). The 267 teenagers who completed the EPQ in this study also responded to questions relating to facets of self esteem and the reasons for selecting their favorite activities. (BT)

  3. Intergenerational Transmission of Preferences

    NARCIS (Netherlands)

    Bulte, E.H.; Horan, R.D.

    2011-01-01

    We propose a perfect empathy model of cultural transmission to capture the evolution of preferences in a population. Unlike existing imperfect empathy models, focusing on stable interior equilibria, we demonstrate that a corner outcome will eventuate. However, which corner outcome emerges is

  4. Immigrants' location preferences

    DEFF Research Database (Denmark)

    Damm, Anna Piil

    This paper exploits a spatial dispersal policy for refugee immigrants to estimate the importance of local and regional factors for refugees' location preferences. The main results of a mixed proportional hazard competing risks model are that placed refugees react to high regional unemployment...

  5. Modeling color preference using color space metrics.

    Science.gov (United States)

    Schloss, Karen B; Lessard, Laurent; Racey, Chris; Hurlbert, Anya C

    2017-07-27

    Studying color preferences provides a means to discover how perceptual experiences map onto cognitive and affective judgments. A challenge is finding a parsimonious way to describe and predict patterns of color preferences, which are complex with rich individual differences. One approach has been to model color preferences using factors from metric color spaces to establish direct correspondences between dimensions of color and preference. Prior work established that substantial, but not all, variance in color preferences could be captured by weights on color space dimensions using multiple linear regression. The question we address here is whether model fits may be improved by using different color metric specifications. We therefore conducted a large-scale analysis of color space models, and focused in-depth analysis on models that differed in color space (cone-contrast vs. CIELAB), coordinate system within the color space (Cartesian vs. cylindrical), and factor degrees (1st degree only, or 1st and 2nd degree). We used k-fold cross validation to avoid over-fitting the data and to ensure fair comparisons across models. The best model was the 2nd-harmonic Lch model ("LabC Cyl2"). Specified in CIELAB space, it included 1st and 2nd harmonics of hue (capturing opponency in hue preferences and simultaneous liking/disliking of both hues on an opponent axis, respectively), lightness, and chroma. These modeling approaches can be used to characterize and compare patterns for group averages and individuals in future datasets on color preference, or other measures in which correspondences between color appearance and cognitive or affective judgments may exist. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Comparison of gastropod mollusc (Apogastropoda: Hydrobiidae) habitats in two crater lakes in Nicaragua.

    Science.gov (United States)

    McCrary, Jeffrey K; Madsen, Henry; González, Liza; Luna, Inti; López, Lorenzo J

    2008-03-01

    The aquatic gastropod mollusc, Pyrgophorus coronatus, may perform an important role in the transmission of an emergent ocular pathology among fishes in Lake Apoyo, Nicaragua. This disease emerged after an introduction of tilapia (Oreochromis niloticus) and the subsequent loss of Chara sp. beds in the lake. We compared the mollusc population densities in three habitats (sandy/muddy substrates, rocks, and Chara vegetation) at varying depths (1.5, 10, 20, and 30 m) in two volcanic crater lakes in Nicaragua: Lake Apoyo and Lake Xiloa. where lower numbers of affected fishes were found and tilapia has not been introduced. Duplicate samples at 1.5 m depth were taken in each habitat monthly for a year, and triplicate samples for bathymetric analysis of snail populations were performed during August, 2005. Samples of fixed surface area were filtered in a 0.4 cm size screen and live snails were counted from each sample. The preferred snail habitat in both lakes, Chara beds, was vastly reduced in Lake Apoyo via consumption by introduced Nile tilapia (Oreochromis niloticus). Structureless sandy substrates (mean +/- standard error 3.1+/-1.3 ind/m2) had lower population densities than other habitats in Lake Xiloa (rocks 590.9+/-185.3 ind/m2; vegetation 3 686.5+/-698.2 ind/m2; ANOVA 1, pfilamentous algae coating this substrate. Snail population densities in Chara were lower at 20 m than more shallow depths in both lakes. Chara was not found at 1.5 m depth in Lake Apoyo, and was not present at 30 m depth in either lake. Shell lengths in rocky substrate in Lake Apoyo (3.62+/-0.12 mm) were greater than in Lake Xiloá (2.39+/-0.12 mm), suggesting differential snail predation levels in the lakes (pstructure in feeding areas for molluscivorous fishes. We found a significant preference toward Chara by the snails (p<0.05) and significant foraging pressure on them (p<0.05) in sandy/muddy substrates. The disruption of Chara by introduced tilapias in Lake Apoyo may play a role in the

  7. The effect of habitat fragmentation on cyclic population dynamics: a numerical study.

    Science.gov (United States)

    Strohm, S; Tyson, R

    2009-08-01

    Through four spatially explicit models, we investigate how habitat fragmentation affects cyclic predator-prey population dynamics. We use a Partial Differential Equation (PDE) framework to describe the dispersal of predators and prey in a heterogeneous landscape made of high quality and low quality habitat patches, subject to increasing fragmentation through habitat separation and/or habitat loss. Our results show that habitat fragmentation decreases the amplitude of the predator-prey population cycles while average population density is not as strongly affected in general. Beyond these simple trends however, the four models show differing responses to fragmentation, indicating that when making predictions about population survival and persistence in the face of habitat fragmentation, the choice of model is important. Our results may inform conservation efforts in fragmented habitats for cyclic species such as the snowshoe hare and Canada lynx.

  8. Varying energetic costs of Brent Geese along a continuum from aquatic to agricultural habitats: the importance of habitat-specific energy expenditure

    DEFF Research Database (Denmark)

    Clausen, Kevin Kuhlmann; Clausen, Preben; Fox, Anthony David

    2013-01-01

    We investigated how habitat-specific differences in behavioural patterns affected Brent Goose energetics along a feeding continuum from natural aquatic to inland agricultural habitats. Time-budgets showed that geese using salt-marshes and inland habitats spent more time flying, being aggressive...... and alert than birds feeding in aquatic areas, and also spent much less time roosting. Frequency of disturbance was found to be higher in terrestrial habitats compared to aquatic habitats. These stress-related behavioural differences between habitats highlight the vulnerability of the species associated...... with adapting to different food sources. Combining time-budgets with activity-specific BMR-multiplicators showed that activity-based metabolic rates ranged from 1.7 to 2.7 × BMR within habitats exploited by Brent Geese, and emphasized that aquatic areas represent the energetically least expensive foraging...

  9. Coastal vertebrate exposure to predicted habitat changes due to sea level rise

    Science.gov (United States)

    Hunter, Elizabeth A.; Nibbelink, Nathan P.; Alexander, Clark R.; Barrett, Kyle; Mengak, Lara F.; Guy, Rachel; Moore, Clinton; Cooper, Robert J.

    2015-01-01

    Sea level rise (SLR) may degrade habitat for coastal vertebrates in the Southeastern United States, but it is unclear which groups or species will be most exposed to habitat changes. We assessed 28 coastal Georgia vertebrate species for their exposure to potential habitat changes due to SLR using output from the Sea Level Affecting Marshes Model and information on the species’ fundamental niches. We assessed forecasted habitat change up to the year 2100 using three structural habitat metrics: total area, patch size, and habitat permanence. Almost all of the species (n = 24) experienced negative habitat changes due to SLR as measured by at least one of the metrics. Salt marsh and ocean beach habitats experienced the most change (out of 16 categorical land cover types) across the three metrics and species that used salt marsh extensively (rails and marsh sparrows) were ranked highest for exposure to habitat changes. Species that nested on ocean beaches (Diamondback Terrapins, shorebirds, and terns) were also ranked highly, but their use of other foraging habitats reduced their overall exposure. Future studies on potential effects of SLR on vertebrates in southeastern coastal ecosystems should focus on the relative importance of different habitat types to these species’ foraging and nesting requirements. Our straightforward prioritization approach is applicable to other coastal systems and can provide insight to managers on which species to focus resources, what components of their habitats need to be protected, and which locations in the study area will provide habitat refuges in the face of SLR.

  10. Cover of tall trees best predicts California spotted owl habitat

    Science.gov (United States)

    Malcolm P. North; Jonathan T. Kane; Van R. Kane; Gregory P. Asner; William Berigan; Derek J. Churchill; Scott Conway; R.J. Gutiérrez; Sean Jeronimo; John Keane; Alexander Koltunov; Tina Mark; Monika Moskal; Thomas Munton; Zachary Peery; Carlos Ramirez; Rahel Sollmann; Angela White; Sheila Whitmore

    2017-01-01

    Restoration of western dry forests in the USA often focuses on reducing fuel loads. In the range of the spotted owl, these treatments may reduce canopy cover and tree density, which could reduce preferred habitat conditions for the owl and other sensitive species. In particular, high canopy cover (≥70%) has been widely reported to be an important feature of spotted owl...

  11. The Current Status of the Tiger Beetle Species of the Coastal Habitats of Sri Lanka

    Directory of Open Access Journals (Sweden)

    C.D. Dangalle

    2014-01-01

    Full Text Available The species of tiger beetles inhabiting coastal habitats of Sri Lanka have not been studied for nearly three decades. We report the tiger beetle species currently occupying the coastal habitats of the island, their distribution, microhabitats and habitat preferences. Species and distributions reported nearly three decades from similar previous studies are also recorded. Southern, North-Western and Western coastal belts (n=22 of Sri Lanka were investigated for the presence of tiger beetles. Three species, Hypaetha biramosa, Lophyra (Lophyra catena, Myriochila (Monelica fastidiosa, were recorded from eleven locations. M. (Monelica fastidiosa was reported for the first time, in a single location of the Southern coastal belt. Habitat parameters of the locations and the length of the body and mandible between H. biramosa and L. (Lophyra catena, were statistically compared to determine specific habitat preferences of the two species. Analysis of Variance using Minitab 16.0 revealed that H. biramosa occupy habitats with high solar radiation (438-1023 w/m2 and soil salinity (0.0-0.1ppt while L. (Lophyra catena occupy habitats with low solar radiation (132-402 and non-saline soils (0.0 ppt. Similar length of mandibles of these two species indicated that habitat selection of the species was not based on prey utilization, but may depend on the intensity of solar radiation and the level of soil salinity of the locations.

  12. A modelling framework to assess the effect of pressures on river abiotic habitat conditions and biota

    NARCIS (Netherlands)

    Kail, Jochem; Guse, Björn; Radinger, Johannes; Schröder, Maria; Kiesel, Jens; Kleinhans, Maarten; Schuurman, Filip; Fohrer, Nicola; Hering, Daniel; Wolter, Christian

    2015-01-01

    River biota are affected by global reach-scale pressures, but most approaches for predicting biota of rivers focus on river reach or segment scale processes and habitats. Moreover, these approaches do not consider long-term morphological changes that affect habitat conditions. In this study, a

  13. Plant Habitat (PH)

    Science.gov (United States)

    Onate, Bryan

    2016-01-01

    The International Space Station (ISS) will soon have a platform for conducting fundamental research of Large Plants. Plant Habitat (PH) is designed to be a fully controllable environment for high-quality plant physiological research. PH will control light quality, level, and timing, temperature, CO2, relative humidity, and irrigation, while scrubbing ethylene. Additional capabilities include leaf temperature and root zone moisture and oxygen sensing. The light cap will have red (630 nm), blue (450 nm), green (525 nm), far red (730 nm) and broad spectrum white LEDs. There will be several internal cameras (visible and IR) to monitor and record plant growth and operations.

  14. Heat Waves, Droughts, and Preferences for Environmental Policy

    Science.gov (United States)

    Owen, Ann L.; Conover, Emily; Videras, Julio; Wu, Stephen

    2012-01-01

    Using data from a new household survey on environmental attitudes, behaviors, and policy preferences, we find that current weather conditions affect preferences for environmental regulation. Individuals who have recently experienced extreme weather (heat waves or droughts) are more likely to support laws to protect the environment. We find…

  15. Estimating exponential scheduling preferences

    DEFF Research Database (Denmark)

    Hjorth, Katrine; Börjesson, Maria; Engelson, Leonid

    time by maximising expected total utility over the day, their departure times are conditional on rates of utility derived at these locations. For forecasting and economic evaluation of planning alternatives, it is desirable to have simple forms of utility rates with few parameters. Several forms......Extended abstract Choice of departure time is a travel choice dimension that transportation planners often need to forecast in appraisal. A traveller may shift departure time in response to changes in expected travel time or travel time variability (TTV) or in response to time......-differentiated congestion pricing. The direction and size of such shifts depend on the traveller’s scheduling preferences, i.e. his preferences for travelling and being at the origin and destination at different times of day (Vickrey, 1973). Moreover, the traveller’s response to and economic value of TTV can be derived...

  16. Behavioural cues surpass habitat factors in explaining prebreeding resource selection by a migratory diving duck

    Science.gov (United States)

    O'Neil, Shawn T.; Warren, Jeffrey M.; Takekawa, John Y.; De La Cruz, Susan E. W.; Cutting, Kyle A.; Parker, Michael W.; Yee, Julie L.

    2014-01-01

    Prebreeding habitat selection in birds can often be explained in part by habitat characteristics. However, females may also select habitats on the basis of fidelity to areas of previous reproductive success or use by conspecifics. The relative influences of sociobehavioural attributes versus habitat characteristics in habitat selection has been primarily investigated in songbirds, while less is known about how these factors affect habitat selection processes in migratory waterfowl. Animal resource selection models often exhibit much unexplained variation; spatial patterns driven by social and behavioural characteristics may account for some of this. We radiomarked female lesser scaup, Aythya affinis, in the southwestern extent of their breeding range to explore hypotheses regarding relative roles of habitat quality, site fidelity and conspecific density in prebreeding habitat selection. We used linear mixed-effects models to relate intensity of use within female home ranges to habitat features, distance to areas of reproductive success during the previous breeding season and conspecific density. Home range habitats included shallow water (≤118 cm), moderate to high densities of flooded emergent vegetation/open water edge and open water areas with submerged aquatic vegetation. Compared with habitat features, conspecific female density and proximity to successful nesting habitats from the previous breeding season had greater influences on habitat use within home ranges. Fidelity and conspecific attraction are behavioural characteristics in some waterfowl species that may exert a greater influence than habitat features in influencing prebreeding space use and habitat selection within home ranges, particularly where quality habitat is abundant. These processes may be of critical importance to a better understanding of habitat selection in breeding birds.

  17. Spawning Habitat Studies of Hanford Reach Fall Chinook Salmon (Oncorhynchus tshawytscha), Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Geist, David R.; Arntzen, Evan V.; Chien, Yi-Ju (Pacific Northwest National Laboratory)

    2009-03-02

    The Pacific Northwest National Laboratory conducted this study for the Bonneville Power Administration (BPA) with funding provided through the Northwest Power and Conservation Council(a) and the BPA Fish and Wildlife Program. The study was conducted in the Hanford Reach of the Columbia River. The goal of study was to determine the physical habitat factors necessary to define the redd capacity of fall Chinook salmon that spawn in large mainstem rivers like the Hanford Reach and Snake River. The study was originally commissioned in FY 1994 and then recommissioned in FY 2000 through the Fish and Wildlife Program rolling review of the Columbia River Basin projects. The work described in this report covers the period from 1994 through 2004; however, the majority of the information comes from the last four years of the study (2000 through 2004). Results from the work conducted from 1994 to 2000 were covered in an earlier report. More than any other stock of Pacific salmon, fall Chinook salmon (Oncorhynchus tshawytscha) have suffered severe impacts from the hydroelectric development in the Columbia River Basin. Fall Chinook salmon rely heavily on mainstem habitats for all phases of their life cycle, and mainstem hydroelectric dams have inundated or blocked areas that were historically used for spawning and rearing. The natural flow pattern that existed in the historic period has been altered by the dams, which in turn have affected the physical and biological template upon which fall Chinook salmon depend upon for successful reproduction. Operation of the dams to produce power to meet short-term needs in electricity (termed power peaking) produces unnatural fluctuations in flow over a 24-hour cycle. These flow fluctuations alter the physical habitat and disrupt the cues that salmon use to select spawning sites, as well as strand fish in near-shore habitat that becomes dewatered. The quality of spawning gravels has been affected by dam construction, flood protection, and

  18. Vacant habitats in the Universe.

    Science.gov (United States)

    Cockell, Charles S

    2011-02-01

    The search for life on other planets usually makes the assumption that where there is a habitat, it will contain life. On the present-day Earth, uninhabited habitats (or vacant habitats) are rare, but might occur, for example, in subsurface oils or impact craters that have been thermally sterilized in the past. Beyond Earth, vacant habitats might similarly exist on inhabited planets or on uninhabited planets, for example on a habitable planet where life never originated. The hypothesis that vacant habitats are abundant in the Universe is testable by studying other planets. In this review, I discuss how the study of vacant habitats might ultimately inform an understanding of how life has influenced geochemical conditions on Earth. Copyright © 2010 Elsevier Ltd. All rights reserved.

  19. PREFERENCE, PRINCIPLE AND PRACTICE

    DEFF Research Database (Denmark)

    Skovsgaard, Morten; Bro, Peter

    2011-01-01

    journalists justify themselves and their work. This article introduces an analytical framework for understanding legitimacy in a journalistic context. A framework based on a review of material ranging from historical accounts to research articles, and book-length studies. The framework comprises three...... distinct, but interconnected categories*preference, principle, and practice. Through this framework, historical attempts to justify journalism and journalists are described and discussed in the light of the present challenges for the profession....

  20. Coaching preferences of athletes.

    Science.gov (United States)

    Terry, P C; Howe, B L

    1984-12-01

    The study examined the coaching preferences of 80 male and 80 female athletes, as measured by the Leadership Scale for Sports (Chelladurai and Saleh, 1978, 1980). In addition, it attempted to assess the applicability to sport of the Life-cycle and Path-goal theories of leadership. Comparisons between groups were made on the basis of sex, age, and type of sport. A MANOVA indicated that athletes in independent sports preferred more democratic behaviour (p less than .001) and less autocratic behaviour (p = .028) than athletes in interdependent sports. No differences in coaching preferences were found which could be attributed to the age or sex of the athlete, or the variability of the sports task. These results partially supported the Path-goal theory, but did not support the Life-cycle theory. Athletes of all groups tended to favour coaches who displayed training behaviour and rewarding behaviour "often", democratic behaviour and social support behaviour "occasionally", and autocratic behaviour "seldom". This consistency may be a useful finding for those organizations and institutions interested in preparing coaches.

  1. Partial gravity habitat study

    Science.gov (United States)

    Capps, Stephen; Lorandos, Jason; Akhidime, Eval; Bunch, Michael; Lund, Denise; Moore, Nathan; Murakawa, Kiosuke

    1989-01-01

    The purpose of this study is to investigate comprehensive design requirements associated with designing habitats for humans in a partial gravity environment, then to apply them to a lunar base design. Other potential sites for application include planetary surfaces such as Mars, variable-gravity research facilities, and a rotating spacecraft. Design requirements for partial gravity environments include locomotion changes in less than normal earth gravity; facility design issues, such as interior configuration, module diameter, and geometry; and volumetric requirements based on the previous as well as psychological issues involved in prolonged isolation. For application to a lunar base, it is necessary to study the exterior architecture and configuration to insure optimum circulation patterns while providing dual egress; radiation protection issues are addressed to provide a safe and healthy environment for the crew; and finally, the overall site is studied to locate all associated facilities in context with the habitat. Mission planning is not the purpose of this study; therefore, a Lockheed scenario is used as an outline for the lunar base application, which is then modified to meet the project needs. The goal of this report is to formulate facts on human reactions to partial gravity environments, derive design requirements based on these facts, and apply the requirements to a partial gravity situation which, for this study, was a lunar base.

  2. Habitat specialization through germination cueing

    DEFF Research Database (Denmark)

    Ten Brink, Dirk-Jan; Hendriksma, Harmen; Bruun, Hans Henrik

    2013-01-01

    This study examined the adaptive association between seed germination ecology and specialization to either forest or open habitats across a range of evolutionary lineages of seed plants, in order to test the hypotheses that (1) species' specialization to open vs. shaded habitats is consistently a...... accompanied by specialization in their regeneration niche; and (2) species are thereby adapted to utilize different windows of opportunity in time (season) and space (habitat)....

  3. Demographic variation and habitat specialization of tree species in a diverse tropical forest of Cameroon

    Directory of Open Access Journals (Sweden)

    David Kenfack

    2014-11-01

    Full Text Available Background Many tree species in tropical forests have distributions tracking local ridge-slope-valley topography. Previous work in a 50-ha plot in Korup National Park, Cameroon, demonstrated that 272 species, or 63% of those tested, were significantly associated with topography. Methods We used two censuses of 329,000 trees ≥1 cm dbh to examine demographic variation at this site that would account for those observed habitat preferences. We tested two predictions. First, within a given topographic habitat, species specializing on that habitat (‘residents’ should outperform species that are specialists of other habitats (‘foreigners’. Second, across different topographic habitats, species should perform best in the habitat on which they specialize (‘home’ compared to other habitats (‘away’. Species’ performance was estimated using growth and mortality rates. Results In hierarchical models with species identity as a random effect, we found no evidence of a demographic advantage to resident species. Indeed, growth rates were most often higher for foreign species. Similarly, comparisons of species on their home vs. away habitats revealed no sign of a performance advantage on the home habitat. Conclusions We reject the hypothesis that species distributions along a ridge-valley catena at Korup are caused by species differences in trees ≥1 cm dbh. Since there must be a demographic cause for habitat specialization, we offer three alternatives. First, the demographic advantage specialists have at home occurs at the reproductive or seedling stage, in sizes smaller than we census in the forest plot. Second, species may have higher performance on their preferred habitat when density is low, but when population builds up, there are negative density-dependent feedbacks that reduce performance. Third, demographic filtering may be produced by extreme environmental conditions that we did not observe during the census interval.

  4. A Dynamic Vegetation Senescence Indicator for Near-Real-Time Desert Locust Habitat Monitoring with MODIS

    Directory of Open Access Journals (Sweden)

    Cécile Renier

    2015-06-01

    Full Text Available Desert locusts (Schistocerca gregaria represent a major threat for agro-pastoral resources and food security over almost 30 million km2 from northern Africa to the Arabian peninsula and India. Given the differential food preferences of this insect pest and the extent and remoteness of the their distribution area, near-real-time remotely-sensed information on potential habitats support control operations by narrowing down field surveys to areas favorable for their development and prone to gregarization and outbreaks. The development of dynamic greenness maps, which detect the onset of photosynthetic vegetation, allowed national control centers to identify potential habitats to survey, as locusts prefer green and fresh vegetation. Their successful integration into the daily control operations led to a new need: the near-real-time identification of the onset of dryness, a synonym for the loss of habitat attractiveness, likely to be abandoned by locusts. The timely availability of this information would enable control centers to focus their surveys on areas more prone to gregarization, leading to more efficiency in the allocation of resources and in decision making. In this context, this work developed an original method to detect in near-real-time the onset of vegetation senescence. The design of the detection relies on the temporal behavior of two indices: the Normalized Difference Vegetation Index, depending on the green vegetation, and the Normalized Difference Tillage Index, sensitive to both green and dry vegetation. The method is demonstrated in Mauritania, an ever-affected country, with 10-day MODIS mean composites for the years 2010 and 2011. The discrimination performance of three classes (“growth”, “density reduction” and “drying” were analyzed for three classification methods: maximum likelihood (61.4% of overall accuracy, decision tree (71.5% and support vector machine (72.3%. The classification accuracy is heterogeneous in

  5. Slipping through the cracks: rubber plantation is unsuitable breeding habitat for frogs in Xishuangbanna, China.

    Directory of Open Access Journals (Sweden)

    Jocelyn E Behm

    Full Text Available Conversion of tropical forests into agriculture may present a serious risk to amphibian diversity if amphibians are not able to use agricultural areas as habitat. Recently, in Xishuangbanna Prefecture, Yunnan Province - a hotspot of frog diversity within China - two-thirds of the native tropical rainforests have been converted into rubber plantation agriculture. We conducted surveys and experiments to quantify habitat use for breeding and non-breeding life history activities of the native frog species in rainforest, rubber plantation and other human impacted sites. Rubber plantation sites had the lowest species richness in our non-breeding habitat surveys and no species used rubber plantation sites as breeding habitat. The absence of breeding was likely not due to intrinsic properties of the rubber plantation pools, as our experiments indicated that rubber plantation pools were suitable for tadpole growth and development. Rather, the absence of breeding in the rubber plantation was likely due to a misalignment of breeding and non-breeding habitat preferences. Analyses of our breeding surveys showed that percent canopy cover over pools was the strongest environmental variable influencing breeding site selection, with species exhibiting preferences for pools under both high and low canopy cover. Although rubber plantation pools had high canopy cover, the only species that bred in high canopy cover sites used the rainforest for both non-breeding and breeding activities, completing their entire life cycle in the rainforest. Conversely, the species that did use the rubber plantation for non-breeding habitat preferred to breed in low canopy sites, also avoiding breeding in the rubber plantation. Rubber plantations are likely an intermediate habitat type that 'slips through the cracks' of species habitat preferences and is thus avoided for breeding. In summary, unlike the rainforests they replaced, rubber plantations alone may not be able to support

  6. Latitudinal variation of diversity in European freshwater animals is not concordant across habitat types

    OpenAIRE

    Hof, Christian; Brändle, Martin; Brandl, Roland

    2008-01-01

    AimWe analysed the variation of species richness in the European freshwater faunaacross latitude. In particular, we compared latitudinal patterns in species richnessandß-diversity among species adapted to different habitat types.LocationEurope.MethodsWe compiled data on occurrence for 14,020 animal species across 25pre-defined biogeographical regions of European freshwaters from theLimnofaunaEuropaea. Furthermore, we extracted information on the habitat preferences ofspecies. We assigned spec...

  7. Pollinator diversity and reproductive success of Epipactis helleborine (L.) Crantz (Orchidaceae) in anthropogenic and natural habitats

    OpenAIRE

    Agnieszka Rewicz; Radomir Jaskuła; Tomasz Rewicz; Grzegorz Tończyk

    2017-01-01

    Background Epipactis helleborine is an Eurasian orchid species which prefers woodland environments but it may also spontaneously and successfully colonise human-made artificial and disturbed habitats such as roadsides, town parks and gardens. It is suggested that orchids colonising anthropogenic habitats are characterised by a specific set of features (e.g., large plant size, fast flower production). However, as it is not well known how pollinator diversity and reproductive success of E. hell...

  8. Modeling of Habitat and Foraging Behavior of Beaked Whales in the Southern California Bight

    Science.gov (United States)

    2015-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. FINAL REPORT Modeling of Habitat and Foraging Behavior of...whale distribution and foraging behavior and to describe inter-specific differences. We investigated spatio-temporal patterns for Cuvier’s beaked whale...distribution and foraging behavior and to describe inter-specific differences. Knowledge about foraging behavior and habitat preference and

  9. Invariant polar bear habitat selection during a period of sea ice loss

    OpenAIRE

    Wilson, Ryan R.; Regehr, Eric V.; Rode, Karyn D.; St Martin, Michelle

    2016-01-01

    Climate change is expected to alter many species' habitat. A species' ability to adjust to these changes is partially determined by their ability to adjust habitat selection preferences to new environmental conditions. Sea ice loss has forced polar bears (Ursus maritimus) to spend longer periods annually over less productive waters, which may be a primary driver of population declines. A negative population response to greater time spent over less productive water implies, however, that prey ...

  10. The Vocational Preference Inventory Scores and Environmental Preferences

    Science.gov (United States)

    Kunce, Joseph T.; Kappes, Bruno Maurice

    1976-01-01

    This study investigated the relationship between vocational interest measured by the Vocational Preference Inventory (VPI) and preferences of 175 undergraduates for structured or unstructured environments. Males having clear-cut preferences for structured situations had significantly higher Realistic-Conventional scores than those without…

  11. Distributive justice preferences and cultural factors in Romania

    Directory of Open Access Journals (Sweden)

    Carmen BUZEA

    2012-01-01

    Full Text Available The paper presents directions to investigate distributive justice preferences in Romania, at national and regional level. Based on previous findings, it was hypothesized that belonging to one of the six major cultural–historical Romanian regions (Moldavia, Transylvania, Wallachia, Banat, Dobruja, Oltenia may affect the preference for a fairness principle. The expectation is that people from Western Romania will prefer to a greater extent an equity-based allocation model, while people from Southern and Eastern parts of the country will prefer a distribution pattern with equality as a stronger predictor. A factorial survey design to investigate distributive justice in Romania is presented and discussed.

  12. Asotin Creek Instream Habitat Alteration Projects : Habitat Evaluation, Adult and Juvenile Habitat Utilization and Water Temperature Monitoring : 2001 Progress Report.

    Energy Technology Data Exchange (ETDEWEB)

    Bumgarner, Joseph D.

    2002-01-01

    Asotin Creek originates from a network of deeply incised streams on the slopes of the Blue Mountains of southeastern Washington. The watershed drains an area of 322 square miles that provides a mean annual flow of 74 cfs. The geomorphology of the watershed exerts a strong influence on biologic conditions for fish within the stream. Historic and contemporary land-use practices have had a profound impact on the kind, abundance, and distribution of anadromous salmonids in the watershed. Fish habitat in Asotin Creek and other local streams has been affected by agricultural development, grazing, tilling practices, logging, recreational activities and implementation of flood control structures (Neilson 1950). The Asotin Creek Model Watershed Master Plan was completed in 1994. The plan was developed by a landowner steering committee for the Asotin County Conservation District (ACCD), with technical support from various Federal, State and local entities. Actions identified within the plan to improve the Asotin Creek ecosystem fall into four main categories: (1) Stream and Riparian, (2) Forestland, (3) Rangeland, and (4) Cropland. Specific actions to be carried out within the stream and in the riparian area to improve fish habitat were: (1) create more pools, (2) increase the amount of large organic debris (LOD), (3) increase the riparian buffer zone through tree planting, and (4) increase fencing to limit livestock access. All of these actions, in combination with other activities identified in the Plan, are intended to stabilize the river channel, reduce sediment input, increase the amount of available fish habitat (adult and juvenile) and protect private property. Evaluation work described within this report was to document the success or failure of the program regarding the first two items listed (increasing pools and LOD). Beginning in 1996, the ACCD, with cooperation from local landowners and funding from Bonneville Power Administration began constructing instream

  13. Eelgrass habitat near Liberty Bay: Chapter 5

    Science.gov (United States)

    Dinicola, Richard S.; Takesue, Renee K.

    2015-01-01

    Seagrasses are a widespread type of marine flowering plants that grow in nearshore intertidal and subtidal zones. Seagrass beds are ecologically important because they affect physical, biological, and chemical characteristics of nearshore habitat, and they are sensitive to changes in coastal water quality (Stevenson and others, 1993; Koch, 2001; Martinez-Crego and others, 2008). Zostera marina, commonly known as eelgrass, is protected by a no-net-loss policy in Washington State where it may be used as spawning habitat by herring, a key prey species for salmon, seabirds, and marine mammals (Bargmann, 1998). Eelgrass forms broad meadows in shallow embayments or narrow fringes on open shorelines (Berry and others, 2003). Anthropogenic activities that increase turbidity, nutrient loading, and physical disturbance at the coast can result in dramatic seagrass decline (Ralph and others, 2006).

  14. Habitat loss and gain: Influence on habitat attractiveness for estuarine fish communities

    Science.gov (United States)

    Amorim, Eva; Ramos, Sandra; Elliott, Michael; Franco, Anita; Bordalo, Adriano A.

    2017-10-01

    Habitat structure and complexity influence the structuring and functioning of fish communities. Habitat changes are one of the main pressures affecting estuarine systems worldwide, yet the degree and rate of change and its impact on fish communities is still poorly understood. In order to quantify historical modifications in habitat structure, an ecohydrological classification system using physiotopes, i.e. units with homogenous abiotic characteristics, was developed for the lower Lima estuary (NW Portugal). Field data, aerial imagery, historical maps and interpolation methods were used to map input variables, including bathymetry, substratum (hard/soft), sediment composition, hydrodynamics (current velocity) and vegetation coverage. Physiotopes were then mapped for the years of 1933 and 2013 and the areas lost and gained over the 80 years were quantified. The implications of changes for the benthic and demersal fish communities using the lower estuary were estimated using the attractiveness to those communities of each physiotope, while considering the main estuarine habitat functions for fish, namely spawning, nursery, feeding and refuge areas and migratory routes. The lower estuary was highly affected due to urbanisation and development and, following a port/harbour expansion, its boundary moved seaward causing an increase in total area. Modifications led to the loss of most of its sandy and saltmarsh intertidal physiotopes, which were replaced by deeper subtidal physiotopes. The most attractive physiotopes for fish (defined as the way in which they supported the fish ecological features) decreased in area while less attractive ones increased, producing an overall lower attractiveness of the studied area in 2013 compared to 1933. The implications of habitat alterations for the fish using the estuary include potential changes in the nursery carrying capacity and the functioning of the fish community. The study also highlighted the poor knowledge of the impacts of

  15. Ecological value of macrophyte cover in creating habitat for microalgae (diatoms and zooplankton (rotifers and crustaceans in small field and forest water bodies.

    Directory of Open Access Journals (Sweden)

    Sofia Celewicz-Gołdyn

    Full Text Available Due to their small area and shallow depth ponds are usually treated as a single sampling unit, while various microhabitats offer different environmental conditions. Thus, we tested the effect of different habitat types typically found within small ponds on the microalgae and zooplankton communities. We found that submerged macrophytes have the strongest impact on microalgae and zooplankton communities out of all the analysed habitats. Some epontic diatoms (e.g. Fragilaria dilatata, Cymbella affinis and littoral-associated zooplankton species (e.g. Simocephalus vetulus, Lecane bulla were significantly related to elodeids. However, pelagic species (e.g. bosminids preferred less complex helophytes, which suggests that the most heterogeneous elodeid habitats were not an anti-predator shelter for cladocerans. Selection of different macrophyte types by taxonomically various organisms suggests that it is not only macrophyte cover that is desired for healthy aquatic environment but that a level of habitat mosaic is required to ensure the well-being of aquatic food webs. Species-specific preferences for different types of macrophytes indicate the high ecological value of macrophyte cover in ponds and a potential direction for the management of small water bodies towards maintaining a great variation of aquatic plants. Moreover, the type of surrounding landscape, reflecting human-induced disturbance (28 field ponds and natural catchment (26 forest ponds, significantly influenced only zooplankton, while diatoms were affected indirectly through the level of conductivity. Nutrient overload (higher content of TRP and increased conductivity in the field landscape contributed to a rise in microalgae (e.g. Amphora pediculus, Gomphonema parvulum and zooplankton (e.g. Thermocyclops oithonoides, Eubosmina coregoni abundance. An awareness of the responses of both components of plankton communities to environmental factors is necessary for maintaining the good state

  16. Ecological value of macrophyte cover in creating habitat for microalgae (diatoms) and zooplankton (rotifers and crustaceans) in small field and forest water bodies.

    Science.gov (United States)

    Celewicz-Gołdyn, Sofia; Kuczyńska-Kippen, Natalia

    2017-01-01

    Due to their small area and shallow depth ponds are usually treated as a single sampling unit, while various microhabitats offer different environmental conditions. Thus, we tested the effect of different habitat types typically found within small ponds on the microalgae and zooplankton communities. We found that submerged macrophytes have the strongest impact on microalgae and zooplankton communities out of all the analysed habitats. Some epontic diatoms (e.g. Fragilaria dilatata, Cymbella affinis) and littoral-associated zooplankton species (e.g. Simocephalus vetulus, Lecane bulla) were significantly related to elodeids. However, pelagic species (e.g. bosminids) preferred less complex helophytes, which suggests that the most heterogeneous elodeid habitats were not an anti-predator shelter for cladocerans. Selection of different macrophyte types by taxonomically various organisms suggests that it is not only macrophyte cover that is desired for healthy aquatic environment but that a level of habitat mosaic is required to ensure the well-being of aquatic food webs. Species-specific preferences for different types of macrophytes indicate the high ecological value of macrophyte cover in ponds and a potential direction for the management of small water bodies towards maintaining a great variation of aquatic plants. Moreover, the type of surrounding landscape, reflecting human-induced disturbance (28 field ponds) and natural catchment (26 forest ponds), significantly influenced only zooplankton, while diatoms were affected indirectly through the level of conductivity. Nutrient overload (higher content of TRP) and increased conductivity in the field landscape contributed to a rise in microalgae (e.g. Amphora pediculus, Gomphonema parvulum) and zooplankton (e.g. Thermocyclops oithonoides, Eubosmina coregoni) abundance. An awareness of the responses of both components of plankton communities to environmental factors is necessary for maintaining the good state of small

  17. Visual Perception of Habitats Adopted for Post-Mining Landscape Rehabilitation

    Science.gov (United States)

    Sklenicka, Petr; Molnarova, Kristina

    2010-09-01

    The study presented here focuses on visual preferences expressed by respondents for five relatively natural habitat types used in land reclamation projects in the North-West Bohemian brown coal basins (Czech Republic). Respondents evaluated the perceived beauty of the habitat types using a photograph questionnaire, on the basis of the positively skewed 6-point Likert scale. The order of the habitat types, from most beautiful to least beautiful, was: managed coniferous forest, wild deciduous forest, managed deciduous forest, managed mixed forest, and managed grassland. Higher visual preferences were indicated for older forest habitats (30-40 years old) than for younger habitats (10-20 years old). In addition, respondents preferred wild deciduous forest to managed deciduous forest. Managed grasslands and non-native managed coniferous forests were preferred by older people with a lower level of education and low income living in the post-mining area. On the other hand, native, wild deciduous forest was awarded the highest perceived beauty score by younger, more educated respondents with higher income, living outside the post-mining landscapes. The study confirms differences in the perception of various forms of land reclamation by residents vs. non-residents, and its findings also confirm the need for sociological research in post-mining landscapes within the process of designing rehabilitated landscapes. From the visual standpoint, the results of our study also support the current trend toward using natural succession in the reclamation of post-mining landscapes.

  18. Response of Anopheles gambiae s.l. (Diptera: Culicidae to larval habitat age in western Kenya highlands

    Directory of Open Access Journals (Sweden)

    Munga Stephen

    2013-01-01

    Full Text Available Abstract Background Larval control is of paramount importance in the reduction of vector populations. Previous observations have suggested that, larvae of Anopheles gambiae s.l occur more often in small temporary habitats while other studies showed that long-lasting stable habitats are more productive than unstable habitats. In addition, the physical and biological conditions and stability of larval habitats can change rapidly in natural conditions. Therefore, we examined the effect of larval habitat age on productivity, larval survival and oviposition preference of Anopheles gambiae. Methods We sampled the three different habitat ages (10, 20 and 30 days on a daily basis for a period of six months to determine mosquito larval abundance. In addition, we tested the effect of age of water (habitat age on the oviposition choice preference of An. gambiae, larval development time and survivorship, and wing lengths of emerging adults. Additionally, chlorophyll a and abundance of mosquito larval predators in these habitats were monitored. Results Anopheles gambiae s.l. larvae were significantly more abundant (P=0.0002 in habitats that were cleared every 10 days compared to the other habitats. In particular, there were 1.7 times more larvae in this habitat age compared to the ones that were cleared every 30 days. There were significantly (PAn. gambiae in the different habitat ages was statistically insignificant (P>0.05. Conclusion The current study confirmed that age of the habitat significantly influences the productivity of malaria vectors in western Kenya highlands. Given that malaria vectors were found in all habitats with varying ages of water, simple environmental methods of maintaining the drainage ditches in the valley bottoms can help reduce larval abundance of malaria vectors. Such inexpensive methods of controlling mosquito breeding could be promoted to supplement other vector control methods, especially in areas where scarce resources

  19. Context-dependent reproductive habitat selection: the interactive roles of structural complexity and cannibalistic conspecifics.

    Science.gov (United States)

    Sadeh, Asaf; Mangel, Marc; Blaustein, Leon

    2009-11-01

    Structural complexity generally reduces predation and cannibalism rates. Although the benefits from this effect vary among environmental contexts and through time, it has been the common explanation for high species abundance in complex habitats. We hypothesized that oviposition habitat selection for structural complexity depends on the expected trophic function of the progeny. In Salamandra infraimmaculata larvae, expected trophic function is dictated by their sequence of deposition. First cohorts cannibalize later-arriving cohorts, while all compete for shared prey resources. In a mesocosm experiment, we show that gravid salamanders facing conspecific-free pools preferred structurally simple habitats (no rocks), while females facing only pools with older conspecific larvae preferred complex habitats (with rocks). Context-dependent preference of habitat complexity for managing food/safety trade-offs may be extended from classic foraging patch decisions to breeding habitat selection. These trade-offs vary with dynamic larval processes such as priority effects and ontogenetic diet shifts, potentially leading to complex maternal parturition behaviours.

  20. Habitat availability vs. flow rate for the Pecos River, Part 1 : Depth and velocity availability.

    Energy Technology Data Exchange (ETDEWEB)

    James, Scott Carlton; Schaub, Edward F.; Jepsen, Richard Alan; Roberts, Jesse Daniel

    2004-02-01

    The waters of the Pecos River in New Mexico must be delivered to three primary users: (1) The Pecos River Compact: each year a percentage of water from natural river flow must be delivered to Texas; (2) Agriculture: Carlsbad Irrigation District has a storage and diversion right and Fort Sumner Irrigation District has a direct flow diversion right; and, (3) Endangered Species Act: an as yet unspecified amount of water is to support Pecos Bluntnose Shiner Minnow habitat within and along the Pecos River. Currently, the United States Department of Interior Bureau of Reclamation, the New Mexico Interstate Stream Commission, and the United States Department of the Interior Fish and Wildlife Service are studying the Pecos Bluntnose Shiner Minnow habitat preference. Preliminary work by Fish and Wildlife personnel in the critical habitat suggest that water depth and water velocity are key parameters defining minnow habitat preference. However, river flows that provide adequate preferred habitat to support this species have yet to be determined. Because there is a limited amount of water in the Pecos River and its reservoirs, it is critical to allocate water efficiently such that habitat is maintained, while honoring commitments to agriculture and to the Pecos River Compact. This study identifies the relationship between Pecos River flow rates in cubic feet per second (cfs) and water depth and water velocity.

  1. Maladaptive habitat selection of a migratory passerine bird in a human-modified landscape.

    Directory of Open Access Journals (Sweden)

    Franck A Hollander

    Full Text Available In human-altered environments, organisms may preferentially settle in poor-quality habitats where fitness returns are lower relative to available higher-quality habitats. Such ecological trapping is due to a mismatch between the cues used during habitat selection and the habitat quality. Maladaptive settlement decisions may occur when organisms are time-constrained and have to rapidly evaluate habitat quality based on incomplete knowledge of the resources and conditions that will be available later in the season. During a three-year study, we examined settlement decision-making in the long-distance migratory, open-habitat bird, the Red-backed shrike (Lanius collurio, as a response to recent land-use changes. In Northwest Europe, the shrikes typically breed in open areas under a management regime of extensive farming. In recent decades, Spruce forests have been increasingly managed with large-size cutblocks in even-aged plantations, thereby producing early-successional vegetation areas that are also colonised by the species. Farmland and open areas in forests create mosaics of two different types of habitats that are now occupied by the shrikes. We examined redundant measures of habitat preference (order of settlement after migration and distribution of dominant individuals and several reproductive performance parameters in both habitat types to investigate whether habitat preference is in line with habitat quality. Territorial males exhibited a clear preference for the recently created open areas in forests with higher-quality males settling in this habitat type earlier. Reproductive performance was, however, higher in farmland, with higher nest success, offspring quantity, and quality compared to open areas in forests. The results showed strong among-year consistency and we can therefore exclude a transient situation. This study demonstrates a case of maladaptive habitat selection in a farmland bird expanding its breeding range to human

  2. Marine fish diversity and habitat use along the western coast of the Black Sea

    Directory of Open Access Journals (Sweden)

    Viorel Dumitru Gavril

    2015-11-01

    I identified 34 species of fish in the Shabla-Tyulenovo area and 39 species in the Constanta area, of which 19 species preferred sandy bottoms, 21 rocky bottoms, 16 rocky habitats with Cystoseira sp., 19 man-made structures and 9 were pelagic. For 7 species habitat preferences could not be determined as a result of capture only by fishing. In conclusion, the scuba visual transects along with fishing methods provide a relevant image to the current state of the fish diversity along the western coast of the Black Sea.

  3. Relevance of multiple spatial scales in habitat models: A case study with amphibians and grasshoppers

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    Altmoos, Michael; Henle, Klaus

    2010-11-01

    Habitat models for animal species are important tools in conservation planning. We assessed the need to consider several scales in a case study for three amphibian and two grasshopper species in the post-mining landscapes near Leipzig (Germany). The two species groups were selected because habitat analyses for grasshoppers are usually conducted on one scale only whereas amphibians are thought to depend on more than one spatial scale. First, we analysed how the preference to single habitat variables changed across nested scales. Most environmental variables were only significant for a habitat model on one or two scales, with the smallest scale being particularly important. On larger scales, other variables became significant, which cannot be recognized on lower scales. Similar preferences across scales occurred in only 13 out of 79 cases and in 3 out of 79 cases the preference and avoidance for the same variable were even reversed among scales. Second, we developed habitat models by using a logistic regression on every scale and for all combinations of scales and analysed how the quality of habitat models changed with the scales considered. To achieve a sufficient accuracy of the habitat models with a minimum number of variables, at least two scales were required for all species except for Bufo viridis, for which a single scale, the microscale, was sufficient. Only for the European tree frog ( Hyla arborea), at least three scales were required. The results indicate that the quality of habitat models increases with the number of surveyed variables and with the number of scales, but costs increase too. Searching for simplifications in multi-scaled habitat models, we suggest that 2 or 3 scales should be a suitable trade-off, when attempting to define a suitable microscale.

  4. Patch dynamics and the timing of colonization-abandonment events by male Kirtland's Warblers in an early succession habitat

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    Deahn M. Donner; Christine A. Ribic; John R. Probst

    2010-01-01

    Habitat colonization and abandonment affects the distribution of a species in space and time, ultimately influencing the duration of time habitat is used and the total area of habitat occupied in any given year. Both aspects have important implications to long-term conservation planning. The importance of patch isolation and area to colonization-extinction events is...

  5. The shared preference niche of sympatric Asiatic black bears and sun bears in a tropical forest mosaic.

    Directory of Open Access Journals (Sweden)

    Robert Steinmetz

    Full Text Available BACKGROUND: Ecologically similar species often coexist by partitioning use of habitats or resources. Such partitioning can occur through divergent or shared niches. We investigated overlap in habitat use and spatial co-occurrence by sympatric Asiatic black bears and sun bears in three habitats in Thailand, and thereby assessed which niche model best accounts for their coexistence. METHODS/PRINCIPAL FINDINGS: We used density of species-specific signs to assess habitat use. Signs of both bear species occurred in all three habitats, and on >60% of sampling transects. Both species fed mostly on fruit; insect feeding signs were uncommon, and were mostly from sun bears. Significant differences in habitat use occurred only in montane forest, the habitat in which fruit was most abundant; incidence of black bear sign there was six times higher than that of sun bears. Habitat use was similar between the two species in the other habitats, which comprised 85% of the area. Of 10 habitat attributes examined, fruiting tree density was the best predictor of occurrence for both species. Models that included interspecific competition (fresh foraging activity of the other species were less supported than the top models without competition. CONCLUSIONS/SIGNIFICANCE: Bear species co-occurrence at both coarse and fine spatial scales and use of the same resources (fruit trees indicated common niche preferences. However, their habitat use differed in ways expected from their physical differences: larger black bears dominated in the most fruit-rich habitat, and smaller sun bears used less-preferred insects. These results indicate broadly overlapping fundamental niches combined with asymmetric competition-features consistent with the concept of shared preference niches. This model of the niche has received little attention in ecology, but appears to be relatively common in nature.

  6. The shared preference niche of sympatric Asiatic black bears and sun bears in a tropical forest mosaic.

    Science.gov (United States)

    Steinmetz, Robert; Garshelis, David L; Chutipong, Wanlop; Seuaturien, Naret

    2011-01-20

    Ecologically similar species often coexist by partitioning use of habitats or resources. Such partitioning can occur through divergent or shared niches. We investigated overlap in habitat use and spatial co-occurrence by sympatric Asiatic black bears and sun bears in three habitats in Thailand, and thereby assessed which niche model best accounts for their coexistence. We used density of species-specific signs to assess habitat use. Signs of both bear species occurred in all three habitats, and on >60% of sampling transects. Both species fed mostly on fruit; insect feeding signs were uncommon, and were mostly from sun bears. Significant differences in habitat use occurred only in montane forest, the habitat in which fruit was most abundant; incidence of black bear sign there was six times higher than that of sun bears. Habitat use was similar between the two species in the other habitats, which comprised 85% of the area. Of 10 habitat attributes examined, fruiting tree density was the best predictor of occurrence for both species. Models that included interspecific competition (fresh foraging activity of the other species) were less supported than the top models without competition. Bear species co-occurrence at both coarse and fine spatial scales and use of the same resources (fruit trees) indicated common niche preferences. However, their habitat use differed in ways expected from their physical differences: larger black bears dominated in the most fruit-rich habitat, and smaller sun bears used less-preferred insects. These results indicate broadly overlapping fundamental niches combined with asymmetric competition-features consistent with the concept of shared preference niches. This model of the niche has received little attention in ecology, but appears to be relatively common in nature.

  7. The Shared Preference Niche of Sympatric Asiatic Black Bears and Sun Bears in a Tropical Forest Mosaic

    Science.gov (United States)

    Steinmetz, Robert; Garshelis, David L.; Chutipong, Wanlop; Seuaturien, Naret

    2011-01-01

    Background Ecologically similar species ofte