Cīrule, Dina; Krama, Tatjana; Krams, Ronalds; Elferts, Didzis; Kaasik, Ants; Rantala, Markus J.; Mierauskas, Pranas; Luoto, Severi; Krams, Indrikis A.
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.
... resultant intensive agricultural projects that follow. Such impacts have resulted in a decline in both bird habitats and biodiversity. Of particular concern are the areas important to all our endemic bird species, and already we are witnessing a series of very worrying developments. Taking each. Scopus 32: 27–34, June 2013 ...
Established in 2009, the Green Energy Act aims to increase the use of renewable energy sources including wind, water, solar and bioenergy in Ontario. The development of these resources is a major component of the province's plan, which aims to mitigate the contribution to climate change and to involve the Ontario's economy in the improvement of the quality of the environment. The Green Energy Act also considers as important the implementation of a coordinated provincial approval process, suggesting the integration of all Ministry requirements into a unique process during the evaluation of newly proposed renewable energy projects. The Ministry of the Environment's Renewable Energy Approval Regulation details the requirements for wind power projects involving significant natural features. Birds are an important part of Ontario's biodiversity and, according to the Ministry of Natural Resources, their habitats are considered as significant wildlife habitat (SWH). The Renewable Energy Approval Regulation and this guideline are meant to provide elements and guidance in order to protect bird SWH during the selection of a location of wind power facilities. . 27 refs., 1 tab., 2 figs.
Laura P. Ponce-Calderón Ponce-Calderón; Dante A. Rodríguez-Trejo; Beatriz C. Aguilar-Váldez; Elvia. López-Pérez
To assess the impact of different-severity wildfires on bird habitat, habitat quality was determined by analyzing the degree of richness association, abundance and diversity of bird species and vegetation structure (richness, abundance, diversity and coverage). These attributes were quantified with four sampling sites for birds and five for quadrant-centered points...
Sprague, Terry; Harrington, M. Elizabeth; Krogh, Carmen M. E.
Bird kill rate and disruption of habitat has been reported when industrial wind turbines are introduced into migratory bird paths or other environments. While the literature could be more complete regarding the documentation of negative effects on birds and bird habitats during the planning, construction, and operation of wind power projects,…
Deborah M. Finch
Bird-habitat relationships along a riparian gradient in southeastern Wyoming were examined from 1982 to 1984. Breeding birds were spot-mapped on ten study grids established over an elevational cline of 933 m. Habitat analyses indicated significant trends of decreasing vegetational complexity from low to high elevations, with declines in number of habitat layers, and...
Study conducted in the forested bitumen belt of Ode-Irele, Ondo state, Nigeria evaluated habitat use by birds using 20- minutes birds point count to a radius of 30 meters, carried out in six selected habitats. The vegetation cover was sampled using 5x5-meters and 1m2quadrants. Data collected were subjected to t-test of ...
Beerens, James M.; Frederick, Peter C; Noonburg, Erik G; Gawlik, Dale E.
Determining habitat quality for wildlife populations requires relating a species' habitat to its survival and reproduction. Within a season, species occurrence and density can be disconnected from measures of habitat quality when resources are highly seasonal, unpredictable over time, and patchy. Here we establish an explicit link among dynamic selection of changing resources, spatio-temporal species distributions, and fitness for predictive abundance and occurrence models that are used for short-term water management and long-term restoration planning. We used the wading bird distribution and evaluation models (WADEM) that estimate (1) daily changes in selection across resource gradients, (2) landscape abundance of flocks and individuals, (3) conspecific foraging aggregation, and (4) resource unit occurrence (at fixed 400 m cells) to quantify habitat quality and its consequences on reproduction for wetland indicator species. We linked maximum annual numbers of nests detected across the study area and nesting success of Great Egrets (Ardea alba), White Ibises (Eudocimus albus), and Wood Storks (Mycteria americana) over a 20-year period to estimated daily dynamics of food resources produced by WADEM over a 7490 km2 area. For all species, increases in predicted species abundance in March and high abundance in April were strongly linked to breeding responses. Great Egret nesting effort and success were higher when birds also showed greater conspecific foraging aggregation. Synthesis and applications: This study provides the first empirical evidence that dynamic habitat selection processes and distributions of wading birds over environmental gradients are linked with reproductive measures over periods of decades. Further, predictor variables at a variety of temporal (daily-multiannual) resolutions and spatial (400 m to regional) scales effectively explained variation in ecological processes that change habitat quality. The process used here allows managers to develop
Using habitat stratification, birds were surveyed along transects in tidal and supralittoral sub-habitats using DISTANCE sampling protocol, and along the river by encounter rates to determine abundance and species richness. Indices of human activity as well as habitat structure parameters including ground cover, plant ...
Full Text Available Bird migration has attracted an increasing attention. The study of habitats has played a vital role in the birds migratory. Previous researches, however, have encountered many problems, such as great limitations on research methods, low data utilization rate, statistics-focused and ineffective data processing and analysis methods. In this paper, the algorithm of habitat discovery is put forward by using computer’s data-mining technology based on the spatio-temporal characteristics of bird-watching data. First the algorithm detects and eliminates duplicate data to guarantee data standardization. Then density-based clustering algorithms are used to identify habitats where birds gathered. Finally the habitats of birds migratory are discovered.
Lerman, Susannah B.; Nislow, Keith H.; Nowak, David J.; DeStefano, Stephen; King, David I.; Jones-Farrand, D. Todd
The alteration of forest cover and the replacement of native vegetation with buildings, roads, exotic vegetation, and other urban features pose one of the greatest threats to global biodiversity. As more land becomes slated for urban development, identifying effective urban forest wildlife management tools becomes paramount to ensure the urban forest provides habitat to sustain bird and other wildlife populations. The primary goal of this study was to integrate wildlife suitability indices to an existing national urban forest assessment tool, i-Tree. We quantified available habitat characteristics of urban forests for ten northeastern U.S. cities, and summarized bird habitat relationships from the literature in terms of variables that were represented in the i-Tree datasets. With these data, we generated habitat suitability equations for nine bird species representing a range of life history traits and conservation status that predicts the habitat suitability based on i-Tree data. We applied these equations to the urban forest datasets to calculate the overall habitat suitability for each city and the habitat suitability for different types of land-use (e.g., residential, commercial, parkland) for each bird species. The proposed habitat models will help guide wildlife managers, urban planners, and landscape designers who require specific information such as desirable habitat conditions within an urban management project to help improve the suitability of urban forests for birds.
Sogge, M.K.; Sferra, S.J.; Paxton, E.H.
Exotic vegetation has become a major habitat component in many ecosystems around the world, sometimes dramatically changing the vegetation community structure and composition. In the southwestern United States, riparian ecosystems are undergoing major changes in part due to the establishment and spread of the exotic Tamarix (saltcedar, tamarisk). There are concerns about the suitability of Tamarix as habitat for birds. Although Tamarix habitats tend to support fewer species and individuals than native habitats, Arizona Breeding Bird Atlas data and Birds of North America accounts show that 49 species use Tamarix as breeding habitat. Importantly, the relative use of Tamarix and its quality as habitat vary substantially by geographic location and bird species. Few studies have examined how breeding in Tamarix actually affects bird survivorship and productivity; recent research on Southwestern Willow Flycatchers has found no negative effects from breeding in Tamarix habitats. Therefore, the ecological benefits and costs of Tamarix control are difficult to predict and are likely to be species specific and site specific. Given the likelihood that high-quality native riparian vegetation will not develop at all Tamarix control sites, restoration projects that remove Tamarix but do not assure replacement by high-quality native habitat have the potential to reduce the net riparian habitat value for some local or regional bird populations. Therefore, an assessment of potential negative impacts is important in deciding if exotic control should be conducted. In addition, measurable project objectives, appropriate control and restoration techniques, and robust monitoring are all critical to effective restoration planning and execution. ?? 2008 Society for Ecological Restoration International.
Scott H. Stoleson
Many birds that are experiencing population declines require extensive tracts of mature forest habitat for breeding. Recent work suggests that at least some may shift their habitat use to early-successional areas after nesting but before migration. I used constant-effort mist netting in regenerating clearcuts (4-8 years postcut) and dense mature-forest understories to...
Sieges, Mason L.; Smolinsky, Jaclyn A.; Baldwin, Michael J.; Barrow, Wylie C.; Randall, Lori A.; Buler, Jeffrey J.
In response to the Deepwater Horizon oil spill in spring 2010, the Natural Resources Conservation Service implemented the Migratory Bird Habitat Initiative (MBHI) to provide temporary wetland habitat for migrating and wintering waterfowl, shorebirds, and other birds along the northern Gulf of Mexico via managed flooding of agricultural lands. We used weather-surveillance radar to conduct broad regional assessments of bird response to MBHI activities within the Mississippi Alluvial Valley and the West Gulf Coastal Plain. Across both regions, birds responded positively to MBHI management by exhibiting greater relative bird densities within sites relative to pre-management conditions in prior years and relative to surrounding non-flooded agricultural lands. Bird density at MBHI sites was generally greatest during winter for both regions. Unusually high flooding in the years prior to implementation of the MBHI confounded detection of overall changes in remotely sensed soil wetness across sites. The magnitude of bird response at MBHI sites compared to prior years and to non-flooded agricultural lands was generally related to the surrounding landscape context: proximity to areas of high bird density, amount of forested wetlands, emergent marsh, non-flooded agriculture, or permanent open water. However, these relationships varied in strength and direction between regions and seasons, a finding which we attribute to differences in seasonal bird composition and broad regional differences in landscape configuration and composition. We detected greater increases in relative bird use at sites in closer proximity to areas of high bird density during winter in both regions. Additionally, bird density was greater during winter at sites with more emergent marsh in the surrounding landscape. Thus, bird use of managed wetlands could be maximized by enrolling lands located near areas of known bird concentration and within a mosaic of existing wetlands. Weather-radar observations
Foraging behavior often reflects food availability in predictable ways. For example, in habitats where food availability is high, predators should attack prey more often and move more slowly than in habitats where food availability is low. To assess relative food availability and habitat quality, I studied the foraging behavior of breeding Prothonotary Warblers (Protonotaria citrea) in two forest habitat types, cypress-gum swamp forest and coastal-plain levee forest. I quantified foraging behavior with focal animal sampling and continuous recording during foraging bouts. I measured two aspects of foraging behavior: 1) prey attack rate (attacks per minute), using four attack maneuvers (glean, sally, hover, strike), and 2) foraging speed (movements per minute), using three types of movement (hop, short flight [???1 m], long flight [>1 m]). Warblers attacked prey more often in cypress-gum swamp forest than in coastal-plain levee forest. Foraging speed, however, was not different between habitats. I also measured foraging effort (% time spent foraging) and relative frequency of attack maneuvers employed in each habitat; neither of these variables was influenced by forest type. I conclude that Prothonotary Warblers encounter more prey when foraging in cypress-gum swamps than in coastal-plain levee forest, and that greater food availability results in higher density and greater reproductive success for birds breeding in cypress-gum swamp.
David Anthony. Kirk
Full Text Available Many common bird species have declined as a result of agricultural intensification and this could be mitigated by organic farming. We paired sites for habitat and geographical location on organic and nonorganic farms in Ontario, Canada to test a priori predictions of effects on birds overall, 9 guilds and 22 species in relation to candidate models for farming practices (13 variables, local habitat features (12 variables, or habitat features that influence susceptibility to predation. We found that: (1 Overall bird abundance, but not richness, was significantly (p < 0.05 higher on organic sites (mean 43.1 individuals per site than nonorganic sites (35.8 individuals per site. Significantly more species of birds were observed for five guilds, including primary grassland birds, on organic vs. nonorganic sites. No guild had higher richness or abundance on nonorganic farms; (2 Farming practice models were the best (Î"AIC < 4 for abundance of birds overall, primary grassland bird richness, sallier aerial insectivore richness and abundance, and abundance of ground nesters; (3 Habitat models were the best for overall richness, Neotropical migrant abundance, richness and abundance of Ontario-USA-Mexico (short-distance migrants and resident richness; (4 Predation models were the best for richness of secondary grassland birds and ground feeders; (5 A combination of variables from the model types were best for richness or abundance overall, 13 of 18 guilds (richness and abundance and 16 of 22 species analyzed. Five of 10 farming practice variables (including herbicide use, organic farm type and 9 of 13 habitat variables (including hedgerow length, proportion of hay were significant in best models. Risk modeling indicated that herbicide use could decrease primary grassland birds by one species (35% decline from 3.4 to 2.3 species per site. Organic farming could benefit species of conservation concern by 49% (an increase from 7.6 to 11.4 grassland birds. An
John M. Tirpak; D. Todd Jones-Farrand; Frank R., III Thompson; Daniel J. Twedt; William B., III Uihlein
Habitat Suitability Index (HSI) models were developed to assess habitat quality for 40 priority bird species in the Central Hardwoods and West Gulf Coastal Plain/Ouachitas Bird Conservation Regions. The models incorporated both site and landscape environmental variables from one of six nationally consistent datasets. Potential habitat was first defined from unique...
Ryan T. DiGaudio
Full Text Available To address the loss of wetlands and riparian forests in California, private lands habitat programs are available through U.S. federal and state government agencies to help growers, ranchers and other private landowners create and enhance wildlife habitat. The programs provide financial and technical assistance for implementing conservation practices. To evaluate the benefits of these programs for wildlife, we examined bird use of private wetlands, postharvest flooded croplands and riparian forests enrolled in habitat programs in the Central Valley and North Coast regions of California. We found that private Central Valley wetlands supported 181 bird species during the breeding season. During fall migration, postharvest flooded croplands supported wetland-dependent species and a higher density of shorebirds than did semipermanent wetlands. At the riparian sites, bird species richness increased after restoration. These results demonstrated that the programs provided habitat for the species they were designed to protect; a variety of resident and migratory bird species used the habitats, and many special status species were recorded at the sites.
McLaren, James D.; Buler, Jeffrey J.; Schreckengost, Tim; Smolinsky, Jaclyn A.; Boone, Matthew; van Loon, E. Emiel; Dawson, Deanna K.; Walters, Eric L.
With many of the world's migratory bird populations in alarming decline, broad-scale assessments of responses to migratory hazards may prove crucial to successful conservation efforts. Most birds migrate at night through increasingly light-polluted skies. Bright light sources can attract airborne migrants and lead to collisions with structures, but might also influence selection of migratory stopover habitat and thereby acquisition of food resources. We demonstrate, using multi-year weather radar measurements of nocturnal migrants across the northeastern U.S., that autumnal migrant stopover density increased at regional scales with proximity to the brightest areas, but decreased within a few kilometers of brightly-lit sources. This finding implies broad-scale attraction to artificial light while airborne, impeding selection for extensive forest habitat. Given that high-quality stopover habitat is critical to successful migration, and hindrances during migration can decrease fitness, artificial lights present a potentially heightened conservation concern for migratory bird populations.
Dawson, D.K.; Robbins, C.S.; Sauer, J.R.
We used mist nets and point counts to sample bird populations in 61 sites in Belize during January-March of 1987-1991. Sites were classified as forest, second growth, woody agricultural crops (citrus, mango, cacao, and cashew), or non-woody agricultural crops (rice and sugar cane). We evaluated patterns of occurence of wintering temperate migrant bird species in these habitats. Mist net captures of 22 of 31 migrant species differed significantly among habitats. Of these, 13 species were captured more frequently in the agricultural habitats. American Redstart (Setophaga ruticilla), Black-and-white Warbler (Mniotilta varia), and Magnolia Warbler (Dendroica magnolia) were among the species captured most frequently in woody agricultural habitats; captures of Common Yellowthroat (Geothlypis trichas), Indigo Bunting (Passerina cyanea), and Northern (lcterus galbula) and Orchard orioles (I. spur/anus) were highest in the non-woody agricultural sites. We relate these occurrence patterns to trends in breeding populations in North America. While count data provide a wide picture of winter habitat distribution of migrants, more intensive work is necessary to assess temporal and geographic variation of migrant bird use of agricultural habitats.
In light of reported declines in grassland bird populations in North America, information about their use of airfield habitats can help inform management decisions in the context of conflicting objectives of minimizing wildlife-aircraft collisions and helping to conserve grasslan...
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
Petit, L.J.; Petit, D.R.; Christian, D.G.; Powell, Hugo D.W.
Only a small proportion of land can realistically be protected as nature reserves and thus conservation efforts also must focus on the ecological value of agroecosystems and developed areas surrounding nature reserves. In this study, avian communities were surveyed in 11 habitat types in central Panama, across a gradient from extensive forest to intensive agricultural land uses, to examine patterns of species richness and abundance and community composition. Wooded habitats, including extensive and fragmented forests, shade coffee plantations, and residential areas supported the most species and individuals. Nearctic-Neotropical migratory species were most numerous in lowland forest fragments, shade coffee, and residential areas. Introduced Pinus caribbea and sugar cane plantations supported the fewest species compared to all other habitats. Cattle pastures left fallow for less than two years supported more than twice as many total species as actively grazed pastures, such that species richness in fallow pastures was similar to that found in wooded habitats. Community similarities were relatively low among all habitat types (none exceeding the observed 65% similarity between extensive and fragmented lowland forests), but communities in shade coffee and residential areas were 43% and 54% similar to lowland forest fragments, respectively. Fallow pastures and residential areas shared 60% of their species. Bird communities in shade coffee and residential areas were characterized by higher proportions of frugivorous and nectarivorous species than in native forests. These same guilds also were better represented in fallow than in grazed pastures. Raptors and piscivorous species were most prevalent in cattle pastures and rice fields. These results, though based upon only species richness and abundance, demonstrate that many human-altered habitats have potential ecological value for birds, and conservation efforts in tropical areas should focus greater attention on
James M Beerens
Full Text Available Species distribution models (SDM link species occurrence with a suite of environmental predictors and provide an estimate of habitat quality when the variable set captures the biological requirements of the species. SDMs are inherently more complex when they include components of a species' ecology such as conspecific attraction and behavioral flexibility to exploit resources that vary across time and space. Wading birds are highly mobile, demonstrate flexible habitat selection, and respond quickly to changes in habitat quality; thus serving as important indicator species for wetland systems. We developed a spatio-temporal, multi-SDM framework using Great Egret (Ardea alba, White Ibis (Eudocimus albus, and Wood Stork (Mycteria Americana distributions over a decadal gradient of environmental conditions to predict species-specific abundance across space and locations used on the landscape over time. In models of temporal dynamics, species demonstrated conditional preferences for resources based on resource levels linked to differing temporal scales. Wading bird abundance was highest when prey production from optimal periods of inundation was concentrated in shallow depths. Similar responses were observed in models predicting locations used over time, accounting for spatial autocorrelation. Species clustered in response to differing habitat conditions, indicating that social attraction can co-vary with foraging strategy, water-level changes, and habitat quality. This modeling framework can be applied to evaluate the multi-annual resource pulses occurring in real-time, climate change scenarios, or restorative hydrological regimes by tracking changing seasonal and annual distribution and abundance of high quality foraging patches.
Beerens, James M.; Noonberg, Erik G.; Gawlik, Dale E.
Species distribution models (SDM) link species occurrence with a suite of environmental predictors and provide an estimate of habitat quality when the variable set captures the biological requirements of the species. SDMs are inherently more complex when they include components of a species' ecology such as conspecific attraction and behavioral flexibility to exploit resources that vary across time and space. Wading birds are highly mobile, demonstrate flexible habitat selection, and respond quickly to changes in habitat quality; thus serving as important indicator species for wetland systems. We developed a spatio-temporal, multi-SDM framework using Great Egret (Ardea alba), White Ibis (Eudocimus albus), and Wood Stork (Mycteria Americana) distributions over a decadal gradient of environmental conditions to predict species-specific abundance across space and locations used on the landscape over time. In models of temporal dynamics, species demonstrated conditional preferences for resources based on resource levels linked to differing temporal scales. Wading bird abundance was highest when prey production from optimal periods of inundation was concentrated in shallow depths. Similar responses were observed in models predicting locations used over time, accounting for spatial autocorrelation. Species clustered in response to differing habitat conditions, indicating that social attraction can co-vary with foraging strategy, water-level changes, and habitat quality. This modeling framework can be applied to evaluate the multi-annual resource pulses occurring in real-time, climate change scenarios, or restorative hydrological regimes by tracking changing seasonal and annual distribution and abundance of high quality foraging patches.
Rafael A. Dias
Full Text Available Nearly all remnants of temperate grasslands in southeastern South America are used for livestock ranching and are subject to habitat degradation resulting from this activity. Exploring how habitat features affect the composition of grassland avifaunal communities is a first step to understand how current cattle-ranching management practices impact avian diversity. We used canonical ordination to test for relationships between five habitat variables and the composition of the bird community in coastal grasslands in southern Brazil. We sampled pastures with different heights, from overgrazed short-grass to tall herbaceous vegetation. We recorded 1,535 individuals and 27 species of birds. The first ordination axis indicated a strong contribution of mean vegetation height on the composition of the bird community, whereas the second axis revealed the influence of herbaceous vegetation patchiness and woody vegetation cover. Three groups of species were revealed by the ordination: one more diffuse associated with intermediate and tall herbaceous vegetation, another with short grass, and a third with vegetation patchiness and woody vegetation. Species restricted to tall herbaceous vegetation are negatively impacted from habitat degradation resulting from overgrazing and trampling by livestock, and mowing and burning of tall plants. Occurrence of these species in our study area is related with the presence of swales immediately behind the dune system and where remnants of tall vegetation persist. Birds of pastures with ample cover of short herbaceous plants, including one globally threatened species and six other restricted to short-grass habitat, apparently benefit from local livestock management practices. Woody vegetation possibly functions as a keystone structure, enabling the occurrence in grasslands of avian species that rely on shrubby habitat. Although livestock ranching promotes the diversity of habitats by creating distinct patches of
Full Text Available Non-native species are frequently considered to influence urban assemblages. The grey squirrel Sciurus carolinensis is one such species that is widespread in the UK and is starting to spread across Europe; it predates birds' nests and can compete with birds for supplementary food. Using distance sampling across the urbanisation intensity gradient in Sheffield (UK we test whether urban grey squirrels influence avian species richness and density through nest predation and competition for supplementary food sources. We also assess how urban bird assemblages respond to supplementary feeding. We find that grey squirrels slightly reduced the abundance of breeding bird species most sensitive to squirrel nest predation by reducing the beneficial impact of woodland cover. There was no evidence that grey squirrel presence altered relationships between supplementary feeding and avian assemblage structure. This may be because, somewhat surprisingly, supplementary feeding was not associated with the richness or density of wintering bird assemblages. These associations were positive during the summer, supporting advocacy to feed birds during the breeding season and not just winter, but explanatory capacity was limited. The amount of green space and its quality, assessed as canopy cover, had a stronger influence on avian species richness and population size than the presence of grey squirrels and supplementary feeding stations. Urban bird populations are thus more likely to benefit from investment in improving the availability of high quality habitats than controlling squirrel populations or increased investment in supplementary feeding.
Khimoun, Aurélie; Eraud, Cyril; Ollivier, Anthony; Arnoux, Emilie; Rocheteau, Vincent; Bely, Marine; Lefol, Emilie; Delpuech, Martin; Carpentier, Marie-Laure; Leblond, Gilles; Levesque, Anthony; Charbonnel, Anaïs; Faivre, Bruno; Garnier, Stéphane
Habitat fragmentation is one of the most severe threats to biodiversity as it may lead to changes in population genetic structure, with ultimate modifications of species evolutionary potential and local extinctions. Nonetheless, fragmentation does not equally affect all species and identifying which ecological traits are related to species sensitivity to habitat fragmentation could help prioritization of conservation efforts. Despite the theoretical link between species ecology and extinction proneness, comparative studies explicitly testing the hypothesis that particular ecological traits underlies species-specific population structure are rare. Here, we used a comparative approach on eight bird species, co-occurring across the same fragmented landscape. For each species, we quantified relative levels of forest specialization and genetic differentiation among populations. To test the link between forest specialization and susceptibility to forest fragmentation, we assessed species responses to fragmentation by comparing levels of genetic differentiation between continuous and fragmented forest landscapes. Our results revealed a significant and substantial population structure at a very small spatial scale for mobile organisms such as birds. More importantly, we found that specialist species are more affected by forest fragmentation than generalist ones. Finally, our results suggest that even a simple habitat specialization index can be a satisfying predictor of genetic and demographic consequences of habitat fragmentation, providing a reliable practical and quantitative tool for conservation biology. © 2016 John Wiley & Sons Ltd.
Michael E. Akresh; David I. King; Robert T. Brooks
Shrubland birds have experienced widespread declines in the eastern United States. Habitat for shrubland birds is typically dynamic, in which available habitat changes temporally and spatially in response to disturbance and succession. Despite widespread concerns among conservationists about shrubland birds, much is still poorly understood regarding fundamental...
Colleen Cassady St. Clair
Full Text Available Forest fragmentation and habitat loss may disrupt the movement or dispersal of forest-dwelling birds. Despite much interest in the severity of these effects and ways of mitigating them, little is known about actual movement patterns in different habitat types. We studied the movement of wintering resident birds, lured by playbacks of mobbing calls, to compare the willingness of forest birds to travel various distances in continuous forest, along narrow corridors (fencerows, and across gaps in forest cover. We also quantified the willingness of Black-capped Chickadees (Poecile atricapillus to cross gaps when alternative forested detour routes were available. All species were less likely to respond to the calls as distance increased to 200 m, although White-breasted Nuthatches (Sitta carolinensis and Hairy Woodpeckers (Picoides villosus were generally less likely to respond than chickadees and Downy Woodpeckers (P. pubescens. Chickadees were as likely to travel in corridors as in continuous forest, but were less likely to cross gaps as the gap distance increased. The other species were less willing to travel in corridors and gaps relative to forest, and the differences among habitats also increased with distance. For chickadees, gap-crossing decisions in the presence of forested detours varied over the range of distances that we tested, and were primarily influenced by detour efficiency (the length of the shortcut relative to the available detour. Over short distances, birds used forested detours, regardless of their efficiency. As absolute distances increased, birds tended to employ larger shortcuts in the open when detour efficiency was low or initial distance in the open was high, but they limited their distance from the nearest forest edge to 25 m. Thus, chickadees were unwilling to cross gaps of > 50 m when they had forested alternatives, yet they sometimes crossed gaps as large as 200 m when no such choice existed. Our results suggest that
Chalfoun, Anna D.; Schmidt, Kenneth A.
The question of why animals choose particular habitats has important implications for understanding behavioral evolution and distribution of organisms in the wild and for delineating between habitats of different quality for conservation and management. Habitats chosen by animals can influence fitness outcomes via the costs (e.g., predation risk) and benefits (e.g., food availability) of habitat use. Habitat preferences should therefore be under selection to favor those that confer fitness advantages (Clark and Shutler 1999). Indeed, prevailing theory suggests that the habitat preferences of animals should be adaptive, such that fitness is higher in preferred habitats (Hildén 1965, Southwood 1977, Martin 1998). However, studies have often identified apparent mismatches between observed habitat preferences and fitness outcomes across a wide variety of taxa (Valladares and Lawton 1991, Mayhew 1997, Kolbe and Janzen 2002, Arlt and Pärt 2007, Mägi et al. 2009). Certainly, one limitation of studies may be that assessment of “fitness” is typically constrained to fitness surrogates such as nest success rather than lifetime reproductive success or classic Fisherian fitness (Endler 1986). Nevertheless, important habitat choices such as nest sites influence the probability that temporarily sedentary, dependent young are discovered by enemies such as predators and parasites. We therefore expect, on average, to see congruence between evolved habitat preferences and relevant components of fitness (e.g., nest success). Here, we (1) review the prevalence of apparent mismatches between avian breeding-habitat preferences and fitness outcomes using nest-site selection as a focus; (2) describe several potential mechanisms for such mismatches, including anthropogenic, methodological, and ecological–evolutionary; and (3) suggest a framework for understanding the contexts in which habitat preferences represent adaptive decisions, with a primary focus on ecological information
Tryjanowski, Piotr; Skórka, Piotr; Sparks, Tim H.; Biaduń, Waldemar; Brauze, Tomasz; Hetmański, Tomasz; Martyka, Rafał; Indykiewicz, Piotr; Myczko, Łukasz; Kunysz, Przemysław; Kawa, Piotr; Czyż, Stanisław; Czechowski, Paweł; Polakowski, Michał; Zduniak, Piotr
Bird feeding is one of the most widespread direct interactions between man and nature, and this has important social and environmental consequences. However, this activity can differ between rural and urban habitats, due to inter alia habitat structure, human behaviour and the composition of wintering bird communities. We counted birds in 156 squares (0.25 km2 each) in December 2012 and again in January 2013 in locations in and around 26 towns and cities across Poland (in each urban area, we ...
Tryjanowski, Piotr; Skórka, Piotr; Sparks, Tim H; Biaduń, Waldemar; Brauze, Tomasz; Hetmański, Tomasz; Martyka, Rafał; Indykiewicz, Piotr; Myczko, Łukasz; Kunysz, Przemysław; Kawa, Piotr; Czyż, Stanisław; Czechowski, Paweł; Polakowski, Michał; Zduniak, Piotr; Jerzak, Leszek; Janiszewski, Tomasz; Goławski, Artur; Duduś, Leszek; Nowakowski, Jacek J; Wuczyński, Andrzej; Wysocki, Dariusz
Bird feeding is one of the most widespread direct interactions between man and nature, and this has important social and environmental consequences. However, this activity can differ between rural and urban habitats, due to inter alia habitat structure, human behaviour and the composition of wintering bird communities. We counted birds in 156 squares (0.25 km(2) each) in December 2012 and again in January 2013 in locations in and around 26 towns and cities across Poland (in each urban area, we surveyed 3 squares and also 3 squares in nearby rural areas). At each count, we noted the number of bird feeders, the number of bird feeders with food, the type of feeders, additional food supplies potentially available for birds (bread offered by people, bins) and finally the birds themselves. In winter, urban and rural areas differ in the availability of food offered intentionally and unintentionally to birds by humans. Both types of food availability are higher in urban areas. Our findings suggest that different types of bird feeder support only those species specialized for that particular food type and this relationship is similar in urban and rural areas.
Stephen A. Laymon
The California Wildlife-Habitat Relationship (WHR) system was tested for birds breeding in the Valley-Foothill Riparian habitat along California's Sacramento and South Fork Kern rivers. The model performed poorly with 33 pct and 21 pct correct predictions respectively at the two locations. Changes to the model for 60 species on the Sacramento River and 66 species...
Chandler, R.B.; King, D.I.; DeStefano, S.
Most scrub-shrub bird species are declining in the northeastern United States, and these declines are largely attributed to regional declines in habitat availability. American Beaver (Castor canadensis; hereafter “beaver”) populations have been increasing in the Northeast in recent decades, and beavers create scrub-shrub habitat through their dam-building and foraging activities. Few systematic studies have been conducted on the value of beaver-modified habitats for scrub-shrub birds, and these data are important for understanding habitat selection of scrub-shrub birds as well as for assessing regional habitat availability for these species. We conducted surveys in 37 beaver meadows in a 2,800-km2 study area in western Massachusetts during 2005 and 2006 to determine the extent to which these beaver-modified habitats are used by scrub-shrub birds, as well as the characteristics of beaver meadows most closely related to bird use. We modeled bird abundance in relation to microhabitat-, patch-, and landscape-context variables while adjusting for survey-specific covariates affecting detectability using N-mixture models. We found that scrub-shrub birds of regional conservation concern occupied these sites and that birds responded differently to microhabitat, patch, and landscape characteristics of beaver meadows. Generally, scrub-shrub birds increased in abundance along a gradient of increasing vegetation complexity, and three species were positively related to patch size. We conclude that these habitats can potentially play an important role in regional conservation of scrub-shrub birds and recommend that conservation priority be given to larger beaver meadows with diverse vegetation structure and composition.
Wild, Teri C.; Kendall, Steven J.; Guldager, Nikki; Powell, Abby N.
Smith's Longspur (Calcarius pictus) is a species of conservation concern which breeds in Arctic habitats that are expected to be especially vulnerable to climate change. We used bird presence and habitat data from point-transect surveys conducted at 12 sites across the Brooks Range, Alaska, 2003–2009, to identify breeding areas, describe local habitat associations, and identify suitable habitat using a predictive model of Smith's Longspur distribution. Smith's Longspurs were observed at seven sites, where they were associated with a variety of sedge–shrub habitats composed primarily of mosses, sedges, tussocks, and dwarf shrubs; erect shrubs were common but sparse. Nonmetric multidimensional scaling ordination of ground cover revealed positive associations of Smith's Longspur presence with sedges and mosses and a negative association with high cover of shrubs. To model predicted distribution, we used boosted regression trees to relate landscape variables to occurrence. Our model predicted that Smith's Longspurs may occur in valleys and foothills of the northeastern and southeastern mountains and in upland plateaus of the western mountains, and farther west than currently documented, over a predicted area no larger than 15% of the Brooks Range. With climate change, shrubs are expected to grow larger and denser, while soil moisture and moss cover are predicted to decrease. These changes may reduce Smith's Longspur habitat quality and limit distribution in the Brooks Range to poorly drained lowlands and alpine plateaus where sedge–shrub tundra is likely to persist. Conversely, northward advance of shrubs into sedge tundra may create suitable habitat, thus supporting a northward longspur distribution shift.
Edgar, E.; Anderson, R. S.; Mathis, T.; Chlus, A.; Gambhir, T.; Schmidt, C.
Oak habitats in the Pacific Northwest have decreased significantly under past land management practices. In turn, concern for bird species that depend on these habitats has increased as agricultural and urban development, fire suppression strategies, and invasive species encroachment have led to declines in oak extent. The richness and abundance of birds may be closely related to the health and diversity of these declining habitats. To identify past and present land cover distributions and understand the relationship between oak habitat and bird abundance, this project used Landsat 8 imagery with topographic, ground survey, and bird count data. A land cover map for 2013 was produced using image segmentation with genetic and machine learning algorithms to classify cover types. This land cover map was used in combination with a change detection analysis to assess the relation between bird abundance and disturbance. We found trends of bird abundance and avian species richness are not associated with local landscape disturbances. When considering change in bird abundance at the local scale, management agencies should exercise caution due to high variability associated with Breeding Bird Survey data. Further study is necessary to assess whether a relationship exists between oak associated bird species and the concentration of oaks or disturbance events.
Burley, J.B.; Hopkins, R.B.
Throughout western North Dakota the number of unreclaimed surface coal and coal-uranium mines might total over 1100. We examined the potential for enhancing the nongame bird habitat values of unreclaimed mine lands in the arid, western region of North Dakota. Generally, the greatest variety of birds occurred in natural and planted woodlands, while fewer birds occurred in unreclaimed mine lands, grasslands, shrublands and croplands. Deciduous woodland types supported more species of birds than coniferous types. Planted woodlands supported about the same number of bird species as some natural deciduous woodland types and more species than coniferous woods. Unreclaimed mine lands supported more species than grasslands and croplands, and about the same number of species as native shrublands. The highest bird densities were in planted woodlands. Bird diversity varied positively with habitat diversity. The bird fauna of unreclaimed mine lands can be enhanced by creating more diverse habitats. Seventeen guidelines to enhance unreclaimed mine lands for nongame birds are presented. These guidelines can be used in preserving habitats threatened by surface mining and reclaiming previously mined lands
National Oceanic and Atmospheric Administration, Department of Commerce — Marine Bird Habitats (F040) is one of a group of seven datasets related to Marine Birds from Coastal Alaska and Puget Sound Data (1975 -1978). Each dataset uses the...
Department of the Interior — Between spring 1976 and fall 1980 we studied the occurrence, abundance, and habitat use of birds over a 2000 km² segment of the northcentral Alaska Peninsula. During...
Wal, van der J.C.; Peña-Álvarez, B.; Arriaga-Weiss, S.L.; Hernández-Daumás, S.
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.
Altman, Bob; Hagar, Joan
This document (hereafter Guide) has been prepared to assist land managers interested in conducting conservation and management activities to benefit breeding birds associated with young conifer forests in the Pacific Northwest. Audiences targeted for use of the Guide include land trusts, watershed councils, non-commercial private land owners, forest products companies, land-managing conservation organizations, government agencies, tribes, and First Nations. We hope the Guide will be a useful and valuable tool to support any of the variety of reasons to manage for bird habitat in young conifer forests (for example, regulatory, biodiversity, bird conservation, and forest certification standards).
Christopher T. Rota; Mark A. Rumble; Chad P. Lehman; Dylan C. Kesler; Joshua J. Millspaugh
Dramatic fluctuations in food resources are a key feature of many habitats, and many species have evolved a movement strategy to exploit food resources that are unpredictable in space and time. The availability of food resources may be a particularly strong determinant of habitat quality for irruptive bird species. We studied the apparent foraging success of Black-...
Jared D. Wolfe; Matthew D. Johnson; C. John Ralph; R. Mark Brigham
Nearctic-neotropic migrant birds need to replenish energy reserves during stopover periods to successfully complete their semiannual movements. In this study we used linear models to examine the habitat use of 11 migrant species in northeastern Costa Rica to better understand the influence of food and structural resources on the presence of birds during stopover...
United States Department of Agriculture, Forest Service
Breeding bird populations ranged from 3.35 to 3.48 individuals/ha over a 3-year study conducted from 1981 to 1983. Brewer's sparrows, sage sparrows, sage thrashers, and black-throated sparrows were numerically dominant. Horned larks and western meadowlarks were less common. Results are compared with bird populations in Great Basin sagebrush habitats elsewhere in the United States.
Rory N. Sandberg
Full Text Available Fynbos habitats are threatened by fragmentation through land use and anthropogenic changes in fire regimes, leading to a loss of suitable habitat for birds. We investigated the response of fynbos-typical avifauna to fragmentation and postfire vegetation age in order to better understand the consequences of these processes for bird communities. Vegetation composition and bird inventory data were collected along wandering transects in three South Outeniqua Sandstone Fynbos habitat configurations: fragmented patches (associated with anthropogenically driven habitat loss < 150 years ago, naturally isolated fynbos islands (formed through climate-driven forest expansion in the Holocene and extensive areas of relatively pristine habitat known as ‘mainland’. The latter configurations served as references against which to investigate bird and vegetation responses to more recent habitat fragmentation. Linear regressions were used to compare the relationships of a number of bird and plant species to areas between each habitat configuration. Bird attribute frequency data were compared between habitat configurations using chi-square tests. Birds and plants showed significant species–area relationships in natural island and mainland sites, but no such relationship occurred in artificial fragments for birds, where the surrounding anthropogenic land uses are likely to have contributed generalist or colonist species. Avifaunal migratory groups were not affected by isolation distances of > 10 km in this study and their frequencies were the same across the three habitat configurations. Certain feeding guilds did, however, respond to postfire vegetation age, with nectarivore species twice as likely to occur in oldgrowth mainland fynbos. Fragmentation can alter fire disturbance regimes, which in turn alter the availability of resources in a habitat, so the impacts of fragmentation on birds are probably indirect through changes in the vegetation component
Craig Watson; Chuck Hayes; Joseph McCauley; Andrew Milliken
In 1999, the Management Board of the Atlantic Coast Joint Venture (ACJV) embraced the vision and framework of the then newly emerging North American Bird Conservation Initiative (NABCI). Traditionally a Joint Venture focused on the conservation of waterfowl and wetlands habitat, the ACJV expanded its role throughout the Atlantic Flyway to all resident and migratory...
Full Text Available Evidence suggests that animal patterns (motifs function in camouflage. Irregular mottled patterns can facilitate concealment when stationary in cluttered habitats, whereas regular patterns typically prevent capture during movement in open habitats. Bird plumage patterns have predominantly converged on just four types—mottled (irregular, scales, bars and spots (regular—and habitat could be driving convergent evolution in avian patterning. Based on sensory ecology, we therefore predict that irregular patterns would be associated with visually noisy closed habitats and that regular patterns would be associated with open habitats. Regular patterns have also been shown to function in communication for sexually competing males to stand-out and attract females, so we predict that male breeding plumage patterns evolved in both open and closed habitats. Here, taking phylogenetic relatedness into account, we investigate ecological selection for bird plumage patterns across the class Aves. We surveyed plumage patterns in 80% of all avian species worldwide. Of these, 2,756 bird species have regular and irregular plumage patterns as well as habitat information. In this subset, we tested whether adult breeding/non-breeding plumages in each sex, and juvenile plumages, were associated with the habitat types found within the species’ geographical distributions. We found no evidence for an association between habitat and plumage patterns across the world’s birds and little phylogenetic signal. We also found that species with regular and irregular plumage patterns were distributed randomly across the world’s eco-regions without being affected by habitat type. These results indicate that at the global spatial and taxonomic scale, habitat does not predict convergent evolution in bird plumage patterns, contrary to the camouflage hypothesis.
Schippers, P.; Grashof, C.J.; Verboom, J.; Baveco, J.M.; Jochem, R.; Meeuwsen, H.A.M.; Adrichem, van M.H.C.
It is generally assumed that large patches of natural habitat are better for the survival of species than the same amount of habitat in smaller fragments or linear elements like hedges and tree rows. We use a spatially explicit individual-based model of a woodland bird to explore this hypothesis. We
Gutiérrez, Jorge S.; Rakhimberdiev, Eldar; Piersma, Theunis; Thieltges, David W.
Aim: Habitat use and migration strategies of animals are often associated with spatial variation in parasite pressure, but how they relate to one another is not well understood. Here, we use a large dataset on helminth species richness of Charadriiform birds to test whether higher habitat diversity
Gutiérrez, J.S.; Rakhimberdiev, E.; Piersma, T.; Thieltges, D.W.
Aim Habitat use and migration strategies of animals are often associated withspatial variation in parasite pressure, but how they relate to one another is notwell understood. Here, we use a large dataset on helminth species richness ofCharadriiform birds to test whether higher habitat diversity and
Roč. 50, č. 4 (2001), s. 281-289 ISSN 0139-7893 R&D Projects: GA AV ČR IBS6093007 Institutional research plan: CEZ:AV0Z6093917 Keywords : forest birds * habitat preference * habitat selection Subject RIV: EH - Ecology, Behaviour Impact factor: 0.287, year: 2001
Moorman, C.E.; D.C. Guynn, Jr.
Research on the effects of creating group-selection openings of various sizes on breeding birds habitat use in a bottomland hardwood forest of the Upper Coastal Plain of South Carolina. Creation of 0.5-ha group selection openings in southern bottomland forests should provide breeding habitat for some field-edge species in gaps and habitat for forest-interior species and canopy-dwelling forest-edge species between gaps provided that enough mature forest is made available.
Full Text Available This paper focuses on using data mining technology to efficiently and accurately discover habitats and stopovers of migratory birds. The three methods we used are as follows: 1. a density-based clustering method, detecting stopovers of birds during their migration through density-based clustering of location points; 2. A location histories parser method, detecting areas that have been overstayed by migratory birds during a set time period by setting time and distance thresholds; and 3. A time-parameterized line segment clustering method, clustering directed line segments to analyze shared segments of migratory pathways of different migratory birds and discover the habitats and stopovers of these birds. Finally, we analyzed the migration data of the bar-headed goose in the Qinghai Lake Area through the three above methods and verified the effectiveness of the three methods and, by comparison, identified the scope and context of the use of these three methods respectively.
The biodiversity of Akagera National Park (ANP), Rwanda, has reportedly been declining since 1990 due to conflict and war in the country between 1990 and 1994. In this paper, we describe bird diversity in the post-war recovery period. We used systematic plots, point counts and presence–absence surveys to estimate bird ...
Fagan, Matthew E; DeFries, Ruth S; Sesnie, Steven E; Arroyo-Mora, J Pablo; Chazdon, Robin L
Re-establishing connectivity between protected areas isolated by habitat clearing is a key conservation goal in the humid tropics. In northeastern Costa Rica, payments for environmental services (PES) and a government ban on deforestation have subsidized forest protection and reforestation in the San Juan-La Selva Biological Corridor (SJLSBC), resulting in a decline in mature forest loss and the expansion of tree plantations. We use field studies and graph models to assess how conservation efforts have altered functional connectivity over the last 25 years for four species of insectivorous understory birds. Field playback studies assessed how reforestation habitat quality affected the willingness of Myrmeciza exsul, Henicorhina leucosticta, Thamnophilus atrinucha, and Glyphorynchus spirurus to travel outside forest habitat for territorial defense. Observed travel distances were greatest in nonnative and native tree plantations with high understory stem density, regardless of overstory composition. In contrast, tree plantations with low stem density had travel responses comparable to open pasture for three of the four bird species. We modeled landscape connectivity for each species using graph models based on varying possible travel distances in tree plantations, gallery forests, and pastures. From 1986 to 2011, connectivity for all species declined in the SJLSBC landscape (5825 km 2 ) by 14% to 21% despite only a 4.9% net loss in forest area and the rapid expansion of tree plantations over 2% of the landscape. Plantation placement in the landscape limited their potential facilitation of connectivity because they were located either far from forest cover or within already contiguous forest areas. We mapped current connectivity bottlenecks and identified priority areas for future reforestation. We estimate that reforestation of priority areas could improve connectivity by 2% with only a 1% gain in forest cover, an impressive gain given the small area reforested
Gauthreaux, Sidney, A.; Steven J. Wagner.
Gauthreaux, Sidney, A., and Steven J. Wagner. 2005. Breeding bird populations and habitat associations within the Savannah River Site (SRS). Final Report. USDA Forest Service, Savannah River, Aiken, SC. 48 pp. Abstract: During the 1970's and 1980's a dramatic decline occurred in the populations of Neotropical migratory birds, species that breed in North America and winter south of the border in Central and South America and in the Caribbean. In 1991 an international initiative was mounted by U. S. governmental land management agencies, nongovernmental conservation agencies, and the academic and lay ornithological communities to understand the decline of Neotropical migratory birds in the Americas. In cooperation with the USDA Forest Service - Savannah River (FS - SR) we began 1992 a project directed to monitoring population densities of breeding birds using the Breeding Bird Census (BBC) methodology in selected habitats within the Savannah River Site SRS. In addition we related point count data on the occurrence of breeding Neotropical migrants and other bird species to the habitat data gathered by the Forest Inventory and Analysis (FIA) program of the USDA Forest Service and data on habitat treatments within forest stands.
Full Text Available BACKGROUND: The ratio of habitat generalists to specialists in birds has been suggested as a good indicator of ecosystem changes due to e.g. climate change and other anthropogenic perturbations. Most studies focusing on this functional component of biodiversity originate, however, from temperate regions. The Eurasian Arctic tundra is currently experiencing an unprecedented combination of climate change, change in grazing pressure by domestic reindeer and growing human activity. METHODOLOGY/PRINCIPAL FINDINGS: Here we monitored bird communities in a tundra landscape harbouring shrub and open habitats in order to analyse bird habitat relationships and quantify habitat specialization. We used ordination methods to analyse habitat associations and estimated the proportions of specialists in each of the main habitats. Correspondence Analysis identified three main bird communities, inhabiting upland, lowland and dense willow shrubs. We documented a stable structure of communities despite large multiannual variations of bird density (from 90 to 175 pairs/km(2. Willow shrub thickets were a hotspot for bird density, but not for species richness. The thickets hosted many specialized species whose main distribution area was south of the tundra. CONCLUSION/SIGNIFICANCE: If current arctic changes result in a shrubification of the landscape as many studies suggested, we would expect an increase in the overall bird abundance together with an increase of local specialists, since they are associated with willow thickets. The majority of these species have a southern origin and their increase in abundance would represent a strengthening of the boreal component in the southern tundra, perhaps at the expense of species typical of the subarctic zone, which appear to be generalists within this zone.
Sokolov, Vasiliy; Ehrich, Dorothée; Yoccoz, Nigel G.; Sokolov, Alexander; Lecomte, Nicolas
Background The ratio of habitat generalists to specialists in birds has been suggested as a good indicator of ecosystem changes due to e.g. climate change and other anthropogenic perturbations. Most studies focusing on this functional component of biodiversity originate, however, from temperate regions. The Eurasian Arctic tundra is currently experiencing an unprecedented combination of climate change, change in grazing pressure by domestic reindeer and growing human activity. Methodology/Principal Findings Here we monitored bird communities in a tundra landscape harbouring shrub and open habitats in order to analyse bird habitat relationships and quantify habitat specialization. We used ordination methods to analyse habitat associations and estimated the proportions of specialists in each of the main habitats. Correspondence Analysis identified three main bird communities, inhabiting upland, lowland and dense willow shrubs. We documented a stable structure of communities despite large multiannual variations of bird density (from 90 to 175 pairs/km2). Willow shrub thickets were a hotspot for bird density, but not for species richness. The thickets hosted many specialized species whose main distribution area was south of the tundra. Conclusion/Significance If current arctic changes result in a shrubification of the landscape as many studies suggested, we would expect an increase in the overall bird abundance together with an increase of local specialists, since they are associated with willow thickets. The majority of these species have a southern origin and their increase in abundance would represent a strengthening of the boreal component in the southern tundra, perhaps at the expense of species typical of the subarctic zone, which appear to be generalists within this zone. PMID:23239978
sagebrush ( Artemisia spp.) in the western United States represent one of the nation’s most imperiled ecosystems due to extensive habitat loss and habitat...hyemalis 6 42 15 63 European Starling Sturnus vulgaris 1 1 17 Table 3: Continued Species
Frank R., III Thompson
Habitat models are widely used in bird conservation planning to assess current habitat or populations and to evaluate management alternatives. These models include species-habitat matrix or database models, habitat suitability models, and statistical models that predict abundance. While extremely useful, these approaches have some limitations.
Horton, Kyle G; Van Doren, Benjamin M; Stepanian, Phillip M; Farnsworth, Andrew; Kelly, Jeffrey F
The lower atmosphere (i.e. aerosphere) is critical habitat for migrant birds. This habitat is vast and little is known about the spatio-temporal patterns of distribution and abundance of migrants in it. Increased human encroachment into the aerosphere makes understanding where and when migratory birds use this airspace a key to reducing human-wildlife conflicts. We use weather surveillance radar to describe large-scale height distributions of nocturnally migrating birds and interpret these distributions as aggregate habitat selection behaviours of individual birds. As such, we detail wind cues that influence selection of flight heights. Using six radars in the eastern USA during the spring (2013-2015) and autumn (2013 and 2014), we found migrants tended to adjust their heights according to favourable wind profit. We found that migrants' flight altitudes correlated most closely with the altitude of maximum wind profit; however, absolute differences in flight heights and height of maximum wind profit were large. Migrants tended to fly slightly higher at inland sites compared with coastal sites during spring, but not during autumn. Migration activity was greater at coastal sites during autumn, but not during spring. This characterization of bird migration represents a critical advance in our understanding of migrant distributions in flight and a new window into habitat selection behaviours. © 2016 The Author(s).
Borges, Friederike; Glemnitz, Michael; Schultz, Alfred; Stachow, Ulrich
Many of the processes behind the decline of farmland birds can be related to modifications in landscape structure (composition and configuration), which can partly be expressed quantitatively with measurable or computable indices, i.e. landscape metrics. This paper aims to identify statistical relationships between the occurrence of birds and the landscape structure. We present a method that combines two comprehensive procedures: the "landscape-centred approach" and "guild classification". Our study is based on more than 20,000 individual bird observations based on a 4-year bird monitoring approach in a typical agricultural area in the north-eastern German lowlands. Five characteristic bird guilds, each with three characteristic species, are defined for the typical habitat types of that area: farmland, grassland, hedgerow, forest and settlement. The suitability of each sample plot for each guild is indicated by the level of persistence (LOP) of occurrence of three respective species. Thus, the sample plots can be classified as "preferred" or "less preferred" depending on the lower and upper quartiles of the LOP values. The landscape structure is characterized by 16 different landscape metrics expressing various aspects of landscape composition and configuration. For each guild, the three landscape metrics with the strongest rank correlation with the LOP values and that are not mutually dependent were identified. For four of the bird guilds, the classification success was better than 80%, compared with only 66% for the grassland bird guild. A subset of six landscape metrics proved to be the most meaningful and sufficiently classified the sample areas with respect to bird guild suitability. In addition, derived logistic functions allowed the production of guild-specific habitat suitability maps for the whole landscape. The analytical results show that the proposed approach is appropriate to assess the habitat suitability of agricultural landscapes for characteristic
Dean E. Medin; Bruce L. Welch; Warren P. Clary
Bird censuses were taken on 11 study plots along an elevational gradient ranging from 5,250 to 11,400 feet. Each plot represented a different vegetative type or zone: shadscale, shadscale-Wyoming big sagebrush, Wyoming big sagebrush, Wyoming big sagebrush-pinyon/juniper, pinyon/juniper, pinyon/juniper-mountain big sagebrush, mountain big sagebrush, mountain big...
We investigated the influence of forest fragment size and isolation on the bird assemblages in the species- and endemic-rich sand forests of the Maputaland Centre of Endemism, southern Mozambique. Point-centre surveys were conducted across 12 sand forest patches that varied in size and isolation. Patch size and ...
Migration routes used by Nearctic migrant birds can cover great distances; they also differ among species, within species, and between years and seasons. As a result, migration routes for an entire migratory avifauna can encompass broad geographic areas, making it impossible to protect continuous stretches of habitat sufficient to connect the wintering and breeding grounds for most species. Consequently, ways to enhance habitats converted for human use (i.e. for pasture, crop cultivation, human settlement) as stopover sites for migrants are especially important. Shelterbelts around pastures and fields, if planted with species targeted to support migrant (and resident) bird species that naturally occupy mature forest habitats and that are at least partially frugivorous, could be a powerful enhancement tool for such species, if the birds will enter the converted areas to feed. I tested this approach for Nearctic migrant birds during the spring migration through an area in Chiapas, Mexico. Mature forest tree species whose fruits are eaten by birds were surveyed. Based on life form, crop size and fruit characteristics, I selected three tree species for study: Cymbopetalum mayanum (Annonaceae), Bursera simaruba (Burseraceae) and Trophis racemosa (Moraceae). I compared the use of fruits of these species by migrants and residents in forest with their use of the fruits of isolated individuals of the same species in pasture and cropland. All three plant species were useful for enhancing converted habitats for forest-occupying spring migrants, although species differed in the degree to which they entered disturbed areas to feed on the fruits. These tree species could probably enhance habitats for migrants at sites throughout the natural geographic ranges of the plants; in other geographic areas for other target bird groups, other tree species might be more appropriate.
Full Text Available Understanding the spatial patterns in species richness is a central issue in macroecology and biogeography. Analyses that have traditionally focused on overall species richness limit the generality and depth of inference. Spatial patterns of species richness and the mechanisms that underpin them in China remain poorly documented. We created a database of the distribution of 580 mammal species and 849 resident bird species from 2376 counties in China and established spatial linear models to identify the determinants of species richness and test the roles of five hypotheses for overall mammals and resident birds and the 11 habitat groups among the two taxa. Our result showed that elevation variability was the most important determinant of species richness of overall mammal and bird species. It is indicated that the most prominent predictors of species richness varied among different habitat groups: elevation variability for forest and shrub mammals and birds, temperature annual range for grassland and desert mammals and wetland birds, net primary productivity for farmland mammals, maximum temperature of the warmest month for cave mammals, and precipitation of the driest quarter for grassland and desert birds. Noteworthily, main land cover type was also found to obviously influence mammal and bird species richness in forests, shrubs and wetlands under the disturbance of intensified human activities. Our findings revealed a substantial divergence in the species richness patterns among different habitat groups and highlighted the group-specific and disparate environmental associations that underpin them. As we demonstrate, a focus on overall species richness alone might lead to incomplete or misguided understanding of spatial patterns. Conservation priorities that consider a broad spectrum of habitat groups will be more successful in safeguarding the multiple services of biodiversity.
David I. King; Richard B. Chandler; Jeffrey M. Collins; Wayne R. Petersen; Thomas E. Lautzenheiser
Concern about declines in scrubâshrub bird populations has resulted in efforts to create and maintain habitat for these species. Vegetation within powerline corridors is managed to prevent contact of vegetation with transmission lines, and comprises approximately 2% of all of habitat for scrubâshrub birds in southern New England. Although previous studies have...
Klug, Page E; Jackrel, Sara L; With, Kimberly A
Extremes in rangeland management, varying from too-frequent fire and intensive grazing to the suppression of both, threaten rangeland ecosystems worldwide. Intensive fire and grazing denude and homogenize vegetation whereas their suppression increases woody cover. Although habitat loss is implicated in grassland bird declines, degradation through intensive management or neglect also decreases breeding habitat and may reduce nesting success through increased rates of nest predation. Snakes are important nest predators, but little is known about how habitat use in snakes relates to predation risk for grassland birds nesting within tallgrass prairie subjected to different grazing and fire frequencies. We evaluated nest survival in the context of habitat used by nesting songbirds and two bird-eating snakes, the eastern yellowbelly racer Coluber constrictor flaviventris and Great Plains ratsnake Pantherophis emoryi. Daily nest survival rates decreased with increasing shrub cover and decreasing vegetation height, which characterize grasslands that have been neglected or intensively managed, respectively. Discriminant function analysis revealed that snake habitats were characterized by higher shrub cover, whereas successful nests were more likely to occur in areas with tall grass and forbs but reduced shrub cover. Because snakes often use shrub habitat, birds nesting in areas with increased shrub cover may be at higher risk of nest predation by snakes in addition to other predators known to use shrub habitat (e.g., mid-sized carnivores and avian predators). Depredated nests also occurred outside the discriminant space of the snakes, indicating that other predators (e.g., ground squirrels Spermophilus spp. and bullsnakes Pituophis catenifer) may be important in areas with denuded cover. Targeted removal of shrubs may increase nest success by minimizing the activity of nest predators attracted to shrub cover.
Susannah B. Lerman; Keith H. Nislow; David J. Nowak; Stephen DeStefano; David I. King; D. Todd. Jones-Farrand
The alteration of forest cover and the replacement of native vegetation with buildings, roads, exotic vegetation, and other urban features pose one of the greatest threats to global biodiversity. As more land becomes slated for urban development, identifying effective urban forest wildlife management tools becomes paramount to ensure the urban forest provides habitat...
Nicholas J. Bayly
Full Text Available Long-distance migratory birds are declining globally and migration has been identified as the primary source of mortality in this group. Despite this, our lack of knowledge of habitat use and quality at stopovers, i.e., sites where the energy for migration is accumulated, remains a barrier to designing appropriate conservation measures, especially in tropical regions. There is therefore an urgent need to assess stopover habitat quality and concurrently identify efficient and cost-effective methods for doing so. Given that fuel deposition rates directly influence stopover duration, departure fuel load, and subsequent speed of migration, they are expected to provide a direct measure of habitat quality and have the advantage of being measurable through body-mass changes. Here, we examined seven potential indicators of quality, including body-mass change, for two ecologically distinct Neotropical migratory landbirds on stopover in shade-coffee plantations and tropical humid premontane forest during spring migration in Colombia: (1 rate of body-mass change; (2 foraging rate; (3 recapture rate; (4 density; (5 flock size; (6 age and sex ratios; and (7 body-mass distribution. We found higher rates of mass change in premontane forest than in shade-coffee in Tennessee Warbler Oreothlypis peregrina, a difference that was mirrored in higher densities and body masses in forest. In Gray-cheeked Thrush Catharus minimus, a lack of recaptures in shade-coffee and higher densities in forest, also suggested that forest provided superior fueling conditions. For a reliable assessment of habitat quality, we therefore recommend using a suite of indicators, taking into account each species' ecology and methodological considerations. Our results also imply that birds stopping over in lower quality habitats may spend a longer time migrating and require more stopovers, potentially leading to important carryover effects on reproductive fitness. Evaluating habitat quality is
Summary. Species-rich tropical forests are becoming increasingly fragmented, degraded and are declining due to human activities, threatening the survival of avian species that depend on them. We assessed the detrimental effects of human activities on birds and their habitats in and around North Nandi Forest.
Carlin C. Chandler; David I. King; Richard B. Chandler
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...
Full Text Available Birds can be used indirectly or directly as a bioindicator of environment. Birds species living in six habitat types of PT Inhutani I Labanan Kalimantan Timur (namely, logged-over areas that has been exploited in 1976/1981 and 1981/1986, forested area that is being exploited in 1999/2000, primary forest that will be exploited in 2001/2002, Labanan Jaya Village inhabited in 1982/1983, and Segah-Malinau Transmigration Settlement inhabited in 1997/1998 were recorded with transect method (long of 3 km and within sighting distance of 25-50 m at 06.30-10.00 and 15.00-17.30 in both dry and rainy seasons. One hundred and two identified species belonging to 34 families and 6 unidentified species were found. Habitat types and seasons affect bird diversity (the number of species and abundance. Percent dissimilarity of birds between habitats ranged 0,53-0,95 in rainy season and 0,54-0,95 in dry season and between seasons ranged 0,50-0,80. Quantitative values have to be completed with qualitative consideration to assess habitat condition or changes.
Robin E. Russell; Victoria A. Saab; Jonathan G. Dudley
Models of habitat suitability in postfire landscapes are needed by land managers to make timely decisions regarding postfire timber harvest and other management activities. Many species of cavity-nesting birds are dependent on postfire landscapes for breeding and other aspects of their life history and are responsive to postfire management activities (e.g., timber...
Brian Kane; Paige S. Warren; Susannah B. Lerman
Trees in towns and cities provide habitat for wildlife. In particular, cavity-nesting birds nest in the deadand decayed stems and branches of these trees. The same dead and decayed stems and branches alsohave a greater likelihood of failure, which, in some circumstances, increases risk. We examined 1760trees in Baltimore, MD, USA and western MA, USA, assessing tree...
Tracey B. Champlin; John C. Kilgo; Christopher E. Moorman
Few attempts have been made to experimentally address the extent to which temporal or spatial variation in food availability influences avian habitat use. We used an experimental approach to investigate whether bird use differed between treated (arthropods reduced through insecticide application) and control (untreated) forest canopy gaps within a bottomland hardwood...
Andrew Milliken; Craig Watson; Chuck Hayes
The Atlantic Coast Joint Venture is a partnership focused on the conservation of habitats for migratory birds within the Atlantic Flyway/Atlantic Coast Region from Maine south to Puerto Rico. In order to be effective in planning and implementing conservation in this large and diverse area, the joint venture must work at multiple spatial scales, from the largest ?...
This session at the Wind Energy and Birds/Bats workshop was consisted of one paper presentation followed by a discussion/question and answer period. The session focused on discussion of non-collision impacts of wind energy projects on birds, primarily impacts to habitat. The presentation included information about the impacts of habitat fragmentation, disturbance, and site avoidance from wind turbines, as well as from roads, transmission facilities, and other related construction at wind project sites. Whether birds habituate to the presence of turbines and the influence of regional factors were also addressed. The paper given by Dale Strickland was titled ''Overview of Non-Collision Related Impacts from Wind Projects''.
Roberto A. Moreno-García
Full Text Available Aim of study: Our objective was to find habitat associations at a microhabitat level for two endemic birds in a Chilean temperate forest (biodiversity “hotspots”, in order to integrate biodiversity into forest planning.Area of study: Nahuelbuta Range, Chile.Material and methods: The two birds studied were Scelorchilus rubecula (Chucao Tapaculo and Scytalopus magellanicus (Magellanic Tapaculo, both belonging to the Rhinocryptidae family. Presence or absence of the two species was sampled in 57 census spots. Habitat was categorized according to presence/absence results. We assessed the influence of abiotic variables (altitude, exposure, slope and vegetation structure (percentage of understory cover, number of strata using a statistical cluster analysis.Main results: The two bird species selected the habitat. Most frequent presence was detected at a range of 600-1100 masl, but Magellanic Tapaculo was associated to more protected sites in terms of vegetation structure (50-75% for understory cover and 2-3 strata. Slope was the most relevant abiotic variable in habitat selection due to its linkage to vegetation traits in this area.Research highlights: Our results can help managers to integrate biodiversity (endemic fauna species into forest planning by preserving certain traits of the vegetation as part of a habitat (at a microhabitat level selected by the fauna species. That planning should be implemented with both an adequate wood harvesting cuts system and specific silvicultural treatments.Key words: Chile; Nahuelbuta; rhinocryptidae; cluster analysis; rorest planning; vegetation structure.
Champlin, Tracey B.; Kilgo, John C.; Moorman, Christopher E.
Abstract. Few attempts have been made to experimentally address the extent to which temporal or spatial variation in food availability influences avian habitat use. We used an experimental approach to investigate whether bird use differed between treated (arthropods reduced through insecticide application) and control (untreated) forest canopy gaps within a bottomland hardwood forest in the Upper Coastal Plain of South Carolina, USA. Gaps were two- to three-year-old group selection timber harvest openings of three sizes (0.13, 0.26, and 0.50 ha). Our study was conducted during four bird use periods (spring migration, breeding, post-breeding, and fall migration) in 2002 and 2003. Arthropods were reduced in treated gaps by 68% in 2002 and 73% in 2003. We used mist-netting captures and foraging attack rates to assess the influence of arthropod abundance on avian habitat use. Evidence that birds responded to arthropod abundance was limited and inconsistent. In 2002, we generally captured more birds in treated gaps of the smallest size (0.13 ha) and fewer birds in treated gaps of the larger sizes. In 2003, we recorded few differences in the number of captures in treated and control gaps. Foraging attack rates generally were lower in treated than in control gaps, indicating that birds were able to adapt to the reduced food availability and remain in treated gaps. We conclude that arthropod abundance was not a proximate factor controlling whether forest birds used our gaps. The abundance of food resources may not be as important in determining avian habitat selection as previous research has indicated, at least for passerines in temperate subtropical regions.
Powell, B.F.; Steidl, R.J.
Vegetation structure and floristic composition strongly influence the structure of bird communities. To assess the influence of vegetation and other environmental characteristics on songbirds, we quantified nest-site characteristics and reproductive success of a riparian songbird community in Arizona. Although we found interspecific variation in characteristics associated with nest sites, we identified two suites of species that chose sites with similar characteristics. These 'nest groups' were explained largely by nest height and characteristics of nest trees. Overall, nest success was low for songbirds in this community, and averaged 23%. The most common cause of nest failure was predation (81%), although brood parasitism by Brown-headed Cowbirds (Molothrus ater) was highest at nests of Bell's Vireos (Vireo bellii) (29%). No vegetation or environmental features were associated with the likelihood of cowbird parasitism for any species; nest success for Bell's Vireos was negatively associated with the amount of netleaf hackberry (Celtis reticulata) in the understory. Arizona sycamore (Platanus wrightii) and netleaf hackberry trees contained 41% and 17% of all nests, respectively, and therefore provide critically important nesting substrates for birds in this rare yet diverse vegetation community.
Norris, D Ryan; Flockhart, D T Tyler; Strickland, Dan
A comprehensive understanding of how natural and anthropogenic variation in habitat influences populations requires long-term information on how such variation affects survival and dispersal throughout the annual cycle. Gray jays Perisoreus canadensis are widespread boreal resident passerines that use cached food to survive over the winter and to begin breeding during the late winter. Using multistate capture-recapture analysis, we examined apparent survival and dispersal in relation to habitat quality in a gray jay population over 34 years (1977-2010). Prior evidence suggests that natural variation in habitat quality is driven by the proportion of conifers on territories because of their superior ability to preserve cached food. Although neither adults (>1 year) nor juveniles (preference ecological trap for birds. Reproductive success, as shown in a previous study, but not survival, is sensitive to natural variation in habitat quality, suggesting that gray jays, despite living in harsh winter conditions, likely favor the allocation of limited resources towards self-maintenance over reproduction.
the physical habitat quality of stream Ledreborg using af habitat hydraulic model • to assess the present and potential physical habitat quality of stream Ledreborg • to evaluate the suitability and applicability of habitat hydraulic models to Danish stream management Results • Precipitation and evaporation...... the best potential physical habitat quality for trout fry and juvenile trout and the lowest potential physical habitat quality for adult trout. This finding supports previous evaluations of the stream as a trout habitat, concluding that stream Ledreborg has very few suitable habitats for adult trout...... in the modelling. • Although more time consuming than present Danish methods for assessment of physical habitat quality in streams, the habitat hydraulic models can be used to evaluate physical habitat conditions at reach level and work as a basis for a more objective assessment method....
Full Text Available Munderikadavu is rich in avifaunal diversity. A total of 82 species of birds from 36 families belonging to 13 orders were recorded in the wetland including wetland dependant species. Lowland vegetation had the highest species richness (46 species followed by upland (41 species, aerial (38 species, emergent vegetation (22 species and paddy fields (21 species. Open water had the lowest species richness. Upland vegetation had the highest species diversity (H′-3.19 followed by aerial (H′-2.52. There was more species overlap between emergent and low land vegetations (Cm-0.7. The threats in Munderikadavu wetland were dumping of waste and conversion of cultivation land into shrimp farming area. Thus land use changes need to be regulated in order to conserve the wetland and bird community.
Farfán, M.A.; Duarte, J.; Real, R.; Muñoz, A.R.; Fa, J.E.; Vargas, J.M.
Onshore wind farms remain one of the most widely used technologies for the production of renewable energy. These are known to affect birds through disturbance or collision. Most research focus on the impact of wind farms on raptors or other large bird species, especially those of conservation concern. However, limited information exists on the effect of wind farms on small birds. Recovery of large versus small bird populations impacted by wind farms is also largely unstudied. A reason for this is the lack of long-term datasets based on standardized, systematic assessments. We monitored birds in the vicinity of a wind farm in an upland habitat in southern Spain (Malaga province), immediately after installation and 6.5 years post-construction. During both study periods, we observed 11 raptor and 38 non-raptor species (including 30 passerines). We found differences in recovery rates between raptors and non-raptors. Raptors showed an upturn in numbers but non-raptor abundance fell significantly. Greater attention should be paid to the recovery of wildlife after initial impact assessments than at present. This study confirms that regulatory authorities and developers should consider the likely impacts of wind farms on small bird populations. Mitigation measures focused particularly on non-raptor species should be considered and implemented as a means to reduce these negative effects.
Hill, Jason M.; Egan, J. Franklin; Stauffer, Glenn E.; Diefenbach, Duane R.
Grassland bird species have experienced substantial declines in North America. These declines have been largely attributed to habitat loss and degradation, especially from agricultural practices and intensification (the habitat-availability hypothesis). A recent analysis of North American Breeding Bird Survey (BBS) “grassland breeding” bird trends reported the surprising conclusion that insecticide acute toxicity was a better correlate of grassland bird declines in North America from 1980–2003 (the insecticide-acute-toxicity hypothesis) than was habitat loss through agricultural intensification. In this paper we reached the opposite conclusion. We used an alternative statistical approach with additional habitat covariates to analyze the same grassland bird trends over the same time frame. Grassland bird trends were positively associated with increases in area of Conservation Reserve Program (CRP) lands and cropland used as pasture, whereas the effect of insecticide acute toxicity on bird trends was uncertain. Our models suggested that acute insecticide risk potentially has a detrimental effect on grassland bird trends, but models representing the habitat-availability hypothesis were 1.3–21.0 times better supported than models representing the insecticide-acute-toxicity hypothesis. Based on point estimates of effect sizes, CRP area and agricultural intensification had approximately 3.6 and 1.6 times more effect on grassland bird trends than lethal insecticide risk, respectively. Our findings suggest that preserving remaining grasslands is crucial to conserving grassland bird populations. The amount of grassland that has been lost in North America since 1980 is well documented, continuing, and staggering whereas insecticide use greatly declined prior to the 1990s. Grassland birds will likely benefit from the de-intensification of agricultural practices and the interspersion of pastures, Conservation Reserve Program lands, rangelands and other grassland
Smith, James A.; Deppe, Jill L.
Understanding bird migration and avian biodiversity is one of the most compelling and challenging problems of modern biology with major implications for human health and conservation biology. Migration and conservation efforts cross national boundaries and are subject to numerous international agreements and treaties presenting challenges in both geographic space and time. Space based technology, coupled with geographic information systems, yields new opportunities to shed light on the distribution and movement of organisms on the planet and their sensitivity to human disturbances and environmental changes. At NASA, we are creating ecological forecasting tools for science and application users to address the consequences of loss of wetlands, flooding, drought or other natural disasters such as hurricanes on avian biodiversity and bird migration. In our work, we use individual organism biophysical models and drive these models with satellite observations and numerical weather predictions of the spatio-temporal gradients in climate and habitat. Geographic information system technology comprises one component of our overall simulation framework, especially for characterizing the changing habitats and conditions encountered by en-route migratory birds. Simulation provides a tool for studying bird migration across multiple scales and can be linked to mechanistic processes describing the time and energy budget states of migrating birds. Such models yield an understanding of how a migratory flyway and its component habitats function as a whole and link stop-over ecology with biological conservation and management. We present examples of our simulation of shorebirds, principally, pectoral sandpipers, along the central flyways of the United States and Canada from the Gulf of Mexico to Alaska.
Holleman, I.; van Gasteren, H.; Bouten, W.
Wind profiles from an operational C-band Doppler radar have been combined with data from a bird tracking radar to assess the wind profile quality during bird migration. The weather radar wind profiles (WRWPs) are retrieved using the well-known volume velocity processing (VVP) technique. The X-band
Theperformance response and egg qualities o laying birds fed enzyme supplemented PKC diets asreplacement for maize was investigated wth 210, 20 week old layng pullets of Dominant Black strain at the Teaching and Research Farm of the Delta State University, Asaba Campus, Nigeria. The birds which ust come into ...
Martin, Thomas E.
Resource selection specialization may increase vulnerability of populations to environmental change. One environmental change that may negatively impact some populations is the broad decline of quaking aspen Populus tremuloides, a preferred nest tree of cavity-nesting organisms who are commonly limited by nest-site availability. However, the long-term consequences of this habitat change for cavity-nesting bird populations are poorly studied.
This report summarizes the results of a study to identify the habitat use and behavior of the upland sandpiper, : a state-endangered bird species, at Portsmouth International Airport (PSM), which is near the Great Bay National : Wildlife Refuge (GBNW...
Anteau, Michael J; Sherfy, Mark H; Wiltermuth, Mark T
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.
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.
Knutson, M.G.; Ribic, C.; Hohman, William
Melinda Knutson (USGS Upper Midwest Environmental Sciences Center) and Christine Ribic (USGS Wisconsin Cooperative Wildlife Research Unit) contributed to a recent report published by the USDA Natural Resources Conservation Service. The report summarizes a workshop held 8 December 1999 in Chicago, IL. Highlights of the report include resources and land management recommendations for riparian zones in the Midwest. The full report will soon be available at the USDA NRCS Wildlife Habitat Management Institute website: http://www.ms.nrcs.usda.gov/whmi/habitat.htm Knutson, M., and C. Ribic. 2000. Management of riparian habitat for mammals, birds, reptiles, and amphibians. Pages 22-24, Appendix C in W. Hohman, ed. NRCS Management and Restoration of Midwestern Riparian Systems Workshop Report. USDA Natural Resources Conservation Service, Chicago, IL.
Gorresen, P. Marcos; Camp, Richard J.; Gaudioso, Jacqueline; Brinck, Kevin W.; Berkowitz, Paul; Jacobi, James D.
Biological diversity, or biodiversity, is the variety and abundance of species in a defined area, and is one of the oldest and most basic descriptions of biological communities. Understanding how populations and communities are structured and change over space and time in response to internal and external forces is a management priority. Effective management practices and conservation strategies depend on our understanding of the relationship between changes in biodiversity and ecological drivers such as invasive species, land use and climate change. To demonstrate how changes in biodiversity may be monitored over a large (400 km2) tract of native forest habitat, we compared bird and plant community composition and structure in an upper montane region of Hawai‘i Island originally surveyed in 1977 as part of the Hawai‘i Forest Bird Survey (Scott et al. 1986) with a comprehensive sample of the same region in 2015.Our findings suggest that across a region spanning an elevation range of 600 to 2,000 m considerable changes occurred in the plant and bird communities between 1977 and 2015. Endemic and indigenous plants species richness (i.e., total number of species) decreased dramatically in the low and middle elevations below an invasive weed front, whereas naturalized plant species richness did not change between the two periods at any elevation. Endemic bird abundance decreased and two species were lost in the lower elevations (environment. Forest habitat in a variety of settings (i.e., islands and regions with differing land-use histories and elevation ranges), however, can provide opportunities to evaluate the influence of ecological drivers. Declines in native bird biodiversity in low-elevation areas may be attributed to invasive species as land use and climate conditions have remained relatively similar over the 40-year period. Thus, the shift from an endemic-naturalized co-dominated community in 1977 to one dominated by naturalized, alien birds in 2015, and
Michelle M Jackson
Full Text Available North America's coastal mountains are particularly vulnerable to climate change, yet harbour a number of endemic species. With little room "at the top" to track shifting climate envelopes, alpine species may be especially negatively affected by climate-induced habitat fragmentation. We ask how climate change will affect the total amount, mean patch size, and number of patches of suitable habitat for Vancouver Island White-tailed Ptarmigan (Lagopus leucura saxatilis; VIWTP, a threatened, endemic alpine bird. Using a Random Forest model and a unique dataset consisting of citizen science observations combined with field surveys, we predict the distribution and configuration of potential suitable summer habitat for VIWTP under baseline and future (2020s, 2050s, and 2080s climates using three general circulation models and two greenhouse gas scenarios. VIWTP summer habitat is predicted to decline by an average of 25%, 44%, and 56% by the 2020s, 2050s, and 2080s, respectively, under the low greenhouse gas scenario and 27%, 59%, and 74% under the high scenario. Habitat patches are predicted to become fragmented, with a 52-79% reduction in mean patch size. The average elevation of suitable habitat patches is expected to increase, reflecting a loss of patches at lower elevations. Thus ptarmigan are in danger of being "squeezed off the mountain", as their remaining suitable habitat will be increasingly confined to mountaintops in the center of the island. The extent to which ptarmigan will be able to persist in increasingly fragmented habitat is unclear. Much will depend on their ability to move throughout a more heterogeneous landscape, utilize smaller breeding areas, and survive increasingly variable climate extremes. Our results emphasize the importance of continued monitoring and protection for high elevation specialist species, and suggest that White-tailed Ptarmigan should be considered an indicator species for alpine ecosystems in the face of
van Hees, S.R.W.
This article discusses two legal issues that relate to the conflict between the interest of protecting habitats and species under the Habitats and Birds Directives, versus the interest of promoting the use of innovative water-related renewable energy, with regard to the quota in the Renewable Energy
Kirsten M. Parris
Full Text Available Roadside habitats are important for a range of taxa including plants, insects, mammals, and birds, particularly in developed countries in which large expanses of native vegetation have been cleared for agriculture or urban development. Although roadside vegetation may provide suitable habitat for many species, resident animals can be exposed to high levels of traffic noise, visual disturbance from passing vehicles, and the risk of collision with cars and trucks. Traffic noise can reduce the distance over which acoustic signals such as song can be detected, an effect known as acoustic interference or masking. Studies from the northern hemisphere show that the singing behavior of birds changes in the presence of traffic noise. We investigated the impact of traffic noise and traffic volume on two species of birds, the Grey Shrike-thrush (Colluricincla harmonica and the Grey Fantail (Rhipidura fuliginosa, at 58 roadside sites on the Mornington Peninsula, southeastern Australia. The lower singing Grey Shrike-thrush sang at a higher frequency in the presence of traffic noise, with a predicted increase in dominant frequency of 5.8 Hz/dB of traffic noise, and a total effect size of 209 Hz. In contrast, the higher singing Grey Fantail did not appear to change its song in traffic noise. The probability of detecting each species on a visit to a site declined substantially with increasing traffic noise and traffic volume, with several lines of evidence supporting a larger effect of traffic noise. Traffic noise could hamper detection of song by conspecifics, making it more difficult for birds to establish and maintain territories, attract mates and maintain pair bonds, and possibly leading to reduced breeding success in noisy roadside habitats. Closing key roads during the breeding season is a potential, but untested, management strategy to protect threatened bird species from traffic noise and collision with vehicles at the time of year when they are most
De Coster, Greet; Banks-Leite, Cristina; Metzger, Jean Paul
Habitat loss often reduces the number of species as well as functional diversity. Dramatic effects to species composition have also been shown, but changes to functional composition have so far been poorly documented, partly owing to a lack of appropriate indices. We here develop three new community indices (i.e. functional integrity, community integrity of ecological groups and community specialization) to investigate how habitat loss affects the diversity and composition of functional traits and species. We used data from more than 5000 individuals of 137 bird species captured in 57 sites in the Brazilian Atlantic Forest, a highly endangered biodiversity hotspot.Results indicate that habitat loss leads to a decrease in functional integrity while measures of functional diversity remain unchanged or are even positively affected. Changes to functional integrity were caused by (i) a decrease in the provisioning of some functions, and an increase in others; (ii) strong within-guild species turnover; and (iii) a replacement of specialists by generalists. Hence, communities from more deforested sites seem to provide different but not fewer functions. We show the importance of investigating changes to both diversity and composition of functional traits and species, as the effects of habitat loss on ecosystem functioning may be more complex than previously thought. Crucially, when only functional diversity is assessed, important changes to ecological functions may remain undetected and negative effects of habitat loss underestimated, thereby imperiling the application of effective conservation actions.
Roger Tankersley, Jr.
Full Text Available Intact migratory routes are critical for the stability of forest-dwelling, neotropical, migratory bird populations, and mortality along migratory pathways may be significant. Yet we know almost nothing about the geography of available stopovers or the possible migratory pathways that connect optimal stopovers. We undertake a spatial analysis of stopover habitat availability and then model potential migratory pathways between optimal stopovers in the eastern United States. Using models of fixed orientation and fixed nightly flight distance between stopovers during spring migration, we explore whether a simple endogenous migratory program is sufficient to ensure successful migration across the modern landscape. Our model runs suggest that the modern distribution of optimum stopovers in the eastern United States can be adequately exploited by birds following migratory pathways defined by fixed-orientation and fixed-distance nightly flights. Longer flight distances may increase the chances of success by enabling migrants to bypass locales offering little habitat. Our results also suggest that most southwest-northeast migratory pathways through the Appalachian mountains are intact. Lack of optimal habitat at key locations in the Southeast causes many modeled pathways to fail. We present a speculative view of regional migration patterns implied by predominant ideas found in stopover ecology literature, and demonstrate the need for broad-scale migration research, in the hope that our approach will foster other continental- and regional-scale projects.
Girma, Zerihun; Mamo, Yosef; Mengesha, Girma; Verma, Ashok; Asfaw, Tsyon
The habitat use and seasonal migratory pattern of birds in Ethiopia is less explored as compared to diversity studies. To this end, this study aimed at investigating the patterns of distribution related to seasonality and the effect of habitat characteristics (elevation, slope, and average vegetation height) on habitat use of birds of Wondo Genet Forest Patch. A stratified random sampling design was used to assess the avian fauna across the four dominant habitat types found in the study area: natural forest, wooded grassland, grassland, and agroforestry land. A point transect count was employed to investigate avian species richness and abundance per habitat type per season. Ancillary data, such as elevation above sea level, latitude and longitude, average vegetation height, and percent slope inclination, were recorded with a GPS and clinometers per plot. A total of 33 migratory bird species were recorded from the area, of which 20 species were northern (Palearctic) migrants while 13 were inter-African migrants. There was a significant difference in the mean abundance of migratory bird species between dry and wet seasons ( t = 2.13, p = .038, df = 44). The variation in mean abundance per plot between the dry and wet seasons in the grassland habitat was significant ( t = 2.35, p = .051, df = 7). In most habitat types during both dry and wet seasons, omnivore birds were the most abundant. While slope was a good predictor for bird species abundance in the dry season, altitude and average vegetation height accounted more in the wet season. The patch of forest and its surrounding is an important bird area for migratory, endemic, and global threatened species. Hence, it is conservation priority area, and the study suggests that conservation coupled with ecotourism development is needed for its sustainability.
Edmund J. Zlonis
Full Text Available Human-induced effects on lowland conifer forests in hemiboreal regions are increasing because of expanded use of these northern ecosystems for raw materials, energy, and minerals as well as the potential effects of climatic changes. These forests support many breeding bird species across the Holarctic and allow the persistence of several boreal bird species in hemiboreal and even temperate regions. These bird species are of particular conservation concern as shifting patterns northward in forest composition caused by climate change will likely affect their populations. However, effective management and conservation options are limited because the specifics of these species' breeding habitats are not well understood. We modeled and mapped habitat suitability for 11 species of boreal birds that breed in the lowland conifer forests of the Agassiz Lowlands Ecological Subsection in northern Minnesota and are likely to have reduced breeding habitat in the future: Spruce Grouse (Falcipennis canadensis, Black-backed Woodpecker (Picoides arcticus, Olive-sided Flycatcher (Contopus cooperi, Yellow-bellied Flycatcher (Empidonax flaviventris, Boreal Chickadee (Poecile hudsonicus, Golden-crowned Kinglet (Regulus satrapa, Ruby-crowned Kinglet (Regulus calendula, Swainson's Thrush (Catharus ustulatus, Connecticut Warbler (Oporornis agilis, Palm Warbler (Setophaga palmarum, and Dark-eyed Junco (Junco hyemalis. Sets of 7 to 16 potential environmental covariates, including both stand-level and landscape attributes, were used to develop individual species models. Within this lowland conifer-dominated ecosystem, we found significant selection for specific forest and landscape characteristics by all but one of these species, with the best models including between one and nine variables. Habitat suitability maps were developed from these models and predictions tested with an independent dataset. Model performance depended on species, correctly predicting 56-96% of
Chalfoun, A.D.; Martin, T.E.
1. Identifying the habitat features that influence habitat selection and enhance fitness is critical for effective management. Ecological theory predicts that habitat choices should be adaptive, such that fitness is enhanced in preferred habitats. However, studies often report mismatches between habitat preferences and fitness consequences across a wide variety of taxa based on a single spatial scale and/or a single fitness component. 2. We examined whether habitat preferences of a declining shrub steppe songbird, the Brewer's sparrow Spizella breweri, were adaptive when multiple reproductive fitness components and spatial scales (landscape, territory and nest patch) were considered. 3. We found that birds settled earlier and in higher densities, together suggesting preference, in landscapes with greater shrub cover and height. Yet nest success was not higher in these landscapes; nest success was primarily determined by nest predation rates. Thus landscape preferences did not match nest predation risk. Instead, nestling mass and the number of nesting attempts per pair increased in preferred landscapes, raising the possibility that landscapes were chosen on the basis of food availability rather than safe nest sites. 4. At smaller spatial scales (territory and nest patch), birds preferred different habitat features (i.e. density of potential nest shrubs) that reduced nest predation risk and allowed greater season-long reproductive success. 5. Synthesis and applications. Habitat preferences reflect the integration of multiple environmental factors across multiple spatial scales, and individuals may have more than one option for optimizing fitness via habitat selection strategies. Assessments of habitat quality for management prescriptions should ideally include analysis of diverse fitness consequences across multiple ecologically relevant spatial scales. ?? 2007 The Authors.
Barrow, Wylie C.; Baldwin, Michael J.; Randall, Lori A.; Pitre, John; Dudley, Kyle J.
This project was initiated to assess migrating and wintering bird use of lands enrolled in the Natural Resources Conservation Service’s (NRCS) Migratory Bird Habitat Initiative (MBHI). The MBHI program was developed in response to the Deepwater Horizon oil spill in 2010, with the goal of improving/creating habitat for waterbirds affected by the spill. In collaboration with the University of Delaware (UDEL), we used weather surveillance radar data (Sieges 2014), portable marine radar data, thermal infrared images, and visual observations to assess bird use of MBHI easements. Migrating and wintering birds routinely make synchronous flights near dusk (e.g., departure during migration, feeding flights during winter). Weather radars readily detect birds at the onset of these flights and have proven to be useful remote sensing tools for assessing bird-habitat relations during migration and determining the response of wintering waterfowl to wetland restoration (e.g., Wetlands Reserve Program lands). However, ground-truthing is required to identify radar echoes to species or species group. We designed a field study to ground-truth a larger-scale, weather radar assessment of bird use of MBHI sites in southwest Louisiana. We examined seasonal bird use of MBHI fields in fall, winter, and spring of 2011-2012. To assess diurnal use, we conducted total area surveys of MBHI sites in the afternoon, collecting data on bird species composition, abundance, behavior, and habitat use. In the evenings, we quantified bird activity at the MBHI easements and described flight behavior (i.e., birds landing in, departing from, circling, or flying over the MBHI tract). Our field sampling captured the onset of evening flights and spanned the period of collection of the weather radar data analyzed. Pre- and post-dusk surveys were conducted using a portable radar system and a thermal infrared camera. Landbirds, shorebirds, and wading birds were commonly found on MBHI fields during diurnal
Wilson, T.L.; Johnson, E.J.; Bissonette, J.A.
There is debate among ecologists about whether total habitat area or patch arrangement contributes most to population and/or community responses to fragmented or patchy landscapes. We tested the relative effects of patch area and isolation for predicting bird occurrence in a naturally patchy landscape in the Bear River Mountains of Northern Utah, USA. We selected focal patches (mountain meadows) ranging in elevation from 1,920 to 2,860 m and in size from 0.6 to 182 ha. Breeding birds were sampled in each focal meadow during the summers of 2003 and 2004 using variable-distance point transects. Logistic regression and likelihood-based model selection were used to determine the relationship between likelihood of occurrence of three bird species (Brewer's sparrow, vesper sparrow, and white-crowned sparrow) and area, isolation, and proximity metrics. We used model weights and model-averaged confidence intervals to assess the importance of each predictor variable. Plots of area versus isolation were used to evaluate complex relationships between the variables. We found that meadow area was the most important variable for explaining occurrence for two species, and that isolation was the most important for the other. We also found that the absolute distance was more appropriate for evaluating isolation responses than was the species-specific proximity metric. Our findings add clarity to the debate between ecologists regarding the relative importance of area and isolation in species responses to patchy landscapes.
Full Text Available There is a lack of data on the population densities of birds breeding in a mosaic of typical urbanized habitats. This study was undertaken to partly fulfil this gap in our knowledge. Counts were conducted in 2008 by means of simplified territory mapping method in a fragment (1197 ha of a large Central European city (Wrocław, SW Poland. In total, 50 bird species were breeding in the study area in 2008. The House Sparrow Passer domesticus, Common Swift Apus apus and Rock Dove comprised about 3/5 of all breeding pairs. The other group of species, each one with a density between 6 and 13 pairs per 100 ha, included seven species, namely the Starling, Sturnus vulgaris, Greenfinch, Carduelis chloris, House Martin, Delichon urbica, Tree Sparrow, Passer montanus, Great Tit, Parus major, Blue Tit, Parus caeruleus, and Jackdaw, Corvus monedula. They comprised together about 1/5. The remaining 40 species nested in a density between 0.1 and 3.5 pairs per 100 ha. The most numerous feeding guild were granivores (53.8% and insectivores (37.9 %. Birds nesting on buildings comprised together 74 % of all breeding pairs. For a few species (Luscinia megarhynchos, Saxicola torquata, Corvus cornix and Turdus pilaris an increase in their numbers in the last three decades has been evidenced.
Ramírez-Albores, Jorge E
In many parts of the neotropics, the original habitats are rapidly changing because of excessive logging, agriculture and livestock activity, with an often negative impact on bird communities. I present an analysis of the diversity and richness of birds in a fragmented landscape of the Central Chiapas Depression. Fieldwork was conducted from February 2003 to January 2004. Using point counts, a total of 35 families and 225 bird species were registered (164 residents and 61 migratory); 3% are abundant and 30% rare. Diversity, species richness and number of individuals were significantly higher in tropical deciduous forest (H'=3.41, 178 species ANOVA p<0.0001), which also had the greatest number of species restricted to a single vegetation type (39 species). The incorporation and maintenance of natural and modified habitats are necessary for the survival and reproduction of many birds species in the study area.
Korfanta, N.M.; Newmark, W.D.; Kauffman, M.J.
Tropical deforestation continues to cause population declines and local extinctions in centers of avian diversity and endemism. Although local species extinctions stem from reductions in demographic rates, little is known about how habitat fragmentation influences survival of tropical bird populations or the relative importance of survival and fecundity in ultimately shaping communities. We analyzed 22 years of mark-recapture data to assess how fragmentation influenced apparent survival, recruitment, and realized population growth rate within 22 forest understory bird species in the Usambara Mountains, Tanzania. This represents the first such effort, in either tropical or temperate systems, to characterize the effect of deforestation on avian survival across such a broad suite of species. Long-term demographic analysis of this suite of species experiencing the same fragmented environment revealed considerable variability in species' responses to fragmentation, in addition to general patterns that emerged from comparison among species. Across the understory bird community as a whole, we found significantly lower apparent survival and realized population growth rate in small fragments relative to large, demonstrating fragmentation effects to demographic rates long after habitat loss. Demographic rates were depressed across five feeding guilds, suggesting that fragmentation sensitivity was not limited to insectivores. Seniority analyses, together with a positive effect of fragmentation on recruitment, indicated that depressed apparent survival was the primary driver of population declines and observed extinctions. We also found a landscape effect, with lower vital rates in one mountain range relative to another, suggesting that fragmentation effects may add to other large-scale drivers of population decline. Overall, realized population growth rate (λ) estimates were < 1 for most species, suggesting that future population persistence even within large forest
Korfanta, Nicole M; Newmark, William D; Kauffman, Matthew J
Tropical deforestation continues to cause population declines and local extinctions in centers of avian diversity and endemism. Although local species extinctions stem from reductions in demographic rates, little is known about how habitat fragmentation influences survival of tropical bird populations or the relative importance of survival and fecundity in ultimately shaping communities. We analyzed 22 years of mark-recapture data to assess how fragmentation influenced apparent survival, recruitment, and realized population growth rate within 22 forest understory bird species in the Usambara Mountains, Tanzania. This represents the first such effort, in either tropical or temperate systems, to characterize the effect of deforestation on avian survival across such a broad suite of species. Long-term demographic analysis of this suite of species experiencing the same fragmented environment revealed considerable variability in species' responses to fragmentation, in addition to general patterns that emerged from comparison among species. Across the understory bird community as a whole, we found significantly lower apparent survival and realized population growth rate in small fragments relative to large, demonstrating fragmentation effects to demographic rates long after habitat loss, Demographic rates were depressed across five feeding guilds, suggesting that fragmentation sensitivity was not limited to insectivores. Seniority analyses, together with a positive effect of fragmentation on recruitment, indicated that depressed apparent survival was the primary driver of population declines and observed extinctions. We also found a landscape effect, with lower vital rates in one mountain range relative to another, suggesting that fragmentation effects may add to other large-scale drivers of population decline. Overall, realized population growth rate (lambda) estimates were fragments, is uncertain in this biodiversity hotspot.
Knick, Steven T.; Hanser, Steve; Grace, James B.; Hollenbeck, Jeff P.; Leu, Matthias
Piñon (Pinus spp.) and juniper (Juniperus spp.) woodlands have been expanding their range across the intermountain western United States into landscapes dominated by sagebrush (Artemisia spp.) shrublands. Management actions using prescribed fire and mechanical cutting to reduce woodland cover and control expansion provided opportunities to understand how environmental structure and changes due to these treatments influence bird communities in piñon-juniper systems. We surveyed 43 species of birds and measured vegetation for 1–3 years prior to treatment and 6–7 years post-treatment at 13 locations across Oregon, California, Idaho, Nevada, and Utah. We used structural equation modeling to develop and statistically test our conceptual model that the current bird assembly at a site is structured primarily by the previous bird community with additional drivers from current and surrounding habitat conditions as well as external regional bird dynamics. Treatment reduced woodland cover by >5% at 80 of 378 survey sites. However, habitat change achieved by treatment was highly variable because actual disturbance differed widely in extent and intensity. Biological inertia in the bird community was the strongest single driver; 72% of the variation in the bird assemblage was explained by the community that existed seven years earlier. Greater net reduction in woodlands resulted in slight shifts in the bird community to one having ecotone or shrubland affinities. However, the overall influence of woodland changes from treatment were relatively small and were buffered by other extrinsic factors. Regional bird dynamics did not significantly influence the structure of local bird communities at our sites. Our results suggest that bird communities in piñon-juniper woodlands can be highly stable when management treatments are conducted in areas with more advanced woodland development and at the level of disturbance measured in our study.
Pomara, Lars Y; Cooper, Robert J; Petit, Lisa J
We examined the importance of mixed-species flock abundance, individual bird home range size, foraging height, and foraging patch characteristics in predicting the propensity for five Neotropical passerine bird species (Slaty Antwren, Myrmotherula schisticolor; Golden-crowned Warbler, Basileuterus culicivorus; Slate-throated Redstart, Myioborus miniatus; Wilson's Warbler, Wilsonia pusilla; and Black-and-white Warbler, Mniotilta varia) to forage within flocks, rather than solitarily. We used study plots in primary mid-elevation forest and in shade coffee fields in western Panama. We expected that all species would spend as much time as possible flocking, but that the social and environmental factors listed above would limit compatibility between flock movements and individual bird movements, explaining variability in flocking propensity both within and among species. Flocking propensity was well predicted by home range size and flock abundance together, for four of the five species. While flock abundance was uniform across plots, home range sizes varied among species and plots, so that home range size appeared to be the principle factor limiting flocking propensity. Estimates of flock abundance were still required, however, for calculating flocking propensity values. Foraging height and patch characteristics slightly improved predictive ability for the remaining species, M. miniatus. In general, individual birds tended to join flocks whenever one was available inside their home range, regardless of a flock's specific location within the home range. Flocking propensities of individual species were lower in shade coffee fields than in forests, and probably vary across landscapes with variations in habitat. This variability affects the stability and species composition of flocks, and may affect survival rates of individual species.
Virkkala, Raimo; Heikkinen, Risto K; Fronzek, Stefan; Leikola, Niko
National reserve networks are one of the most important means of species conservation, but their efficiency may be diminished due to the projected climatic changes. Using bioclimatic envelope models and spatial data on habitats and conservation areas, we studied how efficient the reserve network will be in preserving 100 forest, mire, marshland, and alpine bird species of conservation concern in Finland in 2051-2080 under three different climate scenarios. The occurrences of the studied bird species were related to the amount of habitat preferred by each species in the different boreal zones. We employed a novel integrated habitat suitability index that takes into account both the species' probability of occurrence from the bioclimatic models and the availability of suitable habitat. Using this suitability index, the distribution of the topmost 5% suitability squares ("hotspots") in the four bird species groups in the period 1971-2000 and under the three scenarios were compared with the location of reserves with the highest amounts of the four habitats to study the efficiency of the network. In species of mires, marshlands, and Arctic mountains, a high proportion of protected habitat was included in the 5% hotspots in the scenarios in 2051-2080, showing that protected areas cover a high proportion of occurrences of bird species. In contrast, in forests in the southern and middle boreal zones, only a small proportion of the protected habitat was included in the 5% hotspots, indicating that the efficiency of the protected area network will be insufficient for forest birds in the future. In the northern boreal zone, the efficiency of the reserve network in forests was highly dependent on the strength of climate change varying between the scenarios. Overall, there is no single solution to preserving biodiversity in a changing climate, but several future pathways should be considered.
Full Text Available This study was aimed at preparing an inventory of the avifauna and to document the species composition of birds during winter in different habitat types of Rosekandy Tea Estate of Cachar District of Assam. Four habitat types, viz., tea plantation, ecotone zone, secondary growth forest and water bodies were selected within the tea estate and surveyed from mid-December 2010 (early winter to mid-April 2011 (late winter covering four months of survey. A total of 88 species were recorded during the survey period with the highest number of species in ecotone zone (n=63, followed by secondary forest (n=60, tea plantation (n=48 and water bodies (n=17. The species were further categorized into different feeding and habitat guilds to study the distribution of bird species in different habitat types according to various guilds.
Vepsaelaeinen, Ville [Finnish Museum of Natural History, P.O. Box 17, University of Helsinki, FI-00014 Helsinki (Finland)
Here, I present the first comparison of the abundance of farmland birds in energy grass fields and in cereal-dominated conventionally cultivated fields (CCFs). I demonstrate that in boreal farmland, skylark (Alauda arvensis) densities were significantly lower in reed canary grass (RCG) (Phalaris arundinacea) fields than in CCFs. I found that during the early breeding season RCG fields and CCFs are equally good habitats, but over the ensuing couple of weeks RCG rapidly grows too tall and dense for field-nesting species. Consequently, RCG is an inferior habitat for skylark for laying replacement clutches (after failure of first nesting) or for a second clutch after one successful nesting. The results imply that if RCG cultivation is to be expanded, the establishment of large monocultures should be avoided in farmland landscapes; otherwise the novel habitat may affect detrimentally the seriously depleted skylark population, and probably also other field-nesting bird species with similar breeding habitats. (author)
J. Dananjaya Kottawa-Arachchi
Full Text Available A survey on birds was conducted at St. Coombs Tea Estate, Talawakelle, Sri Lanka with the objective of assessing the avifaunal diversity of a given tea plantation ecosystem. Bird populations were sampled in man-made habitats such as home garden, wetland, tea plantation, Eucalyptus plantation and small scale reservoir. Hundred-and-twenty counts were made for each habitat and in addition, activities of birds, feeding habits and food recourses were also observed. A total of 87 species, including 11 endemic and 11 migrant species of birds, was recorded, which included one globally threatened species, Kashmir Flycatcher Ficedula subrubra and 16 nationally threatened species. A majority of the bird species were observed in home gardens (75%, followed by reservoirs (57%, wetlands (48%, tea plantations (43% and in Eucalyptus plantations (23%. Home gardens support bird diversity while the species richness of endemic bird species increases thereby enabling these findings to be used as guidelines in long term conservational practices. Several conservation measures such as increasing plant diversity, introduction of shade trees and prevention of fire are recommended to conserve and enhance avifaunal diversity in tea plantations.
Kaiser, Sara A; Sillett, T Scott; Risk, Benjamin B; Webster, Michael S
Environmental factors can shape reproductive investment strategies and influence the variance in male mating success. Environmental effects on extrapair paternity have traditionally been ascribed to aspects of the social environment, such as breeding density and synchrony. However, social factors are often confounded with habitat quality and are challenging to disentangle. We used both natural variation in habitat quality and a food supplementation experiment to separate the effects of food availability-one key aspect of habitat quality-on extrapair paternity (EPP) and reproductive success in the black-throated blue warbler, Setophaga caerulescens. High natural food availability was associated with higher within-pair paternity (WPP) and fledging two broods late in the breeding season, but lower EPP. Food-supplemented males had higher WPP leading to higher reproductive success relative to controls, and when in low-quality habitat, food-supplemented males were more likely to fledge two broods but less likely to gain EPP. Our results demonstrate that food availability affects trade-offs in reproductive activities. When food constraints are reduced, males invest in WPP at the expense of EPP. These findings imply that environmental change could alter how individuals allocate their resources and affect the selective environment that drives variation in male mating success. © 2015 The Author(s) Published by the Royal Society. All rights reserved.
The Wadden Sea region is one of the most important breeding areas in Western Europe for coastal breeding bird species. It is expected that management of salt marshes is important for successful conservation of breeding bird populations but the impact of management on the habitat quality for breeding birds is still not fully understood. In this study the effects of management on the three crucial habitat characteristics for breeding birds were studied on mainland salt marshes: effects of manag...
Gillings, Simon; Fuller, Robert J
Farmland bird population trends were examined on a sample of lowland English farms to assess the relative importance of habitat loss and habitat degradation. Data were extracted from 11 farms surveyed by territory mapping between 1966 and 1986 as part of the British Trust for Ornithology's Common Birds Census. The population size of 38 bird species was quantified for each farm in each year. The extents of five non-crop habitats were measured at 4-yearly intervals on each farm. The farms were selected because some had undergone extensive removal of non-crop habitats while others had undergone little or none. Although declines were commonest on farms where the severest habitat loss had taken place, we found no evidence that habitat loss was the main factor causing population declines: all 11 farms had significant numbers of declining species, even where habitat loss was minimal. Furthermore, general linear modelling found no significant effects of habitat loss on population trends and principal-components analysis found limited effects of habitat extent on community composition. These results suggest that habitat loss is of secondary importance in causing farmland bird population declines. We suggest that other processes, such as habitat degradation, may have caused a baseline population decline in at least 10 farmland bird species and that declines may have been exacerbated by localised habitat loss.
Minias, Piotr; Włodarczyk, Radosław; Surmacki, Adrian; Iciek, Tomasz
A silver spoon effect means that individuals who develop under favourable circumstances enjoy a fitness or performance advantage later in life. While there is large empirical support for silver spoon effects acting on different life-history traits in birds, such as survival and reproduction, the evidence for the carry-over effects of rearing conditions on the quality of future plumage generations is lacking. Here, we examined whether abilities of individuals to undergo extensive post-juvenile moult may depend on the quality of juvenile plumage developed during the nestling phase in a small passerine showing large individual variation in the extent of post-juvenile moult, the greenfinch (Carduelis chloris). We found that high structural quality and carotenoid chroma of juvenile feathers were positively linked to the extent of post-juvenile moult in this species, thus allowing young birds to attain more adult-like plumage. Silver spoon effects mediated by the juvenile plumage quality were also found to have other fitness-related consequences, as individuals with high-quality juvenile feathers were in better condition during their first winter. As far as we are aware, the results provide the first correlative evidence for a silver spoon effect acting on general plumage quality in birds.
Ryan Carnie; Daniele Tonina; Jim McKean; Daniel Isaak
Quality of fish habitat at the scale of a single fish, at the metre resolution, which we defined here as microhabitat, has been primarily evaluated on short reaches, and their results have been extended through long river segments with methods that do not account for connectivity, a measure of the spatial distribution of habitat patches. However, recent...
Richard E. Feldman; Pamela G. Krannitz
Garry oak (Quercus garryana) was once a dominant habitat type on southeastern Vancouver Island, British Columbia but urbanization has severely fragmented and reduced its occurrence. This study tests whether bird abundance in remnant patches of Garry oak and adjacent Douglas-fir (Pseudotsuga menziesii) is related to Garry oak volume...
Moens, Michaël A J; Valkiūnas, Gediminas; Paca, Anahi; Bonaccorso, Elisa; Aguirre, Nikolay; Pérez-Tris, Javier
Understanding how parasites fill their ecological niches requires information on the processes involved in the colonization and exploitation of unique host species. Switching to hosts with atypical attributes may favour generalists broadening their niches or may promote specialization and parasite diversification as the consequence. We analysed which blood parasites have successfully colonized hummingbirds, and how they have evolved to exploit such a unique habitat. We specifically asked (i) whether the assemblage of Haemoproteus parasites of hummingbirds is the result of single or multiple colonization events, (ii) to what extent these parasites are specialized in hummingbirds or shared with other birds and (iii) how hummingbirds contribute to sustain the populations of these parasites, in terms of both prevalence and infection intensity. We sampled 169 hummingbirds of 19 species along an elevation gradient in Southern Ecuador to analyse the host specificity, diversity and infection intensity of Haemoproteus by molecular and microscopy techniques. In addition, 736 birds of 112 species were analysed to explore whether hummingbird parasites are shared with other birds. Hummingbirds hosted a phylogenetically diverse assemblage of generalist Haemoproteus lineages shared with other host orders. Among these parasites, Haemoproteus witti stood out as the most generalized. Interestingly, we found that infection intensities of this parasite were extremely low in passerines (with no detectable gametocytes), but very high in hummingbirds, with many gametocytes seen. Moreover, infection intensities of H. witti were positively correlated with the prevalence across host species. Our results show that hummingbirds have been colonized by generalist Haemoproteus lineages on multiple occasions. However, one of these generalist parasites (H. witti) seems to be highly dependent on hummingbirds, which arise as the most relevant reservoirs in terms of both prevalence and
Desmawati, Iska; Indah Trisnawati D., T.; Kurnia, Ory; Hamdani, Albi; Fahmi, Mahsun; Fahmi, Mirza
Migratory Birds are responding to recent climate change in variety of ways. Distribution study of migratory birds will help to understand climate change effect in ecosystem area. Its supported by natural resources all around Indonesia. One of this place is Surabaya city specially Wonorejo area. Wonorejo is one of the Important Bird Area (IBA), specifically for bird conserved by Indonesian law and migratory birds. This research aims to know that distribution study on migratory bird enhances the knowledge of climate change effect. The distribution study use mapping method and the environment variables study analyzed by multivariate analysis. The description about how to analize the climate change effect in this area will be described by map and ilustration model. The result show that migratory bird (Scolopacidae) use different area of preference habitat in Wonorejo during migratory season on 2010-2016. In particular, the details of population and scale is likely to characterize global change biodiversity of migratory birds research need to improve in future.
Dinesh BHATT, Kamal Kant JOSHI
Full Text Available The Indian subcontinent is amongst the biologically better known parts of the tropics and its bird fauna has been well documented. However, avian community composition and diversity along elevational gradients and amongst habitat types remains unclear in India. We attempted to estimate bird assemblages in terms of diversity, species composition, status and abundance in urban and forest habitats of Nainital district of Uttarakhand (350–2450 m asl; 29°N, Western Himalayas. We sampled different elevational gradients and to understand the effect of urbanization and season on avian community composition. Field studies were conducted during January 2005 to January 2007. Results indicated that the forest had more complex bird community structure in terms of higher species richness (14.35 vs 8.69, higher species diversity (Shannon’s index 4.00 vs 3.54, higher evenness (0.838 vs 0.811 and more rare species (17 vs 5 as compared to urban habitat. However, the abundance of 11 species was higher in urban habitats. Bird Species Richness (BSR varied considerably among study areas (91 to 113 species, was highest (113 species at mid elevation (1450–1700 m asl and decreased (22 species at high elevation (1900–2450 m asl. It seems that high BSR at mid altitudes is not caused by the presence of a group of mid altitude specialists but rather that there is an overlap in the distribution of low land and high elevation specialists at this altitude. BSR and Bird Species Diversity fluctuated across seasons but not habitat type [Current Zoology 57 (3: 318–329, 2011].
Crampton, Lisa H.; Brinck, Kevin W.; Pias, Kyle E.; Heindl, Barbara A. P.; Savre, Thomas; Diegmann, Julia S.; Paxton, Eben H.
Accurate estimates of the distribution and abundance of endangered species are crucial to determine their status and plan recovery options, but such estimates are often difficult to obtain for species with low detection probabilities or that occur in inaccessible habitats. The Puaiohi (Myadestes palmeri) is a cryptic species endemic to Kauaʻi, Hawai‘i, and restricted to high elevation ravines that are largely inaccessible. To improve current population estimates, we developed an approach to model distribution and abundance of Puaiohi across their range by linking occupancy surveys to habitat characteristics, territory density, and landscape attributes. Occupancy per station ranged from 0.17 to 0.82, and was best predicted by the number and vertical extent of cliffs, cliff slope, stream width, and elevation. To link occupancy estimates with abundance, we used territory mapping data to estimate the average number of territories per survey station (0.44 and 0.66 territories per station in low and high occupancy streams, respectively), and the average number of individuals per territory (1.9). We then modeled Puaiohi occupancy as a function of two remote-sensed measures of habitat (stream sinuosity and elevation) to predict occupancy across its entire range. We combined predicted occupancy with estimates of birds per station to produce a global population estimate of 494 (95% CI 414–580) individuals. Our approach is a model for using multiple independent sources of information to accurately track population trends, and we discuss future directions for modeling abundance of this, and other, rare species.
Fountain, Emily D; Kang, Jung Koo; Tempel, Douglas J; Palsbøll, Per J; Pauli, Jonathan N; Peery, M Zachariah
Understanding how habitat quality in heterogeneous landscapes governs the distribution and fitness of individuals is a fundamental aspect of ecology. While mean individual fitness is generally considered a key to assessing habitat quality, a comprehensive understanding of habitat quality in
J. Ryan. Zimmerling
Full Text Available We estimated impacts on birds from the development and operation of wind turbines in Canada considering both mortality due to collisions and loss of nesting habitat. We estimated collision mortality using data from carcass searches for 43 wind farms, incorporating correction factors for scavenger removal, searcher efficiency, and carcasses that fell beyond the area searched. On average, 8.2 ± 1.4 birds (95% C.I. were killed per turbine per year at these sites, although the numbers at individual wind farms varied from 0 - 26.9 birds per turbine per year. Based on 2955 installed turbines (the number installed in Canada by December 2011, an estimated 23,300 birds (95% C.I. 20,000 - 28,300 would be killed from collisions with turbines each year. We estimated direct habitat loss based on data from 32 wind farms in Canada. On average, total habitat loss per turbine was 1.23 ha, which corresponds to an estimated total habitat loss due to wind farms nationwide of 3635 ha. Based on published estimates of nest density, this could represent habitat for ~5700 nests of all species. Assuming nearby habitats are saturated, and 2 adults displaced per nest site, effects of direct habitat loss are less than that of direct mortality. Installed wind capacity is growing rapidly, and is predicted to increase more than 10-fold over the next 10-15 years, which could lead to direct mortality of approximately 233,000 birds / year, and displacement of 57,000 pairs. Despite concerns about the impacts of biased correction factors on the accuracy of mortality estimates, these values are likely much lower than those from collisions with some other anthropogenic sources such as windows, vehicles, or towers, or habitat loss due to many other forms of development. Species composition data suggest that < 0.2% of the population of any species is currently affected by mortality or displacement from wind turbine development. Therefore, population level impacts are unlikely
Whytock, Robin C; Fuentes-Montemayor, Elisa; Watts, Kevin; Barbosa De Andrade, Patanjaly; Whytock, Rory T; French, Paul; Macgregor, Nicholas A; Park, Kirsty J
Ecosystem function and resilience are compromised when habitats become fragmented due to land-use change. This has led to national and international conservation strategies aimed at restoring habitat extent and improving functional connectivity (i.e., maintaining dispersal processes). However, biodiversity responses to landscape-scale habitat creation and the relative importance of spatial and temporal scales are poorly understood, and there is disagreement over which conservation strategies should be prioritized. We used 160 years of historic post-agricultural woodland creation as a natural experiment to evaluate biodiversity responses to habitat creation in a landscape context. Birds were surveyed in 101 secondary, broadleaf woodlands aged 10-160 years with ≥80% canopy cover and in landscapes with 0-17% broadleaf woodland cover within 3000 m. We used piecewise structural equation modeling to examine the direct and indirect relationships between bird abundance and diversity, ecological continuity, patch characteristics, and landscape structure and quantified the relative conservation value of local and landscape scales for bird communities. Ecological continuity indirectly affected overall bird abundance and species richness through its effects on stand structure, but had a weaker influence (effect size near 0) on the abundance and diversity of species most closely associated with woodland habitats. This was probably because woodlands were rapidly colonized by woodland generalists in ≤10 years (minimum patch age) but were on average too young (median 50 years) to be colonized by woodland specialists. Local patch characteristics were relatively more important than landscape characteristics for bird communities. Based on our results, biodiversity responses to habitat creation depended on local- and landscape-scale factors that interacted across time and space. We suggest that there is a need for further studies that focus on habitat creation in a landscape
Cardador, Laura; De Cáceres, Miquel; Bota, Gerard; Giralt, David; Casas, Fabián; Arroyo, Beatriz; Mougeot, François; Cantero-Martínez, Carlos; Moncunill, Judit; Butler, Simon J; Brotons, Lluís
European agriculture is undergoing widespread changes that are likely to have profound impacts on farmland biodiversity. The development of tools that allow an assessment of the potential biodiversity effects of different land-use alternatives before changes occur is fundamental to guiding management decisions. In this study, we develop a resource-based model framework to estimate habitat suitability for target species, according to simple information on species' key resource requirements (diet, foraging habitat and nesting site), and examine whether it can be used to link land-use and local species' distribution. We take as a study case four steppe bird species in a lowland area of the north-eastern Iberian Peninsula. We also compare the performance of our resource-based approach to that obtained through habitat-based models relating species' occurrence and land-cover variables. Further, we use our resource-based approach to predict the effects that change in farming systems can have on farmland bird habitat suitability and compare these predictions with those obtained using the habitat-based models. Habitat suitability estimates generated by our resource-based models performed similarly (and better for one study species) than habitat based-models when predicting current species distribution. Moderate prediction success was achieved for three out of four species considered by resource-based models and for two of four by habitat-based models. Although, there is potential for improving the performance of resource-based models, they provide a structure for using available knowledge of the functional links between agricultural practices, provision of key resources and the response of organisms to predict potential effects of changing land-uses in a variety of context or the impacts of changes such as altered management practices that are not easily incorporated into habitat-based models.
Full Text Available European agriculture is undergoing widespread changes that are likely to have profound impacts on farmland biodiversity. The development of tools that allow an assessment of the potential biodiversity effects of different land-use alternatives before changes occur is fundamental to guiding management decisions. In this study, we develop a resource-based model framework to estimate habitat suitability for target species, according to simple information on species' key resource requirements (diet, foraging habitat and nesting site, and examine whether it can be used to link land-use and local species' distribution. We take as a study case four steppe bird species in a lowland area of the north-eastern Iberian Peninsula. We also compare the performance of our resource-based approach to that obtained through habitat-based models relating species' occurrence and land-cover variables. Further, we use our resource-based approach to predict the effects that change in farming systems can have on farmland bird habitat suitability and compare these predictions with those obtained using the habitat-based models. Habitat suitability estimates generated by our resource-based models performed similarly (and better for one study species than habitat based-models when predicting current species distribution. Moderate prediction success was achieved for three out of four species considered by resource-based models and for two of four by habitat-based models. Although, there is potential for improving the performance of resource-based models, they provide a structure for using available knowledge of the functional links between agricultural practices, provision of key resources and the response of organisms to predict potential effects of changing land-uses in a variety of context or the impacts of changes such as altered management practices that are not easily incorporated into habitat-based models.
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.
Full Text Available Research on variation in bill morphology has focused on the role of diet. Bills have other functions, however, including a role in heat and water balance. The role of the bill in heat loss may be particularly important in birds where water is limiting. Song sparrows localized in coastal dunes and salt marsh edge (Melospiza melodia atlantica are similar in size to, but have bills with a 17% greater surface area than, those that live in mesic habitats (M. m. melodia, a pattern shared with other coastal sparrows. We tested the hypotheses that sparrows can use their bills to dissipate "dry" heat, and that heat loss from the bill is higher in M. m. atlantica than M. m. melodia, which would indicate a role of heat loss and water conservation in selection for bill size.Bill, tarsus, and body surface temperatures were measured using thermal imaging of sparrows exposed to temperatures from 15-37°C and combined with surface area and physical modeling to estimate the contribution of each body part to total heat loss. Song sparrow bills averaged 5-10°C hotter than ambient. The bill of M. m atlantica dissipated up to 33% more heat and 38% greater proportion of total heat than that of M. m. melodia. This could potentially reduce water loss requirements by approximately 7.7%.This >30% higher heat loss in the bill of M. m. atlantica is independent of evaporative water loss and thus could play an important role in the water balance of sparrows occupying the hot and exposed dune/salt marsh environments during the summer. Heat loss capacity and water conservation could play an important role in the selection for bill size differences between bird populations and should be considered along with trophic adaptations when studying variation in bill size.
Amos, Nevil; Harrisson, Katherine A; Radford, James Q; White, Matt; Newell, Graeme; Mac Nally, Ralph; Sunnucks, Paul; Pavlova, Alexandra
Loss of functional connectivity following habitat loss and fragmentation could drive species declines. A comprehensive understanding of fragmentation effects on functional connectivity of an ecological assemblage requires investigation of multiple species with different mobilities, at different spatial scales, for each sex, and in different landscapes. Based on published data on mobility and ecological responses to fragmentation of 10 woodland-dependent birds, and using simulation studies, we predicted that (1) fragmentation would impede dispersal and gene flow of eight "decliners" (species that disappear from suitable patches when landscape-level tree cover falls below species-specific thresholds), but not of two "tolerant" species (whose occurrence in suitable habitat patches is independent of landscape tree cover); and that fragmentation effects would be stronger (2) in the least mobile species, (3) in the more philopatric sex, and (4) in the more fragmented region. We tested these predictions by evaluating spatially explicit isolation-by-landscape-resistance models of gene flow in fragmented landscapes across a 50 x 170 km study area in central Victoria, Australia, using individual and population genetic distances. To account for sex-biased dispersal and potential scale- and configuration-specific effects, we fitted models specific to sex and geographic zones. As predicted, four of the least mobile decliners showed evidence of reduced genetic connectivity. The responses were strongly sex specific, but in opposite directions in the two most sedentary species. Both tolerant species and (unexpectedly) four of the more mobile decliners showed no reduction in gene flow. This is unlikely to be due to time lags because more mobile species develop genetic signatures of fragmentation faster than do less mobile ones. Weaker genetic effects were observed in the geographic zone with more aggregated vegetation, consistent with gene flow being unimpeded by landscape
Møller, Anders Pape; Bonisoli-Alquati, Andrea; Mousseau, Timothy A; Rudolfsen, Geir
Following the Chernobyl nuclear power plant accident, large amounts of radionuclides were emitted and spread in the environment. Animals living in such contaminated areas are predicted to suffer fitness costs including reductions in the quality and quantity of gametes. We studied whether aspermy and sperm quality were affected by radioactive contamination by examining ejaculates from wild caught birds breeding in areas varying in background radiation level by more than three orders of magnitude around Chernobyl, Ukraine. The frequency of males with aspermy increased logarithmically with radiation level. While 18.4% of males from contaminated areas had no sperm that was only the case for 3.0% of males from uncontaminated control areas. Furthermore, there were negative relationships between sperm quality as reflected by reduced sperm velocity and motility, respectively, and radiation. Our results suggest that radioactive contamination around Chernobyl affects sperm production and quality. We are the first to report an interspecific difference in sperm quality in relation to radioactive contamination.
Stolen, Eric D.; Breininger, David R.; Smith, Rebecca B.; Quincy, Charlie (Technical Monitor)
This report summarizes results of the first eleven years of monthly aerial surveys of wading bird use of foraging habitats within impoundments on the Kennedy Space Center/Merritt Island National Wildlife Refuge. Some impoundments were used much more heavily by wading birds than were others. Analysis suggests that an increase in interspersion of open water and vegetated habitats is preferred foraging habitat. Many wading bird species increased their use of vegetated habitat in Fall and Winter when impoundments were flooded. The mean number of wading birds per survey was greatest during the Pre-nesting and Nesting seasons, declined during Post-nesting season, and was lowest during Winter when water levels within impoundments were high. During these times, shallow habitat along the IRL shoreline provided alternative habitats for wading birds. Various measures of monthly precipitation and impoundment water level were well correlated with the numbers of wading birds observed. Numbers of nesting attempts was steady during the study period, with the exception of an unusually high number of attempts in 1990. White Ibis accounted for over half of all wading bird nests counted. The mean number of nests per colony decreased during the study period, and the number of individual colonies increased.
Jesus, Shayana DE; Pedro, Wagner A; Bispo, Arthur A
Understanding the factors that affect biodiversity is of central interest to ecology, and essential to species conservation and ecosystems management. We sampled bird communities in 17 forest fragments in the Cerrado biome, the Central-West region of Brazil. We aimed to know the communities structure pattern and the influence of geographical distance and environmental variables on them, along a gradient of fragmented habitats at both local and landscape scales. Eight structural variables of the fragments served as an environmental distance measurement at the local scale while five metrics served as an environmental distance measurement at the landscape scale. Species presence-absence data were used to calculate the dissimilarity index. Beta diversity was calculated using three indices (βsim, βnes and βsor), representing the spatial species turnover, nestedness and total beta diversity, respectively. Spatial species turnover was the predominant pattern in the structure of the communities. Variations in beta diversity were explained only by the environmental variables of the landscape with spatial configuration being more important than the composition. This fact indicates that, in Cerrado of Goiás avian communities structure, deterministic ecological processes associated to differences in species responses to landscape fragmentation are more important than stochastic processes driven by species dispersal.
Singh, Minerva; Tokola, Timo; Hou, Zhengyang; Notarnicola, Claudia
Abstract Avian species persistence in a forest patch is strongly related to the degree of isolation and size of a forest patch and the vegetation structure within a patch and its matrix are important predictors of bird habitat suitability. A combination of space?borne optical (Landsat), ALOS?PALSAR (radar), and airborne Light Detection and Ranging (LiDAR) data was used for assessing variation in forest structure across forest patches that had undergone different levels of forest degradation i...
Willis, E O
Some 231 birds were recorded on a sandy plateau in central Sao Paulo, in an area forming a natural "habitat spectrum", from dry or wet grasslands to bushy ones (campo-cerrado) plus gallery scrub, marshes, and low woods. Subtracting 12 species that mostly flew over, and 56 species that seemed to be vagrants or accidental visitors, 163 species were regular (including 14 that center in nearby anthropogenically-modified zones). The 69 in gallery areas are mostly regionally common woodland species, but one southeastern species has disappeared over the years and three northwestern dry-forest species have entered. The 81 grassland species include several rare birds, and hence are important despite exhibiting lower biodiversity than in regional forest areas. Seven rare species disappeared over the years, some due to lack of fires, others because of either recent "greenhouse" dry years or protected vegetation growing to taller campo-cerrado. Several other species are becoming rare. Low vegetation forms a spectrum of temporally unstable habitats that change rapidly; one needs actively managed large areas and corridors even though many open-area birds can fly long distances to varying habitat patches.
E. O. Willis
Full Text Available Some 231 birds were recorded on a sandy plateau in central São Paulo, in an area forming a natural "habitat spectrum", from dry or wet grasslands to bushy ones (campo-cerrado plus gallery scrub, marshes, and low woods. Subtracting 12 species that mostly flew over, and 56 species that seemed to be vagrants or accidental visitors, 163 species were regular (including 14 that center in nearby anthropogenically-modified zones. The 69 in gallery areas are mostly regionally common woodland species, but one southeastern species has disappeared over the years and three northwestern dry-forest species have entered. The 81 grassland species include several rare birds, and hence are important despite exhibiting lower biodiversity than in regional forest areas. Seven rare species disappeared over the years, some due to lack of fires, others because of either recent "greenhouse" dry years or protected vegetation growing to taller campo-cerrado. Several other species are becoming rare. Low vegetation forms a spectrum of temporally unstable habitats that change rapidly; one needs actively managed large areas and corridors even though many open-area birds can fly long distances to varying habitat patches.
LaGory, K.E.; Chang, Young-Soo; Chun, K.C.; Reeves, T.; Liebich, R.; Smith, K.
This report, conducted from May through July 2000, addressed the potential effect of compressor noise on breeding birds in gas-production areas administered by the FFO, specifically in the Rattlesnake Canyon Habitat Management Area northeast of Farmington, New Mexico. The study was designed to quantify and characterize noise output from these compressors and to determine if compressor noise affected bird populations in adjacent habitat during the breeding season.
Stephen N. Matthews; Louis R. Iverson; Anantha M. Prasad; Matthew P. Peters
Mounting evidence shows that organisms have already begun to respond to global climate change. Advances in our knowledge of how climate shapes species distributional patterns has helped us better understand the response of birds to climate change. However, the distribution of birds across the landscape is also driven by biotic and abiotic components, including habitat...
Full Text Available Studies were carried out in 2010 by mean of simplified version of the mapping method. The study area (395 ha was located close to the city centre. It comprised a mosaic of urbanized habitats, with a clear dominance of green areas, such as parks (41.1 ha, gardens, cemeteries and tree clumps. A total of 48 breeding bird species were recorded in the whole study area. The most common (<25 pairs/100 ha were Passer domesticus, Passer montanus, Sturnus vulgaris, Parus caeruleus, Parus major, Apus apus and Columba livia. Numerous (7-15 pairs/100 ha were also the following species: Columba palumbus, Turdus pilaris, Sylvia atricapilla, Serinus serinus, Turdus merula and Pica pica. Insectivorous birds were the most common birds constituting 63.3%, and granivorous -32.6% of all pairs recorded. Most birds nested in tree holes (39.3%, in/on buildings (30.2% and in trees/shrubs (25.6%. Distribution of breeding pairs of 23 bird species was presented on maps. Population trends for 17 species were documented. Rapid increase in numbers of Turdus pilaris, Corvus cornix and Phoenicurus phoenicurus and decrease of Pica pica were recorded.
The effect or age of birds on shell quality and yield components of egg was studied. The birds' age were 25, 30, 58 or. 78 weeks. The eggs' weight increased by 9.92%, 26.43% and 31.46% for birds at 30, 58 and 78 weeks, respectively. While the shell weight was found to increase by 15.10, 34.55 and 30.44% for birds at 30, ...
Richard E. Feldman; Pam G. Krannitz
The Garry oak (Quercus garryana) ecosystem was once a dominant habitat type on southeastern Vancouver Island, British Columbia, but urbanization has lead to massive habitat loss and fragmentation (Hebda 1993). Most bird species are expected to respond negatively to urbanization because of increased patch isolation, increased predation pressure, and negative edge...
Møller, Anders Pape; Bonisoli-Alquati, Andrea; Mousseau, Timothy A.; Rudolfsen, Geir
Background Following the Chernobyl nuclear power plant accident, large amounts of radionuclides were emitted and spread in the environment. Animals living in such contaminated areas are predicted to suffer fitness costs including reductions in the quality and quantity of gametes. Methodology/Principal Findings We studied whether aspermy and sperm quality were affected by radioactive contamination by examining ejaculates from wild caught birds breeding in areas varying in background radiation level by more than three orders of magnitude around Chernobyl, Ukraine. The frequency of males with aspermy increased logarithmically with radiation level. While 18.4% of males from contaminated areas had no sperm that was only the case for 3.0% of males from uncontaminated control areas. Furthermore, there were negative relationships between sperm quality as reflected by reduced sperm velocity and motility, respectively, and radiation. Conclusions/Significance Our results suggest that radioactive contamination around Chernobyl affects sperm production and quality. We are the first to report an interspecific difference in sperm quality in relation to radioactive contamination. PMID:24963711
KALYA SUBASINGHE; AMILA P. SUMANAPALA
Subasinghe K, Sumanapala AP. 2014. Biological and functional diversity of bird communities in natural and human modified habitats in Northern Flank of Knuckles Mountain Forest Range, Sri Lanka. Biodiversitas 15: 200-205. The Knuckles Mountain Forest Range (KMFR) has a complex mosaic of natural and human modified habitats and the contribution of these habitats to the biological and functional diversities has not been deeply studied. Present study investigated both of these diversities in five ...
Ayup, M. M.; Montti, L.; Aragón, R.; Grau, H. R.
Ligustrum lucidum is the major exotic tree in NW Argentina montane forests (Yungas). To assess the effects of its expanding invasion on avian communities we (1) measured different habitat properties (vertical forest structure and composition, vegetation cover, light availability, air temperature, air relative humidity and soil litter depth), (2) compared bird species composition and diversity in Ligustrum-dominated and native-dominated secondary forests and (3) analyzed seasonal patterns and changes in these variables between forest types. The study was conducted during 2010-2011 wet and dry seasons, at two altitudinal zones: 500-800 and 1100-1450 masl. Compared with native forests, Ligustrum dominated forests had a more homogeneous vertical forest structure and denser canopy cover (resulting in lower understory solar radiation), significantly lower understory cover and lower litter depth. Air temperature and relative humidity did not differ between forests in either season. Solar radiation was higher in the dry season in both forest types, but litter depth showed opposite patterns between seasons depending on forest type. We recorded 59 bird species in 21 families. Bird species abundance, richness and diversity indexes were significantly lower in Ligustrum-dominated relative to native forests of similar successional age, which had almost twice as many species as the former. Avian communities differed between altitudinal zones, but the difference was stronger between Ligustrum and native-dominated forests. Avian community composition was less variable in time and space in native forests than in Ligustrum-dominated ones. Our results suggest that L. lucidum invasion generates structurally homogeneous and simpler forests that represent a less suitable habitat for a diverse avifauna. This illustrates the wide ecological changes (from habitat properties and ecosystem functioning to vertebrate community composition) that the subtropical mountain forests of Argentina are
Verônica Souza da Mota Gomes
Full Text Available Restingas are considered stressful habitats associated with the Brazilian Atlantic forest, and their ecological interactions are poorly known. The goal of the present study was to determine the potential role of frugivorous birds as seed dispersers in a restinga habitat. Data were collected in Parque Nacional da Restinga de Jurubatiba, southeastern Brazil, where the main physiognomy (Open Clusia Formation is characterized by the presence of patches of vegetation covering 20 to 48 % of the sandy soil and reaching a height of 5 m. Birds were captured with mist nets (12 x 2.5 m; 36 mm mesh; 1 680 net-hrs and had their fecal and regurgitate samples inspected for seeds. Six plant species found in these bird samples were studied. The germination of seeds obtained from plants was compared to those from the birds. Both groups of seeds were set on Petri dishes at room temperature and washed when infected with fungi. In general, there was no effect on germination rate, and the effect on germination speed was negative. Germination of seeds from Pilosocereus arrabidae treated by the birds seemed to be influenced by storage of defecated seeds, while few Miconia cinnamomifolia seeds both from plants and from birds germinated. Ocotea notata presented a great variation in time to the onset of germination, perhaps an advantage against dissecation. Aechmea nudicaulis, Clusia hilariana and Erythroxylum subsessile probably take advantage of the arrival to favorable microhabitats, not by the gut effect on the seeds. All plant species studied are numerically important for the community and some of them are main actors in the succession of vegetation patches. Among the birds, Mimus gilvus is an important resident species, endemic to restingas in Brazil, while Turdus amaurochalinus is a visitor and may be important for plants that fructify during its passage by the study site. Although the effect of pulp removal was only tested for one species (Achmea nudicaulis in the
Camp, Richard J.; Gorresen, P. Marcos
This report was commissioned by the U.S. Fish and Wildlife Service (USFWS). The purpose was to develop a monitoring program for Kaua`i forest birds in the USFWS Strategic Habitat Conservation and adaptive management frameworks. Monitoring within those frameworks is a tool to assess resource responses to management and conservation actions, and through an iterative learning process improve our understanding of species recovery, effective management, and knowledge gaps. This report provides only the monitoring component of both frameworks, and we apply the monitoring program to the East Alaka`i Protective Fence Project.
Full Text Available Behavioural flexibility is thought to be a major factor in evolution. It may facilitate the discovery and exploitation of new resources, which in turn may expose populations to novel selective forces and facilitate adaptive radiation. Darwin's finches are a textbook example of adaptive radiation. They are fast learners and show a range of unusual foraging techniques, probably as a result of their flexibility. In this study we aimed to test whether variability of the environment is correlated with flexibility. We compared woodpecker finches from a dry area (hereafter, Arid Zone, where food availability is variable, with individuals from a cloud forest (hereafter, Scalesia zone where food abundance is stable. As parameters for flexibility, we measured neophilia and neophobia, which are two aspects of reaction to novelty, reversal learning and problem-solving. We found no differences in performance on a problem-solving task but, in line with our prediction, individuals from the Arid Zone were significantly faster reversal learners and more neophilic than their conspecifics from the Scalesia zone. The latter result supports the notion that environmental variability drives flexibility. In contrast to our prediction, Arid Zone birds were even more neophobic than birds from the Scalesia Zone. The latter result could be the consequence of differences in predation pressure between the two vegetation zones.
Full Text Available Subasinghe K, Sumanapala AP. 2014. Biological and functional diversity of bird communities in natural and human modified habitats in Northern Flank of Knuckles Mountain Forest Range, Sri Lanka. Biodiversitas 15: 200-205. The Knuckles Mountain Forest Range (KMFR has a complex mosaic of natural and human modified habitats and the contribution of these habitats to the biological and functional diversities has not been deeply studied. Present study investigated both of these diversities in five habitat types (two natural habitats: Sub-montane forest and Pitawala Patana grassland; three modified habitats: cardamom, pinus and abandoned tea plantations in Northern Flank of KMFR using birds as the indicator group. Bird communities were surveyed using point count method. A total of 1,150 individuals belonging to 56 species were observed. The highest species richness was reported from the cardamom plantation where as sub-montane forest had the highest feeding guild diversity in terms of Shannon Weiner index. The abandoned tea plantation and the Pitawala Patana grasslands with fairly open habitats, showed relatively lower levels of feeding guild diversities. It is clear that the structurally complex habitats contribute more to the area’s biological and functional diversities and need to be taken into consideration when developing conservation plans.
DAVE CURRIE; JOSEPH M. WUNDERLE JR.; DAVID N. EWERT; MATTHEW R. ANDERSON; ANCILLENO DAVIS; JASMINE TURNER
We studied winter avian distribution in three representative pine-dominated habitats and three broadleaf habitats in an area recently designated as a National Park on Andros Island, The Bahamas, 1-23 February 2002. During 180 five-minute point counts, 1731 individuals were detected (1427 permanent residents and 304 winter residents) representing 51 species (29...
Kastner, Brandi; Christensen, Victoria G.; Williamson, Tanja N.; Sanocki, Chris A.
The Prairie Pothole Region (PPR) is home to more than 50% of the migratory waterfowl in North America. Although the PPR provides an abundance of temporary and permanent wetlands for nesting and feeding, increases in commodity prices and agricultural drainage practices have led to a trend of wetland drainage. The Northern Shoveler is a migratory dabbling duck species that uses wetland habitats and cultivated croplands in the PPR. Richland County in North Dakota and Roberts County in South Dakota have an abundance of wetlands and croplands and were chosen as the study areas for this research to assess the wetland size and cultivated cropland in relation to hydrologic soil groups for the Northern Shoveler habitat. This study used geographic information system data to analyze Northern Shoveler habitats in association with Natural Resource Conservation Service soil data. Habitats, which are spatially associated with certain hydrologic soil groups, may be at risk of artificial drainage installations because of their proximity to cultivated croplands and soil lacking in natural drainage that may become wet or inundated. Findings indicate that most wetlands that are part of Northern Shoveler habitats were within or adjacent to cultivated croplands. The results also revealed soil hydrologic groups with high runoff potential and low water transmission rates account for most of the soil within the Northern Shoveler‘s wetland and cropland habitats. Habitats near agriculture with high runoff potential are likely to be drained and this has the potential of reducing Northern Shoveler habitat.
Endemic species are most closely dependent on continuous forest cover. 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 ...
Miserendino, María Laura; Casaux, Ricardo; Archangelsky, Miguel; Di Prinzio, Cecilia Yanina; Brand, Cecilia; Kutschker, Adriana Mabel
Changes in land-use practices have affected the integrity and quality of water resources worldwide. In Patagonia there is a strong concern about the ecological status of surface waters because these changes are rapidly occurring in the region. To test the hypothesis that greater intensity of land-use will have negative effects on water quality, stream habitat and biodiversity we assessed benthic macroinvertebrates, riparian/littoral invertebrates, fish and birds from the riparian corridor and environmental variables of 15 rivers (Patagonia) subjected to a gradient of land-use practices (non-managed native forest, managed native forest, pine plantations, pasture, urbanization). A total of 158 macroinvertebrate taxa, 105 riparian/littoral invertebrate taxa, 5 fish species, 34 bird species, and 15 aquatic plant species, were recorded considering all sites. Urban land-use produced the most significant changes in streams including physical features, conductivity, nutrients, habitat condition, riparian quality and invertebrate metrics. Pasture and managed native forest sites appeared in an intermediate situation. The highest values of fish and bird abundance and diversity were observed at disturbed sites; this might be explained by the opportunistic behavior displayed by these communities which let them take advantage of increased trophic resources in these environments. As expected, non-managed native forest sites showed the highest integrity of ecological conditions and also great biodiversity of benthic communities. Macroinvertebrate metrics that reflected good water quality were positively related to forest land cover and negatively related to urban and pasture land cover. However, by offering stream edge areas, pasture sites still supported rich communities of riparian/littoral invertebrates, increasing overall biodiversity. Macroinvertebrates were good indicators of land-use impact and water quality conditions and resulted useful tools to early alert of
Michelle A Labbe
Full Text Available Many species of mature forest-nesting birds ("forest birds" undergo a pronounced shift in habitat use during the post-fledging period and move from their forest nesting sites into areas of early-successional vegetation. Mortality is high during this period, thus understanding the resource requirements of post-fledging birds has implications for conservation. Efforts to identify predictors of abundance of forest birds in patches of early-successional habitats have so far been equivocal, yet these previous studies have primarily focused on contiguously forested landscapes and the potential for landscape-scale influences in more fragmented and modified landscapes is largely unknown. Landscape composition can have a strong influence on the abundance and productivity of forest birds during the nesting period, and could therefore affect the number of forest birds in the landscape available to colonize early-successional habitats during the post-fledging period. Therefore, the inclusion of landscape characteristics should increase the explanatory power of models of forest bird abundance in early-successional habitat patches during the post-fledging period. We examined forest bird abundance and body condition in relation to landscape and habitat characteristics of 15 early-successional sites during the post-fledging season in Massachusetts. The abundance of forest birds was influenced by within-patch habitat characteristics, however the explanatory power of these models was significantly increased by the inclusion of landscape fragmentation and the abundance of forest birds in adjacent forest during the nesting period for some species and age groups. Our findings show that including factors beyond the patch scale can explain additional variation in the abundance of forest birds in early-successional habitats during the post-fledging period. We conclude that landscape composition should be considered when siting early-successional habitat to maximize its
Catry, Inês; Franco, Aldina M. A.; Rocha, Pedro; Alcazar, Rita; Reis, Susana; Cordeiro, Ana; Ventim, Rita; Teodósio, Joaquim; Moreira, Francisco
Among birds, breeding numbers are mainly limited by two resources of major importance: food supply and nest-site availability. Here, we investigated how differences in land-use and nest-site availability affected the foraging behaviour, breeding success and population trends of the colonial cavity-dependent lesser kestrel Falco naumanni inhabiting two protected areas. Both areas were provided with artificial nests to increase nest-site availability. The first area is a pseudo-steppe characterized by traditional extensive cereal cultivation, whereas the second area is a previous agricultural zone now abandoned or replaced by forested areas. In both areas, lesser kestrels selected extensive agricultural habitats, such as fallows and cereal fields, and avoided scrubland and forests. In the second area, tracked birds from one colony travelled significantly farther distances (6.2 km ±1.7 vs. 1.8 km ±0.4 and 1.9 km ±0.6) and had significant larger foraging-ranges (144 km2 vs. 18.8 and 14.8 km2) when compared to the birds of two colonies in the extensive agricultural area. Longer foraging trips were reflected in lower chick feeding rates, lower fledging success and reduced chick fitness. Availability and occupation of artificial nests was high in both areas but population followed opposite trends, with a positive increment recorded exclusively in the first area with a large proportion of agricultural areas. Progressive habitat loss around the studied colony in the second area (suitable habitat decreased from 32% in 1990 to only 7% in 2002) is likely the main driver of the recorded population decline and suggests that the effectiveness of bird species conservation based on nest-site provisioning is highly constrained by habitat quality in the surrounding areas. Therefore, the conservation of cavity-dependent species may be enhanced firstly by finding the best areas of remaining habitat and secondly by increasing the carrying capacity of high-quality habitat areas
Full Text Available Among birds, breeding numbers are mainly limited by two resources of major importance: food supply and nest-site availability. Here, we investigated how differences in land-use and nest-site availability affected the foraging behaviour, breeding success and population trends of the colonial cavity-dependent lesser kestrel Falco naumanni inhabiting two protected areas. Both areas were provided with artificial nests to increase nest-site availability. The first area is a pseudo-steppe characterized by traditional extensive cereal cultivation, whereas the second area is a previous agricultural zone now abandoned or replaced by forested areas. In both areas, lesser kestrels selected extensive agricultural habitats, such as fallows and cereal fields, and avoided scrubland and forests. In the second area, tracked birds from one colony travelled significantly farther distances (6.2 km ± 1.7 vs. 1.8 km ± 0.4 and 1.9 km ± 0.6 and had significant larger foraging-ranges (144 km(2 vs. 18.8 and 14.8 km(2 when compared to the birds of two colonies in the extensive agricultural area. Longer foraging trips were reflected in lower chick feeding rates, lower fledging success and reduced chick fitness. Availability and occupation of artificial nests was high in both areas but population followed opposite trends, with a positive increment recorded exclusively in the first area with a large proportion of agricultural areas. Progressive habitat loss around the studied colony in the second area (suitable habitat decreased from 32% in 1990 to only 7% in 2002 is likely the main driver of the recorded population decline and suggests that the effectiveness of bird species conservation based on nest-site provisioning is highly constrained by habitat quality in the surrounding areas. Therefore, the conservation of cavity-dependent species may be enhanced firstly by finding the best areas of remaining habitat and secondly by increasing the carrying capacity of high-quality
da Silva Júnior, Wilson Marcelo; Alves Meira-Neto, João Augusto; da Silva Carmo, Flávia Maria; Rodrigues de Melo, Fabiano; Santana Moreira, Leandro; Ferreira Barbosa, Elaine; Dias, Luiz Gustavo; da Silva Peres, Carlos Augusto
This study examines how habitat structure affects the home range use of a group of Brachyteles hypoxanthus in the Brigadeiro State Park, Brazil. It has been reported that most of the annual feeding time of woolly spider monkeys is spent eating leaves, but they prefer fruits when available. We hypothesise that the protein-to-fibre ratio (PF; best descriptor of habitat quality for folivorous primates) is a better descriptor of habitat quality and abundance for these primates than the structural attributes of forests (basal area is the best descriptor of habitat quality for frugivorous primates of Africa and Asia). We evaluated plant community structure, successional status, and PF of leaf samples from the dominant tree populations, both within the core and from a non-core area of the home range of our study group. Forest structure was a combination of stem density and basal area of dominant tree populations. The core area had larger trees, a higher forest basal area, and higher stem density than the non-core area. Mean PF did not differ significantly between these sites, although PF was influenced by differences in tree regeneration guilds. Large-bodied monkeys could be favoured by later successional stages of forests because larger trees and denser stems prevent the need for a higher expenditure of energy for locomotion as a consequence of vertical travel when the crowns of trees are disconnected in early successional forests. Forest structure variables (such as basal area of trees) driven by succession influence woolly spider monkey abundance in a fashion similar to frugivorous monkeys of Asia and Africa, and could explain marked differences in ranging behaviour and home range use by B. hypoxanthus. Copyright 2009 S. Karger AG, Basel.
Dan A. Roberts; Jimmie R. Parrish; Frank P. Howe
We present data on capture and recapture of neotropical migrants at constant-effort mist net sampling locations in Utah between 1994 and 2002. Data were collected in accordance with MAPS (Monitoring Avian Productivity and Survivorship) protocols. Since 1994, a total of 23,789 birds have been captured (i.e., total captures include new captures, recaptures, and unbanded...
Jane A. Fitzgerald; Jonathan Bart; Harold D. Brown; Kathy Lee
We used fixed-distance point counts to monitor bird populations from 1994-1998 in a rapidly urbanizing region of southwestern Missouri. Prior to the early 1990s, the rural landscape was a mosaic of forest, dolomite glades, and pasture but development proceeded rapidly in the 1990s with increased promotion of Branson, Missouri as a vacation and retirement destination....
Galván, Ismael; Wakamatsu, Kazumasa; Camarero, Pablo R; Mateo, Rafael; Alonso-Alvarez, Carlos
The mechanisms that make that the costs of producing high-quality signals are unaffordable to low-quality signalers are a current issue in animal communication. The size of the melanin-based bib of male house sparrows Passer domesticus honestly signals quality. We induced the development of new bibs while treating males with buthionine-sulfoximine (BSO), a substance that depletes the levels of the antioxidant glutathione (GSH) and the amino acid cysteine, two elements that switch melanogenesis from eumelanin to pheomelanin. Final bib size is negatively related to pheomelanin levels in the bib feathers. BSO reduced cysteine and GSH levels in all birds, but improved phenotypes (bibs larger than controls) were only expressed by high-quality birds (BSO birds with largest bibs initially). Negative associations between final bib size and cysteine levels in erythrocytes, and between pheomelanin and cysteine levels, were observed in high-quality birds only. These findings suggest that a mechanism uncoupling pheomelanin and cysteine levels may have evolved in low-quality birds to avoid producing bibs of size not corresponding to their quality and greater relative costs. Indeed, greater oxidative stress in cells was not observed in low-quality birds. This may represent the first mechanism maintaining signal honesty without producing greater relative costs on low-quality signalers. PMID:25330349
Davis, J. Brian; Webb, Elisabeth B.; Kaminski, Richard M.; Barbour, Philip J.; Vilella, Francisco
Following the Deepwater Horizon oil spill in the Gulf of Mexico in April 2010, the USDA Natural Resources Conservation Service (NRCS) established and funded the Migratory Bird Habitat Initiative (MBHI), with the goal of improving and increasing wetland habitats on private lands to benefit wintering and migrating waterbirds displaced from oil-impacted coastal wetlands. The NRCS and conservation partners provided financial and technical assistance to landowners and managers of sites enrolled in various conservation easement programs, and incorporated approximately 190,000 ha of wetlands and agricultural lands in the Mississippi Alluvial Valley (MAV) and Gulf Coast regions in the MBHI. In fall 2010, the NRCS worked with scientists and graduate students from three universities and various conservation agencies to design and implement landscape-scale evaluations of (1) the use of MBHI-managed wetlands and comparable non-MBHI wetlands by Charadriiformes(shorebirds), Anseriformes (waterfowl), and other waterbirds; and (2) the relative effectiveness of different MBHI practices for providing habitat and food resources for migrating, resident, and wintering waterbirds. In this paper, we describe the scientific framework designed to evaluate the MBHI in improving waterbird habitats on private lands in the MAV, the Gulf Coast Prairies in Louisiana and Texas, and Gulf coastal wetlands of Mississippi and Alabama. The results of our evaluation will enhance our understanding of the influence of MBHI, other Farm Bill Conservation Initiative managed lands (e.g., Wetland Reserve Program), and selected agricultural working lands (e.g., Oryza sativa L. [Rice] fields in southern Louisiana and Texas) on wintering and migrating waterbirds. A proactive approach that uses science to evaluate governmental conservation programs is relevant and can inform development of meaningful public policy that likely will be needed for effective delivery of future conservation programs and to justify
Reif, J.; Marhoul, P.; Čížek, O.; Konvička, Martin
Roč. 20, č. 14 (2011), s. 3645-3662 ISSN 0960-3115 R&D Projects: GA MŠk LC06073 Grant - others:Ministry of Environment of the Czech Republic(CZ) SP/2D3/153/08 Institutional research plan: CEZ:AV0Z50070508 Keywords : abundance * bird * disturbance Subject RIV: EH - Ecology, Behaviour Impact factor: 2.238, year: 2011
Anders Pape Møller; Piotr Tryjanowski; Mario Díaz; Zbigniew Kwieciński; Piotr Indykiewicz; Cezary Mitrus; Artur Goławski; Michał Polakowski
Animals respond to approaching predators by taking flight at a distance that optimizes the costs and benefits of such flight. Previous studies have shown that urban populations of birds have shorter flight initiation distances than rural populations of the same species, that this difference is partly explained by differences in the community of predators, and that a longer history of urbanization implies a greater reduction in flight initiation distance in urban populations. The use of birdfe...
Loehle, C.; Van Deusen, P.; Wigley, T.B.; Mitchell, M.S.; Rutzmoser, S.H.; Aggett, J.; Beebe, J.A.; Smith, M.L.
Wildlife-habitat relationship models have sometimes been linked with forest simulators to aid in evaluating outcomes of forest management alternatives. However, linking wildlife-habitat models with harvest scheduling software would provide a more direct method for assessing economic and ecological implications of alternative harvest schedules in commercial forest operations. We demonstrate an approach for frontier analyses of wildlife benefits using the Habplan harvest scheduler and spatially explicit wildlife response models in the context of operational forest planning. We used the Habplan harvest scheduler to plan commercial forest management over a 40-year horizon at a landscape scale under five scenarios: unmanaged, an unlimited block-size option both with and without riparian buffers, three cases with different block-size restrictions, and a set-asides scenario in which older stands were withheld from cutting. The potential benefit to wildlife was projected based on spatial models of bird guild richness and species probability of detection. Harvested wood volume provided a measure of scenario costs, which provides an indication of management feasibility. Of nine species and guilds, none appeared to benefit from 50 m riparian buffers, response to an unmanaged scenario was mixed and expensive, and block-size restrictions (maximum harvest unit size) provided no apparent benefit and in some cases were possibly detrimental to bird richness. A set-aside regime, however, appeared to provide significant benefits to all species and groups, probably through increased landscape heterogeneity and increased availability of older forest. Our approach shows promise for evaluating costs and benefits of forest management guidelines in commercial forest enterprises and improves upon the state of the art by utilizing an optimizing harvest scheduler as in commercial forest management, multiple measures of biodiversity (models for multiple species and guilds), and spatially
Full Text Available Habitat features can have a profound effect on the nesting success of birds. Savannas are often managed with predators and large herbivores as priority species, with little thought to the many bird species that management decisions could affect. Using a data set spanning seven breeding seasons, we examined how nesting success of Southern Ground-hornbills (SGHs Bucorvus leadbeateri in the Kruger National Park varied as a result of various environmental and habitat factors within a radius of 3 km surrounding the nest site. Identifying which factors affect nesting success will allow for targeted management efforts to ensure the long-term survival of SGHs both within and outside of protected areas. Habitat structure and diversity of the vegetation surrounding the nest were the most influential factors on SGH nesting success. SGHs require open grassy areas for foraging and areas with large trees for nesting. Savanna habitat drivers such as elephants and fire should be managed to ensure that sufficient large trees are able to establish in the landscape and to control for bush encroachment. This is especially important in areas earmarked for SGH reintroductions. Nest sites of SGHs should be monitored to mitigate any structural changes in the habitat surrounding the nests. Nests should be modified or artificial nest sites provided, where nests have been damaged or lost, to ensure the continued presence of these birds in African savannas. Conservation implications: Habitat structure and diversity surrounding Southern Groundhornbill nests has a significant impact on their nesting success. This highlights the importance of monitoring vegetation change in savanna habitats where they occur. Management of savanna areas should take factors that influence bush encroachment, such as fire and elephants, into account to ensure the long-term persistence of these birds.
The Grey-headed Parrot Poicephalus fuscicollis suahelicus has a widespread distribution in sub-Saharan Africa yet is uncommon in its natural range. In some areas seasonal movements are recorded. This study, conducted in north-eastern South Africa, showed that habitat use varied seasonally between two sites, Levubu ...
Šálek, Martin; Havlíček, J.; Riegert, J.; Nešpor, M.; Fuchs, R.; Kipson, M.
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
Fredriksson, G.M.; Nijman, V.
We studied the distribution and habitat-use of two endemic ground birds, the Borneon groundcuckoo Carpococcyx radiatus and the Bornean peacockpheasant Polyplectron schleiermacheri in the Sungai Wain protection Forest, East Kalimantan. Both species are highly elusive and neither has been subject to
Lawrence, William T.; Imhoff, Marc L.; Sisk, Thomas D.; Stutzer, David
The seasonally flooded forest and upland sites in the Kakadu National Park, near Jabiru, Northern Territories, Australia were the site of extensive field measurements, bird community observations and airborne remote sensing during an initial NASA/Jet Propulsion Lab AIRSAR campaign in 1993, a field visit in 1994 and combined remote sensing and field activities during the PACRIM I Project in fall 1996. The overarching purpose of these studies was to use remote sensing technology as a way to extend intensive avian biodiversity and census field observations, as well as structural vegetation measurements from a limited survey area to the regional scale. During these two visits to the Kakadu area, field measurements were made within the dominant forest types in this region, primarily mixed Eucalyptus sp. woodlands, and open- and closed-forest sites dominated by Melaleuca sp. across a range of dry to perennially-flooded sites. Bird community measurements showed vegetation structure is needed to understand habitat relationships. A major vegetation difference between the two years was an increase of 2-3 times in leaf area index at comparison sites from 1994 to 1996. The greatest LAI at any site was 2.52 in the wet Melaleuca site near Munmalary in 1994.
Rodrigues, V. B.
Full Text Available We evaluated the effect of anthropogenic disturbance on nest predation in Brazilian Atlantic forest. Artificial nests were distributed in fragments with distinct degrees of anthropogenic disturbance. We found a higher proportion of egg predation on the ground and in the fragments classified as ‘high’ and ‘medium’ disturbance than in the fragments classified as ‘low’ degree of disturbance. The higher egg predation is probably linked to low structural complexity of vegetation and high accessibility of these areas to opportunistic predators. We suggest that forest fragments with high vegetation complexity and low human activity should be preserved in order to maintain the biodiversity of bird species.
Loges, Brian W.; Lyons, James E.; Tavernia, Brian G.
The Clarence Cannon National Wildlife Refuge (CCNWR) in the Mississippi River flood plain of eastern Missouri provides high quality emergent marsh and moist-soil habitat benefitting both nesting marsh birds and migrating waterfowl. Staff of CCNWR manipulate water levels and vegetation in the 17 units of the CCNWR to provide conditions favorable to these two important guilds. Although both guilds include focal species at multiple planning levels and complement objectives to provide a diversity of wetland community types and water regimes, additional decision support is needed for choosing how much emergent marsh and moist-soil habitat should be provided through annual management actions.To develop decision guidance for balanced delivery of high-energy waterfowl habitat and breeding marsh bird habitat, two measureable management objectives were identified: nonbreeding Anas Linnaeus (dabbling duck) use-days and Rallus elegans (king rail) occupancy of managed units. Three different composite management actions were identified to achieve these objectives. Each composite management action is a unique combination of growing season water regime and soil disturbance. The three composite management actions are intense moist-soil management (moist-soil), intermediate moist-soil (intermediate), and perennial management, which idles soils disturbance (perennial). The two management objectives and three management options were used in a multi-criteria decision analysis to indicate resource allocations and inform annual decision making. Outcomes of the composite management actions were predicted in two ways and multi-criteria decision analysis was used with each set of predictions. First, outcomes were predicted using expert-elicitation techniques and a panel of subject matter experts. Second, empirical data from the Integrated Waterbird Management and Monitoring Initiative collected between 2010 and 2013 were used; where data were lacking, expert judgment was used. Also, a
Full Text Available The Natura 2000 network contains many different habitats in Estonia, including old-growth forests and semi-natural woodlands. Ten years after the establishment of the Natura 2000 network in Estonia, changes have occurred in habitat type and habitat quality. Vegetation composition as well as the structural and functional qualities of a forest habitat type – Fennoscandian herbrich forests with Picea abies (EU Habitats Directive habitat type 9050 – are analysed in this study. The study is based on sample plots measured in 2014 and are located in protected and non-protected areas. Aegopodium, Filipendula and Oxalis vegetation types are included for assessment of vegetation, tree structure and deadwood composition. Habitat composition and dynamics on conservation sites are compared with commercial forests and possible ecosystem restoration measures are discussed in the study. The 46% of the studied habitats had considerably lowered their initial conservation value and 49% were developed towards habitat type 9010 during 2004–2014.
Huang, Wei; Mynnet, Arthur
Schizothorax Yunnansis is an unique fish species only existing in Lugu Lake, which is located in the southwestern China. The simulation and research on Schizothorax Yunnansis habitat environment have a vital significance to protect this rare fish. With the development of the tourism industry, there bring more pressure on the environmental protection. The living environment of Schizothorax Yunnansis is destroyed seriously because the water quality is suffering the sustaining pollution of domestic sewage from the peripheral villages. This paper analyzes the relationship between water quality change and Schizothorax Yunnansis ecological habitat and evalutes Schizothorax Yunnansis's ecological habitat impact based on HABITAT model. The results show that when the TP concentration in Lugu Lake does not exceed Schizothorax Yunnansis's survival threshold, Schizothorax Yunnansis can get more nutrients and the suitable habitat area for itself is increased. Conversely, it can lead to TP toxicity in the Schizothorax Yunnansis and even death. Therefore, unsuitable habitat area for Schizothorax Yunnansis is increased. It can be seen from the results that HABITAT model can assist in ecological impact assessment studies by translating results of hydrological, water quality models into effects on the natural environment and human society.
Tarjuelo, Rocío; Morales, Manuel B; Arroyo, Beatriz; Mañosa, Santiago; Bota, Gerard; Casas, Fabián; Traba, Juan
Interspecific competition is a dominant force in animal communities that induces niche shifts in ecological and evolutionary time. If competition occurs, niche expansion can be expected when the competitor disappears because resources previously inaccessible due to competitive constraints can then be exploited (i.e., ecological release). Here, we aimed to determine the potential effects of interspecific competition between the little bustard ( Tetrax tetrax ) and the great bustard ( Otis tarda ) using a multidimensional niche approach with habitat distribution data. We explored whether the degree of niche overlap between the species was a density-dependent function of interspecific competition. We then looked for evidences of ecological release by comparing measures of niche breadth and position of the little bustard between allopatric and sympatric situations. Furthermore, we evaluated whether niche shifts could depend not only on the presence of great bustard but also on the density of little and great bustards. The habitat niches of these bustard species partially overlapped when co-occurring, but we found no relationship between degree of overlap and great bustard density. In the presence of the competitor, little bustard's niche was displaced toward increased use of the species' primary habitat. Little bustard's niche breadth decreased proportionally with great bustard density in sympatric sites, in consistence with theory. Overall, our results suggest that density-dependent variation in little bustard's niche is the outcome of interspecific competition with the great bustard. The use of computational tools like kernel density estimators to obtain multidimensional niches should bring novel insights on how species' ecological niches behave under the effects of interspecific competition in ecological communities.
Flitcroft, Rebecca L; Falke, Jeffrey A.; Reeves, Gordon H.; Hessburg, Paul F.; McNyset, Kris M.; Benda, Lee E.
Pacific Northwest salmonids are adapted to natural disturbance regimes that create dynamic habitat patterns over space and through time. However, human land use, particularly long-term fire suppression, has altered the intensity and frequency of wildfire in forested upland and riparian areas. To examine the potential impacts of wildfire on aquatic systems, we developed stream-reach-scale models of freshwater habitat for three life stages (adult, egg/fry, and juvenile) of spring Chinook salmon (Oncorhynchus tshawytscha) in the Wenatchee River subbasin, Washington. We used variables representing pre- and post-fire habitat conditions and employed novel techniques to capture changes in in-stream fine sediment, wood, and water temperature. Watershed-scale comparisons of high-quality habitat for each life stage of spring Chinook salmon habitat suggested that there are smaller quantities of high-quality juvenile overwinter habitat as compared to habitat for other life stages. We found that wildfire has the potential to increase quality of adult and overwintering juvenile habitat through increased delivery of wood, while decreasing the quality of egg and fry habitat due to the introduction of fine sediments. Model results showed the largest effect of fire on habitat quality associated with the juvenile life stage, resulting in increases in high-quality habitat in all watersheds. Due to the limited availability of pre-fire high-quality juvenile habitat, and increased habitat quality for this life stage post-fire, occurrence of characteristic wildfires would likely create a positive effect on spring Chinook salmon habitat in the Wenatchee River subbasin. We also compared pre- and post-fire model results of freshwater habitat for each life stage, and for the geometric mean of habitat quality across all life stages, using current compared to the historic distribution of spring Chinook salmon. We found that spring Chinook salmon are currently distributed in stream channels in
An assessment of water and habitat quality, based on macroinvertebrate assemblage indices and qualitative habitat scores (QHS), was undertaken in the Honi and Naro Moru rivers, Kenya, in 2011. The two rivers are important as water sources for the local communities and as habitat for organisms such as invertebrates in ...
Amos, J. Nevil; Bennett, Andrew F.; Mac Nally, Ralph; Newell, Graeme; Pavlova, Alexandra; Radford, James Q.; Thomson, James R.; White, Matt; Sunnucks, Paul
Inference concerning the impact of habitat fragmentation on dispersal and gene flow is a key theme in landscape genetics. Recently, the ability of established approaches to identify reliably the differential effects of landscape structure (e.g. land-cover composition, remnant vegetation configuration and extent) on the mobility of organisms has been questioned. More explicit methods of predicting and testing for such effects must move beyond post hoc explanations for single landscapes and species. Here, we document a process for making a priori predictions, using existing spatial and ecological data and expert opinion, of the effects of landscape structure on genetic structure of multiple species across replicated landscape blocks. We compare the results of two common methods for estimating the influence of landscape structure on effective distance: least-cost path analysis and isolation-by-resistance. We present a series of alternative models of genetic connectivity in the study area, represented by different landscape resistance surfaces for calculating effective distance, and identify appropriate null models. The process is applied to ten species of sympatric woodland-dependant birds. For each species, we rank a priori the expectation of fit of genetic response to the models according to the expected response of birds to loss of structural connectivity and landscape-scale tree-cover. These rankings (our hypotheses) are presented for testing with empirical genetic data in a subsequent contribution. We propose that this replicated landscape, multi-species approach offers a robust method for identifying the likely effects of landscape fragmentation on dispersal. PMID:22363508
Beerens, James M.; Gawlik, Dale E.; Herring, Garth; Cook, Mark I.
Seasonal and annual variation in food availability during the breeding season plays an influential role in the population dynamics of many avian species. In highly dynamic ecosystems like wetlands, finding and exploiting food resources requires a flexible behavioral response that may produce different population trends that vary with a species' foraging strategy. We quantified dynamic foraging-habitat selection by breeding and radiotagged White Ibises (Eudocimus albus) and Great Egrets (Ardea alba) in the Florida Everglades, where fluctuation in food resources is pronounced because of seasonal drying and flooding. The White Ibis is a tactile “searcher” species in population decline that specializes on highly concentrated prey, whereas the Great Egret, in a growing population, is a visual “exploiter” species that requires lower prey concentrations. In a year with high food availability, resource-selection functions for both species included variables that changed over multiannual time scales and were associated with increased prey production. In a year with low food availability, resource-selection functions included short-term variables that concentrated prey (e.g., water recession rates and reversals in drying pattern), which suggests an adaptive response to poor foraging conditions. In both years, the White Ibis was more restricted in its use of habitats than the Great Egret. Real-time species—habitat suitability models were developed to monitor and assess the daily availability and quality of spatially explicit habitat resources for both species. The models, evaluated through hindcasting using independent observations, demonstrated that habitat use of the more specialized White Ibis was more accurately predicted than that of the more generalist Great Egret.
In relation to the European Water Framework Directive (WFD), Danish water management has to change to a holistic management approach considering both groundwaters and surface waters at the same time. Furthermore the WFD introduces the concept "Good ecological status" where the quality of the biol......In relation to the European Water Framework Directive (WFD), Danish water management has to change to a holistic management approach considering both groundwaters and surface waters at the same time. Furthermore the WFD introduces the concept "Good ecological status" where the quality...... in Danish stream management and stream quality assessment. The stream Ledreborg catchment is modelled using a precipitation-run-off-model (NAM) and as an addition to the normal calibration procedure (Kronvang et al., 2000) the model is calibrated using DAISY adjusted evaporation data. The impact from...... groundwater abstraction upon stream discharge is assessed and in relation to this the relative importance of variations in precipitation, evaporation/temperature and groundwater abstraction are discussed. Physical habitat preferences for trout in the stream Ledreborg are assessed through a series of field...
Mark D. Nelson; Richard R. Buech
We tested 3 models of Kirtland's warbler (Dendroica kirtlandii) habitat suitability during a period when we believe there was a surplus of good quality breeding habitat. A jack pine canopy-cover model was superior to 2 jack pine stem-density models in predicting Kirtland's warbler habitat use and non-use. Estimated density of birds in high...
Mosser, Anna; Fryxell, John M; Eberly, Lynn; Packer, Craig
Habitat quality is typically inferred by assuming a direct relationship between consumer density and resource abundance, although it has been suggested that consumer fitness may be a more accurate measure of habitat quality. We examined density vs. fitness-based measures of habitat quality for lions in the Serengeti National Park, Tanzania. A 40-year average of female reproductive success (yearling cubs per female) was best explained by proximity to river confluences, whereas patterns of productivity (yearling cubs per km(2)) and adult female density (individuals per km(2)) were associated with more general measures of habitat quality and areas of shelter in poor habitat. This suggests that density may not accurately distinguish between high-quality 'source' areas and low-quality sites that merely provide refuges for effectively non-reproductive individuals. Our results indicate that density may be a misleading indicator of real estate value, particularly for populations that do not conform to an ideal free distribution.
Camp, Richard J.; Gorresen, P. Marcos; Banko, Paul C.
This report describes the results of a pilot forest bird survey and a consequent forest bird monitoring protocol that was developed for the O'ahu Forest National Wildlife Refuge, O'ahu Island, Hawai'i. The pilot survey was conducted to inform aspects of the monitoring protocol and to provide a baseline with which to compare future surveys on the Refuge. The protocol was developed in an adaptive management framework to track bird distribution and abundance and to meet the strategic habitat conservation requirements of the Refuge. Funding for this research was provided through a Science Support Partnership grant sponsored jointly by the U.S. Geological Survey (USGS) and the U.S. Fish and Wildlife Service (USFWS).
Breed, M F; Ottewell, K M; Gardner, M G; Marklund, M H K; Stead, M G; Harris, J B C; Lowe, A J
Habitat fragmentation has been shown to disrupt ecosystem processes such as plant-pollinator mutualisms. Consequently, mating patterns in remnant tree populations are expected to shift towards increased inbreeding and reduced pollen diversity, with fitness consequences for future generations. However, mating patterns and phenotypic assessments of open-pollinated progeny have rarely been combined in a single study. Here, we collected seeds from 37 Eucalyptus incrassata trees from contrasting stand densities following recent clearance in a single South Australian population (intact woodland=12.6 trees ha(-1); isolated pasture=1.7 trees ha(-1); population area=10 km(2)). 649 progeny from these trees were genotyped at eight microsatellite loci. We estimated genetic diversity, spatial genetic structure, indirect contemporary pollen flow and mating patterns for adults older than the clearance events and open-pollinated progeny sired post-clearance. A proxy of early stage progeny viability was assessed in a common garden experiment. Density had no impact on mating patterns, adult and progeny genetic diversity or progeny growth, but was associated with increased mean pollen dispersal. Weak spatial genetic structure among adults suggests high historical gene flow. We observed preliminary evidence for inbreeding depression related to stress caused by fungal infection, but which was not associated with density. Higher observed heterozygosities in adults compared with progeny may relate to weak selection on progeny and lifetime-accumulated mortality of inbred adults. E. incrassata appears to be resistant to the negative mating pattern and fitness changes expected within fragmented landscapes. This pattern is likely explained by strong outcrossing and regular long-distance pollen flow.
Vitalis W. Temu
Full Text Available Agricultural intensification in America has replaced native warm-season grasses (NWSG with introduced forages causing wildlife habitat loss and population declines for the northern bobwhite (Colinus virginianus and similar ground-nesting birds. Reintroducing NWSGs onto managed grasslands to reverse grassland bird population declines lacks information about appropriate multi-purpose management. Post-season nesting habitat quality of mixed NWSGs (indiangrass (IG, Sorghastrum nutans, big bluestem (BB, Andropogon gerardii and little bluestem (LB, Schizachyrium scoparium responding to previous-year(s harvest intervals (treatments, 30-, 40-, 60-, 90 or 120-d and duration (years in production, were assessed on late-spring-early-summer re-growths. Yearly phased harvestings were initiated in May on sets of randomized plots, ≥90-cm apart, in five replications (blocks to produce one-, two-, and three-year old stands by the third year. Sward heights and canopy closure were recorded a day before harvest, followed a week after by visual estimates of ground cover of plant species and litter. Harvesting increased post-season grass cover and reduced forbs following a high rainfall year. Harvested plot swards showed no treatment differences, but were shorter and intercepted more sunlight. Similarly, harvest duration increased grass cover with no year effect but reduced forbs following a high rainfall year. One- or two-year full-season harvesting of similar stands may not compromise subsequent bobwhite nesting-cover provided post-season harvesting starts after the breeding cycle is completed.
Rebolo-Ifrán, Natalia; Carrete, Martina; Sanz-Aguilar, Ana; Rodríguez-Martínez, Sol; Cabezas, Sonia; Marchant, Tracy A; Bortolotti, Gary R; Tella, José L
Urban endocrine ecology aims to understand how organisms cope with new sources of stress and maintain allostatic load to thrive in an increasingly urbanized world. Recent research efforts have yielded controversial results based on short-term measures of stress, without exploring its fitness effects. We measured feather corticosterone (CORTf, reflecting the duration and amplitude of glucocorticoid secretion over several weeks) and subsequent annual survival in urban and rural burrowing owls. This species shows high individual consistency in fear of humans (i.e., flight initiation distance, FID), allowing us to hypothesize that individuals distribute among habitats according to their tolerance to human disturbance. FIDs were shorter in urban than in rural birds, but CORTf levels did not differ, nor were correlated to FIDs. Survival was twice as high in urban as in rural birds and links with CORTf varied between habitats: while a quadratic relationship supports stabilizing selection in urban birds, high predation rates may have masked CORTf-survival relationship in rural ones. These results evidence that urban life does not constitute an additional source of stress for urban individuals, as shown by their near identical CORTf values compared with rural conspecifics supporting the non-random distribution of individuals among habitats according to their behavioural phenotypes.
Invasive species can alter habitat quality over broad scales, so they pose a severe threat to songbird populations. Through our long-term research program supported by BEMRP, we have found that changes in habitat quality induced by exotic plants like spotted knapweed can lead to subtle yet profound changes in songbird populations. For example, in knapweed-invaded...
Ye, X.; Skidmore, A.K.; Wang, T.
Patch geometry and habitat quality among patches are widely recognized as important factors affecting population dynamics in fragmented landscapes. Little is known, however, about the influence of within-patch habitat quality on population dynamics. In this paper, we investigate the relative
Kleijn, D.; Langevelde, van F.
Landscape context and habitat quality may have pronounced effects on the diversity of flower visiting insects. We investigated whether the effects of landscape context and habitat quality on flower visiting insects interact in agricultural landscapes in the Netherlands. Landscape context was
Bruggeman, Jason E.; Swem, Ted; Andersen, David E.; Kennedy, Patricia L.; Nigro, Debora A.
Intrinsic and extrinsic factors affect vital rates and population-level processes, and understanding these factors is paramount to devising successful management plans for wildlife species. For example, birds time migration in response, in part, to local and broadscale climate fluctuations to initiate breeding upon arrival to nesting territories, and prolonged inclement weather early in the breeding season can inhibit egg-laying and reduce productivity. Also, density-dependent regulation occurs in raptor populations, as territory size is related to resource availability. Arctic Peregrine Falcons (Falco peregrinus tundrius; hereafter Arctic peregrine) have a limited and northern breeding distribution, including the Colville River Special Area (CRSA) in the National Petroleum Reserve–Alaska, USA. We quantified influences of climate, topography, nest productivity, prey habitat, density dependence, and interspecific competition affecting Arctic peregrines in the CRSA by applying the Dail-Madsen model to estimate abundance and vital rates of adults on nesting cliffs from 1981 through 2002. Arctic peregrine abundance increased throughout the 1980s, which spanned the population's recovery from DDT-induced reproductive failure, until exhibiting a stationary trend in the 1990s. Apparent survival rate (i.e., emigration; death) was negatively correlated with the number of adult Arctic peregrines on the cliff the previous year, suggesting effects of density-dependent population regulation. Apparent survival and arrival rates (i.e., immigration; recruitment) were higher during years with earlier snowmelt and milder winters, and apparent survival was positively correlated with nesting season maximum daily temperature. Arrival rate was positively correlated with average Arctic peregrine productivity along a cliff segment from the previous year and initial abundance was positively correlated with cliff height. Higher cliffs with documented higher productivity (presumably
Yan, S.; Wang, X.
Abstract: Water level changes in a shallow lake always introduce dramatic land pattern changes. To achieve sustainable ecosystem service, it is necessary to evaluate habitat quality dynamic and its spatio-temporal variation resulted from water level changes, which can provide a scientific basis for protection of biodiversity and planning of wetland ecological system. Landsat data in the spring was chosen to obtain landscape data at different times based on the high, moderate and low water level of Baiyangdian Shallow Lake. We used the InVEST to evaluate the habitat quality, habitat degradation, and habitat scarcity. The result showed that: 1) the water level of shallow lake changes from high to low lead to an obvious landscape pattern changes and habitat degradation. 2) the most change area occurred in northwestward and southwest of Baiyangdian Shallow Lake, which there was a 21 percent of suitable habitat and 42 percent of moderately suitable habitat lost. Our findings show that the changes of water level in the shallow lake would have a strong relationship with the habitat quality.Keywords: Habitat quality; Habitat degradation; Water level changes; InVEST model; Shallow lake
Boves, Than J.; Rodewald, Amanda D.; Wood, Petra Bohall; Buehler, David A.; Larkin, Jeffrey L.; Wigley, T. Bently; Keyser, Patrick D.
Many wildlife management prescriptions are either implicitly or explicitly designed to improve habitat quality for a focal species, but habitat quality is often difficult to quantify. Depending upon the approach used to define and identify high-quality habitat, management decisions may differ widely. Although individual-level measures of habitat quality based on per capita reproduction (e.g., average nesting success, number of young produced per pair) are most common in the literature, they may not align with population-level measures that reflect number of young produced within a defined area. Using data on the cerulean warbler (Setophaga cerulea) collected in the Cumberland Mountains (Tennessee, USA; 2008–2010) as an example, we illustrate how lack of concordance between individual- and population-level measures of habitat quality can have real-world management implications.
Harrington, Carolyn Lang
Describes a lesson for third-grade students that begins with an examination of bird prints done by John James Audubon and moves into the students creating their own torn paper birds. Introduces the students to the beauty of birds and focuses on the environmental issues that face birds and their habitats. (CMK)
Belgrad, Benjamin A; Griffen, Blaine D
Assessing the stability of animal personalities has become a major goal of behavioral ecologists. Most personality studies have utilized solitary individuals, but little is known on the extent that individuals retain their personality across ecologically relevant group settings. We conducted a field survey which determined that mud crabs, Panopeus herbstii, remain scattered as isolated individuals on degraded oyster reefs while high quality reefs can sustain high crab densities (>10 m -2 ). We examined the impact of these differences in social context on personality by quantifying the boldness of the same individual crabs when in isolation and in natural cohorts. Crabs were also exposed to either a treatment of predator cues or a control of no cue throughout the experiment to assess the strength of this behavioral reaction norm. Crabs were significantly bolder when in groups than as solitary individuals with predator cue treatments exhibiting severally reduced crab activity levels in comparison to corresponding treatments with no predator cues. Behavioral plasticity depended on the individual and was strongest in the presence of predator cues. While bold crabs largely maintained their personality in isolation and group settings, shy crabs would become substantially bolder when among conspecifics. These results imply that the shifts in crab boldness were a response to changes in perceived predation risk, and provide a mechanism for explaining variation in behavioral plasticity. Such findings suggest that habitat degradation may produce subpopulations with different behavioral patterns because of differing social interactions between individual animals.
Gaüzère, Pierre; Princé, Karine; Devictor, Vincent
The spatial tracking of climatic shifts is frequently reported as a biodiversity response to climatic change. However, species' range shifts are often idiosyncratic and inconsistent with climatic shift predictions. At the community scale, this discrepancy can be measured by comparing the spatial shift in the relative composition of cold- vs. warm-adapted species in a local assemblage [the community temperature index (CTI)] with the spatial shift in temperature isotherms. While the local distribution of climate change velocity is a promising approach to downscaling climate change pressure and responses, CTI velocity has only been investigated on a continental or national scale. In this study, we coupled French Breeding Bird Survey data, collected from 2133 sites monitored between 2001 and 2012, with climatic data in order to estimate the local magnitude and direction of breeding season temperature shift, CTI shift, and their spatiotemporal divergence - the local climatic debt. We also tested whether landscape characteristics that are known to affect climate velocity and spatial tracking of climate change mediated the climatic debt on the local scale. We found a clear spatial structure, together with heterogeneity in both temperature and CTI spatial shifts. Local climatic debt decreased as the elevation, habitat diversity, and the naturalness of the landscape increased. These results suggest the complementary effects of the local topographic patterns sheltering more diverse microclimates and the increasing permeability of natural and diversified landscape. Our findings suggest that a more nuanced evaluation of spatial variability in climatic and biotic shifts is necessary in order to properly describe biodiversity responses to climate change rather than the oversimplified descriptions of uniform poleward shifts. © 2016 John Wiley & Sons Ltd.
Klok, C.; Roos, de A.M.
1. The effects of changes in habitat size and quality on the expected population density and the expected time to extinction of Sorex araneus are studied by means of mathematical models that incorporate demographic stochasticity. 2. Habitat size is characterized by the number of territories, while
Matthew J. McCarthy
Full Text Available Habitat mapping can be accomplished using many techniques and types of data. There are pros and cons for each technique and dataset, therefore, the goal of this project was to investigate the capabilities of new satellite sensor technology and to assess map accuracy for a variety of image classification techniques based on hundreds of field-work sites. The study area was Masonboro Island, an undeveloped area in coastal North Carolina, USA. Using the best map results, a habitat change assessment was conducted between 2002 and 2010. WorldView-2, QuickBird, and IKONOS satellite sensors were tested using unsupervised and supervised methods using a variety of spectral band combinations. Light Detection and Ranging (LiDAR elevation and texture data pan-sharpening, and spatial filtering were also tested. In total, 200 maps were generated and results indicated that WorldView-2 was consistently more accurate than QuickBird and IKONOS. Supervised maps were more accurate than unsupervised in 80% of the maps. Pan-sharpening the images did not consistently improve map accuracy but using a majority filter generally increased map accuracy. During the relatively short eight-year period, 20% of the coastal study area changed with intertidal marsh experiencing the most change. Smaller habitat classes changed substantially as well. For example, 84% of upland scrub-shrub experienced change. These results document the dynamic nature of coastal habitats, validate the use of the relatively new Worldview-2 sensor, and may be used to guide future coastal habitat mapping.
Open-Habitat Birds in Recently Burned Areas: the Role of the Fire Extent and Species’ Habitat Breadth = Aves de medios abiertos en áreas quemadas recientemente: la importancia de la extensión del fuego y la amplitud de hábitat de las especies
Pons Ferran, Pere; Bas Lay, Josep Maria
To evaluate the occurrence of open-habitat and steppe-land bird species in Western Mediterranean burned areas and to assess the role of the extent and location of the fire on species richness and composition. At the species level, the relationship was explored between habitat breadth, distribution extent and the ability to occupy recently burned areas. Location: Iberia and Southern France Methods: Fieldwork and bibliography were assembled to obtain breeding bird inventories for 21 burned area...
Full Text Available Habitat quality is the ability of the environment to provide conditions appropriate for individual and species persistence. Measuring or monitoring habitat quality requires complex integration of many properties of the ecosystem, where traditional terrestrial data collection methods have proven extremely time-demanding. Remote sensing has known potential to map various ecosystem properties, also allowing rigorous checking of accuracy and supporting standardized processing. Our Special Issue presents examples where remote sensing has been successfully used for habitat mapping, quantification of habitat quality parameters, or multi-parameter modelling of habitat quality itself. New frontiers such as bathymetric scanning, grassland vegetation classification and operational use were explored, various new ecological verification methods were introduced and integration with ongoing habitat conservation schemes was demonstrated. These studies show that remote sensing and Geoinformation Science for habitat quality analysis have evolved from isolated experimental studies to an active field of research with a dedicated community. It is expected that these new methods will substantially contribute to biodiversity conservation worldwide.
Full Text Available Recent research reports that many populations of species showing a wide trophic niche (generalists are made up of both generalist individuals and individuals with a narrow trophic niche (specialists, suggesting trophic specializations at an individual level. If true, foraging strategies should be associated with individual quality and fitness. Optimal foraging theory predicts that individuals will select the most favourable habitats for feeding. In addition, the "landscape heterogeneity hypothesis" predicts a higher number of species in more diverse landscapes. Thus, it can be predicted that individuals with a wider realized trophic niche should have foraging territories with greater habitat diversity, suggesting that foraging strategies, territory quality and habitat diversity are inter-correlated. This was tested for a population of common kestrels Falco tinnunculus. Diet diversity, territory occupancy (as a measure of territory quality and habitat diversity of territories were measured over an 8-year period. Our results show that: 1 territory quality was quadratically correlated with habitat diversity, with the best territories being the least and most diverse; 2 diet diversity was not correlated with territory quality; and 3 diet diversity was negatively correlated with landscape heterogeneity. Our study suggests that niche generalist foraging strategies are based on an active search for different prey species within or between habitats rather than on the selection of territories with high habitat diversity.
Since June 9, 1999 the Oregon Department of Transportation (ODOT) has implemented the Routine Road Maintenance: Water Quality and Habitat Guide Best Management Practices (the Guide), and is considered the cornerstone of the ODOT'd Office of Maintenan...
Paul H. EVANGELISTA, John NORMAN III, Paul SWARTZINKI, Nicholas E. YOUNG
Full Text Available Populations of the endangered mountain nyala Tragelaphus buxtoni are significantly threatened by the loss of critical habitat. Population estimates are tentative, and information on the species’ distribution and available habitat is required for formulating immediate management and conservation strategies. To support management decisions and conservation priorities, we integrated information from a number of small-scale observational studies, interviews and reports from multiple sources to define habitat parameters and create a habitat quality model for mountain nyala in the Bale Mountains. For our analysis, we used the FunConn model, an expertise-based model that considers spatial relationships (i.e., patch size, distance between the species and vegetation type, topography and disturbance to create a habitat quality surface. The habitat quality model showed that approximately 18,610 km2 (82.7% of our study area is unsuitable or poor habitat for the mountain nyala, while 2,857 km2 (12.7% and 1,026 km2 (4.6% was ranked as good or optimal habitat, respectively. Our results not only reflected human induced habitat degradation, but also revealed an extensive area of intact habitat on the remote slopes of the Bale Mountain’s southern and southeastern escarpments. This study provides an example of the roles that expert knowledge can still play in modern geospatial modeling of wildlife habitat. New geospatial tools, such as the FunConn model, are readily available to wildlife managers and allow them to perform spatial analyses with minimal software, data and training requirements. This approach may be especially useful for species that are obscure to science or when field surveys are not practical [Current Zoology 58 (4: 525–535, 2012].
Arend, Kristin K.; Beletsky, Dmitry; DePinto, Joseph; Ludsin, Stuart A.; Roberts, James J.; Rucinski, Daniel K.; Scavia, Donald; Schwab, David J.; Höök, Tomas O.
1. Hypoxia occurs seasonally in many stratified coastal marine and freshwater ecosystems when bottom dissolved oxygen (DO) concentrations are depleted below 2–3 mg O2 L-1. 2. We evaluated the effects of hypoxia on fish habitat quality in the central basin of Lake Erie from 1987 to 2005, using bioenergetic growth rate potential (GRP) as a proxy for habitat quality. We compared the effect of hypoxia on habitat quality of (i) rainbow smelt, Osmerus mordax mordax Mitchill (young-of-year, YOY, and adult), a cold-water planktivore, (ii) emerald shiner, Notropis atherinoides Rafinesque (adult), a warm-water planktivore, (iii) yellow perch, Perca flavescens Mitchill (YOY and adult), a cool-water benthopelagic omnivore and (iv) round goby Neogobius melanostomus Pallas (adult) a eurythermal benthivore. Annual thermal and DO profiles were generated from 1D thermal and DO hydrodynamics models developed for Lake Erie’s central basin. 3. Hypoxia occurred annually, typically from mid-July to mid-October, which spatially and temporally overlaps with otherwise high benthic habitat quality. Hypoxia reduced the habitat quality across fish species and life stages, but the magnitude of the reduction varied both among and within species because of the differences in tolerance to low DO levels and warm-water temperatures. 4. Across years, trends in habitat quality mirrored trends in phosphorus concentration and water column oxygen demand in central Lake Erie. The per cent reduction in habitat quality owing to hypoxia was greatest for adult rainbow smelt and round goby (mean: -35%), followed by adult emerald shiner (mean: -12%), YOY rainbow smelt (mean: -10%) and YOY and adult yellow perch (mean: -8.5%). 5. Our results highlight the importance of differential spatiotemporally interactive effects of DO and temperature on relative fish habitat quality and quantity. These effects have the potential to influence the performance of individual fish species as well as population dynamics
Stepenuck, K.F.; Crunkilton, R.L.; Bozek, Michael A.; Wang, L.
We compared benthic macroinvertebrate assemblage structure at snag and riffle habitats in 43 Wisconsin streams across a range of watershed urbanization using a variety of stream quality metrics. Discriminant analysis indicated that dominant taxa at riffles and snags differed; Hydropsychid caddisflies (Hydropsyche betteni and Cheumatopsyche spp.) and elmid beetles (Optioservus spp. and Stenemlis spp.) typified riffles, whereas isopods (Asellus intermedius) and amphipods (Hyalella azteca and Gammarus pseudolimnaeus) predominated in snags. Analysis of covariance indicated that samples from snag and riffle habitats differed significantly in their response to the urbanization gradient for the Hilsenhoff biotic index (BI), Shannon's diversity index, and percent of filterers, shredders, and pollution intolerant Ephemeroptera, Plecoptera, and Trichoptera (EPT) at each stream site (p ??? 0.10). These differences suggest that although macroinvertebrate assemblages present in either habitat type are sensitive to detecting the effects of urbanization, metrics derived from different habitats should not be intermixed when assessing stream quality through biomonitoring. This can be a limitation to resource managers who wish to compare water quality among streams where the same habitat type is not available at all stream locations, or where a specific habitat type (i.e., a riffle) is required to determine a metric value (i.e., BI). To account for differences in stream quality at sites lacking riffle habitat, snag-derived metric values can be adjusted based on those obtained from riffles that have been exposed to the same level of urbanization. Comparison of nonlinear regression equations that related stream quality metric values from the two habitat types to percent watershed urbanization indicated that snag habitats had on average 30.2 fewer percent EPT individuals, a lower diversity index value than riffles, and a BI value of 0.29 greater than riffles. ?? 2008 American Water
Edwin C Rowe
Full Text Available Atmospheric nitrogen (N deposition has had detrimental effects on species composition in a range of sensitive habitats, although N deposition can also increase agricultural productivity and carbon storage, and favours a few species considered of importance for conservation. Conservation targets are multiple, and increasingly incorporate services derived from nature as well as concepts of intrinsic value. Priorities vary. How then should changes in a set of species caused by drivers such as N deposition be assessed? We used a novel combination of qualitative semi-structured interviews and quantitative ranking to elucidate the views of conservation professionals specialising in grasslands, heathlands and mires. Although conservation management goals are varied, terrestrial habitat quality is mainly assessed by these specialists on the basis of plant species, since these are readily observed. The presence and abundance of plant species that are scarce, or have important functional roles, emerged as important criteria for judging overall habitat quality. However, species defined as 'positive indicator-species' (not particularly scarce, but distinctive for the habitat were considered particularly important. Scarce species are by definition not always found, and the presence of functionally important species is not a sufficient indicator of site quality. Habitat quality as assessed by the key informants was rank-correlated with the number of positive indicator-species present at a site for seven of the nine habitat classes assessed. Other metrics such as species-richness or a metric of scarcity were inconsistently or not correlated with the specialists' assessments. We recommend that metrics of habitat quality used to assess N pollution impacts are based on the occurrence of, or habitat-suitability for, distinctive species. Metrics of this type are likely to be widely applicable for assessing habitat change in response to different drivers. The novel
Rowe, Edwin C; Ford, Adriana E S; Smart, Simon M; Henrys, Peter A; Ashmore, Mike R
Atmospheric nitrogen (N) deposition has had detrimental effects on species composition in a range of sensitive habitats, although N deposition can also increase agricultural productivity and carbon storage, and favours a few species considered of importance for conservation. Conservation targets are multiple, and increasingly incorporate services derived from nature as well as concepts of intrinsic value. Priorities vary. How then should changes in a set of species caused by drivers such as N deposition be assessed? We used a novel combination of qualitative semi-structured interviews and quantitative ranking to elucidate the views of conservation professionals specialising in grasslands, heathlands and mires. Although conservation management goals are varied, terrestrial habitat quality is mainly assessed by these specialists on the basis of plant species, since these are readily observed. The presence and abundance of plant species that are scarce, or have important functional roles, emerged as important criteria for judging overall habitat quality. However, species defined as 'positive indicator-species' (not particularly scarce, but distinctive for the habitat) were considered particularly important. Scarce species are by definition not always found, and the presence of functionally important species is not a sufficient indicator of site quality. Habitat quality as assessed by the key informants was rank-correlated with the number of positive indicator-species present at a site for seven of the nine habitat classes assessed. Other metrics such as species-richness or a metric of scarcity were inconsistently or not correlated with the specialists' assessments. We recommend that metrics of habitat quality used to assess N pollution impacts are based on the occurrence of, or habitat-suitability for, distinctive species. Metrics of this type are likely to be widely applicable for assessing habitat change in response to different drivers. The novel combined
Ménard, Nelly; Motsch, Peggy; Delahaye, Alexia; Saintvanne, Alice; Le Flohic, Guillaume; Dupé, Sandrine; Vallet, Dominique; Qarro, Mohamed; Tattou, Mohamed Ibn; Pierre, Jean-Sébastien
Barbary macaques live in extreme temperate environments characterized by strongly seasonal resource availability. They are mainly terrestrial while foraging, harvesting food from the herbaceous layer. These monkeys are threatened mainly because of anthropogenic habitat degradation. We studied the adaptive capacities of wild groups of Barbary macaques that lived in different cedar forests undergoing varying extents of grazing pressure from domestic livestock. In all three sites, diet varied seasonally. Heavy grazing led to a significant decrease in herbaceous production and species richness. As a consequence, the monkeys' diet in this poor habitat showed a decreased plant species richness. Moreover, it incorporated fewer above-ground herbaceous resources, and a greater proportion of subterranean resources (especially hypogeous fungi and subterranean invertebrates such as earthworms, eggs and adults of earwigs, and ant's larvae) than the diet of monkeys inhabiting ungrazed forest. Cedar bark, cedar strobiles, earthworms, and earwigs were part of the monkeys' diet only in grazed forest. Monkeys in heavily grazed forest compensated for a lack of herbaceous foods by eating subterranean foods preferentially to tree and shrub products. The foods they consumed take longer to harvest and process than the seeds or leaves consumed by Barbary macaques in less heavily grazed forest habitats. Our results suggest that monkeys do differ in their diets according to the degree of habitat change induced by human activities. They also highlight the dietary flexibility of Barbary macaques as a key element that allows them to cope with degraded habitats. We later compare the dietary adjustments of Barbary macaques facing environmental change to dietary strategies of other macaques and temperate-zone primates. © 2014 Wiley Periodicals, Inc.
Sallustio, Lorenzo; De Toni, Andrea; Strollo, Andrea; Di Febbraro, Mirko; Gissi, Elena; Casella, Laura; Geneletti, Davide; Munafò, Michele; Vizzarri, Matteo; Marchetti, Marco
The conservation of species and habitats is increasingly threatened by anthropogenic impacts, particularly land use change, from local to global scales. Although many efforts have been carried out so far to halt or at least reduce the biodiversity loss (e.g., the establishment of protected areas' networks), there are still both knowledge and policy gaps slowing the conservation of species and habitats in complex environments, such as the Mediterranean region. In particular, the human-driven impacts and threats on biodiversity need more careful analysis. Accordingly, this paper aims to assess the habitat quality and degradation in Italy in relation with the spatial pattern of the current protected areas' network, mainly to identify priority areas of intervention, thus supporting large-scale conservation strategies. A survey of experts was conducted to identify the main threats for biodiversity from different land uses at the national scale. The InVEST software was then applied to assess and map habitat quality and degradation with a high spatial resolution (20 m). The relationship between habitat quality and degradation as well as their hotspots, and alternative PA categories were also explored. Results indicate that: (i) habitat quality and degradation depend on the location and intensity of the anthropogenic impacts and are sensitive to different protection levels; (ii) the combination of the survey of experts and the spatially-explicit assessment of habitat quality and degradation is useful to highlight variations of the current conditions of biodiversity and habitats; and (iii) the identification of hotspots allows one to identify priority areas for conservation. Accordingly, the proposed approach may be used to strengthen the conservation efforts in similar contexts, and thus support the implementation of the biodiversity-related policies over the long term. Copyright © 2017 Elsevier Ltd. All rights reserved.
Terrado, Marta; Sabater, Sergi; Chaplin-Kramer, Becky; Mandle, Lisa; Ziv, Guy; Acuña, Vicenç
There is a growing pressure of human activities on natural habitats, which leads to biodiversity losses. To mitigate the impact of human activities, environmental policies are developed and implemented, but their effects are commonly not well understood because of the lack of tools to predict the effects of conservation policies on habitat quality and/or diversity. We present a straightforward model for the simultaneous assessment of terrestrial and aquatic habitat quality in river basins as a function of land use and anthropogenic threats to habitat that could be applied under different management scenarios to help understand the trade-offs of conservation actions. We modify the InVEST model for the assessment of terrestrial habitat quality and extend it to freshwater habitats. We assess the reliability of the model in a severely impaired basin by comparing modeled results to observed terrestrial and aquatic biodiversity data. Estimated habitat quality is significantly correlated with observed terrestrial vascular plant richness (R(2)=0.76) and diversity of aquatic macroinvertebrates (R(2)=0.34), as well as with ecosystem functions such as in-stream phosphorus retention (R(2)=0.45). After that, we analyze different scenarios to assess the suitability of the model to inform changes in habitat quality under different conservation strategies. We believe that the developed model can be useful to assess potential levels of biodiversity, and to support conservation planning given its capacity to forecast the effects of management actions in river basins. Copyright © 2015 Elsevier B.V. All rights reserved.
Hodgson, Jenny A; Moilanen, Atte; Thomas, Chris D
Many species have to track changes in the spatial distribution of suitable habitat from generation to generation. Understanding the dynamics of such species will likely require spatially explicit models, and patch-based metapopulation models are potentially appropriate. However, relatively little attention has been paid to developing metapopulation models that include habitat dynamics, and very little to testing the predictions of these models. We tested three predictions from theory about the differences between dynamic habitat metapopulations and their static counterparts using long-term survey data from two metapopulations of the butterfly Plebejus argus. As predicted, we showed first that the metapopulation inhabiting dynamic habitat had a lower level of habitat occupancy, which could not be accounted for by other differences between the metapopulations. Secondly, we found that patch occupancy did not significantly increase with increasing patch connectivity in dynamic habitat, whereas there was a strong positive connectivity-occupancy relationship in static habitat. Thirdly, we found no significant relationship between patch occupancy and patch quality in dynamic habitat, whereas there was a strong, positive quality-occupancy relationship in static habitat. Modeling confirmed that the differences in mean patch occupancy and connectivity-occupancy slope could arise without changing the species' metapopulation parameters-importantly, without changing the dependence of colonization upon connectivity. We found that, for a range of landscape scenarios, successional simulations always produced a lower connectivity-occupancy slope than comparable simulations with static patches, whether compared like-for-like or controlling for mean occupancy. We conclude that landscape-scale studies may often underestimate the importance of connectivity for species occurrence and persistence because habitat turnover can obscure the connectivity-occupancy relationship in commonly
Somura, H.; Takeda, I.; Masunaga, T.; Mori, Y.; Ide, J.
Thousands of migratory birds such as tundra swan came to the paddy fields for overwintering in recent years in the study area. They stayed in paddy fields during night time for sleeping and used around the fields as a feeding ground during day time. During the birds stay, it was observed that water pooled in the paddy fields gradually turned green and gave off a bad smell. In this study, we tried to estimate the influence of the bird’s feces to water quality in the paddy fields. The study area is in the southeastern portion of Matsue City in Shimane Prefecture, Japan. In several paddy fields, puddling procedure was executed after harvesting rice and then water was stored in the paddy fields during winter season. This is because of being easier of farming activities such as weeding next season and of avoiding using pesticide for weeding with rising of environmental awareness. Water in the paddy fields was collected once or twice a month from the target fields and analyzed nitrogen, phosphorus, and organic carbon in 2007. In the study in 2006, as water was sampled once a week and the changes in the water quality had been grasped, we paid attention to behavior of the birds in a day in the field investigation in 2007. The number of the birds was counted once an hour from visible 7 am to 6 pm once a month. In addition to this, fresh feces were sampled from the fields and analyzed the contents of nitrogen, phosphorus, and organic carbon in the feces. As results, average water qualities of TN, TP, and TOC from November 2007 to March 2008 showed very high concentrations compared with a river water concentration used as irrigation water. More than 70% of TN in the water was ammonia nitrogen. Moreover, comparing with a standard fertilizer amount of nitrogen and phosphorus for paddy fields during irrigation period, it was estimated that the amount of nitrogen excreted by the bird’s feces during the winter season was equivalent to the standard fertilizer amount and the
Brett G Dickson
Full Text Available The impact of landscape changes on the quality and connectivity of habitats for multiple wildlife species is of global conservation concern. In the southwestern United States, pumas (Puma concolor are a well distributed and wide-ranging large carnivore that are sensitive to loss of habitat and to the disruption of pathways that connect their populations. We used an expert-based approach to define and derive variables hypothesized to influence the quality, location, and permeability of habitat for pumas within an area encompassing the entire states of Arizona and New Mexico. Survey results indicated that the presence of woodland and forest cover types, rugged terrain, and canyon bottom and ridgeline topography were expected to be important predictors of both high quality habitat and heightened permeability. As road density, distance to water, or human population density increased, the quality and permeability of habitats were predicted to decline. Using these results, we identified 67 high quality patches across the study area, and applied concepts from electronic circuit theory to estimate regional patterns of connectivity among these patches. Maps of current flow among individual pairs of patches highlighted possible pinch points along two major interstate highways. Current flow summed across all pairs of patches highlighted areas important for keeping the entire network connected, regardless of patch size. Cumulative current flow was highest in Arizona north of the Colorado River and around Grand Canyon National Park, and in the Sky Islands region owing to the many small habitat patches present. Our outputs present a first approximation of habitat quality and connectivity for dispersing pumas in the southwestern United States. Map results can be used to help target finer-scaled analyses in support of planning efforts concerned with the maintenance of puma metapopulation structure, as well as the protection of landscape features that facilitate
Dickson, Brett G; Roemer, Gary W; McRae, Brad H; Rundall, Jill M
The impact of landscape changes on the quality and connectivity of habitats for multiple wildlife species is of global conservation concern. In the southwestern United States, pumas (Puma concolor) are a well distributed and wide-ranging large carnivore that are sensitive to loss of habitat and to the disruption of pathways that connect their populations. We used an expert-based approach to define and derive variables hypothesized to influence the quality, location, and permeability of habitat for pumas within an area encompassing the entire states of Arizona and New Mexico. Survey results indicated that the presence of woodland and forest cover types, rugged terrain, and canyon bottom and ridgeline topography were expected to be important predictors of both high quality habitat and heightened permeability. As road density, distance to water, or human population density increased, the quality and permeability of habitats were predicted to decline. Using these results, we identified 67 high quality patches across the study area, and applied concepts from electronic circuit theory to estimate regional patterns of connectivity among these patches. Maps of current flow among individual pairs of patches highlighted possible pinch points along two major interstate highways. Current flow summed across all pairs of patches highlighted areas important for keeping the entire network connected, regardless of patch size. Cumulative current flow was highest in Arizona north of the Colorado River and around Grand Canyon National Park, and in the Sky Islands region owing to the many small habitat patches present. Our outputs present a first approximation of habitat quality and connectivity for dispersing pumas in the southwestern United States. Map results can be used to help target finer-scaled analyses in support of planning efforts concerned with the maintenance of puma metapopulation structure, as well as the protection of landscape features that facilitate the dispersal
Zhao, C. S.; Yang, S. T.; Xiang, H.; Liu, C. M.; Zhang, H. T.; Yang, Z. L.; Zhang, Y.; Sun, Y.; Mitrovic, S. M.; Yu, Q.; Lim, R. P.
Aquatic ecological rehabilitation is attracting increasing public and research attention, but without knowledge of the responses of aquatic species to their habitats the success of habitat restoration is uncertain. Thus efficient study of species response to habitat, through which to prioritize the habitat factors influencing aquatic ecosystems, is highly important. However many current models have too high requirement for assemblage information and have great bias in results due to consideration of only the species' attribute of presence/absence, abundance or biomass, thus hindering the wider utility of these models. This paper, using fish as a case, presents a framework for identification of high-priority habitat factors based on the responses of aquatic species to their habitats, using presence/absence, abundance and biomass data. This framework consists of four newly developed sub-models aiming to determine weightings for the evaluation of species' contributions to their communities, to quantitatively calculate an integrated habitat suitability index for multi-species based on habitat factors, to assess the suitable probability of habitat factors and to assess the rehabilitation priority of habitat factors. The framework closely links hydrologic, physical and chemical habitat factors to fish assemblage attributes drawn from monitoring datasets on hydrology, water quality and fish assemblages at a total of 144 sites, where 5084 fish were sampled and tested. Breakpoint identification techniques based on curvature in cumulated dominance along with a newly developed weighting calculation model based on theory of mass systems were used to help identify the dominant fish, based on which the presence and abundance of multiple fish were normalized to estimate the integrated habitat suitability index along gradients of various factors, based on their variation with principal habitat factors. Then, the appropriate probability of every principal habitat factor was
... assistance, 24 hours a day, 7 days a week. SUPPLEMENTARY INFORMATION: Background We published a notice in the...: February 24, 2011. Jeffrey L. Underwood, Deputy Assistant Director, Fisheries and Habitat Conservation. [FR...
Sonny S. Bleicher
Full Text Available In environments where food resources are spatially variable and temporarily impoverished, consumers that encounter habitat patches with different food density should focus their foraging initially where food density is highest before they move to patches where food density is lower. Increasing missed opportunity costs should drive individuals progressively to patches with lower food density as resources in the initially high food density patches deplete. To test these expectations, we assessed the foraging decisions of two species of dasyurid marsupials (dunnarts: Sminthopsis hirtipes and S. youngsoni during a deep drought, or bust period, in the Simpson Desert of central Australia. Dunnarts were allowed access to three patches containing different food densities using an interview chamber experiment. Both species exhibited clear preference for the high density over the lower food density patches as measured in total harvested resources. Similarly, when measuring the proportion of resources harvested within the patches, we observed a marginal preference for patches with initially high densities. Models analyzing behavioral choices at the population level found no differences in behavior between the two species, but models analyzing choices at the individual level uncovered some variation. We conclude that dunnarts can distinguish between habitat patches with different densities of food and preferentially exploit the most valuable. As our observations were made during bust conditions, experiments should be repeated during boom times to assess the foraging economics of dunnarts when environmental resources are high.
Cheyne Susan M
Full Text Available Abstract Background Assessing the suitability of a habitat prior to the release of animals is vital. Proper assessment of the flora will allow reintroduction programmes to determine whether the area will be capable of supporting the released animals in the long-term. Here data are presented from an island in Central Kalimantan, Indonesia which has been used as a release site for agile gibbons (Hylobates agilis albibarbis since January 2003. Results Methods and results regarding fruit abundance, fruit productivity, tree density and diversity are presented. This information is then analysed in the context of the island's suitability to sustain released gibbons and without impact on the resident fauna. Based on the above ecological characteristics, the final carrying capacity of the island is estimated to be between 3 and 19 gibbons. Conclusion These data highlight the need to survey areas being considered for release of gibbon prior to the release taking place. For reintroductions to be successful, long-term habitat assessment is vital, both pre- and post-release.
Full Text Available Para las aves, ambientes salobres como los marinos y los salares, son en la práctica hábitats secos. Cuando las aves beben agua o consumen presas saladas, sus fluidos corporales aumentan la osmolaridad. Para mantener el equilibrio osmótico, las aves tienen que eliminar el exceso de electrolitos ingerido en los alimentos y el agua. Las estrategias adaptativas utilizadas por las aves marinas incluyen la utilización de la glándula de la sal, la cual produce soluciones de excreción más concentradas que el agua de mar. Tanto la fisiología y la plasticidad de la glándula nasal se correlaciona con las características ecológicas de las especies. Además, las aves pueden minimizar el estrés osmótico escogiendo presas hipo-osmóticas, o con menor contenido de agua, disminuyendo de este modo la ingestión de sales. Aun cuando la capacidad de concentración de la orina del riñón de aves es limitada, existen diferencias interespecíficas en su estructura y fisiología, lo que representa un mecanismo adaptativo para evitar la pérdida de agua. Este órgano es particularmente importante en aquellos taxa que no poseen la glándula de la sal, como paseriformes. Sin embargo, estas aves que aparentemente poseerían una restricción fisiológica para explotar ambientes salobres, incluyen algunas especies que habitan costas oceánicas y de salares. En esta revisión muestro que la interacción funcional del riñón y el intestino grueso en la fisiología osmoregulatoria, junto con la conducta de alimentación juegan un papel crucial en la mantención del balance hídrico y en la adaptación de estas especies a ambientes salobresFor birds, saline environments such as maritime and salt marsh habitats are essentially dry habitats. When birds drink saline water or consume salt-loaded preys, the osmolarity of their body fluids increases. In order to maintain the osmotic equilibrium, they have to eliminate the excess of electrolytes ingested with preys or
Platteeuw, M.; Foppen, R.P.B.; Eerden, van M.R.
All over Europe, wetlands have decreased in size, lost their original dynamics and became fragmented as the consequence of an ever increasing human land use. These processes have resulted in losses of nature values, among which declines in marshland bird populations. Ecological restoration of
JoAnn M. Hanowski; Gerald J. Niemi
We established bird monitoring programs in two regions of Minnesota: the Chippewa National Forest and the Superior National Forest. The experimental design defined forest cover types as strata in which samples of forest stands were randomly selected. Subsamples (3 point counts) were placed in each stand to maximize field effort and to assess within-stand and between-...
Koen, J H; Crowe, T M
Effects of forest plant species composition and physiognomy on bird and invertebrate communities were investigated in three discrete, relatively undisturbed forest types along a dry-wet soil moisture gradient. Using discriminant function analysis, a 100% floristic and a 78% vegetation structural discrimination were obtained between the three forest types. However, the bird communities of these different forest types were very similar in species composition, and had much lower densities than those normally encountered in other, superficially similar forests. Although an 81% discrimination between forest types was attained through analysis of ground surface invertebrates, measures of litter and aerial invertebrate abundance were also of limited use as discriminators. Historical and biogeographic factors, as well as the low nutritional levels in the soil and vegetation may be the causes of low bird and invertebrate density and diversity. It is concluded that floristics and vegetation structure have, at best, a minor influence on bird community structure, and possibly also on invertebrate community structure in the Knysna Forest.
Luke L. Powell; Gustavo Zurita; Jared D. Wolfe; Erik I. Johnson; Philip C Stouffer
Primary tropical rain forests are being rapidly perforated with new edges via roads, logging, and pastures, and vast areas of secondary forest accumulate following abandonment of agricultural lands. To determine how insectivorous Amazonian understory birds respond to edges between primary rain forest and three age classes of secondary forest, we radio-tracked two...
Differential effects of habitat fragmentation on birds and mammals in Valdivian temperate rainforests Efectos diferenciales de la fragmentación del hábitat sobre aves y mamíferos del bosque valdiviano
DOUGLAS A. KELT
Full Text Available Four recent studies on Chilean vertebrates underscore the very different effects that habitat fragmentation may have under different conditions. In southern Chile, birds exhibited significant species-area relationships, whereas the more depauperate small mammal community did not. The avifauna of highly isolated rainforest remnants in Fray Jorge National Park (IV Región presented steeper species-area relations than those in southern Chile, reminiscent of land-bridge islands after faunal relaxation. The small mammal results were unexpected but may reflect the reduced vagility and immigration potential of this group. Additionally, the inter-remnant matrix habitat may support large populations of only some species, allowing them to capitalize on resources that are available in forest remnants. Such an effect is less likely for birds due to their greater vagility. Although the influence of remnant area is more clearly demonstrated for birds in Chile, it appears that small mammal assemblages may be more immediately impacted by habitat fragmentation than are birds, and that further fragmentation of temperate rainforests will seriously impoverish the small mammal assemblage, many of whose members are endemic to this region. Further research should emphasize the role of the inter-remnant matrix, of habitat corridors, and of the relative sensitivity of different species to matrix/corridor quality and remnant isolationCuatro estudios recientes en vertebrados chilenos subrayan los efectos muy diversos que la fragmentación del hábitat puede tener bajo diversas condiciones. En el sur de Chile, las aves exhibieron relaciones significativas entre la riqueza de especies y el área de hábitat ("especies-area", mientras que tal relación no se observó en la comunidad de pequeños mamíferos, la cual tiene menos especies. La avifauna de los fragmentos remanentes altamente aislados del Parque Nacional Fray Jorge (IV Región presentaron relaciones especies
Mairota, Paola; Cafarelli, Barbara; Labadessa, Rocco; Lovergine, Francesco P.; Tarantino, Cristina; Nagendra, Harini; Didham, Raphael K.
Modelling the empirical relationships between habitat quality and species distribution patterns is the first step to understanding human impacts on biodiversity. It is important to build on this understanding to develop a broader conceptual appreciation of the influence of surrounding landscape structure on local habitat quality, across multiple spatial scales. Traditional models which report that 'habitat amount' in the landscape is sufficient to explain patterns of biodiversity, irrespective of habitat configuration or spatial variation in habitat quality at edges, implicitly treat each unit of habitat as interchangeable and ignore the high degree of interdependence between spatial components of land-use change. Here, we test the contrasting hypothesis, that local habitat units are not interchangeable in their habitat attributes, but are instead dependent on variation in surrounding habitat structure at both patch- and landscape levels. As the statistical approaches needed to implement such hierarchical causal models are observation-intensive, we utilise very high resolution (VHR) Earth Observation (EO) images to rapidly generate fine-grained measures of habitat patch internal heterogeneities over large spatial extents. We use linear mixed-effects models to test whether these remotely-sensed proxies for habitat quality were influenced by surrounding patch or landscape structure. The results demonstrate the significant influence of surrounding patch and landscape context on local habitat quality. They further indicate that such an influence can be direct, when a landscape variable alone influences the habitat structure variable, and/or indirect when the landscape and patch attributes have a conjoined effect on the response variable. We conclude that a substantial degree of interaction among spatial configuration effects is likely to be the norm in determining the ecological consequences of habitat fragmentation, thus corroborating the notion of the spatial context
To preliminary explore the difference of the morphological, quality and germinal characteristics of Acanthopanax trifoliatus seeds under different habitats. Collect the wild seeds from different habitats in West Mountain, and then observe their external appearances and internal structure, and test the thousand seeds weight,water content and seed vigor. What's more, the influence to germination rates of the seeds from different temperatures and light intensities in artificial bioclimatic chamber was studied. Orthogonal test in experimental plots was carried out to screen the different sowing dates, matrix types and soil depths which may influence germination rate. The external appearances and quality characteristics of wild seeds from three habitats were different. Seeds could germinate in the both light and dark, the germination rate of the habitat II was as high as 70.5% at the optimum temperature 20 degrees C in artificial bioclimatic chamber. The optimal combination A1, B1, C1 was screened out through orthogonal test, namely, the germination rate would be the highest when the seeds sowed in autumn covering with 2 cm depth of matrix type which component of the ratio of soil, sand and organic fertilizer was 6: 3: 1. There was significant difference in the morphology and germination rate of the three habitats seeds. The habitat II seeds were the optimal choice when culture seedling. The influences of different temperatures on germination rate were different, and the dried seeds should sow in current autumn, better than the next spring.
Full Text Available Impacts of habitat loss and fragmentation on distribution and population size of many taxa are well established. In contrast, less is known about the role of within-patch habitat quality for the spatial dynamics of species, even though within-patch habitat quality may substantially influence the dynamics of population networks. We studied occurrence patterns of two Orthopteran species in relation to size, isolation and quality of habitat patches in an intensively managed agricultural landscape (16.65 km(2 in the Swiss lowland. Occurrence of field crickets (Gryllus campestris was positively related to patch size and negatively to the distance to the nearest occupied patch, two measures of patch geometry. Moreover, field crickets were more likely to occur in extensively managed meadows, meadows used at low intensity and meadows dominated by Poa pratensis, three measures of patch quality. Occurrence of the large gold grasshopper (Chrysochraon dispar was negatively related to two measures of patch geometry, distance to the nearest occupied patch and perimeter index (ratio of perimeter length to patch area. Further, large gold grasshoppers were more likely to occupy patches close to water and patches with vegetation left uncut over winter, two measures of patch quality. Finally, examination of patch occupancy dynamics of field crickets revealed that patches colonized in 2009 and patches occupied in both 2005 and 2009 were larger, better connected and of other quality than patches remaining unoccupied and patches from which the species disappeared. The strong relationships between Orthopteran occurrence and aspects of patch geometry found in this study support the "area-and-isolation paradigm". Additionally, our study reveals the importance of patch quality for occurrence patterns of both species, and for patch occupancy dynamics in the field cricket. An increased understanding of patch occupancy patterns may be gained if inference is based on
Bieri, Joanna A.; Sample, Christine; Thogmartin, Wayne E.; Diffendorfer, James E.; Earl, Julia E.; Erickson, Richard A.; Federico, Paula; Flockhart, D. T. Tyler; Nicol, Sam; Semmens, Darius J.; Skraber, T.; Wiederholt, Ruscena; Mattsson, Brady J.
Many metrics exist for quantifying the relative value of habitats and pathways used by highly mobile species. Properly selecting and applying such metrics requires substantial background in mathematics and understanding the relevant management arena. To address this multidimensional challenge, we demonstrate and compare three measurements of habitat quality: graph-, occupancy-, and demographic-based metrics. Each metric provides insights into system dynamics, at the expense of increasing amounts and complexity of data and models. Our descriptions and comparisons of diverse habitat-quality metrics provide means for practitioners to overcome the modeling challenges associated with management or conservation of such highly mobile species. Whereas previous guidance for applying habitat-quality metrics has been scattered in diversified tracks of literature, we have brought this information together into an approachable format including accessible descriptions and a modeling case study for a typical example that conservation professionals can adapt for their own decision contexts and focal populations.Considerations for Resource ManagersManagement objectives, proposed actions, data availability and quality, and model assumptions are all relevant considerations when applying and interpreting habitat-quality metrics.Graph-based metrics answer questions related to habitat centrality and connectivity, are suitable for populations with any movement pattern, quantify basic spatial and temporal patterns of occupancy and movement, and require the least data.Occupancy-based metrics answer questions about likelihood of persistence or colonization, are suitable for populations that undergo localized extinctions, quantify spatial and temporal patterns of occupancy and movement, and require a moderate amount of data.Demographic-based metrics answer questions about relative or absolute population size, are suitable for populations with any movement pattern, quantify demographic
The suitability of watershed habitat to support the livelihood of its biota primarily depends on managing flow. Ecological restoration requires finding opportunities to reallocate available water in a watershed to increase ecological benefits and maintain other beneficial uses. We present the Watershed Area of Suitable Habitat (WASH) systems model that recommends reservoir releases, streamflows, and water allocations throughout a watershed to maximize the ecosystem habitat quality. WASH embeds and aggregates area-weighted metrics for aquatic, floodplain, and wetland habitat components as an ecosystem objective to maximize, while maintaining water deliveries for domestic and agricultural uses, mass balance, and available budget for restoration actions. The metrics add spatial and temporal functionality and area coverage to traditional habitat quality indexes and can accommodate multiple species of concern. We apply the WASH model to the Utah portion of the Bear River watershed which includes 8 demand sites, 5 reservoirs and 37 nodes between the Utah-Idaho state line and the Great Salt Lake. We recommend water allocations to improve current conservation efforts and show tradeoffs between human and ecosystem uses of water. WASH results are displayed on an open-source web mapping application that allows stakeholders to access, visualize, and interact with the model data and results and compare current and model-recommended operations. Results show that the Bear River is largely developed and appropriated for human water uses. However, increasing reservoirs winter and early spring releases and minimizing late spring spill volumes can significantly improve habitat quality without harming agricultural or urban water users. The spatial and temporal reallocation of spring spills to environmental uses creates additional 70 thousand acres of suitable habitat in the watershed without harming human users. WASH also quantifies the potential environmental gains and losses from
Modifying greenspaces to enhance habitat value has been proposed as a means towards protecting or restoring biodiversity in urban landscapes. In this report, we provide a framework for developing low-cost, low-impact enhancements that can be incorporated during the restoration of...
Jennifer L. Reidy; Frank R. Thompson; Sarah W. Kendrick
Savanna and woodland were once common in the Midwest, but land use changes have led to increasing scarcity of these communities. These transitional habitats are being restored across the Midwest, but few studies have evaluated the response of wildlife to restoration or the vegetative gradient created by management. We conducted point counts for 25 songbirds at sites...
Li, Ning; Li, Xin-Hai; An, Shu-Qing; Lu, Chang-Hu
Frugivorous birds generally exhibit an unequal contribution to dispersal effectiveness of plant species as a function of their habitat adaptation and body size. In our study, we compared the effectiveness of multiple bird species that contribute to the dispersal of the endangered relic Chinese yew, Taxus chinensis. Seven bird species dispersed T. chinensis seeds, with Picus canus, Turdus hortulorum, and Urocissa erythrorhyncha being the main dispersers. The quantity part of dispersal effectiveness was strongly influenced by two inherent characteristics of disperser species: body size and habitat adaptation. However, the quality part of dispersal effectiveness was only influenced by disperser type. For instance, small generalist birds and large specialist birds removed more seeds than other type dispersers. Moreover, small birds and specialist birds contributed slightly more to the dispersal quality of T. chinensis than large birds and generalist birds respectively; however, these differences were not significant. Our results suggest that dispersal effectiveness is affected by variety in the body size and habitat adaptation of different dispersers. Therefore, such variation should be incorporated into spatial and temporal management actions of relic plant species in patchy, human-disturbed habitats.
We present the results of monthly sediment and water quality surveys to evaluate the impact of intermittent, seasonal hypoxia on benthic habitat condition. This study was conducted in the Pensacola Bay (Florida) estuary across nine sites extending from the mouth of the Escambia ...
Adámek, Z.; Jurajda, Pavel
Roč. 1, č. 3 (2001), s. 305-311 ISSN 1642-3593. [Ecohydrology as a tool for restoration of physically degraded fish habitats. Warsaw, 11.06.2001-13.06.2001] Institutional research plan: CEZ:AV0Z6093917 Keywords : stream ecology * water quality * fish communities Subject RIV: EH - Ecology, Behaviour
Anderson, James T.; Zadnik, Andrew K.; Wood, Petra Bohall; Bledsoe, Kerry
The islands and associated back channels on the Ohio River, USA, are believed to provide critical habitat features for several wildlife species. However, few studies have quantitatively evaluated habitat quality in these areas. Our main objective was to evaluate the habitat quality of back and main channel areas for several species using habitat suitability index (HSI) models. To test the effectiveness of these models, we attempted to relate HSI scores and the variables measured for each model with measures of relative abundance for the model species. The mean belted kingfisher (Ceryle alcyon) HSI was greater on the main than back channel. However, the model failed to predict kingfisher abundance. The mean reproduction component of the great blue heron (Ardea herodias) HSI, total common muskrat (Ondatra zibethicus) HSI, winter cover component of the snapping turtle (Chelydra serpentina) HSI, and brood-rearing component of the wood duck (Aix sponsa) HSI were all greater on the back than main channel, and were positively related with the relative abundance of each species. We found that island back channels provide characteristics not found elsewhere on the Ohio River and warrant conservation as important riparian wildlife habitat. The effectiveness of using HSI models to predict species abundance on the river was mixed. Modifications to several of the models are needed to improve their use on the Ohio River and, likely, other large rivers.
European agriculture is undergoing widespread changes that are likely to have profound impacts on farmland biodiversity.The development of tools that allow an assessment of the potential biodiversity effects of different land-use alternatives before changes occur is fundamental to guiding management decisions. In this study, we develop a resource-based model framework to estimate habitat suitability for target species, according to simple information on species’ key resource requirements (die...
Kittle, Andrew M; Anderson, Morgan; Avgar, Tal; Baker, James A; Brown, Glen S; Hagens, Jevon; Iwachewski, Ed; Moffatt, Scott; Mosser, Anna; Patterson, Brent R; Reid, Douglas E B; Rodgers, Arthur R; Shuter, Jen; Street, Garrett M; Thompson, Ian D; Vander Vennen, Lucas M; Fryxell, John M
1. Although local variation in territorial predator density is often correlated with habitat quality, the causal mechanism underlying this frequently observed association is poorly understood and could stem from facultative adjustment in either group size or territory size. 2. To test between these alternative hypotheses, we used a novel statistical framework to construct a winter population-level utilization distribution for wolves (Canis lupus) in northern Ontario, which we then linked to a suite of environmental variables to determine factors influencing wolf space use. Next, we compared habitat quality metrics emerging from this analysis as well as an independent measure of prey abundance, with pack size and territory size to investigate which hypothesis was most supported by the data. 3. We show that wolf space use patterns were concentrated near deciduous, mixed deciduous/coniferous and disturbed forest stands favoured by moose (Alces alces), the predominant prey species in the diet of wolves in northern Ontario, and in proximity to linear corridors, including shorelines and road networks remaining from commercial forestry activities. 4. We then demonstrate that landscape metrics of wolf habitat quality - projected wolf use, probability of moose occupancy and proportion of preferred land cover classes - were inversely related to territory size but unrelated to pack size. 5. These results suggest that wolves in boreal ecosystems alter territory size, but not pack size, in response to local variation in habitat quality. This could be an adaptive strategy to balance trade-offs between territorial defence costs and energetic gains due to resource acquisition. That pack size was not responsive to habitat quality suggests that variation in group size is influenced by other factors such as intraspecific competition between wolf packs. © 2015 The Authors. Journal of Animal Ecology © 2015 British Ecological Society.
Samplonius, Jelmer M.; Kromhout Van Der Meer, Iris M; Both, Christiaan
Background: Social learning allows animals to eavesdrop on ecologically relevant knowledge of competitors in their environment. This is especially important when selecting a habitat if individuals have relatively little personal information on habitat quality. It is known that birds can use both
Glemnitz, Michael; Zander, Peter; Stachow, Ulrich
The environmental impacts of land use vary regionally. Differences in geomorphology, climate, landscape structure, and biotope inventories are regarded as the main causes of this variation. We present a methodological approach for identifying regional responses in land use type to large-scale changes and the implications for the provision of habitat for farmland birds. The methodological innovations of this approach are (i) the coupling of impact assessments with economic models, (ii) the linking of cropping techniques at the plot scale with the regional distribution of land use, and (iii) the integration of statistical or monitoring data on recent states. This approach allows for the regional differentiation of farmers' responses to changing external conditions and for matching the ecological impacts of land use changes with regional environmental sensitivities. An exemplary scenario analysis was applied for a case study of an area in Germany, assessing the impacts of increased irrigation and the promotion of energy cropping on farmland birds, evaluated as a core indicator for farmland biodiversity. The potential effects on farmland birds were analyzed based on the intrinsic habitat values of the crops and cropping techniques. The results revealed that the strongest decrease in habitat availability for farmland birds occurred in regions with medium-to-low agricultural yields. As a result of the limited cropping alternatives, the increase in maize production was highest in marginal regions for both examined scenarios. Maize production replaced many crops with good-to-medium habitat suitability for birds. The declines in habitat quality were strongest in regions that are not in focus for conservation efforts for farmland birds.
Banko, Paul C.; Camp, Richard J.; Farmer, Chris; Brinck, Kevin W.; Leonard, David L.; Stephens, Robert M.
Extinction has claimed half of all historically-known Hawaiian passerines, and today many extant species are increasingly threatened due to the combined effects of invasive species and climate change. Habitat disturbance has affected populations of feeding specialists most profoundly, and our results indicate that specialists continue to be most vulnerable, although even some abundant, introduced, generalist species also may be affected. Surveys of passerines during 1998–2011 in subalpine woodland habitat on Mauna Kea Volcano, Island of Hawai′i, revealed that the abundance of the critically endangered palila (Loxioides bailleui), a seed specialist, declined by 79% after 2003. The ′akiapōlā′au (Hemignathus munroi), an endangered specialist insectivore, was not detected in the survey area after 1998. The Hawai′i ′amakihi (Hemignathus virens virens), a generalist feeder and the most abundant species on Mauna Kea, was the only native species to maintain a stable population. The Japanese white-eye (Zosterops japonicus), a well-entrenched generalist and one of the three most common introduced species, declined. Drought prevailed in 74% of months during 2000–2011, and dry conditions contributed to the recent decline of the palila by reducing the annual māmane (Sophora chrysophylla) seed pod crop, which influences palila breeding and survival. Sustained browsing by introduced ungulates also lowered habitat carrying capacity, and their elimination should reduce the effects of drought and promote forest restoration. Our results illustrate how the feeding ecology of a species can influence its response to interacting environmental perturbations, and they underscore the value of long-term monitoring to detect population trends of sensitive species.
Copplestone, D.; Wood, M.D.; Bielby, S.; Jones, S.R.; Vives, J.; Beresford, N.A.; Zinger, I.
In the UK, research funded by the Environment Agency/English Nature has provided a tool for calculating doses received by biota in coastal, freshwater and terrestrial ecosystems. The approach uses the reference organism concept where the organism of interest (feature organism) is equated to a particular reference organism (based on its physical geometry and ecology). The exposure of the reference organism, and consequently the feature organism, to different radionuclides and dose rates can be assessed using a spreadsheet-based mathematical tool. This assessment tool was developed in 2001 and provided an internationally recognised starting point from which more refined assessment tools could develop. As the need for conducting specific assessments under the UK Habitat Regulations became apparent, it was recognised that some targeted refinement of the assessment tool was required. One of the major problems with the tool related to a lack of species-specific data and a lack of information on certain radionuclides appearing in discharges that may be impacting on sites/species to be protected. A second research and development project was therefore undertaken to reduce the uncertainties associated with the assessment tool by collating additional species-specific data, developing a mathematical system for ensuring that the most appropriate reference organism was selected and extending the range of radionuclides included in the assessment. This specific expansion to the assessment tool was directed towards ensuring that species at Natura 2000 sites (Special Protection Areas (SPAs) and Special Areas of Conservation (SACs)) were adequately protected. The species targeted (feature species) for this assessment were species protected under the EC Habitats Directive and those that are characteristic of habitats protected under the Directive. The paper will show how typical dimensions of each feature species are collated and each feature species mathematically aligned with the
Lewis, Michael A. [U.S. Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Gulf Ecology Division, 1 Sabine Island Drive, Gulf Breeze, FL 32561 (United States)]. E-mail: email@example.com; Dantin, Darrin D. [U.S. Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Gulf Ecology Division, 1 Sabine Island Drive, Gulf Breeze, FL 32561 (United States); Chancy, Cynthia A. [U.S. Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Gulf Ecology Division, 1 Sabine Island Drive, Gulf Breeze, FL 32561 (United States); Abel, Kathryn C. [Department of Biological Sciences, University of West Florida, Pensacola, FL 32514 (United States); Lewis, Christopher G. [Department of Water and Soil Science, University of Florida, Gainesville, FL 32103 (United States)
Contaminant concentrations were determined for media associated with 13 Florida seagrass beds. Concentrations of 10 trace metals were more commonly detected in surface water, sediment and two seagrass species than PAHs, pesticides and PCBs. Concentrations of copper and arsenic in surface water exceeded Florida aquatic life criteria more frequently than other trace elements. Total organic carbon, mercury, chromium, zinc, total chlordane, total PAHs, total PCBs, DDD and DDE were significantly greater in seagrass-rooted sediments than adjacent non-vegetated sediments. Total DDT, DDD, DDE, total chlordane, arsenic, copper and nickel exceeded proposed sediment quality guidelines at six of 13 grass beds. Pesticides, PAHs, and PCBs were below detection in seagrass tissues. Mercury, cadmium, nickel, lead and silver were detected in 50% or more of the tissues for Thalassia testudinum (turtle grass) and Halodule wrightii (shoal grass). Spatial, interspecific and tissue differences were usually an order of magnitude or less. - Some anthropogenic contaminants were prevalent in seagrass and their rooted sediments but the biological significance is unknown.
Brooker, R. M.; Munday, P. L.; Mcleod, I. M.; Jones, G. P.
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.
Full Text Available The territorial behavior of the red-whiskered bulbul, Pycnonotus jocosus, was studied in the semiwild habitat of a bird farm compound in the District of Chana, Songkhla Province, the south of Thailand. The male and female birds were bred and reared in the farm till they reached maturity following which they were released to the wild. A mating pair was later formed and their territory established in the farm area. A decoy was used to simulate a natural intruder to the defended area. Ten test stations were sited in the four cardinal points of the compass and with reference to the farmhouse. The experiments were conducted during the pre-nesting and nesting periods. It was found that territorial boundary was marked by the resident male’s aggressive calls and threat displays to the decoy. The territory covered an area of approximately 0.3 hectare in which it was used for foraging and nesting. The size remained the same in both pre-nesting and nesting periods, but the territorial behavior during the nesting period was evidently more vigorous than that in the pre-nesting period. The intensities of territorial behavior had been hypothesized to be associated with diurnal foraging rhythms. But the finding was contradictory to this prediction. There was no significant difference in the intensity of territorial behavior (P > 0.05 at the three time regimes in the morning, at noon, and in the afternoon. It was suggested that the resident bird’s aggressive behavior might be associated with the degree of hunger pang.
Liao, Hehuan; Sarver, Emily; Krometis, Leigh-Anne H
Ecological degradation of streams remains a major environmental concern worldwide. While stream restoration has received considerable attention, mitigation efforts focused on the improvement of physical habitat have not proven completely effective. Several small-scale studies have emphasized that effective restoration strategies require a more holistic understanding of the variables at play, although the generalization of the findings based on the small-scale studies remains unclear. Using a comprehensive statewide stream monitoring database from West Virginia (WV), a detailed landscape dataset, and a machine learning algorithm, this study explores the interactive impacts of water quality and physical habitat on stream ecosystem health as indicated by benthic macroinvertebrate scores. Given the long history of energy extraction in this region (i.e., coal mining and oil/gas production), investigation of energy extraction influences is highlighted. Our results demonstrate that a combination of good habitat and low specific conductance is generally associated with favorable benthic macroinvertebrate scores, whereas poor habitat combined with water quality conditions typically indicative of high ionic strength are associated with impaired stream status. In addition, streams impacted by both energy extraction and residential development had a higher percentage of impairment compared to those impacted predominantly by energy extraction or residential development alone. While water quality played a more important role in the ecosystem health of streams impacted primarily by energy extraction activities, habitat seems to be more influential in streams impacted by residential development. Together, these findings emphasize that stream restoration strategies should consider interactive effects of multiple environmental stressors tailored to specific sites or site types - as opposed to considering a single stressor or multiple stressors separately. Copyright © 2017 Elsevier
Walters, D.M.; Freeman, Mary C.; Leigh, D.S.; Freeman, B.J.; Pringle, C.P.; Brown, Larry R.; Gray, Robert H.; Hughes, Robert H.; Meador, Michael
We quantified the relationships among urban land cover, fishes, and habitat quality to determine how fish assemblages respond to urbanization and if a habitat index can be used as an indirect measure of urban effects on stream ecosystems. We sampled 30 wadeable streams along an urban gradient (5?37% urban land cover) in the Etowah River basin, Georgia. Fish assemblages, sampled by electrofishing standardized stream reaches, were assessed using species richness, density, and species composition metrics. Habitat quality was scored using the Rapid Habitat Assessment Protocol (RHAP) of the U.S. Environmental Protection Agency. Urban land cover (including total, high-, and low-density urban) was estimated for the drainage basin above each reach. A previous study of these sites indicated that stream slope and basin area were strongly related to local variation in assemblage structure. We used multiple linear regression (MLR) analysis to account for this variation and isolate the urban effect on fishes. The MLR models indicated that urbanization lowered species richness and density and led to predictable changes in species composition. Darters and sculpin, cyprinids, and endemics declined along the urban gradient whereas centrarchids persisted and became the dominant group. The RHAP was not a suitable indicator of urban effects because RHAP-urban relationships were confounded by an overriding influence of stream slope on RHAP scores, and urban-related changes in fish assemblage structure preceded gross changes in stream habitat quality. Regression analysis indicated that urban effects on fishes accrue rapidly (<10 years) and are detectable at low levels (~5?10% urbanization). We predict that the decline of endemics and other species will continue and centrarchid-dominated streams will become more common as development proceeds within the Etowah basin.
Erwin, R.M.; Laubhan, M.K.; Cornely, J.E.; Bradshaw, D.M.; Bonney, Rick; Pashley, David N.; Cooper, Robert; Niles, Larry
Wetlands are the most productive ecosystems in the world, yet they have suffered more loss and degradation than any other ecosystem. Not surprisingly, 50% (29 of 58) of all the bird species in the U. S. (excluding Hawaii and territories) that are listed either as federally threatened or endangered, or are on the U. S. Fish & Wildlife Service 1995 List of Migratory Nongame Birds of Management Concern, occupy wetland or aquatic habitats even though many remaining wetlands across the North American landscape already are managed primarily for waterbirds. Some of these wetlands are administered by federal and state entities (e.g., national wildlife refuges, national and state parks, state wetland management areas) or are maintained on private lands through federally supported restoration and enhancement programs (e.g., Conservation Reserve Program, Wetland Reserve Program, Waterfowl Production Areas, and Partners for Wildlife). Private organizations, such as the National Audubon Society, The Nature Conservancy, and private hunting clubs, also own wetland areas that are managed specifically to benefit wildlife. If management philosophies are altered to consider the entire complex of wetlands, many wetlands can provide benefits to a broad array of waterbirds, as opposed to just one or a few species. However, challenges for natural resource managers are in forming partnerships with owners-managers of wetlands where the objectives are not primarily wildlife oriented. These owners or managers need to be included in wetland training workshops in an attempt to educate them about wetland values and secondary wildlife benefits that may be derived in flooded agricultural lands, aquaculture ponds, altered coastal marshes (mosquito control), and salt evaporation ponds. In some cases, compensation for crop damages by wildlife may be a necessary part of any cooperative agreements. In the development of a North American Bird Conservation Plan we propose a four-step approach and
The use of wetland treatment systems (WTS), or constructed wetlands, for treating municipal wastewater is increasing in the United States, but little is known about the ability of these systems to duplicate or sustain wetland functions. The pilot study was designed to examine methods and the usefulness of various wetland indicators for assessing the wildlife habitat quality in six WTS sites throughout the United States. The report focusses on two Mississippi sites, one located near Collins, and one near Ocean Springs.
Turgeon, Katrine; Kramer, Donald L
1. Populations experiencing localized mortality can recover in the short term by net movement of individuals from adjacent areas, a process called compensatory immigration or spillover. Little is known about the factors influencing the magnitude of compensatory immigration or its impact on source populations. Such information is important for understanding metapopulation dynamics, the use of protected areas for conservation, management of exploited populations and pest control. 2. Using two small, territorial damselfish species (Stegastes diencaeus and S. adustus) in their naturally fragmented habitat, we quantified compensatory immigration in response to localized mortality, assessed its impact on adjacent source populations and examined the importance of potential immigrants, habitat quality and landscape connectivity as limiting factors. On seven experimental sites, we repeatedly removed 15% of the initial population size until none remained and immigration ceased. 3. Immigrants replaced 16-72% of original residents in S. diencaeus and 0-69% in S. adustus. The proportion of the source population that immigrated into depleted areas varied from 9% to 61% in S. diencaeus and from 3% to 21% in S. adustus. In S. diencaeus, compensatory immigration was strongly affected by habitat quality, to a lesser extent by the abundance of potential immigrants and not by landscape connectivity. In S. adustus, immigration was strongly affected by the density of potential migrants and not by habitat quality and landscape connectivity. On two control sites, immigration in the absence of creation of vacancies was extremely rare. 4. Immigration occurred in response to localized mortality and was therefore compensatory. It was highly variable, sometimes producing substantial impacts on both depleted and source populations. The magnitude of compensatory immigration was influenced primarily by the availability of immigrants and by the potential improvement in territory quality that they
Full Text Available The use of anatomical features from the leaf has been evaluated in solving different kind of problems.The interactions between different plant species and urban habitat quality were extensively investigated by different authors. Studies concerning the anatomy of the vegetative organs under conditions of pollution have been carried out. The necessity of studying the capacity of plant species for bioindication of anthropogenic pollution defines the aim of this study: to analyze some anatomical leaf characteristics in urban area. The photos were taken with an Cannon photo camera, using an Optika research microscope. In the mesophyll and epidermis of the plants from polluted sites isolate dark spots or massive deposits of polyphenolic compounds could be observed. We conclude that Plantago is a suitable bioindicator of urban habitat quality as it is a commonly distributed species, which is easy to sample and shows a clear anatomical response to differences in habitat quality. The thickness of the foliar lamina has decreased. The stomatal density was higher at the abaxial side in comparison with the adaxial side. The present study provides a good basis for further research on impact of the environment to anatomical structure of the plants.
Alexander S Anderson
Full Text Available Indices of relative abundance do not control for variation in detectability, which can bias density estimates such that ecological processes are difficult to infer. Distance sampling methods can be used to correct for detectability, but in rainforest, where dense vegetation and diverse assemblages complicate sampling, information is lacking about factors affecting their application. Rare species present an additional challenge, as data may be too sparse to fit detection functions. We present analyses of distance sampling data collected for a diverse tropical rainforest bird assemblage across broad elevational and latitudinal gradients in North Queensland, Australia. Using audio and visual detections, we assessed the influence of various factors on Effective Strip Width (ESW, an intuitively useful parameter, since it can be used to calculate an estimate of density from count data. Body size and species exerted the most important influence on ESW, with larger species detectable over greater distances than smaller species. Secondarily, wet weather and high shrub density decreased ESW for most species. ESW for several species also differed between summer and winter, possibly due to seasonal differences in calling behavior. Distance sampling proved logistically intensive in these environments, but large differences in ESW between species confirmed the need to correct for detection probability to obtain accurate density estimates. Our results suggest an evidence-based approach to controlling for factors influencing detectability, and avenues for further work including modeling detectability as a function of species characteristics such as body size and call characteristics. Such models may be useful in developing a calibration for non-distance sampling data and for estimating detectability of rare species.
Full Text Available Grasslands host a high diversity of plant and animal species. In Serbia, most alkali grasslands are located in the province of Vojvodina. The majority are not subject to conservation. The aim of the study was to investigate the relationship between the proportion of croplands and (1 the number of breeding species and (2 the number of breeding pairs in the alkali grasslands of the upper Mostonga River catchment basin (NW Serbia. The size of the study area was 400 ha. Birds were surveyed along seven parallel transects eight times per breeding season. Lengths of the cross sections of both grasslands and croplands were measured. The proportion of croplands per transect was calculated by dividing the total length of cross sections of croplands by the total length of transect. The relationship between the proportion of croplands and the number of breeding pairs and the number of breeding species, respectively, was studied using simple linear regression. We recorded a total of 171 nesting pairs belonging to 23 species in the alkali grassland investigated, with breeding densities between 2.2 and 10.3 pairs per 10 ha. The number of species per transect ranged between 6 and 11. The most abundant species were Skylark Alauda arvensis, Yellow Wagtail Motacilla flava and Corn Bunting Emberiza calandra. The numbers of breeding pairs (F6 = 21.761, P < 0.0001 and of breeding species (F6 = 13.758, P = 0.001 were both influenced negatively by the proportion of croplands. These findings highlight the need for coordinated conservation measures on the alkali grasslands of Vojvodina.
John N. Macey; D. Brent Burt; Daniel Saenz; Richard N. Conner
Picoides borealis (Red-cockaded Woodpecker) is an endangered bird endemic to the Pinus (pine) ecosystems of the southeastern US. Mature pine savannahs with a minimal midstory and lush herbaceous groundcover represent high-quality habitat. This study examines the foraging-habitat patterns of Red-cockaded Woodpeckers in East...
... resources including migratory birds and their habitats. Large-scale efforts to influence bird migration and... timing and speed of bird migrations. It is possible that re-distribution of birds at smaller scales could...-0040; 91200-1231-9BPP-L2] RIN 1018-AX06 Migratory Bird Hunting; Final Frameworks for Early-Season...
Kim, Kyu-Ho [Korea Institute of Construction Technology, Koyang (Korea); Cho, Won-cheol [Yonsei University, Seoul (Korea); Jun, Byong-Ho [Korea Military Academy, Seoul (Korea)
The primary objective of this study is to estimate the suitable flow in need for conservation and restoration of the fish habitat in running water ecosystem, which has very important status in the instream flow for stream environment. Year, monthly low flows are estimated to properly maintain the fish habitat. Water depth and velocity are simulated, and also water temperature and Dissolved Oxygen(DO) are predicted at gradually varied flow using estimated low flows. These simulated conditions for each low flow are graphically compared with the requirements to maintain fish habitat at each life stage. These processes were applied to 3 riffle transect located at Dalcheon(Dal stream) in the South Han river. Pirami (Zacco platypus) was selected as a representative fish species in Dalcheon. It was shown that the suitable flow for maintaining the representative fish habitat at each life stage depends on hydraulic conditions rather than water quality conditions, and the flow ranges from the 10-year minimum low flow to consecutive 7-day 2.33-year low flow. (author). 17 refs., 6 tabs., 4 figs.
Joseph R. Benjamin; Jason B. Dunham; Matthew R. Dare
Theoretical models and empirical evidence suggest that the invasion of nonnative species in freshwaters is facilitated through the interaction of three factors: habitat quality, biotic resistance, and connectivity. We measured variables that represented each factor to determine which were associated with the occurrence of nonnative brook trout Salvelinus...
Kalarus, Konrad; Nowicki, Piotr
Most studies dealing with species distribution patterns on fragmented landscapes focus on the characteristics of habitat patches that influence local occurrence and abundance, but they tend to neglect the question of what drives colonization of previously unoccupied patches. In a study of the dryad butterfly, we combined classical approaches derived from metapopulation theory and landscape ecology to investigate the factors driving colonization from a recent refugium. In three consecutive transect surveys, we recorded the presence and numbers of imagos in 27 patches of xerothermic grassland and 26 patches of wet meadow. Among the predictors affecting the occurrence and abundance of the dryad, we considered environmental variables reflecting (i) habitat patch quality (e.g., goldenrod cover, shrub density, vegetation height); (ii) factors associated with habitat spatial structure (patch size, patch isolation and fragmentation); and (iii) features of patch surroundings (100-m buffers around patches) that potentially pose barriers or provide corridors. Patch colonization by the dryad was strongly limited by the distance from the species refugium in the region; there was a slight positive effect of shrub density in this respect. Butterfly abundance increased in smaller and more fragmented habitat patches; it was negatively impacted by invasive goldenrod cover, and positively influenced by the density of watercourses in patch surroundings. Nectar plant availability was positively related to species abundance in xerothermic grassland, while in wet meadow the effect was the reverse. We conclude that dryad colonization of our study area is very recent, since the most important factor limiting colonization was distance from the refugium, while the habitat quality of target patches had less relevance. In order to preserve the species, conservation managers should focus on enhancing the quality of large patches and should also direct their efforts on smaller and more
Wu, Jian-sheng; Cao, Qi-wen; Shi, Shu-qin; Huang, Xiu-lan; Lu, Zhi-qiang
Land use change is the core content of global change. To achieve sustainable land use planning, it is necessary to evaluate the habitat quality pattern and its spatio-temporal variation resulted from land use change, which can provide basis for the formulation of land management policy. Based on the analysis of land use change from 2000 to 2010, this study investigated the spatio-temporal variation of habitat quality pattern of Beijing-Tianjin-Hebei Area. We used the watershed profile sampling points and spatial autocorrelation analysis based on watershed subdivision. The results showed that the main land use change types from 2000 to 2010 in this area included the transition from cultivated land to construction land, the transition between forest and grassland, and the transition from water bodies to cultivated land. This land use/cover change process led to the decrease of heterogeneity of landscape structure and increase of fragmentation. The overall spatial pattern of habitat quality was that southeast and south areas were relatively lower, while north and west areas were relatively higher. The analysis based on watershed profile showed that the habitat quality of each watershed presented significant difference in each part. Habitat quality of most sampling points degraded in a way, while some improved compared with 2000. In general, the habitat quality of the bottom part of Luanhe River basin, the medium part of Bai-Chaobai-Chaobaixin River basin, the medium and the bottom part of Yongding River basin and medium part of Laozhang-Fudongpai- Beipai River basin were poor and volatile, while other parts were relatively good. There was a decreasing agglomeration characteristic of distribution of habitat quality in Beijing-Tianjin-Hebei Area under the disturbance of human activities. Areas of high habitat quality in 2000 were mainly located in Luanhe River basin and top part of Baihe basin. Areas of low habitat quality were mainly located in medium and bottom part
Full Text Available Rice is often damaged by birds, especially sparrows, in Asia. Bird nets are sometimes used as countermeasures; however this approach is expensive and labor intensive. For this reason, farmers generally eschew bird nets, even though no alternative countermeasures are available. This study focused on exploiting the bird behavior of scanning for predators to reduce crop damage. When birds forage for seeds on the ground they often stop pecking and briefly raise their heads, apparently to scan for predators. Low visibility habitats increase scanning behavior and increased scanning behavior reduces habitat quality from the bird’s perspective; therefore, this study tested the relationship between rice damage rate and visibility at the periphery of rice fields, where tree sparrows rest after feeding. Overall, low visibility reduced damage to rice. Because visibility was mainly affected by weeds, weed management techniques contribute to crop damage management. To reduce damage, weeding can be decreased; therefore, this technique is cost- and labor-efficient.
Piazza, Bryan P.; La Peyre, M.K.
Numerous indices have been used to estimate fish growth and condition however, differences in sensitivity and reliability of the methods have hampered efforts to identify appropriate indicators for routine evaluation of habitat quality in the field. We compared common morphometric (length, weight, somatic growth, length-weight condition) and biochemical (RNA:DNA ratio, relative DNA content, energy density) growth indices on the same wild-caught mosquitofish Gambusia affinis to examine their usefulness as indicators of habitat quality. A laboratory experiment was used to quantify growth rates of wild-caught G. affinis under different feeding treatments. Field studies consisted of both a short-term enclosure experiment (10 d) and weekly (7 wk) fish collections to compare growth indices in managed inflow and reference marshes during a winter/spring freshwater pulse event in upper Breton Sound, Louisiana, USA. Marshes flooded by restored freshwater pulses were capable of producing optimum growth (0.001 g DW d-1 DW = dry weight) and energetically valuable habitat (>6000 cal g-1 DW) for trophic transport. Because of differences in timing of response, morphometric and biochemical indices were generally not directly correlated, but there was clear agreement in direction and magnitude of response. The most striking difference in timing was that biochemical indices (RNA:DNA) responded more slowly to treatments than did morphometric growth indices. While gross patterns are comparable between indicators, differences in sensitivity and response time between indicators suggest that choice of indicator needs to be accounted for in interpretation and analysis of effects. ?? Inter-Research 2010, www.int-res.com.
Full Text Available The effects of environmental perturbations or stressors on individual states can be carried over to subsequent life stages and ultimately affect survival and reproduction. The concentration of corticosterone (CORT in feathers is an integrated measure of hypothalamic-pituitary-adrenal activity during the molting period, providing information on the total baseline and stress-induced CORT secreted during the period of feather growth. Common eiders and greater snow geese replace all flight feathers once a year during the pre-basic molt, which occurs following breeding. Thus, CORT contained in feathers of pre-breeding individuals sampled in spring reflects the total CORT secreted during the previous molting event, which may provide insight into the magnitude or extent of stress experienced during this time period. We used data from multiple recaptures to disentangle the contribution of individual quality vs. external factors (i.e., breeding investment or environmental conditions on feather CORT in arctic-nesting waterfowl. Our results revealed no repeatability of feather CORT within individuals of either species. In common eiders, feather CORT was not affected by prior reproductive investment, nor by pre-breeding (spring body condition prior to the molting period. Individual feather CORT greatly varied according to the year, and August-September temperatures explained most of the annual variation in feather CORT. Understanding mechanisms that affect energetic costs and stress responses during molting will require further studies either using long-term data or experiments. Although our study period encompassed only five years, it nonetheless provides evidence that CORT measured in feathers likely reflects responses to environmental conditions experienced by birds during molt, and could be used as a metric to study carry-over effects.
Increasing numbers of abandoned wells, ant nests and termite mounds increased the probability of territory occupation. Territory size increased with the number of anteater-chats but decreased with increasing number of ant nests and overall bird diversity that were probably proxies for habitat quality. Overall, choice of ...
Full Text Available The Conservation Reserve Program (CRP is a voluntary set-aside program in the United States designed to amelioratesoil erosion, control crop overproduction, enhance water quality, and provide wildlife habitat by replacing crops with other forms of land cover. Because CRP includes primarily grass habitats, it has great potential to benefitdeclining North American grassland bird populations. We looked at the change in national and state population trends of grassland birds and related changes to cover-specific CRP variables (previous research grouped all CRP practices. Changes in national trends after the initiation of the CRP were inconclusive, but we observed signficant bird-CRP relations at the state level. Most bird-CRP relations were positive, except for some species associated with habitats that CRP replaced. Practice- and configuration-specific CRP variables were related to grassland bird trends, rather than a generic measure of all CRP types combined. Considering all CRP land as a single, distinct habitat type may obscure actual relations between birds and set-aside characteristics. Understanding and predictingthe effects of set-aside programs (like CRP or agri-environment schemes on grassland birds is complex and difficult. Because available broad-scale datasets are less than adequate, studies should be conducted at a variety of spatial and temporal scales.
Bos, D; Drent, RH; Rubinigg, M; Stahl, J
We studied the relative importance of food biomass and food quality for habitat preference in Brent Geese Branta bernicla by expefimentally manipulating forage parameters. Levels of biomass and ford quality (nitrogen content) were independently enhanced in plots of 2 x 6 m by temporary exclusion
Soniat, Thomas M.; Conzelmann, Craig P.; Byrd, Jason D.; Roszell, Dustin P.; Bridevaux, Joshua L.; Suir, Kevin J.; Colley, Susan B.
In an attempt to decelerate the rate of coastal erosion and wetland loss, and protect human communities, the state of Louisiana developed its Comprehensive Master Plan for a Sustainable Coast. The master plan proposes a combination of restoration efforts including shoreline protection, marsh creation, sediment diversions, and ridge, barrier island, and hydrological restoration. Coastal restoration projects, particularly the large-scale diversions of fresh water from the Mississippi River, needed to supply sediment to an eroding coast potentially impact oyster populations and oyster habitat. An oyster habitat suitability index model is presented that evaluates the effects of a proposed sediment and freshwater diversion into Lower Breton Sound. Voluminous freshwater, needed to suspend and broadly distribute river sediment, will push optimal salinities for oysters seaward and beyond many of the existing reefs. Implementation and operation of the Lower Breton Sound diversion structure as proposed would render about 6,173 ha of hard bottom immediately east of the Mississippi River unsuitable for the sustained cultivation of oysters. If historical harvests are to be maintained in this region, a massive and unprecedented effort to relocate private leases and restore oyster bottoms would be required. Habitat suitability index model results indicate that the appropriate location for such efforts are to the east and north of the Mississippi River Gulf Outlet.
Krebs, Justin M.; Bell, Susan S.; McIvor, Carole C.
To assess the potential influence of coastal development on habitat quality for estuarine nekton, we characterized body condition and reproduction for common nekton from tidal tributaries classified as undeveloped, industrial, urban or man-made (i.e., mosquito-control ditches). We then evaluated these metrics of nekton performance, along with several abundance-based metrics and community structure from a companion paper (Krebs et al. 2013) to determine which metrics best reflected variation in land-use and in-stream habitat among tributaries. Body condition was not significantly different among undeveloped, industrial, and man-made tidal tributaries for six of nine taxa; however, three of those taxa were in significantly better condition in urban compared to undeveloped tributaries. Palaemonetes shrimp were the only taxon in significantly poorer condition in urban tributaries. For Poecilia latipinna, there was no difference in body condition (length–weight) between undeveloped and urban tributaries, but energetic condition was significantly better in urban tributaries. Reproductive output was reduced for both P. latipinna (i.e., fecundity) and grass shrimp (i.e., very low densities, few ovigerous females) in urban tributaries; however a tradeoff between fecundity and offspring size confounded meaningful interpretation of reproduction among land-use classes for P. latipinna. Reproductive allotment by P. latipinna did not differ significantly among land-use classes. Canonical correspondence analysis differentiated urban and non-urban tributaries based on greater impervious surface, less natural mangrove shoreline, higher frequency of hypoxia and lower, more variable salinities in urban tributaries. These characteristics explained 36 % of the variation in nekton performance, including high densities of poeciliid fishes, greater energetic condition of sailfin mollies, and low densities of several common nekton and economically important taxa from urban tributaries
Students use a dead bird to learn about bird life, anatomy, and death. Students examine a bird body and discuss what happened to the bird. Uses outdoor education as a resource for learning about animals. (SAH)
Carvell, C; Osborne, J L; Bourke, A F G; Freeman, S N; Pywell, R F; Heard, M S
The global decline of insect pollinators, especially bees, is cause for concern, and there is an urgent need for cost-effective conservation measures in agricultural landscapes. While landscape context and habitat quality are known to influence species richness and abundance of bees, there is a lack of evidence from manipulative field experiments on bees' responses to adaptive management across differently structured landscapes. We present the results of a large-scale study that investigated the effects of a targeted agri-environment scheme (AES) on bumble bees (Bombus spp.) over three years in the United Kingdom. Forage patches of different sizes were sown with a conservation flower mixture across eight sites covering a broad range of agricultural land use types. Species richness and worker densities (especially of the longer-tongued Bombus species for which the mixture was targeted) were significantly higher on sown forage patches than on existing non-crop control habitats throughout the three-year study, but the strength of this response depended on both the proportions of arable land and abundance of herbaceous forb species in the surrounding landscape. The size of sown patches also affected worker density, with smaller patches (0.25 ha) attracting higher densities of some species than larger patches (1.0 ha). Our models show that a targeted AES can deliver greater net benefits in more intensively farmed areas, in terms of the number and species richness of bumble bees supported, than in heterogeneous landscapes where other foraging habitats exist. These findings serve to strengthen the evidence base for extending agri-environment schemes to boost declining pollinator populations to a larger number of agricultural landscapes across the globe.
Theodorakis, Christopher W; Adams, S Marshall; Smith, Chandra; Rotter, Jamie; Hay, Ashley; Eslick, Joy
Department of Defense lands are essential for providing important habitat for threatened, endangered, and at-risk species (TER-S). However, there is little information on the effects of military-related contaminants on TER-S on these lands in field situations. Thus, this study examined genotoxicity and oxidative stress in gopher tortoises (Gopherus polyphemus) on Camp Shelby, MS-the largest known population of this species, which is listed as an "endangered species" in Mississippi and a "threatened species" by the U.S. government. Blood was collected from tortoises at 19 different sites on the base with different levels of habitat quality (high-quality and low-quality habitat) and military activity (high, low, and no military activity). Oxidative stress was quantified as lipid peroxidation and GSSG/GSH ratios, while DNA damage was determined using flow cytometry. Our results suggest that: (1) for tortoises residing in low-quality habitats, oxidative stress and DNA damage increased with increasing military activity, while in high-quality habitats, oxidative stress and DNA damage decreased with increasing military activity; (2) in the absence of military activity, tortoises in high-quality habitat had higher levels of oxidative stress and DNA damage than those in low-quality habitat, and (3) there were interactions between military activity, habitat quality, and landuse in terms of the amount of observable DNA damage and oxidative stress. In particular, on high-quality habitat, tortoises from areas with high levels of military activity had lower levels of oxidative stress and DNA damage biomarkers than on reference sites. This may represent a compensatory or hormetic response. Conversely, on low-quality habitats, the level of oxidative stress and DNA damage was lower on the reference sites. Thus, tortoises on higher-quality habitats may have a greater capacity for compensatory responses. In terms of management implications, it is suggested that low quality habitats
Daniel P. Shustack
Full Text Available Although studies often report that densities of many forest birds are negatively related to urbanization, the mechanisms guiding this pattern are poorly understood. Our objective was to use a population simulation to examine the relative influence of six demographic and behavioral processes on patterns of avian abundance in urbanizing landscapes. We constructed an individual-based population simulation model representing the annual cycle of a Neotropical migratory songbird. Each simulation was performed under two landscape scenarios. The first scenario had similar proportions of high- and low-quality habitat across the urban to rural gradient. Under the first scenario, avian density was negatively related to urbanization only when rural habitats were perceived to be of higher quality than they actually were. The second landscape scenario had declining proportions of high-quality habitat as urbanization increased. Under the second scenario, each mechanism generated a negative relationship between density and urbanization. The strongest effect on density resulted when birds preferentially selected habitats in landscapes from which they fledged or were constrained from dispersing. The next strongest patterns occurred when birds directly evaluated habitat quality and accurately selected the highest-quality available territories. When birds selected habitats based on the presence of conspecifics, the density-urbanization relationship was only one-third the strength of other habitat selection mechanisms and only occurred under certain levels of population survival. Although differences in adult or nest survival in the face of random habitat selection still elicited reduced densities in urban landscapes, the relationships between urbanization and density were weaker than those produced by the conspecific attraction mechanism. Results from our study identify key predictions and areas for future research, including assessing habitat quality in urban and
Han, Zhi-Fu; Hu, Gao-Sheng; Li, Na; Fan, Xing; Jia, Jing-Ming
To determine the contents of lignans, crude polysaccharides (CP) and total phenolic compounds (TPC) of Schisandra chinensis from various habitats in Liaoning province and evaluate their quality and free radical scavenging (FRS) activity. Contents of schisandrol, deoxyschizandrin and schisandrin B were determined by RP-HPLC. Contents of TPC, CP and FRS activity were determined by Folin-Cicalteu's, phenol-sulfuric acid and DPPH x method, respectively. Sample from Liaoyang city had the highest contents of lignans (21.75 mg/g); Sample from Shenbei New district of Shenyang city had the highest contents of CP (88.72 mg/g); Sample from Guanmenshan district of Benxi city had the highest contents of TPC and FRS activity (26.06 mg/g and 86.3%, respectively). Linear regression analysis results showed that contents of TPC had higher correlation coefficient with FRS activity than that of lignans. Their linear regression equations were Y = 1.3677X + 46.97, R2 = 0.6869 and Y = 2.5916X + 57.927, R2 = 0.1747 for TPC and lignans with FRS activity, respectively. The contents of lignans, CP and TPC are significantly different from samples collected from various habitats in Liaoning province. The main antioxidative substances are TPC, and lignans have no significant correlation with FRS activity.
Martínez-Abraín, Alejandro; Galán, Pedro
Most examples that support the substitution-habitat hypothesis (human-made habitats act as substitutes of original habitat) deal with birds and mammals. We tested this hypothesis in 14 amphibians by using percentage occupancy as a proxy of habitat quality (i.e., higher occupancy percentages indicate higher quality). We classified water body types as original habitat (no or little human influence) depending on anatomical, behavioral, or physiological adaptations of each amphibian species. Ten species had relatively high probabilities (0.16-0.28) of occurrence in original habitat, moderate probability of occurrence in substitution habitats (0.11-0.14), and low probability of occurrence in refuge habitats (0.05-0.08). Thus, the substitution-habitat hypothesis only partially applies to amphibians because the low occupancy of refuges could be due to the negligible human persecution of this group (indicating good conservation status). However, low occupancy of refuges could also be due to low tolerance of refuge conditions, which could have led to selective extinction or colonization problems due to poor dispersal capabilities. That original habitats had the highest probabilities of occupancy suggests amphibians have a good conservation status in the region. They also appeared highly adaptable to anthropogenic substitution habitats. © 2017 Society for Conservation Biology.
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.
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.
Iola Gonçalves Boëchat
Full Text Available Land-use change is among the most important human impacts on habitat quality and species diversity. In this study, we investigated the effects of land use on river habitat quality and sediment granulometry in a larger tropical river, affected by urbanization and agricultural land use. We selected 15 representative sampling reaches in the Rio das Mortes basin, 12 of them along the main river from its headwater to its mouth, and 3 in major tributaries. A habitat survey was conducted in these reaches in the dry season 2010 and sediment samples were taken for granulometry analyses. Sub-basin land cover of reaches was dominated by natural vegetation (41.6 to 60.2% of total land cover, followed by agricultural land cover (38.4% to 56.9% and urban land cover (1.4% to 5.6%. Sediments were dominated by poorly to moderately sorted silts to sands, little conducive to diverse biological communities. According to the river habitat survey, all investigated river reaches exhibited moderately to totally disturbed habitat integrity, due to diverse and often co-occurring human impacts, such as riparian deforestation, water abstraction, sand and gravel extraction, and margin erosion. Only one of the investigated sampling reaches exhibited the minimum riparian forest corridor width demanded by the Brazilian Forest Code. Our results indicated that river habitat and sediment quality mainly depended on conditions in the direct vicinity of river reaches. Accordingly, initial cost-effective restoration of aquatic habitats could be achieved by relatively simple channel restoration measures and the protection of the riparian corridor in the investigated tropical river.
Wetlands are among the most productive ecosystems in the world which support critical ecological services and high biological diversity yet are vulnerable to climate change and human activities. In this thesis, I investigated the capabilities of satellite remote sensing with medium spatial resolution and object-based image analysis (OBIA) methods to elucidate seasonal composition and dynamics of wetland ecosystems and indicators of habitat for wintering waterbirds in a large conservation hotspot of Poyang Lake, PR China. I first examined changes in major wetland cover types during the low water period when Poyang Lake provides habitat to large numbers of migratory birds from the East Asian pathway. I used OBIA to map and analyze the transitions among water, vegetation, mudflat and sand classes from four 32-m Beijing-1 microsatellite images between late fall 2007 and early spring 2008. This analysis revealed that, while transitions among wetland classes were strongly associated with precipitation and flood-driven hydrological variation, the overall dynamics were a more complex interplay of vegetation phenology, disturbance and post-flood exposure. Remote sensing signals of environmental processes were more effectively captured by changes in fuzzy memberships to each class per location than by changes in spatial extents of the best-matching classes alone. The highest uncertainty in the image analysis corresponded to transitional wetland states at the end of the major flood recession in November and to heterogeneous mudflat areas at the land-water interface during the whole study period. Results suggest seasonally exposed mudflat features as important targets for future research due to heterogeneity and uncertainty of their composition, variable spatial distribution and sensitivity to hydrological dynamics. I further explored the potential of OBIA to overcome the limitations of the traditional pixel-based image classification methods in characterizing Poyang Lake
The positive association between habitat heterogeneity and species diversity has been well-documented for many taxa at various spatial and temporal scales, and the maintenance of habitat heterogeneity in agricultural landscapes has been promoted as a key strategy in efforts to conserve biodiversity....
Full Text Available The habitats and the anthropogenic pressure are two major causes that affect the presence of birds in every place where they live. The species from the dam reservoirs from the Argeş River do not constitute an exception, the more so as these water bodies are created by people and are situated in an area with a dense network of human settlements. Even if the aspects were discussed with other occasions, we propound here another approaching. Some considerations regarding the main forms of anthropogenic pressure (the hydrotechnical factor, the anthropogenic disturb, the pollution with rubbish, the fishing and the nautical sporting activities exercised on the birds from the area are made. The anthropogenic disturb appeared to be the most important factor on the general scale, in opposition with the fishing and the nautical sporting activities, which, although have strong impact at local level, seem to be the least significant ones. Of the five accumulation lakes taken into consideration (Vâlcele, Budeasa, Bascov, Piteşti and Goleşti, Budeasa is the best affected and Goleşti, the least one. The habitats have a considerable importance, regarding the land cover, and a smaller one, from a phytocoenologic perspective.
Kallimanis, A S; Panitsa, M; Dimopoulos, P
EU biodiversity conservation policy is based on the Habitats Directive (92/43/EC), which aims that habitat types and species of Community interest should reach 'favourable conservation status'. To this end, Member States are obliged to perform periodic assessment of species and habitat conservation status through biodiversity monitoring, which, in almost all cases, was performed by experts implementing standardized field protocols. Here, we examine the quality of data collected in the field by non-experts (citizen scientists) for the conservation status assessment of habitat types, and specifically for the criteria 'typical species', 'specific structures and functions', and 'pressures and threats'. This task is complicated and demands different types of field data. We visited two Natura 2000 sites and investigated four habitat types (two in each site) with non-experts and compared their data to the data collected by experts for accuracy, completeness and spatial arrangement. The majority of the non-expert data were accurate (i.e. non-experts recorded information they observed in the field), but they were incomplete (i.e. non-experts detected less information than the experts). Also, non-experts chose their sampling locations closer to the edge of the habitat, i.e. in more marginal conditions and thus in potentially more degraded conditions, than experts.
Craig W. Johnson; Susan Buffler
Intermountain West planners, designers, and resource managers are looking for science-based procedures for determining buffer widths and management techniques that will optimize the benefits riparian ecosystems provide. This study reviewed the riparian buffer literature, including protocols used to determine optimum buffer widths for water quality and wildlife habitat...
Rohan Benjankar; Daniele Tonina; James McKean
Studies of the effects of hydrodynamic model dimensionality on simulated flow properties and derived quantities such as aquatic habitat quality are limited. It is important to close this knowledge gap especially now that entire river networks can be mapped at the microhabitat scale due to the advent of point-cloud techniques. This study compares flow properties, such...
Joseph R. Benjamin
Theoretical models suggest the invasion of nonnative freshwater species is facilitated through the interaction of three factors: biotic resistance, habitat quality, and connectivity. We measured variables that represented each component to determine which were associated with small (150 mm) brook trout occurrence in Panther Creek, a tributary...
Juan M Requena-Mullor
Full Text Available As climate change is expected to have a significant impact on species distributions, there is an urgent challenge to provide reliable information to guide conservation biodiversity policies. In addressing this challenge, we propose a remote sensing-based approach to forecast the future habitat quality for European badger, a species not abundant and at risk of local extinction in the arid environments of southeastern Spain, by incorporating environmental variables related with the ecosystem functioning and correlated with climate and land use. Using ensemble prediction methods, we designed global spatial distribution models for the distribution range of badger using presence-only data and climate variables. Then, we constructed regional models for an arid region in the southeast Spain using EVI (Enhanced Vegetation Index derived variables and weighting the pseudo-absences with the global model projections applied to this region. Finally, we forecast the badger potential spatial distribution in the time period 2071-2099 based on IPCC scenarios incorporating the uncertainty derived from the predicted values of EVI-derived variables. By including remotely sensed descriptors of the temporal dynamics and spatial patterns of ecosystem functioning into spatial distribution models, results suggest that future forecast is less favorable for European badgers than not including them. In addition, change in spatial pattern of habitat suitability may become higher than when forecasts are based just on climate variables. Since the validity of future forecast only based on climate variables is currently questioned, conservation policies supported by such information could have a biased vision and overestimate or underestimate the potential changes in species distribution derived from climate change. The incorporation of ecosystem functional attributes derived from remote sensing in the modeling of future forecast may contribute to the improvement of the
Stoll, Stefan; Breyer, Philippa; Tonkin, Jonathan D; Früh, Denise; Haase, Peter
Although most stream restoration projects succeed in improving hydromorphological habitat quality, the ecological quality of the stream communities often remains unaffected. We hypothesize that this is because stream communities are largely determined by environmental properties at a larger-than-local spatial scale. Using benthic invertebrate community data as well as hydromorphological habitat quality data from 1087 stream sites, we investigated the role of local- (i.e. 100 m reach) and regional-scale (i.e. 5 km ring centered on each reach) stream hydromorphological habitat quality (LQ and RQ, respectively) on benthic invertebrate communities. The analyses showed that RQ had a greater individual effect on communities than LQ, but the effects of RQ and LQ interacted. Where RQ was either good or poor, communities were exclusively determined by RQ. Only in areas of intermediate RQ, LQ determined communities. Metacommunity analysis helped to explain these findings. Species pools in poor RQ areas were most depauperated, resulting in insufficient propagule pressure for species establishment even at high LQ (e.g. restored) sites. Conversely, higher alpha diversity and an indication of lower beta dispersion signals at mass effects occurring in high RQ areas. That is, abundant neighboring populations may help to maintain populations even at sites with low LQ. The strongest segregation in species co-occurrence was detected at intermediate RQ levels, suggesting that communities are structured to the highest degree by a habitat/environmental gradient. From these results, we conclude that when restoring riverine habitats at the reach scale, restoration projects situated in intermediate RQ settings will likely be the most successful in enhancing the naturalness of local communities. With a careful choice of sites for reach-scale restoration in settings of intermediate RQ and a strategy that aims to expand areas of high RQ, the success of reach-scale restoration in promoting the
To evaluate bird use of a widespread matrix habitat in forested landscapes of western Uganda, I used mist nets to compare bird communities in the understory of continuous forest and adjacent banana plantations. Frugivorous and insectivorous birds accounted for a higher proportion of captures in the forest habitat than in ...
We describe and illustrate Niditinea sabroskyi new species, a species mostly associated with bird nests. We provide diagnostic information to distinguish the new species from the other two species occurring in the United States, Niditinea fuscella (Linnaeus, 1758) and Niditinea orleansella (Chambers...
National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for wading birds, shorebirds, waterfowl, raptors, diving birds, seabirds, passerine birds, and gulls and...
National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for wading birds, shorebirds, waterfowl, raptors, diving birds, seabirds, passerine birds, gulls, and terns...
Warburton, Elizabeth M; Khokhlova, Irina S; Kiefer, Daniel; Krasnov, Boris R
Morphological asymmetry is widely used to measure developmental instability and higher levels of asymmetry often correlate with decreased mating success, increased inbreeding, increased stress and decreased habitat quality. We studied asymmetry and relationships between asymmetry and host identity in two flea species, host generalist Xenopsylla ramesis and host specialist Parapulex chephrenis , and asked: (1) what the level of asymmetry was in their femurs and tibiae; (2) which type of asymmetry predominates; and (3) whether fleas that fed on host species distantly related to their principal host species produced offspring that exhibited greater asymmetry compared with offspring of fleas that fed on their principal host species. We found fluctuating asymmetry in femurs and tibiae of X. ramesis and in the tibiae of P. chephrenis as well as significantly left-handed directional asymmetry in the femurs of P. chephrenis Host species identity significantly impacted asymmetry in leg segments of P. chephrenis but not in those of X. ramesis Offspring asymmetry increased when mother fleas fed on a host that was distantly related to the principal host. Fleas parasitizing multiple host species might compensate for developmental instability when utilizing a novel host species; therefore, host-switching events in host-specific parasites could be constrained by the relatedness between a novel and a principal host species. © 2017. Published by The Company of Biologists Ltd.
Full Text Available Anthropogenic disturbances to habitats influence the fitness of individual animals, the abundance of their populations, and the composition of their communities. Wetlands in particular are frequently degraded and destroyed, impacting the animals that inhabit these important ecosystems. The creation of wetlands during and following sand extraction processes is inevitable, and thus, sand quarries have the potential to support aquatic animals. To determine how amphibians utilise these wetlands, I conducted nocturnal call surveys at wetlands within the Kables Sands quarry, New South Wales, Australia, and within surrounding reference wetlands, and quantified levels of developmental instability (DI as a proxy for fitness. Whilst quarry and reference wetlands were largely similar in terms of environmental characteristics, quarry wetlands consistently harboured more amphibian species and individuals. Using unsigned asymmetry as a measure of DI, frogs from the quarry sites exhibited significantly lower levels of DI compared to reference wetlands, indicating that quarry wetlands may be comparatively higher quality. Levels of DI within quarry wetlands also compared favourably to data from healthy frog populations extracted from the literature. Further enhancing the suitability of quarry wetlands would require minimal effort, with potentially significant increases in local and regional biodiversity. Documenting species presence and quantifying individual fitness by measuring limb lengths is an economically and logistically feasible method to assess the health of quarry wetlands. Overall, the methods outlined here provide a powerful, yet simple, tool to assess the overall health and suitability of quarry wetlands that could be easily adopted at quarries throughout the world.
Full Text Available In the present study we tried to quantify the indication value of A. torrentium referring to habitat quality. This variable is expressed as the availability of appropriate refuge stones on the bottom and banks of running waters. The brooks occupied by the indigenous stone crayfish in Lower Austria show a high variability in the current velocity and substrate heterogeneity. Having some experience in hand searching we assumed that the distribution pattern of the crayfish on the stream bed is strongly correlated with the distribution of cobble and pebbles within a certain grain size. The aim of our study was to quantify the dependence of the shelter requirements for A. torrentium on grain size and water velocity, as well as the seasonal mobility of the crayfish. Shelters where velocity exceeded 25 cm s-1 were not occupied. Pebbles with a bearing surface greater than 300 cm2 were preferred, and the probability of crayfish occupation rose quickly as the stone’s bearing surface increased up to 900 cm2. Most individuals changed their location only a few meters (median 4 m. The distance from the point of first capture increased only little within the length of time passed until re-capture, suggesting a conservative use of space.
Vogiatzakis, I.N.; Stirpe, M.T.; Rickebusch, S.; Metzger, M.J.; Xu, G.; Rounsevell, M.D.A.; Bommarco, R.; Potts, S.G.
Changes in landscape composition and structure may impact the conservation and management of protected areas. Species that depend on specific habitats are at risk of extinction when these habitats are degraded or lost. Designing robust methods to evaluate landscape composition will assist decision-
Brown, Larry R.; Short, Terry M.
Four studies were done in the upper Merced River drainage in Yosemite National Park and nearby areas from 1993 to 1996. First, monitoring studies of benthic algae, benthic invertebrates, fish, and habitat were undertaken at sites near Happy Isles and Pohono bridges from 1993 to 1995 as part of the National Water-Quality Assessment Program of the U.S. Geological Survey. Second, an ecological survey of benthic algae, benthic invertebrates, fish, and habitat was done in the upper Merced River drainage in 1994. Third, a special study of benthic algae, habitat, and water quality was done in the reach of the Merced River within Yosemite Valley to deter-mine whether human activities were having measurable effects on the ecosystem. Fourth, baseline data on benthic algae, benthic invertebrates, and habitat were collected in 1996 at four sites, two of which were undergoing extensive streambank restoration activities. Comparisons of the baseline data with future collections could be used to assess the effects of streambank restoration on aquatic biota.
Full Text Available Shorebirds also known as waders comprise several adaptations, which enable them to forage on exposed mudflats. The population of birds in any ecosystem shows the environmental quality of the area, pollution level, security and availability of food and habitat. Thane Creek located in Mumbai is one of the unique mangrove ecosystems, maintaining a good population of sediment-dwelling organisms that support a myriad of migratory and non-migratory bird populations. Bird surveys were carried out using the point count method across two different locations at Thane Creek. In total 95 species of birds were recorded during the study and distinguished as per the pattern of their foraging. A healthy diversity of bird species observed indicates the high productivity of the creek.
Hu, Han; O’Connor, Jingmai K.; Zhou, Zhonghe
We describe a new enantiornithine bird, Parapengornis eurycaudatus gen. et sp. nov. from the Lower Cretaceous Jiufotang Formation of Liaoning, China. Although morphologically similar to previously described pengornithids Pengornis houi, Pengornis IVPP V18632, and Eopengornis martini, morphological differences indicate it represents a new taxon of the Pengornithidae. Based on new information from this specimen we reassign IVPP V18632 to Parapengornis sp. The well preserved pygostyle of the new specimen elucidates the morphology of this element for the clade, which is unique in pengornithids among Mesozoic birds. Similarities with modern scansores such as woodpeckers may indicate a specialized vertical climbing and clinging behavior that has not previously been inferred for early birds. The new specimen preserves a pair of fully pennaceous rachis-dominated feathers like those in the holotype of Eopengornis martini; together with the unique morphology of the pygostyle, this discovery lends evidence to early hypotheses that rachis-dominated feathers may have had a functional significance. This discovery adds to the diversity of ecological niches occupied by enantiornithines and if correct reveals are remarkable amount of locomotive differentiation among Enantiornithes. PMID:26039693
N.L. Rodenhouse; S.N. Matthews; K.P. McFarland; J.D. Lambert; L.R. Iverson; A. Prasad; T.S. Stillett; R.T. Holmes
We used three approaches to assess potential effects of climate change on birds of the Northeast. First, we created distribution and abundance models for common bird species using climate, elevation, and tree species variables and modeled how bird distributions might change as habitats shift. Second, we assessed potential effects on high-elevation birds, especially...
Smith, Erik A.; Kiesling, Richard L.; Ziegeweid, Jeffrey R.; Elliott, Sarah M.; Magdalene, Suzanne
Lake St. Croix is a naturally impounded, riverine lake that makes up the last 40 kilometers of the St. Croix River. Substantial land-use changes during the past 150 years, including increased agriculture and urban development, have reduced Lake St. Croix water-quality and increased nutrient loads delivered to Lake St. Croix. A recent (2012–13) total maximum daily load phosphorus-reduction plan set the goal to reduce total phosphorus loads to Lake St. Croix by 20 percent by 2020 and reduce Lake St. Croix algal bloom frequencies. The U.S. Geological Survey, in cooperation with the National Park Service, developed a two-dimensional, carbon-based, laterally averaged, hydrodynamic and water-quality model, CE–QUAL–W2, that addresses the interaction between nutrient cycling, primary production, and trophic dynamics to predict responses in the distribution of water temperature, oxygen, and chlorophyll a. Distribution is evaluated in the context of habitat for lake sturgeon, including a combination of temperature and dissolved oxygen conditions termed oxy-thermal habitat.The Lake St. Croix CE–QUAL–W2 model successfully reproduced temperature and dissolved oxygen in the lake longitudinally (from upstream to downstream), vertically, and temporally over the seasons. The simulated water temperature profiles closely matched the measured water temperature profiles throughout the year, including the prediction of thermocline transition depths (often within 1 meter), the absolute temperature of the thermocline transitions (often within 1.0 degree Celsius), and profiles without a strong thermocline transition. Simulated dissolved oxygen profiles matched the trajectories of the measured dissolved oxygen concentrations at multiple depths over time, and the simulated concentrations matched the depth and slope of the measured concentrations.Additionally, trends in the measured water-quality data were captured by the model simulation, gaining some potential insights into the
Davari, B.; Vatandoost, H.
Using of insecticides depends on the knowledge of the susceptibility levels of malaria vectors to these chemical. In this study, the chemical quality of water in the larval breeding habitats and the susceptibility levels of Anopheles stephensi to DDT 4% dieldrin 0.4% permethrin 0.75, cyfluthrin 0.15 deltamethrin 0.05% and lambdacyhalothrin 0.05% were investigated according to WHO method in south eastern of Iran. (Author)
The variegated beetle, Lanternarius brunneus (Melsh.), was found inhabiting a slurry area at an orphaned coal mine site in Illinois. Water quality analyses indicated the beetle lived in coal fines and mud saturated with water indicative of acid mine drainage i.e., pH < 4.0 and elevated sulfate and heavy metal concentrations. This is the first report of Heteroceridae occurring in this type of habitat and in conditions normally toxic to other aquatic or semiaquatic insects.
Cram, Jeremy M.; Torgersen, Christian E.; Klett, Ryan S.; Pess, George R.; May, Darran; Pearsons, Todd N.; Dittman, Andrew H.
Spawning site selection by female salmon is based on complex and poorly understood tradeoffs between the homing instinct and the availability of appropriate habitat for successful reproduction. Previous studies have shown that hatchery-origin Chinook salmon (Oncorhynchus tshawytscha) released from different acclimation sites return with varying degrees of fidelity to these areas. To investigate the possibility that homing fidelity is associated with aquatic habitat conditions, we quantified physical habitat throughout 165 km in the upper Yakima River basin (Washington, USA) and mapped redd and carcass locations from 2004 to 2008. Principal components analysis identified differences in substrate, cover, stream width, and gradient among reaches surrounding acclimation sites, and canonical correspondence analysis revealed that these differences in habitat characteristics were associated with spatial patterns of spawning (p < 0.01). These analyses indicated that female salmon may forego spawning near their acclimation area if the surrounding habitat is unsuitable. Evaluating the spatial context of acclimation areas in relation to surrounding habitat may provide essential information for effectively managing supplementation programs and prioritizing restoration actions.
Smith, Erik A.; Kiesling, Richard L.; Ziegeweid, Jeffrey R.
Fish habitat can degrade in many lakes due to summer blue-green algal blooms. Predictive models are needed to better manage and mitigate loss of fish habitat due to these changes. The U.S. Geological Survey (USGS), in cooperation with the Minnesota Department of Natural Resources, developed predictive water-quality models for two agricultural land-use dominated lakes in Minnesota—Madison Lake and Pearl Lake, which are part of Minnesota’s sentinel lakes monitoring program—to assess algal community dynamics, water quality, and fish habitat suitability of these two lakes under recent (2014) meteorological conditions. The interaction of basin processes to these two lakes, through the delivery of nutrient loads, were simulated using CE-QUAL-W2, a carbon-based, laterally averaged, two-dimensional water-quality model that predicts distribution of temperature and oxygen from interactions between nutrient cycling, primary production, and trophic dynamics.The CE-QUAL-W2 models successfully predicted water temperature and dissolved oxygen on the basis of the two metrics of mean absolute error and root mean square error. For Madison Lake, the mean absolute error and root mean square error were 0.53 and 0.68 degree Celsius, respectively, for the vertical temperature profile comparisons; for Pearl Lake, the mean absolute error and root mean square error were 0.71 and 0.95 degree Celsius, respectively, for the vertical temperature profile comparisons. Temperature and dissolved oxygen were key metrics for calibration targets. These calibrated lake models also simulated algal community dynamics and water quality. The model simulations presented potential explanations for persistently large total phosphorus concentrations in Madison Lake, key differences in nutrient concentrations between these lakes, and summer blue-green algal bloom persistence.Fish habitat suitability simulations for cool-water and warm-water fish indicated that, in general, both lakes contained a large
Measuring Phenological Changes due to Defoliation of the Non-Native Species, Saltcedar (Tamarisk) Following Episodic Foliage Removal by the Beetle Diorhabda elongate and Phenological Impacts on Forage Quality for Insectivorous Birds on the Dolores River
Nagler, P. L.; Dennison, P. E.; Hultine, K. R.; van Riper, C.; Glenn, E. P.
Since its introduction to the western U.S. more than a century ago, tamarisk (Tamarix spp.) has become dominant or sub-dominant over many major arid, and semi-arid river systems and their tributaries. The presence of tamarisk has been cited for reducing water availability for human enterprise and biodiversity, displacing native vegetation and for reducing habitat quality for wildlife. With increasing emphasis by public and private sectors on controlling saltcedar (Tamarix chinensis) in the western US, there will likely be a dramatic change in riparian vegetation composition over the course of the next several decades. The rates at which these changes will occur, and the resultant effects on riparian insects and birds that utilize insects for food, are presently unknown. Effects on riparian vegetation communities, resulting from changes in host plant species composition, will likely include changes in plant biomass, microclimate changes, and plant species diversity. These changes could potentially have a profound impact on migratory and breeding birds within riparian corridors throughout the southwest. Recently, the saltcedar leaf beetle (Diorhabda elongata) was released as a tamarisk biocontrol agent. This beetle has successfully defoliated tamarisk where it has been introduced, but there are currently no comprehensive programs in place for monitoring the rapid spread of Diorhabda, the impact of defoliation on habitat and water resources, or the long-term impact of defoliation on tamarisk. We used higher spatial resolution ASTER data and coarser MODIS data for monitoring defoliation caused by Diorhabda elongata and subsequent changes in evapotranspiration (ET). Widespread tamarisk defoliation was observed in an eastern Utah study area during summers 2007, 2008. We measured stem sap flux, leaf carbon isotope ratios, leaf area, LAI, and vegetation indices from mounted visible and infrared cameras and satellite imagery. The cameras were paired on towers installed 30
Milbrandt, Eric C.; Bartleson, Richard D.; Coen, Loren D.; Rybak, Olexandr; Thompson, Mark A.; DeAngelo, Jacquelyn A.; Stevens, Philip W.
Blind Pass is an inlet that separates Sanibel and Captiva Islands in southwest Florida but has historically closed and opened by both anthropogenic and natural processes. In July 2010, a dredging project to open the small inlet between the two barrier islands was completed. The objective of this study was to use and supplement ongoing estuary-monitoring programs to examine the responses of water quality, seagrass habitat metrics, and fish assemblages both in the immediate vicinity of the inlet and at broader scales (up to 40 km2). As far as we are aware, there are no previous studies with this intensity of sampling, both before and after an inlet opening. Significant increases in salinity and turbidity were observed inside Blind Pass, with significant decreases in CDOM and chlorophyll a, however, the effects were not far-reaching and limited to less than 1.7 km from the inlet within Pine Island Sound. Seagrass habitat metrics were expected to respond rapidly after the inlet was opened given the reduced light attenuation. However, there were no changes in shoot densities, species composition, and epiphytic algae within the approximately one-year duration of the study. The reopening of the pass did not substantially change fish assemblage structure, except for those from deeper habitats. Although immediate increases in the abundances of estuarine-dependent species were predicted in shallow habitats post opening, this did not occur. In conclusion, the effects of reopening a relatively small ocean inlet on water quality were apparent in the immediate vicinity of the inlet (within 1.7 km), but far-reaching effects on water quality, seagrass metrics, and fish assemblages were not immediately apparent in this well-flushed estuary. If subtle changes in tidal exchange and circulation affect productivity of seagrasses or its fish assemblages at broad scales, it may take several years to reach a steady state.
Viedma, Olga; Torres, Ivan; Moreno, Jose Manuel
In fire-prone ecosystems, it is very common that, following fire, plant species richness increases very markedly, mainly due to an explosion of annuals, following a rapid change during the first few years after the blaze. Herbs play a major role in the system, among other, by fixing nutrients that might be lost, or by changing competitive interactions with shrubs or tree seedlings. But assessing species richness, particularly, herbaceous one, in space and at large scale is very costly. Furthermore, the scale of measurement is also important. In this work we attempted to asses plant species richness during the first year after fire in an abandoned dehesa (open parkland) at three scales (1 m2, 25 m2 and 100 m2) using QuickBird images. The study area was located in Central Spain (Anchuras, Ciudad Real), and was affected by a large summer fire (ca. 2000 ha). Before the fire the system was composed of a shrubland intermixed with trees and open spaces. Two 90x180 m plots were selected and field species richness measures were made at the three scales, using a nested design. Field-based data were related to remotely sensed data using Regression Trees (RT) and Boosted Regression Trees (BRT) modelling. Explanatory spectral and textural remotely sensed data were ecologically interpreted based on vegetation cover ground-based data. We found that areas with low spectral contrast and high reflectivity were dominated by herbaceous species, and had greater species richness than those characterized by low contrast and medium-low reflectivity, which were dominated by shrubs and trees. The highest species richness was found in the areas characterized by high contrast and medium-high reflectivity, which had a mix of herbs and woody layers. Variance explained varied depending on the modelling approach and the scale, from 21% and 50% for 1 m2 using RT and BRT, respectively; to 65% and 79% for 100 m2. The contribution of different life forms in model fitting was scale-dependent. At
Lawler, J.J.; Edwards, T.C.
The ability to predict species occurrences quickly is often crucial for managers and conservation biologists with limited time and funds. We used measured associations with landscape patterns to build accurate predictive habitat models that were quickly and easily applied (i.e., required no additional data collection in the field to make predictions). We used classification trees (a nonparametric alternative to discriminant function analysis, logistic regression, and other generalized linear models) to model nesting habitat of red-naped sapsuckers (Sphyrapicus nuchalis), northern flickers (Colaptes auratus), tree swallows (Tachycineta bicolor), and mountain chickadees (Parus gambeli) in the Uinta Mountains of northeastern Utah, USA. We then tested the predictive capability of the models with independent data collected in the field the following year. The models built for the northern flicker, red-naped sapsucker, and tree swallow were relatively accurate (84%, 80%, and 75% nests correctly classified, respectively) compared to the models for the mountain chickadee (50% nests correctly classified). All four models were more selective than a null model that predicted habitat based solely on a gross association with aspen forests. We conclude that associations with landscape patterns can be used to build relatively accurate, easy to use, predictive models for some species. Our results stress, however, that both selecting the proper scale at which to assess landscape associations and empirically testing the models derived from those associations are crucial for building useful predictive models.
Bowie, Rauri C K
It is often assumed that species which exhibit a greater propensity for dispersal are less susceptible to the impacts of habitat fragmentation; however, a growing body of literature suggests that such generalizations should be carefully evaluated as not all species appear to be equally sensitive to fragmentation. In this issue of Molecular Ecology, Callens et al. (2011) take an innovative approach to compare contemporary estimates of dispersal from an extensive mark-recapture and patch occupancy data set with historical estimates derived from multilocus population genetic models for seven sympatric forest-dependent species in the Taita Hills, Africa. As has been observed for forest-dependent species from the Amazon, populations of sedentary species were more strongly differentiated and clustered when compared to those of more dispersive taxa. The most intriguing result recovered though, was that the five species with similar historical estimates of gene flow (dispersal) differed substantially in their contemporary dispersal rates, suggesting that for some species the propensity for dispersal has decreased over time. As a consequence, the authors suggest that post-fragmentation estimates of dispersal on their own may not be the best predictors of how habitat fragmentation could affect forest-dependent animal communities.This work significantly advances our understanding of the dynamics of habitat fragmentation and makes a strong case for the need to integrate data on historical processes with contemporary data. © 2011 Blackwell Publishing Ltd.
Zhao, Zhi-Xuan; Yan, Deng-Hua; Geng, Lei-Hua; Lin, Jin; Feng, Hua-Li
The Baiyangdian Wetland Natural Reserve is an important breeding habitat for oriental great reed warbler (OGRWs), Acrocephalus orientalis, in North China Plain. We investigated the nesting sites of OGRWs by line transect method during June-July, 2011, and 112 nests were found out in total. The ecological-niche factor analysis (ENFA) was applied in nesting habitat suitability assessment for OGRWs in Baiyangdian. The results showed that OGRWs in this reserve preferred nesting in dry land reed landscapes, which located at relatively high altitudes and away from anthropocentric disturbance. In 2011, the suitable and the most suitable nesting habitats of OGRWs in this reserve were 2474.69 hm2 and 1131.19 hm2, accounting 7.6% and 3.5% of the total reserve area, respectively. The most suitable nesting habitats shaped a circle-like structure, and they all clustered together around Damai and Shaoche core area, which located in the east part of the reserve. In order to protect the nesting habitats for OGRWs within Baiyangdian wetland reserve, it was suggested that the functional zone should be reorganized, and that the Damai and Shaoche core area should be integrated into one. This new core area would be bigger and more concentrated, at the same time the buffer zone should also be established appropriately, so as to protect the natural landscapes in this reserve as much as possible.
Jeremiah R. Alexander
Full Text Available Understanding the temporal and spatial scale at which habitat alteration impacts populations is important for conservation and management. Amphibians have declined more than other vertebrates, and pond-breeding species are particularly susceptible to habitat loss and fragmentation because they have terrestrial and aquatic life stages. One approach to management of pond-breeding species is protection of core upland habitat surrounding the breeding pond. We used genetic variation as an indicator of population status in a common amphibian species, spotted salamanders (Ambystoma maculatum, to determine how amount of suitable upland habitat relates to population status in the greater Charlotte, North Carolina, USA metropolitan area. We developed candidate models to evaluate the relative influence of historical and contemporary forested habitat availability on population genetic variation at two spatial scales of upland area (164 m and 2000 m at four time intervals over the past seven decades (1938, 1978, 1993, 2005. We found that historical land cover best predicted contemporary allelic richness. Inbreeding coefficient and observed heterozygosity were not effectively predicted by forest cover at either spatial or temporal scales. Allelic richness was best predicted at the smaller spatial scale in the 1993 time interval. Predicting and understanding how future landscape configuration affects genetic variation of common and rare species is imperative for the conservation of amphibian and other wildlife populations.
Susannah B Lerman
Full Text Available Urban bird communities have higher densities but lower diversity compared with wildlands. However, recent studies show that residential urban yards with native plantings have higher native bird diversity compared with yards with exotic vegetation. Here we tested whether landscape designs also affect bird foraging behavior. We estimated foraging decisions by measuring the giving-up densities (GUD; amount of food resources remaining when the final forager quits foraging on an artificial food patch, i.e seed trays in residential yards in Phoenix, AZ, USA. We assessed how two yard designs (mesic: lush, exotic vegetation; xeric: drought-tolerant and native vegetation differed in foraging costs. Further, we developed a statistical model to calculate GUDs for every species visiting the seed tray. Birds foraging in mesic yards depleted seed trays to a lower level (i.e. had lower GUDs compared to birds foraging in xeric yards. After accounting for bird densities, the lower GUDs in mesic yards appeared largely driven by invasive and synanthropic species. Furthermore, behavioral responses of individual species were affected by yard design. Species visiting trays in both yard designs had lower GUDs in mesic yards. Differences in resource abundance (i.e., alternative resources more abundant and of higher quality in xeric yards contributed to our results, while predation costs associated with foraging did not. By enhancing the GUD, a common method for assessing the costs associated with foraging, our statistical model provided insights into how individual species and bird densities influenced the GUD. These differences we found in foraging behavior were indicative of differences in habitat quality, and thus our study lends additional support for native landscapes to help reverse the loss of urban bird diversity.
Tarby, Sara; Cermak, Daniel
Sara Tarby, Daniel Cermak-Sassenrath. Screamy Bird. Digital game. Kulturnatten 2016, Danish Science Ministry, Copenhagen, DK, Oct 14, 2016.......Sara Tarby, Daniel Cermak-Sassenrath. Screamy Bird. Digital game. Kulturnatten 2016, Danish Science Ministry, Copenhagen, DK, Oct 14, 2016....
Coates, Peter S; Casazza, Michael L; Ricca, Mark A; Brussee, Brianne E; Blomberg, Erik J; Gustafson, K Benjamin; Overton, Cory T; Davis, Dawn M; Niell, Lara E; Espinosa, Shawn P; Gardner, Scott C; Delehanty, David J
Predictive species distributional models are a cornerstone of wildlife conservation planning. Constructing such models requires robust underpinning science that integrates formerly disparate data types to achieve effective species management.Greater sage-grouse Centrocercus urophasianus , hereafter 'sage-grouse' populations are declining throughout sagebrush-steppe ecosystems in North America, particularly within the Great Basin, which heightens the need for novel management tools that maximize the use of available information.Herein, we improve upon existing species distribution models by combining information about sage-grouse habitat quality, distribution and abundance from multiple data sources. To measure habitat, we created spatially explicit maps depicting habitat selection indices (HSI) informed by >35 500 independent telemetry locations from >1600 sage-grouse collected over 15 years across much of the Great Basin. These indices were derived from models that accounted for selection at different spatial scales and seasons. A region-wide HSI was calculated using the HSI surfaces modelled for 12 independent subregions and then demarcated into distinct habitat quality classes.We also employed a novel index to describe landscape patterns of sage-grouse abundance and space use (AUI). The AUI is a probabilistic composite of the following: (i) breeding density patterns based on the spatial configuration of breeding leks and associated trends in male attendance; and (ii) year-round patterns of space use indexed by the decreasing probability of use with increasing distance to leks. The continuous AUI surface was then reclassified into two classes representing high and low/no use and abundance. Synthesis and application s. Using the example of sage-grouse, we demonstrate how the joint application of indices of habitat selection, abundance and space use derived from multiple data sources yields a composite map that can guide effective allocation of management
Applied behavior analysts have been helping people to enhance the quality of their lives for decades. Its characteristics as described by Baer, Wolf, and Risley continue to guide efforts to help clients and their significant others. Yet, this knowledge often languishes unused and unappreciated. Distortions and misrepresentations of applied…
Riebel, Katharina; Holveck, Marie-Jeanne; Verhulst, Simon; Fawcett, Tim W.
Sexual selection theory posits that females should choose mates in a way that maximizes their reproductive success. But what exactly is the optimal choice? Most empirical research is based on the assumption that females seek a male of the highest possible quality (in terms of the genes or resources
Jedlikowski, Jan; Chibowski, Piotr; Karasek, Tomasz; Brambilla, Mattia
Habitat selection often involves choices made at different spatial scales, but the underlying mechanisms are still poorly understood, and studies that investigate the relative importance of individual scales are rare. We investigated the effect of three spatial scales (landscape, territory, nest-site) on the occurrence pattern of little crake Zapornia parva and water rail Rallus aquaticus at 74 ponds in the Masurian Lakeland, Poland. Habitat structure, food abundance and water chemical parameters were measured at nests and random points within landscape plots (from 300-m to 50-m radius), territory (14-m) and nest-site plots (3-m). Regression analyses suggested that the most relevant scale was territory level, followed by landscape, and finally by nest-site for both species. Variation partitioning confirmed this pattern for water rail, but also highlighted the importance of nest-site (the level explaining the highest share of unique variation) for little crake. The most important variables determining the occurrence of both species were water body fragmentation (landscape), vegetation density (territory) and water depth (at territory level for little crake, and at nest-site level for water rail). Finally, for both species multi-scale models including factors from different levels were more parsimonious than single-scale ones, i.e. habitat selection was likely a multi-scale process. The importance of particular spatial scales seemed more related to life-history traits than to the extent of the scales considered. In the case of our study species, the territory level was highly important likely because both rallids have to obtain all the resources they need (nest site, food and mates) in relatively small areas, the multi-purpose territories they defend.
Rohan Benjankar; Daniele Tonina; Alessandra Marzadri; Jim McKean; Daniel J. Isaak
Understanding the role of stream hydrologic and morphologic variables on the selection of spawning sites by salmonid fishes at high resolution across broad scales is needed for effective habitat restoration and protection. Here we used remotely sensed meter-scale channel bathymetry for a 13.5 km reach of Chinook salmon spawning stream in central Idaho to...
Derek K. Alkire; Andrew W. Ezell; Andrew B. Self
Bottomland hardwoods can provide both wildlife habitat and timber. However, past high-grading practices limit future income potential and have resulted in undesirable species composition in many areas. Thus, prevalence of desirable oak species should be increased. Our study will attempt to determine the proper harvest level for bottomland hardwoods which will optimize...
Yvette K. Ortega; David E. Capen
Numerous studies have reported lower densities of breeding Ovenbirds (Seiurus aurocapillus) adjacent to forest edges. However, none of these studies has considered habitat use and reproductive success to address mechanisms underlying the observed pattern, and most were conducted in fragmented landscapes and ignored juxtapositions of forest with...
Rebecca L. Flitcroft; Jeffrey A. Falke; Gordon H. Reeves; Paul F. Hessburg; Kris M. McNyset; Lee E. Benda
Pacific Northwest salmonids are adapted to natural disturbance regimes that create dynamic habitat patterns over space and through time. However, human land use, particularly long-term fire suppression, has altered the intensity and frequency of wildfire in forested upland and riparian areas. To examine the potential impacts of wildfire on aquatic systems, we developed...
Ahmadi-Nedushan, B.; St-Hilaire, A.; Ouarda, T.B.M.J.
Fuzzy logic was used to estimate the habitat suitability indices for the spawning and parr rearing stages of Atlantic salmon located in the Romaine River in northeastern Quebec. Fuzzy sets and fuzzy preference rules were developed by experienced fish biologists and technicians. The fuzzy suitability indices were then used to estimate the weighted usable area (WUA) for a range of flows. Fuzzy rule-based approaches allow for the numerical processing of qualitative knowledge of experts about fish habitat, and can consider multivariate effects of variables without the assumption of independence of input parameters. Habitat suitability and inputs were subdivided into different classes. Velocity and substrate diameters were used as input parameters and were defined by 3 linguistic variables and fuzzy sets corresponding to a combination of simple linear functions for a total of 27 rules. Substrates were also measured in the field. A hydraulic model was used to calculate water depth and velocity for different flow values. The fuzzy sets of the input variables were weighted with degrees of fulfilment and combined into a final fuzzy set. The final fuzzy set was transformed back into a standardized crisp number to describe the habitat suitability index. A sensitivity analysis of the rules indicated that the results were highly dependent on the way in which the rules were defined. Results of the study suggested that biologists using the method may wish to revise sensitive rules and investigate the implications of rules in order to define the range of values of the input variables. It was concluded that future research will compare the results of the fuzzy models developed based on contributions from experts in spawning and parr habitats. 19 refs., 1 tab., 4 figs
Ducro Bart J
Full Text Available Abstract Background Turkey is an important agricultural species and is largely used as a meat bird. In 2004, turkey represented 6.5% of the world poultry meat production. The world-wide turkey population has rapidly grown due to increased commercial farming. Due to the high demand for turkey meat from both consumers and industry global turkey stocks increased from 100 million in 1970 to over 276 million in 2004. This rapidly increasing importance of turkeys was a reason to design this study for the estimation of genetic parameters that control body weight, body composition, meat quality traits and parameters that shape the growth curve in turkey birds. Results The average heritability estimate for body weight traits was 0.38, except for early weights that were strongly affected by maternal effects. This study showed that body weight traits, upper asymptote (a growth curve trait, percent breast meat and redness of meat had high heritability whereas heritabilities of breast length, breast width, percent drip loss, ultimate pH, lightness and yellowness of meat were medium to low. We found high positive genetic and phenotypic correlations between body weight, upper asymptote, most breast meat yield traits and percent drip loss but percent drip loss was found strongly negatively correlated with ultimate pH. Percent breast meat, however, showed genetic correlations close to zero with body weight traits and upper asymptote. Conclusion The results of this analysis and the growth curve from the studied population of turkey birds suggest that the turkey birds could be selected for breeding between 60 and 80 days of age in order to improve overall production and the production of desirable cuts of meat. The continuous selection of birds within this age range could promote high growth rates but specific attention to meat quality would be needed to avoid a negative impact on the quality of meat.
Aslam, Muhammad L; Bastiaansen, John Wm; Crooijmans, Richard Pma; Ducro, Bart J; Vereijken, Addie; Groenen, Martien Am
Turkey is an important agricultural species and is largely used as a meat bird. In 2004, turkey represented 6.5% of the world poultry meat production. The world-wide turkey population has rapidly grown due to increased commercial farming. Due to the high demand for turkey meat from both consumers and industry global turkey stocks increased from 100 million in 1970 to over 276 million in 2004. This rapidly increasing importance of turkeys was a reason to design this study for the estimation of genetic parameters that control body weight, body composition, meat quality traits and parameters that shape the growth curve in turkey birds. The average heritability estimate for body weight traits was 0.38, except for early weights that were strongly affected by maternal effects. This study showed that body weight traits, upper asymptote (a growth curve trait), percent breast meat and redness of meat had high heritability whereas heritabilities of breast length, breast width, percent drip loss, ultimate pH, lightness and yellowness of meat were medium to low. We found high positive genetic and phenotypic correlations between body weight, upper asymptote, most breast meat yield traits and percent drip loss but percent drip loss was found strongly negatively correlated with ultimate pH. Percent breast meat, however, showed genetic correlations close to zero with body weight traits and upper asymptote. The results of this analysis and the growth curve from the studied population of turkey birds suggest that the turkey birds could be selected for breeding between 60 and 80 days of age in order to improve overall production and the production of desirable cuts of meat. The continuous selection of birds within this age range could promote high growth rates but specific attention to meat quality would be needed to avoid a negative impact on the quality of meat.
Scheibler, D R; Christoff, A U
We inventoried terrestrial small mammals in an agricultural area in southern Brazil by using trapping and prey consumed by Barn Owls (Tyto alba) and White-tailed Kites (Elanus leucurus). Small mammals were trapped in three habitat types: corn fields, uncultivated fields ("capoeiras"), and native forest fragments. A total of 1,975 small mammal specimens were trapped, another 2,062 identified from the diet of Barn Owls, and 2,066 from the diet of White-tailed Kites. Both trapping and prey in the predators' diet yielded 18 small mammal species: three marsupials (Didelphis albiventris, Gracilinanus agilis, and Monodelphis dimidiata) and 15 rodents (Akodon paranaensis, Bruceppatersonius iheringi, Calomys sp., Cavia aperea, Euryzygomatomys spinosus, Holochilus brasiliensis, Mus musculus, Necromys lasiurus, Nectomys squamipes, Oligoryzomys nigripes, Oryzomys angouya, Oxymycterus sp.1, Oxymycterus sp.2, Rattus norvegicus, and Rattus rattus (Linnaeus, 1758)). The greatest richness was found in the uncultivated habitat. We concluded that the three methods studied for inventorying small mammals (prey in the diet of Barn Owls, White-tailed Kites, and trapping) were complementary, since together, rather than separately, they produced a better picture of local richness.
Full Text Available We inventoried terrestrial small mammals in an agricultural area in southern Brazil by using trapping and prey consumed by Barn Owls (Tyto alba and White-tailed Kites (Elanus leucurus. Small mammals were trapped in three habitat types: corn fields, uncultivated fields ("capoeiras", and native forest fragments. A total of 1,975 small mammal specimens were trapped, another 2,062 identified from the diet of Barn Owls, and 2,066 from the diet of White-tailed Kites. Both trapping and prey in the predators' diet yielded 18 small mammal species: three marsupials (Didelphis albiventris, Gracilinanus agilis, and Monodelphis dimidiata and 15 rodents (Akodon paranaensis, Bruceppatersonius iheringi, Calomys sp., Cavia aperea, Euryzygomatomys spinosus, Holochilus brasiliensis, Mus musculus, Necromys lasiurus, Nectomys squamipes, Oligoryzomys nigripes, Oryzomys angouya, Oxymycterus sp.1, Oxymycterus sp.2, Rattus norvegicus, and Rattus rattus (Linnaeus, 1758. The greatest richness was found in the uncultivated habitat. We concluded that the three methods studied for inventorying small mammals (prey in the diet of Barn Owls, White-tailed Kites, and trapping were complementary, since together, rather than separately, they produced a better picture of local richness.
Larsen, Stefano; Sorace, Alberto; Mancini, Laura
Riparian areas link aquatic and terrestrial habitats, supporting species-rich bird communities, which integrate both terrestrial and aquatic processes. For this reason, inclusion of riparian birds in stream bioassessment could add to the information currently provided by existing programs that monitor aquatic organisms. To assess if bird community metrics could indicate stream conditions, we sampled breeding birds in the riparian zone of 37 reaches in 5 streams draining watersheds representing a gradient of agricultural intensity in central Italy. As a more direct indicator of water quality, stream macroinvertebrates were also sampled for computation of the Italian Extended Biotic Index (IBE). An anthropogenic index was calculated within 1 km of sampled reaches based on satellite-derived land-use classifications. Predictive models of macroinvertebrate integrity based on land-use and avian metrics were compared using an information-theoretic approach (AIC). We also determined if stream quality related to the detection of riverine species. Apparent bird species diversity and richness peaked at intermediate levels of land-use modification, but increased with IBE values. Water quality did not relate to the detection of riverine species as a guild, but two species, the dipper Cinclus cinclus and the grey wagtail Motacilla cinerea, were only observed in reaches with the highest IBE values. Small-bodied insectivorous birds and arboreal species were detected more often in reaches with better water quality and in less modified landscapes. In contrast, larger and granivorous species were more common in disturbed reaches. According to the information-theoretic approach, the best model for predicting water quality included the anthropogenic index, bird species diversity, and an index summarizing the trophic structure of the bird community. We conclude that, in combination with landscape-level information, the diversity and trophic structure of riparian bird communities could
Full Text Available Appropriate management of (semi-natural areas requires detailed knowledge of the ecosystems present and their status. Remote sensing can provide a systematic, synoptic view at regular time intervals, and is therefore often suggested as a powerful tool to assist with the mapping and monitoring of protected habitats and vegetation. In this study, we present a multi-step mapping framework that enables detailed NATURA 2000 (N2000 heathland habitat patch mapping and the assessment of their conservation status at patch level. The method comprises three consecutive steps: (1 a hierarchical land/vegetation type (LVT classification using airborne AHS imaging spectroscopy and field reference data; (2 a spatial re-classification to convert the LVT map to a patch map based on life forms; and (3 identification of the N2000 habitat type and conservation status parameters for each of the patches. Based on a multivariate analysis of 1325 vegetation reference plots acquired in 2006–2007, 24 LVT classes were identified that were considered relevant for the assessment of heathland conservation status. These labelled data were then used as ground reference for the supervised classification of the AHS image data to an LVT classification map, using Linear Discriminant Analysis in combination with Sequential-Floating-Forward-Search feature selection. Overall classification accuracies for the LVT mapping varied from 83% to 92% (Kappa ≈ 0.82–0.91, depending on the level of detail in the hierarchical classification. After converting the LVT map to a N2000 habitat type patch map, an overall accuracy of 89% was obtained. By combining the N2000 habitat type patch map with the LVT map, two important conservation status parameters were directly deduced per patch: tree and shrub cover, and grass cover, showing a strong similarity to an independent dataset with estimates made in the field in 2009. The results of this study indicate the potential of imaging spectroscopy
Battaglin, William A.; Smalling, Kelly L.; Anderson, Chauncey; Calhoun, Daniel L.; Chestnut, Tara E.; Muths, Erin L.
To investigate interactions among disease, pesticides, water quality, and adjacent land cover, we collected samples of water, sediment, and frog tissue from 21 sites in 7 States in the United States (US) representing a variety of amphibian habitats. All samples were analyzed for > 90 pesticides and pesticide degradates, and water and frogs were screened for the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) using molecular methods. Pesticides and pesticide degradates were detected frequently in frog breeding habitats (water and sediment) as well as in frog tissue. Fungicides occurred more frequently in water, sediment, and tissue than was expected based upon their limited use relative to herbicides or insecticides. Pesticide occurrence in water or sediment was not a strong predictor of occurrence in tissue, but pesticide concentrations in tissue were correlated positively to agricultural and urban land, and negatively to forested land in 2-km buffers around the sites. Bd was detected in water at 45% of sites, and on 34% of swabbed frogs. Bd detections in water were not associated with differences in land use around sites, but sites with detections had colder water. Frogs that tested positive for Bd were associated with sites that had higher total fungicide concentrations in water and sediment, but lower insecticide concentrations in sediments relative to frogs that were Bd negative. Bd concentrations on frog swabs were positively correlated to dissolved organic carbon, and total nitrogen and phosphorus, and negatively correlated to pH and water temperature.Data were collected from a range of locations and amphibian habitats and represent some of the first field-collected information aimed at understanding the interactions between pesticides, land use, and amphibian disease. These interactions are of particular interest to conservation efforts as many amphibians live in altered habitats and may depend on wetlands embedded in these landscapes to
Stone, Mandy L; Whiles, Matt R; Webber, Jeremy A; Williard, Karl W J; Reeve, John D
Relationships between riparian land cover, in-stream habitat, water chemistry, and macroinvertebrates were examined in headwater streams draining an agricultural region of Illinois. Macroinvertebrates and organic matter were collected monthly for one year from three intensively monitored streams with a gradient of riparian forest cover (6, 22, and 31% of riparian area). Bioassessments and physical habitat analyses were also performed in these three streams and 12 other nearby headwater streams. The intensively monitored site with the least riparian forest cover had significantly greater percent silt substrates than the sites with medium and high forest cover, and significantly higher very fine organics in substrates than the medium and high forested sites. Macroinvertebrates were abundant in all streams, but communities reflected degraded conditions; noninsect groups, mostly oligochaetes and copepods, dominated density and oligochaetes and mollusks, mostly Sphaerium and Physella, dominated biomass. Of insects, dipterans, mostly Chironomidae, dominated density and dipterans and coleopterans were important contributors to biomass. Collector-gatherers dominated functional structure in all three intensively monitored sites, indicating that functional structure metrics may not be appropriate for assessing these systems. The intensively monitored site with lowest riparian forest cover had significantly greater macroinvertebrate density and biomass, but lowest insect density and biomass. Density and biomass of active collector-filterers (mostly Sphaerium) decreased with increasing riparian forest. Hilsenhoff scores from all 15 sites were significantly correlated with in-stream habitat scores, percent riparian forest, and orthophosphate concentrations, and multiple regression indicated that in-stream habitat was the primary factor influencing biotic integrity. Our results show that these "drainage ditches" harbor abundant macroinvertebrates that are typical of degraded
Cimino, Megan A; Fraser, William R; Irwin, Andrew J; Oliver, Matthew J
Pygoscelis penguins are experiencing general population declines in their northernmost range whereas there are reported increases in their southernmost range. These changes are coincident with decadal-scale trends in remote sensed observations of sea ice concentrations (SIC) and sea surface temperatures (SST) during the chick-rearing season (austral summer). Using SIC, SST, and bathymetry, we identified separate chick-rearing niche spaces for the three Pygoscelis penguin species and used a maximum entropy approach (MaxEnt) to spatially and temporally model suitable chick-rearing habitats in the Southern Ocean. For all Pygoscelis penguin species, the MaxEnt models predict significant changes in the locations of suitable chick-rearing habitats over the period of 1982-2010. In general, chick-rearing habitat suitability at specific colony locations agreed with the corresponding increases or decreases in documented population trends over the same time period. These changes were the most pronounced along the West Antarctic Peninsula where there has been a rapid warming event during at least the last 50 years. © 2012 Blackwell Publishing Ltd.
Fritsch, Mark A.
The number of anadromous fish returning to the Columbia River and its tributaries has declined sharply in recent years. Changes in their freshwater, estuarine, and ocean environments and harvest have all contributed to declining runs of anadromous fish. Restoration of aquatic resources is of paramount importance to the Confederated Tribes of the Warm Springs (CTWS) Reservation of Oregon. Watersheds on the Warm Springs Reservation provide spawning and rearing habitat for several indigenous species of resident and anadromous fish. These streams are the only ones in the Deschutes River basin that still sustain runs of wild spring chinook salmon, Oncorhynchus, tshawytscha. Historically, reservation streams supplied over 169 km of anadromous fish habitat. Because of changes in flows, there are now only 128 km of habitat that can be used on the reservation. In 1981, the CTWS began a long-range, 3-phase study of existing and potential fish resources on the reservation. The project, consistent with the Northwest Power Planning Council`s Fish and Wildlife Program, was designed to increase the natural production of anadromous salmonids on the reservation.
The number of anadromous fish returning to the Columbia River and its tributaries has declined sharply in recent years. Changes in their freshwater, estuarine, and ocean environments and harvest have all contributed to declining runs of anadromous fish. Restoration of aquatic resources is of paramount importance to the Confederated Tribes of the Warm Springs (CTWS) Reservation of Oregon. Watersheds on the Warm Springs Reservation provide spawning and rearing habitat for several indigenous species of resident and anadromous fish. These streams are the only ones in the Deschutes River basin that still sustain runs of wild spring chinook salmon, Oncorhynchus, tshawytscha. Historically, reservation streams supplied over 169 km of anadromous fish habitat. Because of changes in flows, there are now only 128 km of habitat that can be used on the reservation. In 1981, the CTWS began a long-range, 3-phase study of existing and potential fish resources on the reservation. The project, consistent with the Northwest Power Planning Council's Fish and Wildlife Program, was designed to increase the natural production of anadromous salmonids on the reservation
Hinck, Jo Ellen; Ingersoll, Christopher G.; Wang, Ning; Augspurger, Tom; Barnhart, M. Christopher; McMurray, Stephen E.; Roberts, Andrew D.; Schrader, Lynn
The Meramec River Basin in east-central Missouri is an important stronghold for native freshwater mussels (Order: Unionoida) in the United States. Whereas the basin supports more than 40 mussel species, previous studies indicate that the abundance and distribution of most species are declining. Therefore, resource managers have identified the need to prioritize threats to native mussel populations in the basin and to design a mussel monitoring program. The objective of this study was to identify threats of habitat and water-quality degradation to mussel diversity in the basin. Affected habitat parameters considered as the main threats to mussel conservation included excess sedimentation, altered stream geomorphology and flow, effects on riparian vegetation and condition, impoundments, and invasive non-native species. Evaluating water-quality parameters for conserving mussels was a main focus of this study. Mussel toxicity data for chemical contaminants were compared to national water quality criteria (NWQC) and Missouri water quality standards (MWQS). However, NWQC and MWQS have not been developed for many chemical contaminants and some MWQS may not be protective of native mussel populations. Toxicity data indicated that mussels are sensitive to ammonia, copper, temperature, certain pesticides, pharmaceuticals, and personal care products; these compounds were identified as the priority water-quality parameters for mussel conservation in the basin. Measures to conserve mussel diversity in the basin include expanding the species and life stages of mussels and the list of chemical contaminants that have been assessed, establishing a long term mussel monitoring program that measures physical and chemical parameters of high priority, conducting landscape scale modeling to predict mussel distributions, determining sublethal effects of primary contaminants of concern, deriving risk-based guidance values for mussel conservation, and assessing the effects of wastewater
The conservation and management of wading birds has received considerable attention over the past twenty years, through research, population monitoring, habitat protection, and through activities of specialist groups devoted to all three groups, the herons, ibises and allies, and flamingos. While populations are best known in North America, greatest advances in knowledge may have come in Australasia. The status of most species and many populations is now sufficiently known to allow assessment of risk. Conservation and management techniques allow creation of global and regional action plans for conservation of many species. Global action plans are being developed, but few regional plans have been undertaken. Management of nesting sites is now particularly well appreciated. Although known in broad stroke, much remains to be learned about managing feeding habitat. Problems related to disturbance, conflict with humans, habitat loss, contaminants and other environmental stresses remain for some species and many populations. New challenges lie in creating conservation action that account for genetic stocks.
Nancy E. Monsen
Full Text Available We use selected monitoring data to illustrate how localized water diversions from seasonal barriers, gate operations, and export pumps alter water quality across the Sacramento-San Joaquin Delta (California. Dynamics of water-quality variability are complex because the Delta is a mixing zone of water from the Sacramento and San Joaquin Rivers, agricultural return water, and the San Francisco Estuary. Each source has distinct water-quality characteristics, and the contribution of each source varies in response to natural hydrologic variability and water diversions. We use simulations with a tidal hydrodynamic model to reveal how three diversion events, as case studies, influence water quality through their alteration of Delta-wide water circulation patterns and flushing time. Reduction of export pumping decreases the proportion of Sacramento- to San Joaquin-derived fresh water in the central Delta, leading to rapid increases in salinity. Delta Cross Channel gate operations control salinity in the western Delta and alter the freshwater source distribution in the central Delta. Removal of the head of Old River barrier, in autumn, increases the flushing time of the Stockton Ship Channel from days to weeks, contributing to a depletion of dissolved oxygen. Each shift in water quality has implications either for habitat quality or municipal drinking water, illustrating the importance of a systems view to anticipate the suite of changes induced by flow manipulations, and to minimize the conflicts inherent in allocations of scarce resources to meet multiple objectives.
Shannon Curley; Terry Master; Gregory George
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...
Árnason, Sighvatur S; Elbrønd, Vibeke S; Laverty, Gary
Dietary salt intake in domestic fowl affects epithelial transport and morphology of the lower intestine (colon and coprodeum). This study investigated lower intestinal morphology and transport activity in two wild bird species with natural diets containing either low or high salt. Tissues from rock ptarmigan (Lagopus mutus) and common murres (Uria aalge) were sampled for histology and electrophysiological analyses. The ptarmigan exists on a low salt diet, while the murre lives on a high protein and high salt diet. The ptarmigan colon and coprodeum had villi/folds and crypts and the epithelium contained absorptive epithelial cells, mitochondria-rich cells and goblet cells. The colon had significant amiloride-inhibitable Isc, 5-15 μA/cm(2), with no glucose-stimulated Isc, and no significant phloridzin inhibition. The coprodeum also had high amiloride-inhibitable Isc. This transport pattern corresponded to that of chickens on low-salt diets. However, the ptarmigan colon also had a significant lysine/leucine-stimulated Isc of 3±1.0 μA/cm(2). The short U. aalge colon was similar to that of ptarmigans, but with no villi. It demonstrated a significant lysine/leucine-stimulated Isc (11±3.5 μA/cm(2)) with no amiloride-inhibitable Isc, similar to the high-salt chicken colon, but with no Na(+)-glucose cotransport. The murre coprodeum was inert to all substances and showed high resistance (1000 Ω·cm(2)), with a multilayered squamous epithelium. Despite some variations possibly associated with dietary protein intake, we conclude that natural high and low salt diets in different avian species are associated with different lower intestinal transport patterns, providing for post-renal adjustments in ion and water excretion. Copyright © 2015 Elsevier Inc. All rights reserved.
Quinn, Nigel W.T.; Hanlon, Jeremy S.; Burns, Josephine R.; Stromayer, Karl A.K.; Jordan, Brandon M.; Ennis, Mike J.; Woolington,Dennis W.
The project report describes a two year experiment to control wetland drainage to the San Joaquin River of California from the San Luis National Wildlife Refuge using a decision support system for real-time water quality management. This system required the installation and operation of one inlet and three drainage flow and water quality monitoring stations which allowed a simple mass balance model to be developed of the seasonally managed wetlands in the study area. Remote sensing methods were developed to document long-term trends in wetland moist soil vegetation and soil salinity in response to management options such as delaying the initiation of seasonal wetland drainage. These environmental management tools provide wetland managers with some of the tools necessary to improve salinity conditions in the San Joaquin River and improve compliance with State mandated salinity objectives without inflicting long-term harm on the wild fowl habitat resource.
Tremblay, Junior A; Boulanger, Yan; Cyr, Dominic; Taylor, Anthony R; Price, David T; St-Laurent, Martin-Hugues
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
Junior A Tremblay
Full Text Available 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
The American kestrel, Falco sparveriushas sex-related differences in habitat use during the non-breeding season, with females occupying more open habitats than males. Two competing hypotheses have been proposed to explain this phenomenon: (1) males and females prefer different habitats, and (2) males and females prefer similar habitats, but larger females exclude smaller males from preferred areas. This study experimentally investigated habitat selection in wintering kestrels by temporarily removing kestrels from areas, and then observing the numbers and sex of the kestrels that occupied vacated areas. The home ranges of 20 birds (10 males and 10 females) were mapped and their occupants removed. Areas vacated in early winter (November 1994) were filled more quickly than those vacated in late winter (February 1995). Areas previously held by females were reoccupied more frequently than were those previously occupied by males. Female kestrels reoccupied vacated female areas more than vacated male areas. Male kestrels reoccupied vacated female and male areas equally. The results demonstrate that (1) high-quality kestrel habitat may be limited in the non-breeding season, (2) vacated areas are more likely to be reoccupied in the early winter than in late winter, (3) female kestrels appear at an advantage relative to males in occupying scarce and competed-for areas, and (4) male kestrels will use female areas when female occupants have been removed. It is hypothesized that open habitats are preferred over less open habitats because the former offer reduced risk of predation from bird-eating hawks.
Full Text Available Rusiyantono Y, Tanari M, Mumu MI (2011 Conservation of maleo bird (Macrocephalon maleo through egg hatching modification and ex situ management. Biodiversitas 12: 171-176. Over exploitation of maleo bird eggs has become the main problem. In addition, habitat demolition and fragmentation have also caused decrease in maleo bird population. This research aimed to know the effectiveness of hatching pattern to produce maleo breeding, studying breeding pattern of maleo bird through hatching approaches of feed quality and temperature adjustment, and studying maleo bird respond towards caring pattern adjustment by measuring plasticity value. There were two phases in this research. The first phase was hatching by using modified incubator. The other one was the caring of the breeding from the result of hatching through feed pattern management using protein and energy balancing. The results of the research indicated that the hatching success was 65%; however, life endurance of the birds from birth to one month of age was only 40%. Their growth showed sufficiently high increase after passing critical period in their body-weght based on feeding pattern containing 21% of protein that was 64.93 g and 62.59 g for maleo in Lore Lindu National Park (LLNP and Bangkiriang Wildlife Reserve (BWR, respectively. Their monthly body-weght increase was 33.06 g in average of feeding pattern containing 13% of protein for LLNP maleo birds and 36.99 g for the maleo in BWR. It was found that feeding pattern containing higher content of protein (21% promoted significant increase in the body-weight of maleo birds. Feeding such birds with high protein content feed along with sufficient energy triggered their growth speed. Based on the findings, it was concluded that maleo birds could be preserved by way of hatching, while the birds could be fed with feed containing high protein and energy in order to accelerate their growth after hatching.
Ji Yoon Kim
Full Text Available This study evaluated integrative river ecosystem health using stressor-based models of physical habitat health, chemical water health, and biological health of fish and identified multiple-stressor indicators influencing the ecosystem health. Integrated health responses (IHRs, based on star-plot approach, were calculated from qualitative habitat evaluation index (QHEI, nutrient pollution index (NPI, and index of biological integrity (IBI in four different longitudinal regions (Groups I–IV. For the calculations of IHRs values, multi-metric QHEI, NPI, and IBI models were developed and their criteria for the diagnosis of the health were determined. The longitudinal patterns of the river were analyzed by a self-organizing map (SOM model and the key major stressors in the river were identified by principal component analysis (PCA. Our model scores of integrated health responses (IHRs suggested that mid-stream and downstream regions were impaired, and the key stressors were closely associated with nutrient enrichment (N and P and organic matter pollutions from domestic wastewater disposal plants and urban sewage. This modeling approach of IHRs may be used as an effective tool for evaluations of integrative ecological river health..
Drum, Ryan G.; Ribic, Christine; Koch, Katie; Lonsdorf, Eric V.; Grant, Edward C.; Ahlering, Marissa; Barnhill, Laurel; Dailey, Thomas; Lor, Socheata; Mueller, Connie; Pavlacky, D.C.; Rideout, Catherine; Sample, David W.
Grassland bird habitat has declined substantially in the United States. Remaining grasslands are increasingly fragmented, mostly privately owned, and vary greatly in terms of habitat quality and protection status. A coordinated strategic response for grassland bird conservation is difficult, largely due to the scope and complexity of the problem, further compounded by biological, sociological, and economic uncertainties. We describe the results from a collaborative Structured Decision Making (SDM) workshop focused on linking social and economic drivers of landscape change to grassland bird population outcomes. We identified and evaluated alternative strategies for grassland bird conservation using a series of rapid prototype models. We modeled change in grassland and agriculture cover in hypothetical landscapes resulting from different landowner decisions in response to alternative socio-economic conservation policy decisions. Resulting changes in land cover at all three stages of the annual cycle (breeding, wintering, and migration) were used to estimate changes in grassland bird populations. Our results suggest that successful grassland bird conservation may depend upon linkages with ecosystem services on working agricultural lands and grassland-based marketing campaigns to engage the public. With further development, spatial models that link landowner decisions with biological outcomes can be essential tools for making conservation policy decisions. A coordinated non-traditional partnership will likely be necessary to clearly understand and systematically respond to the many conservation challenges facing grassland birds.
Drum, Ryan G.; Ribic, Christine A.; Koch, Katie; Lonsdorf, Eric; Grant, Evan; Ahlering, Marissa; Barnhill, Laurel; Dailey, Thomas; Lor, Socheata; Mueller, Connie; Pavlacky, David C.; Rideout, Catherine; Sample, David
Grassland bird habitat has declined substantially in the United States. Remaining grasslands are increasingly fragmented, mostly privately owned, and vary greatly in terms of habitat quality and protection status. A coordinated strategic response for grassland bird conservation is difficult, largely due to the scope and complexity of the problem, further compounded by biological, sociological, and economic uncertainties. We describe the results from a collaborative Structured Decision Making (SDM) workshop focused on linking social and economic drivers of landscape change to grassland bird population outcomes. We identified and evaluated alternative strategies for grassland bird conservation using a series of rapid prototype models. We modeled change in grassland and agriculture cover in hypothetical landscapes resulting from different landowner decisions in response to alternative socio-economic conservation policy decisions. Resulting changes in land cover at all three stages of the annual cycle (breeding, wintering, and migration) were used to estimate changes in grassland bird populations. Our results suggest that successful grassland bird conservation may depend upon linkages with ecosystem services on working agricultural lands and grassland-based marketing campaigns to engage the public. With further development, spatial models that link landowner decisions with biological outcomes can be essential tools for making conservation policy decisions. A coordinated non-traditional partnership will likely be necessary to clearly understand and systematically respond to the many conservation challenges facing grassland birds. PMID:26569108
Drum, Ryan G; Ribic, Christine A; Koch, Katie; Lonsdorf, Eric; Grant, Evan; Ahlering, Marissa; Barnhill, Laurel; Dailey, Thomas; Lor, Socheata; Mueller, Connie; Pavlacky, David C; Rideout, Catherine; Sample, David
Grassland bird habitat has declined substantially in the United States. Remaining grasslands are increasingly fragmented, mostly privately owned, and vary greatly in terms of habitat quality and protection status. A coordinated strategic response for grassland bird conservation is difficult, largely due to the scope and complexity of the problem, further compounded by biological, sociological, and economic uncertainties. We describe the results from a collaborative Structured Decision Making (SDM) workshop focused on linking social and economic drivers of landscape change to grassland bird population outcomes. We identified and evaluated alternative strategies for grassland bird conservation using a series of rapid prototype models. We modeled change in grassland and agriculture cover in hypothetical landscapes resulting from different landowner decisions in response to alternative socio-economic conservation policy decisions. Resulting changes in land cover at all three stages of the annual cycle (breeding, wintering, and migration) were used to estimate changes in grassland bird populations. Our results suggest that successful grassland bird conservation may depend upon linkages with ecosystem services on working agricultural lands and grassland-based marketing campaigns to engage the public. With further development, spatial models that link landowner decisions with biological outcomes can be essential tools for making conservation policy decisions. A coordinated non-traditional partnership will likely be necessary to clearly understand and systematically respond to the many conservation challenges facing grassland birds.
Ryan G Drum
Full Text Available Grassland bird habitat has declined substantially in the United States. Remaining grasslands are increasingly fragmented, mostly privately owned, and vary greatly in terms of habitat quality and protection status. A coordinated strategic response for grassland bird conservation is difficult, largely due to the scope and complexity of the problem, further compounded by biological, sociological, and economic uncertainties. We describe the results from a collaborative Structured Decision Making (SDM workshop focused on linking social and economic drivers of landscape change to grassland bird population outcomes. We identified and evaluated alternative strategies for grassland bird conservation using a series of rapid prototype models. We modeled change in grassland and agriculture cover in hypothetical landscapes resulting from different landowner decisions in response to alternative socio-economic conservation policy decisions. Resulting changes in land cover at all three stages of the annual cycle (breeding, wintering, and migration were used to estimate changes in grassland bird populations. Our results suggest that successful grassland bird conservation may depend upon linkages with ecosystem services on working agricultural lands and grassland-based marketing campaigns to engage the public. With further development, spatial models that link landowner decisions with biological outcomes can be essential tools for making conservation policy decisions. A coordinated non-traditional partnership will likely be necessary to clearly understand and systematically respond to the many conservation challenges facing grassland birds.
McDermott, M.E.; Wood, P.B.
has identified habitat use patterns for different species in timber harvests, understanding habitat-specific bird survival is needed to help determine the quality of silvicultural harvests for post-breeding birds. ?? 2011 Elsevier B.V.
Ethiopia harbours 837 bird species, 18 of which are endemic and a further 14 near endemic (shared with Eritrea) (Ash & Atkins 2009). To promote the conservation of these birds and their habitats, 69 Important Bird Areas (IBAs) were identified for. Ethiopia (Fishpool & Evans 2001). These important areas were selected ...
D. M. Finch; K. E. Bagne; M. M. Friggens; D. M. Smith; K. M. Brodhead
We evaluated existing literature on predicted and known climate change effects on terrestrial rangeland birds. We asked the following questions: 1) How does climate change affect birds? 2) How will birds respond to climate change? 3) Are species already responding? 4) How will habitats be impacted?
Fairchild, Dana M [Armour, SD
The bird guard provides a device to protect electrical insulators comprising a central shaft; a clamp attached to an end of the shaft to secure the device to a transmission tower; a top and bottom cover to shield transmission tower insulators; and bearings to allow the guard to rotate in order to frighten birds away from the insulators.
Roberts, James J.; Bruce, James F.; Zuellig, Robert E.
The analysis described in this report is part of a longterm project monitoring the biological communities, habitat, and water quality of the Fountain Creek Basin. Biology, habitat, and water-quality data have been collected at 10 sites since 2003. These data include annual samples of aquatic invertebrate communities, fish communities, water quality, and quantitative riverine habitat. This report examines trends in biological communities from 2003 to 2016 and explores relationships between biological communities and abiotic variables (antecedent streamflow, physical habitat, and water quality). Six biological metrics (three invertebrate and three fish) and four individual fish species were used to examine trends in these data and how streamflow, habitat, and (or) water quality may explain these trends. The analysis of 79 trends shows that the majority of significant trends decreased over the trend period. Overall, 19 trends before adjustments for streamflow in the fish (12) and invertebrate (7) metrics were all decreasing except for the metric Invertebrate Species Richness at the most upstream site in Monument Creek. Seven of these trends were explained by streamflow and four trends were revealed that were originally masked by variability in antecedent streamflow. Only two sites (Jimmy Camp Creek at Fountain, CO and Fountain Creek near Pinon, CO) had no trends in the fish or invertebrate metrics. Ten of the streamflow-adjusted trends were explained by habitat, one was explained by water quality, and five were not explained by any of the variables that were tested. Overall, from 2003 to 2016, all the fish metric trends were decreasing with an average decline of 40 percent, and invertebrate metrics decreased on average by 9.5 percent. A potential peak streamflow threshold was identified above which there is severely limited production of age-0 flathead chub (Platygobio gracilis).
McKinnon, Emily A; Stanley, Calandra Q; Stutchbury, Bridget J M
For migratory animals, conditions during the nonbreeding period may carry-over to influence spring migration performance. Animals in low-quality habitats are predicted to be in poorer condition, show later migration timing, and travel at slower speeds. This can result in subsequent negative effects on fitness. We tested the hypothesis that nonbreeding season body condition and habitat quality carry-over to affect spring migration performance of a long-distance migratory songbird, the Wood Thrush (Hylocichla mustelina). We tracked individual birds between multiple breeding sites in North America and nonbreeding sites in Central America. First, we compared body condition of nonbreeding birds migrating to the same general region of the breeding range with spring migration performance (timing, speed, and duration) obtained from light-level geolocators. Second, we assessed the Normalized Difference Vegetation Index (NDVI) as a proxy for nonbreeding habitat quality, and predicted that birds from wetter habitat or in wetter years (higher NDVI) would show improved migration performance relative to birds from drier sites. We found no evidence of individual-level carry-over effects of nonbreeding season body condition on spring migration performance. Lower NDVI of nonbreeding habitat resulted in delayed spring migration departure, but this effect disappeared by arrival at breeding sites. Birds occupying drier nonbreeding sites migrated faster and for fewer days, compensating for their relatively late departure. We also documented a broader pattern in NDVI and migration timing and distance, in that birds that occupied the wettest areas in the southern part of the nonbreeding range departed significantly later and migrated farther. Our results suggest that individual carry-over effects of nonbreeding habitat quality may be compensated for by a faster and shorter migration strategy. At a broad scale, consistently later spring timing and longer migration distances were
Emily A McKinnon
Full Text Available For migratory animals, conditions during the nonbreeding period may carry-over to influence spring migration performance. Animals in low-quality habitats are predicted to be in poorer condition, show later migration timing, and travel at slower speeds. This can result in subsequent negative effects on fitness. We tested the hypothesis that nonbreeding season body condition and habitat quality carry-over to affect spring migration performance of a long-distance migratory songbird, the Wood Thrush (Hylocichla mustelina. We tracked individual birds between multiple breeding sites in North America and nonbreeding sites in Central America. First, we compared body condition of nonbreeding birds migrating to the same general region of the breeding range with spring migration performance (timing, speed, and duration obtained from light-level geolocators. Second, we assessed the Normalized Difference Vegetation Index (NDVI as a proxy for nonbreeding habitat quality, and predicted that birds from wetter habitat or in wetter years (higher NDVI would show improved migration performance relative to birds from drier sites. We found no evidence of individual-level carry-over effects of nonbreeding season body condition on spring migration performance. Lower NDVI of nonbreeding habitat resulted in delayed spring migration departure, but this effect disappeared by arrival at breeding sites. Birds occupying drier nonbreeding sites migrated faster and for fewer days, compensating for their relatively late departure. We also documented a broader pattern in NDVI and migration timing and distance, in that birds that occupied the wettest areas in the southern part of the nonbreeding range departed significantly later and migrated farther. Our results suggest that individual carry-over effects of nonbreeding habitat quality may be compensated for by a faster and shorter migration strategy. At a broad scale, consistently later spring timing and longer migration
Migratory movements of birds has always fascinated man and led to many questions concerning the ecological drivers behind, the necessary adaptations and the navigational abilities required. However, especially for the long-distance migrants, basic descriptions of their movements are still lacking...... and a forest reserve. In the degraded habitat all species used more space, although the consequence on bird density is less clear. Two manuscripts relate the migratory movements of a long-distance migrant with models of navigation. One compares model predictions obtained by simulation with actual movements......, and conclude that the currently believed theoretical framework is insufficient to explain the observed performance. The other study investigates the ability of a displaced experienced migrant to navigate back to the normal migration route. It documents the capability, but also finds interesting patterns...
The Mobile Bay estuary provides rich habitat for many fish and shellfish, including those identified as economically and ecologically important. The National Estuary Program has focused on restoration of degraded estuarine habitat on which these species depend. To support this ...
Jeffrey V. Wells; Daniel K. Niven; John Cecil
The Important Bird Area (IBA) program is an international effort to identify, conserve, and monitor a network of sites that provide essential habitat for bird populations. BirdLife International began the IBA program in Europe in 1985. Since that time, BirdLife partners in more than 100 countries have joined together to build the global IBA network. Audubon (BirdLife...
Diehl, Robert Howard
The challenge for migratory bird conservation is habitat preservation that sustains breeding, migration, and non-breeding biological processes. In choosing an appropriately scaled conservation arena for habitat preservation, a conservative and thorough examination of stopover habitat use patterns by migrants works back from the larger scales at which such relationships may occur. Because the use of stopover habitats by migrating birds occurs at spatial scales larger than traditional field techniques can easily accommodate, I quantify these relationship using the United States system of weather surveillance radars (popularly known as NEXRAD). To provide perspective on use of this system for biologists, I first describe the technical challenges as well as some of the biological potential of these radars for ornithological research. Using data from these radars, I then examined the influence of Lake Michigan and the distribution of woodland habitat on migrant concentrations in northeastern Illinois habitats during stopover. Lake Michigan exerted less influence on migrant abundance and density than the distribution and availability of habitat for stopover. There was evidence of post-migratory movement resulting in habitats within suburban landscapes experiencing higher migrant abundance but lower migrant density than habitats within nearby urban and agricultural landscapes. Finally, in the context of hierarchy theory, I examined the influence of landscape ecological and behavioral processes on bird density during migratory stopover. Migrant abundance did not vary across landscapes that differed considerably in the amount of habitat available for stopover. As a result, smaller, more isolated patches held higher densities of birds. Spatial models of migrant habitat selection based on migrant proximity to a patch explained nearly as much variance in the number of migrants occupying patches (R2 = 0.88) as selection models based on migrant interception of patches during
Sneck-Fahrer, Debra A.; East, Jeffery W.
The U.S. Geological Survey, in cooperation with the Houston-Galveston Area Council and the Texas Commission on Environmental Quality, collected water-quality, stream-habitat, and biological data from six sites (downstream order M6-M1) primarily in Brazoria County southeast of Houston, Texas, during September 2004-August 2005 and collected bed sediment data from one site in September 2005. Water-quality data collection consisted of continuously monitored (for periods of 24 hours to several days, six times) water temperature, pH, specific conductance, and dissolved oxygen and periodically collected samples of several properties and constituents. Monitored dissolved oxygen measurements were below minimum and 24-hour criteria at all sites except M2. Nitrogen compounds, phosphorus, biochemical oxygen demand, chlorophyll-a, E. coli, chloride, sulfate, solids, suspended sediment concentration, and pesticides were assessed at all sites. Concentrations of nitrogen compounds and phosphorus did not exceed Texas State screening levels. Biochemical oxygen demand was less than 4.0 milligrams per liter at all sites except M6, where the maximum concentration was 8.1 milligrams per liter. Concentrations of chlorophyll-a were less than the State screening level at all sites except M6, where four of eight samples equaled or exceeded the screening level. Twenty of 48 samples from Mustang Bayou had E. coli densities that exceeded the State single-sample water-quality standard. Median chloride concentrations from each site were between 42.2 and 123 milligrams per liter. Fifteen pesticide compounds (six herbicides and nine insecticides) were detected in 24 water samples. The most frequently detected pesticide was atrazine, which was found in every sample. Other frequently detected pesticides were 2-chloro-4-isopropylamino-6-amino-s-triazine (CIAT), prometon, tebuthiuron, fipronil, and the pesticide degradates, fipronil sulfide and fipronil sulfone. Sediment samples were collected from
Franklin, Janet; Steadman, David W.
Background We examined species composition of forest and bird communities in relation to environmental and human disturbance gradients on Lakeba (55.9 km2), Nayau (18.4 km2), and Aiwa Levu (1.2 km2), islands in the Lau Group of Fiji, West Polynesia. The unique avifauna of West Polynesia (Fiji, Tonga, Samoa) has been subjected to prehistoric human-caused extinctions but little was previously known about this topic in the Lau Group. We expected that the degree of human disturbance would be a strong determinant of tree species composition and habitat quality for surviving landbirds, while island area would be unrelated to bird diversity. Methodology/Principal Findings All trees >5 cm diameter were measured and identified in 23 forest plots of 500 m2 each. We recognized four forest species assemblages differentiated by composition and structure: coastal forest, dominated by widely distributed species, and three forest types with differences related more to disturbance history (stages of secondary succession following clearing or selective logging) than to environmental gradients (elevation, slope, rockiness). Our point counts (73 locations in 1 or 2 seasons) recorded 18 of the 24 species of landbirds that exist on the three islands. The relative abundance and species richness of birds were greatest in the forested habitats least disturbed by people. These differences were due mostly to increased numbers of columbid frugivores and passerine insectivores in forests on Lakeba and Aiwa Levu. Considering only forested habitats, the relative abundance and species richness of birds were greater on the small but completely forested (and uninhabited) island of Aiwa Levu than on the much larger island of Lakeba. Conclusions/Significance Forest disturbance history is more important than island area in structuring both tree and landbird communities on remote Pacific islands. Even very small islands may be suitable for conservation reserves if they are protected from human
Full Text Available We examined species composition of forest and bird communities in relation to environmental and human disturbance gradients on Lakeba (55.9 km², Nayau (18.4 km², and Aiwa Levu (1.2 km², islands in the Lau Group of Fiji, West Polynesia. The unique avifauna of West Polynesia (Fiji, Tonga, Samoa has been subjected to prehistoric human-caused extinctions but little was previously known about this topic in the Lau Group. We expected that the degree of human disturbance would be a strong determinant of tree species composition and habitat quality for surviving landbirds, while island area would be unrelated to bird diversity.All trees > 5 cm diameter were measured and identified in 23 forest plots of 500 m² each. We recognized four forest species assemblages differentiated by composition and structure: coastal forest, dominated by widely distributed species, and three forest types with differences related more to disturbance history (stages of secondary succession following clearing or selective logging than to environmental gradients (elevation, slope, rockiness. Our point counts (73 locations in 1 or 2 seasons recorded 18 of the 24 species of landbirds that exist on the three islands. The relative abundance and species richness of birds were greatest in the forested habitats least disturbed by people. These differences were due mostly to increased numbers of columbid frugivores and passerine insectivores in forests on Lakeba and Aiwa Levu. Considering only forested habitats, the relative abundance and species richness of birds were greater on the small but completely forested (and uninhabited island of Aiwa Levu than on the much larger island of Lakeba.Forest disturbance history is more important than island area in structuring both tree and landbird communities on remote Pacific islands. Even very small islands may be suitable for conservation reserves if they are protected from human disturbance.
California Department of Resources — This layer depicts areas designated for Steelhead Critical Habitat as well as habitat type and quality in the Coastal California Steelhead ESUs (evolutionarily...
Daniel P. Shustack
Full Text Available In the northeastern United States, grassland birds regularly use agricultural fields as nesting habitat. However, birds that nest in these fields regularly experience nest failure as a result of agricultural practices, such as mowing and grazing. Therefore, information on both spatial and temporal patterns of habitat use is needed to effectively manage these species. We addressed these complex habitat use patterns by conducting point counts during three time intervals between May 21, 2002 and July 2, 2002 in agricultural fields across the Champlain Valley in Vermont and New York. Early in the breeding season, Bobolinks (Dolichonyx oryzivorus used fields in which the landscape within 2500 m was dominated by open habitats. As mowing began, suitable habitat within 500 m became more important. Savannah Sparrows (Passerculus sandwichensis initially used fields that contained a high proportion of suitable habitat within 500 m. After mowing, features of the field (i.e., size and amount of woody edge became more important. Each species responded differently to mowing: Savannah Sparrows were equally abundant in mowed and uncut fields, whereas Bobolinks were more abundant in uncut fields. In agricultural areas in the Northeast, large areas (2000 ha that are mostly nonforested and undeveloped should be targeted for conservation. Within large open areas, smaller patches (80 ha should be maintained as high-quality, late-cut grassland habitat.
Lumpkin, Heather A; Pearson, Scott M
Land-use dynamics and climatic gradients have large effects on many terrestrial systems. Exurban development, one of the fastest growing forms of land use in the United States, may affect wildlife through habitat fragmentation and building presence may alter habitat quality. We studied the effects of residential development and temperature gradients on bird species occurrence at 140 study sites in the southern Appalachian Mountains (North Carolina, U.S.A.) that varied with respect to building density and elevation. We used occupancy models to determine 36 bird species' associations with building density, forest canopy cover, average daily mean temperature, and an interaction between building density and mean temperature. Responses varied with habitat requirement, breeding range, and migration distance. Building density and mean temperature were both included in the top occupancy models for 19 of 36 species and a building density by temperature interaction was included in models for 8 bird species. As exurban development expands in the southern Appalachians, interior forest species and Neotropical migrants are likely to decline, but shrubland or edge species are not likely to benefit. Overall, effects of building density were greater than those of forest canopy cover. Exurban development had a greater effect on birds at high elevations due to a greater abundance of sensitive forest-interior species and Neotropical migrants. A warming climate may exacerbate these negative effects. © 2013 Society for Conservation Biology.
Gan, Xiaojing; Cai, Yinting; Choi, Chiyeung; Ma, Zhijun; Chen, Jiakuan; Li, Bo
Invasive smooth cordgrass ( Spartina alterniflora, hereafter Spartina) has been expanding rapidly in the estuarine wetlands at Chongming Dongtan (East China) at the expense of native sea-bulrush ( Scirpus mariqueter, hereafter Scirpus) and common reed ( Phragmites australis, hereafter Phragmites). To examine the potential impacts of the Spartina invasion on bird diversity, we compared the abundance and species richness of birds in habitats created by Spartina, Phragmites, Spartina mixed with Phragmites, Scirpus, and the bare intertidal zone at Chongming Dongtan in spring 2008. Most birds were recorded in the native habitats, with songbirds and breeding birds being most abundant in the Phragmites habitats, and waterbirds and migrants being most abundant in the Scirpus habitats and bare intertidal zone. Both species number and population densities of birds were lower in the exotic Spartina habitats than in the other four habitats. Although some songbirds and breeding birds used the Spartina-invaded habitats, and even preferred Spartina-invaded habitats to Scirpus habitats and bare intertidal zone, their densities were lower in the Spartina-invaded habitats than in the native Phragmites habitats. This might have resulted from the dense Spartina stands restricting bird movement and providing insufficient useable food for most birds. We conclude that the spread of exotic Spartina has negative impacts on local bird communities. Because Chongming Dongtan is an important stopover site for energy replenishment of shorebirds in the East Asian-Australasian Flyway, urgent measures are needed to control further spread of Spartina and to restore the native habitats for birds.
Scopus: Journal of East African Ornithology. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 32 (2012) >. Log in or Register to get access to full text downloads.
Kamler, Jiří; Homolka, Miloslav
Roč. 54, 1-2 (2005), s. 89-98 ISSN 0139-7893 R&D Projects: GA ČR(CZ) GA206/99/D053; GA AV ČR(CZ) IBS6093003 Institutional research plan: CEZ:AV0Z60930519 Keywords : free-living ungulates * faecal indicators * diet quality Subject RIV: EG - Zoology Impact factor: 0.585, year: 2005 http://www.ivb.cz/folia/54/1-2/89-98.pdf
Peterjohn, Bruce G.
Located along Delaware Bay and the Atlantic coast, the state of Delaware’s significance for bird conservation has been well established for decades. The extensive tidal habitats and marshes bordering Delaware Bay host shorebird and waterbird populations of hemispheric importance, and protecting these populations has become an urgent conservation priority in recent years. Other habitats found in the state vary from barrier beaches to dry coniferous woods on the coastal plain and mesophytic communities along the Piedmont in the north, allowing a diverse avifauna to prosper within a small geographic area. Ornithologists and birders have actively studied birds within the state for more than a century, but surprisingly, no single reference has provided a complete summary of the status and distribution of the state’s birds until publication of the Birds of Delaware.Review info: Birds of Delaware. By Gene K. Hess, Richard L. West, Maurice V. Barnhill III, and Lorraine M. Fleming, 2000. ISBN: 0-8229-4069-8, 635 pp.
Nicol, Sam; Wiederholt, Ruscena; Diffendorfer, James E.; Mattsson, Brady; Thogmartin, Wayne E.; Semmens, Darius J.; Laura Lopez-Hoffman,; Norris, Ryan
Mobile species with complex spatial dynamics can be difficult to manage because their population distributions vary across space and time, and because the consequences of managing particular habitats are uncertain when evaluated at the level of the entire population. Metrics to assess the importance of habitats and pathways connecting habitats in a network are necessary to guide a variety of management decisions. Given the many metrics developed for spatially structured models, it can be challenging to select the most appropriate one for a particular decision. To guide the management of spatially structured populations, we define three classes of metrics describing habitat and pathway quality based on their data requirements (graph-based, occupancy-based, and demographic-based metrics) and synopsize the ecological literature relating to these classes. Applying the first steps of a formal decision-making approach (problem framing, objectives, and management actions), we assess the utility of metrics for particular types of management decisions. Our framework can help managers with problem framing, choosing metrics of habitat and pathway quality, and to elucidate the data needs for a particular metric. Our goal is to help managers to narrow the range of suitable metrics for a management project, and aid in decision-making to make the best use of limited resources.
National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for endangered waterbirds and passerine birds, migratory shorebirds and waterfowl, gulls and terns,...
Scharf, Inon; Fischer-Blass, Birgit; Foitzik, Susanne
Natural communities are structured by intra-guild competition, predation or parasitism and the abiotic environment. We studied the relative importance of these factors in two host-social parasite ecosystems in three ant communities in Europe (Bavaria) and North America (New York, West Virginia). We tested how these factors affect colony demography, life-history and the spatial pattern of colonies, using a large sample size of more than 1000 colonies. The strength of competition was measured by the distance to the nearest competitor. Distance to the closest social parasite colony was used as a measure of parasitism risk. Nest sites (i.e., sticks or acorns) are limited in these forest ecosystems and we therefore included nest site quality as an abiotic factor in the analysis. In contrast to previous studies based on local densities, we focus here on the positioning and spatial patterns and we use models to compare our predictions to random expectations. Colony demography was universally affected by the size of the nest site with larger and more productive colonies residing in larger nest sites of higher quality. Distance to the nearest competitor negatively influenced host demography and brood production in the Bavarian community, pointing to an important role of competition, while social parasitism was less influential in this community. The New York community was characterized by the highest habitat variability, and productive colonies were clustered in sites of higher quality. Colonies were clumped on finer spatial scales, when we considered only the nearest neighbors, but more regularly distributed on coarser scales. The analysis of spatial positioning within plots often produced different results compared to those based on colony densities. For example, while host and slavemaker densities are often positively correlated, slavemakers do not nest closer to potential host colonies than expected by random. The three communities are differently affected by biotic and
Full Text Available Abstract Background Natural communities are structured by intra-guild competition, predation or parasitism and the abiotic environment. We studied the relative importance of these factors in two host-social parasite ecosystems in three ant communities in Europe (Bavaria and North America (New York, West Virginia. We tested how these factors affect colony demography, life-history and the spatial pattern of colonies, using a large sample size of more than 1000 colonies. The strength of competition was measured by the distance to the nearest competitor. Distance to the closest social parasite colony was used as a measure of parasitism risk. Nest sites (i.e., sticks or acorns are limited in these forest ecosystems and we therefore included nest site quality as an abiotic factor in the analysis. In contrast to previous studies based on local densities, we focus here on the positioning and spatial patterns and we use models to compare our predictions to random expectations. Results Colony demography was universally affected by the size of the nest site with larger and more productive colonies residing in larger nest sites of higher quality. Distance to the nearest competitor negatively influenced host demography and brood production in the Bavarian community, pointing to an important role of competition, while social parasitism was less influential in this community. The New York community was characterized by the highest habitat variability, and productive colonies were clustered in sites of higher quality. Colonies were clumped on finer spatial scales, when we considered only the nearest neighbors, but more regularly distributed on coarser scales. The analysis of spatial positioning within plots often produced different results compared to those based on colony densities. For example, while host and slavemaker densities are often positively correlated, slavemakers do not nest closer to potential host colonies than expected by random. Conclusions The
Lundgren, Robert F.; Rowland, Kathleen M.; Lindsay, Matthew J.
In 2010, data on physical habitat, water quality, and riverine biological assemblages were collected at selected reaches in four locations (Kleven, Sheyenne, Cooperstown, and West Fargo) on the Sheyenne River in east-central North Dakota. Three of the locations (Kleven, Sheyenne, and Cooperstown) are above Baldhill Dam and one location (West Fargo) is below Baldhill Dam on the Sheyenne River. The 2010 data provide information to establish a better understanding of the water-quality and ecological conditions of the Sheyenne River. Concerns were raised about the water-quality and ecological conditions of the Sheyenne River because of the interbasin transfer of water from nearby Devils Lake. The transfer of water from Devils Lake to the Sheyenne River occurs through the Devils Lake State Outlet near Peterson Coulee or, if lake elevations exceed 1,459 feet above National Geodetic Vertical Datum of 1929 (NGVD 29), through a natural outlet, Tolna Coulee. The field measurements of water-quality characteristics and results of chemical analyses generally are comparable to summary statistics calculated for Sheyenne River for 1980 through 2006. Overall, water-quality results show differences between the Kleven, Sheyenne, Cooperstown, and West Fargo reaches. Sulfate concentrations were less than the State of North Dakota criterion of 750 milligrams per liter for the upper Sheyenne River above Baldhill Dam and less than the criterion of 450 milligrams per liter for the lower Sheyenne River below Baldhill Dam. Arsenic concentrations at most reaches exceeded the U.S. Environmental Protection Agency drinking-water standard of 10 micrograms per liter. Nutrient concentrations (nitrogen, phosphorus) were higher in the upper Sheyenne River above Baldhill Dam than below Baldhill Dam where concentrations decreased by about half. In 2010, 35 families and 44 genera of benthic macroinvertebrates were collected and identified. On the basis of the index of biotic intergrity scores for
Using line transect methods, the effect of habitat structure and altitudinal gradients on bird species diversity at Kurra Falls Forest were studied. A total of 175 bird species were recorded, two of which are among the four endemic birds to Nigeria. Tree height, tree number, and canopy cover together had a significant effect on ...
Richards, Stephanie E. (Compiler); Levine, Howard G.; Reed, David W.
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.
Christopher J. Norment
Full Text Available Declining grassland breeding bird populations have led to increased efforts to assess habitat quality, typically by estimating density or relative abundance. Because some grassland habitats may function as ecological traps, a more appropriate metric for determining quality may be breeding success. Between 1994 and 2003 we gathered data on the nest fates of Eastern Meadowlarks (Sturnella magna, Bobolinks (Dolichonyx oryzivorous, and Savannah Sparrows (Passerculus sandwichensis in a series of fallow fields and pastures/hayfields in western New York State. We calculated daily survival probabilities using the Mayfield method, and used the logistic-exposure method to model effects of predictor variables on nest success. Nest survival probabilities were 0.464 for Eastern Meadowlarks (n = 26, 0.483 for Bobolinks (n = 91, and 0.585 for Savannah Sparrows (n = 152. Fledge dates for first clutches ranged between 14 June and 23 July. Only one obligate grassland bird nest was parasitized by Brown-headed Cowbirds (Molothrus ater, for an overall brood parasitism rate of 0.004. Logistic-exposure models indicated that daily nest survival probabilities were higher in pastures/hayfields than in fallow fields. Our results, and those from other studies in the Northeast, suggest that properly managed cool season grassland habitats in the region may not act as ecological traps, and that obligate grassland birds in the region may have greater nest survival probabilities, and lower rates of Brown-headed Cowbird parasitism, than in many parts of the Midwest.
Cleary, Gráinne P; Parsons, Holly; Davis, Adrian; Coleman, Bill R; Jones, Darryl N; Miller, Kelly K; Weston, Michael A
Private gardens provide habitat and resources for many birds living in human-dominated landscapes. While wild bird feeding is recognised as one of the most popular forms of human-wildlife interaction, almost nothing is known about the use of bird baths. This citizen science initiative explores avian assemblages at bird baths in private gardens in south-eastern Australia and how this differs with respect to levels of urbanisation and bioregion. Overall, 992 citizen scientists collected data over two, four-week survey periods during winter 2014 and summer 2015 (43% participated in both years). Avian assemblages at urban and rural bird baths differed between bioregions with aggressive nectar-eating species influenced the avian assemblages visiting urban bird baths in South Eastern Queensland, NSW North Coast and Sydney Basin while introduced birds contributed to differences in South Western Slopes, Southern Volcanic Plains and Victorian Midlands. Small honeyeaters and other small native birds occurred less often at urban bird baths compared to rural bird baths. Our results suggest that differences between urban versus rural areas, as well as bioregion, significantly influence the composition of avian assemblages visiting bird baths in private gardens. We also demonstrate that citizen science monitoring of fixed survey sites such as bird baths is a useful tool in understanding large-scale patterns in avian assemblages which requires a vast amount of data to be collected across broad areas.
Cleary, Gráinne P.; Parsons, Holly; Davis, Adrian; Coleman, Bill R.; Jones, Darryl N.; Miller, Kelly K.; Weston, Michael A.
Private gardens provide habitat and resources for many birds living in human-dominated landscapes. While wild bird feeding is recognised as one of the most popular forms of human-wildlife interaction, almost nothing is known about the use of bird baths. This citizen science initiative explores avian assemblages at bird baths in private gardens in south-eastern Australia and how this differs with respect to levels of urbanisation and bioregion. Overall, 992 citizen scientists collected data over two, four-week survey periods during winter 2014 and summer 2015 (43% participated in both years). Avian assemblages at urban and rural bird baths differed between bioregions with aggressive nectar-eating species influenced the avian assemblages visiting urban bird baths in South Eastern Queensland, NSW North Coast and Sydney Basin while introduced birds contributed to differences in South Western Slopes, Southern Volcanic Plains and Victorian Midlands. Small honeyeaters and other small native birds occurred less often at urban bird baths compared to rural bird baths. Our results suggest that differences between urban versus rural areas, as well as bioregion, significantly influence the composition of avian assemblages visiting bird baths in private gardens. We also demonstrate that citizen science monitoring of fixed survey sites such as bird baths is a useful tool in understanding large-scale patterns in avian assemblages which requires a vast amount of data to be collected across broad areas. PMID:26962857
Full Text Available The paper presents the classification of the ecological condition of Wardynka river according to the River Habitat Survey method. The research has been carried out within the project entitled Carrying out the assessment of the condition of natural resources of the reception basin of the river Ina within the project LIFE+: “Building of the blue corridor along the valley of the Ina river and its tributaries” financed from the funds of the European Community financial instrument LIFE+ and the National Fund of Environmental Protection and Water Management. The obtained data facilitated the calculation of two synthetic hydro-morphological indices HQA (Habitat Quality Assessment and HMS (Habitat Modification Score, which constitute the result of many singular basic parameters. The calculated numerical values of the indices HQA amounting to 48 and HMS amounting to 3 proved that the waters of the Wardynka river correspond with the fourth class, which means a moderate environmental condition.
Wolf, Isabelle D; Hagenloh, Gerald; Croft, David B
Bird communities inhabiting ecosystems adjacent to recreational tracks may be adversely affected by disturbance from passing tourism traffic, vehicle-related mortality, habitat alteration and modified biotic relationships such as the increase of strong competitors. This study investigated the effects of tourist usage of roads vs. hiking trails on bird communities in gorges of the Flinders Ranges, a popular South Australian tourist destination in the arid-lands. High tourist usage along roads decreased the individual abundance and species richness of birds relative to low usage trails. The decrease in species richness, though less pronounced, also occurred at high-usage sites along trails. Changes in the species response to recreational disturbance/impacts varied depending on the ecology of the species. Bigger, more competitive birds with a generalist diet were overrepresented at high-usage sites along roads and trails. Species using microhabitats in lower vegetation layers were more sensitive. However, structural and floristic complexity of vegetation was a more important factor influencing bird abundance than tourist usage. Sites with a better developed shrub and tree layer sustained higher species abundance and richer communities. Importantly, vegetation qualities moderated the negative effect of high usage on the individual abundance of birds along roads, to the extent that such an effect was absent at sites with the best developed shrub and tree layer. To protect avifauna along recreational tracks in arid-lands gorges, we recommend the closure of some gorges or sections for vehicle or any access. Further, open space particularly for camping needs to be minimized as it creates areas of high tourist usage with modified habitat that provides birds with little buffer from disturbance. Copyright © 2013 Elsevier Ltd. All rights reserved.
Reynolds-Hogland, M. J.; Mitchell, M.S.
We tested the hypothesis that gravel roads, not paved roads, had the largest negative effect on habitat quality for a population of American black bears (Ursus americanus) that lived in a protected area, where vehicle collision was a relatively minimal source of mortality. We also evaluated whether road use by bears differed by sex or age and whether annual variation in hard mast productivity affected the way bears used areas near roads. In addition, we tested previous findings regarding the spatial extent to which roads affected bear behavior negatively. Using summer and fall home ranges for 118 black bears living in the Pisgah Bear Sanctuary in western North Carolina during 1981-2001, we estimated both home-range-scale (2nd-order) and within-home-range-scale (3rd-order) selection for areas within 250, 500, 800, and 1,600 m of paved and gravel roads. All bears avoided areas near gravel roads more than they avoided areas near paved roads during summer and fall for 2nd-order selection and during summer for 3rd-order selection. During fall, only adult females avoided areas near gravel roads more than they avoided areas near paved roads for 3rd-order selection. We found a positive relationship between use of roads by adults and annual variability in hard mast productivity. Overall, bears avoided areas within 800 m of gravel roads. Future research should determine whether avoidance of gravel roads by bears affects bear survival. ?? 2007 American Society of Mammalogists.
Full Text Available A survey of the macroinvertebrates of three brooks harbouring the white-clawed crayfish was conducted in Haute-Vienne department (France. Its aim was to increase our understanding of these ecosystems to help the conservation of A. pallipes. These brooks run through pastoral areas with well-developed riparian vegetation, which offers an important shade. Water temperature, dissolved oxygen concentration, pH, and conductivity fell within the ranges found for this species. A total of 34, 31, 29 taxa and 1 502, 1 364, 2 707 individuals of macrobenthos were collected in Holme, Besque and Bellecombe streams, respectively. Results showed good to very good water quality with IBGN scores ranging from 15 (Bellecombe to 17 (Holme and Besque, reflecting a limited impact of the anthropogenic disturbances. Taxa diversity were high for Holme and Besque with Shannon index around 3.2, translating a great heterogeneity of habitat and an equilibrated faunal community. Bellecombe showed a limited diversity with Shannon index of 1.42, resulting from the presence of numberous Chironomidae. This brook suffers probably weak organic pollution which could be related to the low water flow observed during the sampling. The similarity test according to Jaccard index showed high percentage of common taxa among ETP (Ephemeroptera-Trichoptera-Plecoptera between all sites. The high similarity of benthic macroinvertebrate communities could be an useful criteria to identify brooks for restocking purpose.
National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for wading birds, shorebirds, waterfowl, diving birds, seabirds, passerine birds, gulls, and terns in...
Rasmussen, Jes Jessen; Baattrup-Pedersen, Annette; Larsen, Søren Erik; Kronvang, Brian
The combination of intensive agricultural activities and the close connectivity between land and stream emphasise the potential risk of pesticide exposure in Danish streams. Benthic macroinvertebrates are applied in the assessment of stream ecological status, and some sensitive species have been shown to respond strongly to brief pulses of pesticide contamination. In this study we investigate the impact of agriculturally derived pesticides on stream macroinvertebrate communities in Denmark. As a measure of toxic pressure we apply the Runoff Potential. We investigated a total of 212 streams. These were grouped into distinct classes according to the magnitude of pesticide contamination in the period from 2003-2006. A total of 24 different macroinvertebrate indices were applied to detect effects of pesticide runoff (e.g. the SPEAR-index and the number of EPT taxa). We found high predicted pesticide runoff in 39% of the streams, but we found no significant effect of predicted pesticide exposure on stream macroinvertebrate indices. We, additionally, examined the influence of a series of environmental parameters ranging from site scale to catchment scale on the macroinvertebrate community. Relative proportions of gravel, sand and silt in bed sediments explained most of the variation in macroinvertebrate indices as well as the upstream riparian habitat quality. We suggest that the Runoff Potential model overestimate pesticide runoff contamination in Danish streams due the presence of buffer strips enforced by Danish legislation. When pesticide runoff contamination is low to moderate, poor physical properties (indirectly related to agricultural activity) are the main impediment for the ecological quality of Danish streams.
Blank, P.J.; Dively, G.P.; Gill, D.E.; Rewa, C.A.
Filter strips are strips of herbaceous vegetation planted along agricultural field margins adjacent to streams or wetlands and are designed to intercept sediment, nutrients, and agrichemicals. Roughly 16,000 ha of filter strips have been established in Maryland through the United States Department of Agriculture's Conservation Reserve Enhancement Program. Filter strips often represent the only uncultivated herbaceous areas on farmland in Maryland and therefore may be important habitat for early-successional bird species. Most filter strips in Maryland are planted to either native warm-season grasses or cool-season grasses and range in width from 10.7 m to 91.4 m. From 2004 to 2007 we studied the breeding and wintering bird communities in filter strips adjacent to wooded edges and non-buffered field edges and the effect that grass type and width of filter strips had on bird community composition. We used 5 bird community metrics (total bird density, species richness, scrub-shrub bird density, grassland bird density, and total avian conservation value), species-specific densities, nest densities, and nest survival estimates to assess the habitat value of filter strips for birds. Breeding and wintering bird community metrics were greater in filter strips than in non-buffered field edges but did not differ between cool-season and warm-season grass filter strips. Most breeding bird community metrics were negatively related to the percent cover of orchardgrass (Dactylis glomerata) in ???1 yr. Breeding bird density was greater in narrow (60 m) filter strips. Our results suggest that narrow filter strips adjacent to wooded edges can provide habitat for many bird species but that wide filter strips provide better habitat for grassland birds, particularly obligate grassland species. If bird conservation is an objective, avoid planting orchardgrass in filter strips and reduce or eliminate orchardgrass from filter strips through management practices. Copyright ?? 2011 The
... of pet birds. Because of the risk of avian influenza (bird flu), USDA restricts the importation of pet birds from ... or look dirty may be ill. Learn the signs of illness in a bird, which include appearing ...
Tripathi, G.; Deora, R.; Singh, G.
Studies to understand litter processes and soil properties are useful for maintaining pastureland productivity as animal husbandry is the dominant occupation in the hot arid region. We aimed to quantify how micro-habitats and combinations of litters of the introduced leguminous tree Colophospermum mopane with the grasses Cenchrus ciliaris or Lasiurus sindicus influence decomposition rate and soil nutrient changes in a hot desert silvopasture system. Litter bags with tree litter alone (T), tree + C. ciliaris in 1:1 ratio (TCC) and tree + L. sindicus 1:1 ratio (TLS) litter were placed inside and outside of the C. mopane canopy and at the surface, 3-7 cm and 8-12 cm soil depths. We examined litter loss, soil fauna abundance, organic carbon (SOC), total (TN), ammonium (NH4-N) and nitrate (NO3-N) nitrogen, phosphorus (PO4-P), soil respiration (SR) and dehydrogenase activity (DHA) in soil adjacent to each litter bag. After 12 months exposure, the mean residual litter was 40.2% of the initial value and annual decomposition rate constant (k) was 0.98 (0.49-1.80). Highest (p < 0.01) litter loss was in the first four months, when faunal abundance, SR, DHA and humidity were highest but it decreased with time. These variables and k were highest under the tree canopies. The litter loss and k were highest (p < 0.01) in TLS under the tree canopy, but the reverse trend was found for litter outside the canopy. Faunal abundance, litter loss, k, nutrient release and biochemical activities were highest (p < 0.01) in the 3-7 cm soil layer. Positive correlations of litter loss and soil fauna abundance with soil nutrients, SR and DHA demonstrated the interactions of litter quality and micro-habitats together with soil fauna on increased soil fertility. These results suggest that a Colophospermum mopane and L. sindicus silvopasture system best promotes faunal abundance, litter decomposition and soil fertility. The properties of these species and the associated faunal resources may be
Megan M. Friggens; Stephen N. Matthews
Species distribution models for 147 bird species have been derived using climate, elevation, and distribution of current tree species as potential predictors (Matthews et al. 2011). In this case study, a risk matrix was developed for two bird species (fig. A2-5), with projected change in bird habitat (the x axis) based on models of changing suitable habitat resulting...
Etnoyer, P. J.; Hourigan, T. F.; Reser, B.; Monaco, M.
The growing fleet of telepresence-enabled research vessels equipped with deep-sea imaging technology provides a new opportunity to catalyze and coordinate research efforts among ships. This development is particularly useful for studying the distribution and diversity of deep-sea corals, which occur worldwide from 50 to 8600 m depth. Marine managers around the world seek to conserve these habitats, but require a clear consensus on what types of information are most important and most relevant for marine conservation. The National Oceanic and Atmospheric Administration (NOAA) seeks to develop a reproducible, non-invasive set of ROV methods designed to measure conservation value, or habitat quality, for deep-sea corals and sponges. New tools and methods will be proposed to inform ocean resource management, as well as facilitate research, outreach, and education. A new database schema will be presented, building upon the Ocean Biogeographic Information System (OBIS) and efforts of submersible and ROV teams over the years. Visual information about corals and sponges has proven paramount, particularly high-quality images with standard attributes for marine geology and marine biology, including scientific names, colony size, health, abundance, and density. Improved habitat suitability models can be developed from these data if presence and absence are measured. Recent efforts to incorporate physical sampling into telepresence protocols further increase the value of such information. It is possible for systematic observations with small file sizes to be distributed as geo-referenced, time-stamped still images with environmental variables for water chemistry and a standardized habitat classification. The technique is common among researchers, but a distributed network for this information is still in its infancy. One goal of this presentation is to make progress towards a more integrated network of these measured observations of habitat quality to better facilitate
Kusnierz, Paul C.; Holbrook, Christopher; Feldman, David L.
Managers of aquatic resources benefit from indices of habitat quality that are reproducible and easy to measure, demonstrate a link between habitat quality and biota health, and differ between human-impacted (i.e., managed) and reference (i.e., nonimpacted or minimally impacted) conditions. The instability index (ISI) is an easily measured index that describes the instability of a streambed by relating the tractive force of a stream at bankfull discharge to the median substrate size. Previous studies have linked ISI to biological condition but have been limited to comparisons of sites within a single stream or among a small number of streams. We tested ISI as an indicator of human impact to habitat and biota in mountain streams of the northwestern USA. Among 1428 sites in six northwestern states, ISI was correlated with other habitat measures (e.g., residual pool depth, percent fine sediment) and indices of biotic health (e.g., number of intolerant macroinvertebrate taxa, fine sediment biotic index) and differed between managed and reference sites across a range of stream types and ecoregions. While ISI could be useful in mountain streams throughout the world, this index may be of particular interest to aquatic resource managers in the northwestern USA where a large dataset, from which ISI can be calculated, exists.
Ulrich, Werner; Lens, Luc; Tobias, Joseph A; Habel, Jan C
Rapid fragmentation and degradation of large undisturbed habitats constitute major threats to biodiversity. Several studies have shown that populations in small and highly isolated habitat patches are prone to strong environmental and demographic stochasticity and increased risk of extinction. Based on community assembly theory, we predict recent rapid forest fragmentation to cause a decline in species and functional guild richness of forest birds combined with a high species turnover among habitat patches, and well defined dominance structures, if competition is the major driver of community assembly. To test these predictions, we analysed species co-occurrence, nestedness, and competitive strength to infer effects of interspecific competition, habitat structure, and species' traits on the assembly of bird species communities from 12 cloud forest fragments in southern Kenya. Our results do not point to a single ecological driver of variation in species composition. Interspecific competition does not appear to be a major driver of species segregation in small forest patches, while its relative importance appears to be higher in larger ones, which may be indicative for a generic shift from competition-dominated to colonisation-driven community structure with decreasing fragment size. Functional trait diversity was independent of fragment size after controlling for species richness. As fragmentation effects vary among feeding guilds and habitat generalists, in particular, tend to decline in low quality forest patches, we plead for taking species ecology fully into account when predicting tropical community responses to habitat change.
Full Text Available Rapid fragmentation and degradation of large undisturbed habitats constitute major threats to biodiversity. Several studies have shown that populations in small and highly isolated habitat patches are prone to strong environmental and demographic stochasticity and increased risk of extinction. Based on community assembly theory, we predict recent rapid forest fragmentation to cause a decline in species and functional guild richness of forest birds combined with a high species turnover among habitat patches, and well defined dominance structures, if competition is the major driver of community assembly. To test these predictions, we analysed species co-occurrence, nestedness, and competitive strength to infer effects of interspecific competition, habitat structure, and species' traits on the assembly of bird species communities from 12 cloud forest fragments in southern Kenya. Our results do not point to a single ecological driver of variation in species composition. Interspecific competition does not appear to be a major driver of species segregation in small forest patches, while its relative importance appears to be higher in larger ones, which may be indicative for a generic shift from competition-dominated to colonisation-driven community structure with decreasing fragment size. Functional trait diversity was independent of fragment size after controlling for species richness. As fragmentation effects vary among feeding guilds and habitat generalists, in particular, tend to decline in low quality forest patches, we plead for taking species ecology fully into account when predicting tropical community responses to habitat change.
Fendekova, M.; Fendek, M.; Macura, V.; Kralova, J.
Hydrological drought is being broadly studied within last decades in many countries. It is because of increasing frequency of drought periods occurrence also in mild climate conditions, leading to unexpected and undesired consequences for environment and various spheres of the state economy. Drought affects water availability for plants, animals and human society. Natural conditions of drought occurrence are often combined with human activities strengthening drought consequences. Lack of water in the nature, connected to meteorological and hydrological drought occurrence, increases at the same time needs for surface and groundwater in many types of human activities (agriculture, industrial production, electric power generation…). Drought can be identified within the low flow phase of the flow regime. Flow regime is considered for one of the most important conditions influencing quality of the river ecosystems. Occurrence of meteorological, surface and groundwater droughts was analyzed for the upper part of the Nitra River catchment in Slovakia. Drought occurrence was studied in two gauging profiles on the Nitra River - in Klacno and Nedozery, both representing the headwater profiles. The threshold level method was used for groundwater drought analysis. Base flow values were separated from the discharge hydrograms using the HydroOffice 2010 statistical program package. The influence of surface water drought on groundwater level was analyzed. Habitat suitability curves derived according to IFIM methodology were constructed for different fish species at Nedozery profile. The influence of different low flow values from 600 to 150 L/s on fish amount, size and species variability was studied. In the end, the minimum flow, bellow which unfavourable life conditions occur, was estimated. The results showed the necessity of taking into account the ecological parameters when estimating the ecological status of surface water bodies. Such an approach is fully compatible with
California Natural Resource Agency — Agriculture crops in the Imperial Valley of California provide valuable habitat for many resident and migratory birds and are a very important component of the...
Forested floristic quality index: An assessment tool for forested wetland habitats using the quality and quantity of woody vegetation at Coastwide Reference Monitoring System (CRMS) vegetation monitoring stations
Wood, William B.; Shaffer, Gary P.; Visser, Jenneke M.; Krauss, Ken W.; Piazza, Sarai C.; Sharp, Leigh Anne; Cretini, Kari F.
The U.S. Geological Survey, in cooperation with the Coastal Protection and Restoration Authority of Louisiana and the Coastal Wetlands Planning, Protection and Restoration Act, developed the Forested Floristic Quality Index (FFQI) for the Coastwide Reference Monitoring System (CRMS). The FFQI will help evaluate forested wetland sites on a continuum from severely degraded to healthy and will assist in defining areas where forested wetland restoration can be successful by projecting the trajectories of change. At each CRMS forested wetland site there are stations for quantifying the overstory, understory, and herbaceous vegetation layers. Rapidly responding overstory canopy cover and herbaceous layer composition are measured annually, while gradually changing overstory basal area and species composition are collected on a 3-year cycle.A CRMS analytical team has tailored these data into an index much like the Floristic Quality Index (FQI) currently used for herbaceous marsh and for the herbaceous layer of the swamp vegetation. The core of the FFQI uses basal area by species to assess the quality and quantity of the overstory at each of three stations within each CRMS forested wetland site. Trees that are considered by experts to be higher quality swamp species like Taxodium distichum (bald cypress) and Nyssa aquatica (water tupelo) are scored higher than tree species like Triadica sebifera (Chinese tallow) and Salix nigra (black willow) that are indicators of recent disturbance. This base FFQI is further enhanced by the percent canopy cover in the overstory and the presence of indicator species at the forest floor. This systemic approach attempts to differentiate between locations with similar basal areas that are on different ecosystem trajectories. Because of these varying states of habitat degradation, paired use of the FQI and the FFQI is useful to interpret the vegetative data in transitional locations. There is often an inverse relation between the health of the
Full Text Available For the study of the macroecology and conservation of Taiwan’s birds, there was an urgent need to develop distribution models of bird species whose distribution had never before been modeled. Therefore, we here model the distributions of 27 mostly rare and cryptic breeding bird species using a statistical approach which has been shown to be especially reliable for modeling species with a low sample size of presence localities, namely the maximum entropy (Maxent modeling technique. For this purpose, we began with a dedicated attempt to collate as much high-quality distributional data as possible, assembling databases from several scientific reports, contacting individual data recorders and searching publicly accessible database, the internet and the available literature. This effort resulted in 2022 grid cells of 1 × 1 km size being associated with a presence record for one of the 27 species. These records and 10 pre-selected environmental variables were then used to model each species’ probability distribution which we show here with all grid cells below the lowest presence threshold being converted to zeros. We then in detail discuss the interpretation and applicability of these distributions, whereby we pay close attention to habitat requirements, the intactness and fragmentation of their habitat, the general detectability of the species and data reliability. This study is another one in an ongoing series of studies which highlight the usefulness of using large electronic databases and modern analytical methods to help with the monitoring and assessment of Taiwan’s bird species.
The purpose of the investigations of birds is to establish a knowledge and data base that can make possible to enlighten the extent and character of potential influences the offshore wind farm might have on the birds. The potential influences the offshore wind farm might have on birds include: a) modification of the habitat, b) collision effects, and c) disturbances. (BA)
Blus, L.J.; Wiemeyer, Stanley N.; Kerwin, J.A.; Stendell, R.C.; Ohlendorf, H.M.; Stickel, L.F.
Pollution of estuaries affects bird populations indirectly through changes in habitat and food supply. The multi-factor pollution of Chesapeake Bay has resulted in diminution of submerged aquatic plants and consequent change in food habits of the canvasback duck. Although dredge-spoil operations can improve wildlife habitat, they often result in its demise. Pollution of estuaries also affects birds directly, through chemical toxication, which may result in outright mortality or in reproductive impairment. Lead from industrial sources and roadways enters the estuaries and is accumulated in tissues of birds. Lead pellets deposited in estuaries as a result of hunting are consumed by ducks with sufficient frequency .to result m large annual die-offs from lead poisoning. Fish in certain areas, usually near industrial sources, may contain levels of mercury high enough to be hazardous to birds that consume them. Other heavy metals are present in estuarine birds, but their significance is poorly known. Oil exerts lethal or sublethal effects on birds by oiling their feathers, oiling eggs and young by contaminated parents, and by ingestion of oil-contaminated food. Organochlorine chemicals, of both agricultural and industrial origin, travel through the food chains and reach harmful levels in susceptible species of birds in certain estuarine ecosystems. Both outright mortality and reproductive impairment have occurred.
Polycyclic aromatic hydrocarbons (PAH) are present throughout the global environment and are produced naturally and by activities of humans. Effects of PAH on birds have been determined by studies employing egg injection, egg immersion, egg shell application, single and multiple oral doses, subcutaneous injection, and chemical analysis of field-collected eggs and tissue. The four-to six-ring aromatic compounds are the most toxic to embryos, young birds, and adult birds. For embryos, effects include death, developmental abnormalities, and a variety of cellular and biochemical responses. For adult and young birds, effects include reduced egg production and hatching, increased clutch or brood abandonment, reduced growth, increased organweights, and a variety of biochemical responses. Trophic level accumulation is unlikely. Environmental exposure to PAH in areas of high human population or habitats affected by recent petroleum spills might be sufficient to adversely affect reproduction. Evidence of long-term effects of elevated concentrations of environmental PAH on bird populations is very limited and the mechanisms of effect are unclear.
Blank, Peter J; Sample, David W; Williams, Carol L; Turner, Monica G
Demand for bioenergy is increasing, but the ecological consequences of bioenergy crop production on working lands remain unresolved. Corn is currently a dominant bioenergy crop, but perennial grasslands could produce renewable bioenergy resources and enhance biodiversity. Grassland bird populations have declined in recent decades and may particularly benefit from perennial grasslands grown for bioenergy. We asked how breeding bird community assemblages, vegetation characteristics, and biomass yields varied among three types of potential bioenergy grassland fields (grass monocultures, grass-dominated fields, and forb-dominated fields), and assessed tradeoffs between grassland biomass production and bird habitat. We also compared the bird communities in grassland fields to nearby cornfields. Cornfields had few birds compared to perennial grassland fields. Ten bird Species of Greatest Conservation Need (SGCN) were observed in perennial grassland fields. Bird species richness and total bird density increased with forb cover and were greater in forb-dominated fields than grass monocultures. SGCN density declined with increasing vertical vegetation density, indicating that tall, dense grassland fields managed for maximum biomass yield would be of lesser value to imperiled grassland bird species. The proportion of grassland habitat within 1 km of study sites was positively associated with bird species richness and the density of total birds and SGCNs, suggesting that grassland bioenergy fields may be more beneficial for grassland birds if they are established near other grassland parcels. Predicted total bird density peaked below maximum biomass yields and predicted SGCN density was negatively related to biomass yields. Our results indicate that perennial grassland fields could produce bioenergy feedstocks while providing bird habitat. Bioenergy grasslands promote agricultural multifunctionality and conservation of biodiversity in working landscapes.
Peter J Blank
Full Text Available Demand for bioenergy is increasing, but the ecological consequences of bioenergy crop production on working lands remain unresolved. Corn is currently a dominant bioenergy crop, but perennial grasslands could produce renewable bioenergy resources and enhance biodiversity. Grassland bird populations have declined in recent decades and may particularly benefit from perennial grasslands grown for bioenergy. We asked how breeding bird community assemblages, vegetation characteristics, and biomass yields varied among three types of potential bioenergy grassland fields (grass monocultures, grass-dominated fields, and forb-dominated fields, and assessed tradeoffs between grassland biomass production and bird habitat. We also compared the bird communities in grassland fields to nearby cornfields. Cornfields had few birds compared to perennial grassland fields. Ten bird Species of Greatest Conservation Need (SGCN were observed in perennial grassland fields. Bird species richness and total bird density increased with forb cover and were greater in forb-dominated fields than grass monocultures. SGCN density declined with increasing vertical vegetation density, indicating that tall, dense grassland fields managed for maximum biomass yield would be of lesser value to imperiled grassland bird species. The proportion of grassland habitat within 1 km of study sites was positively associated with bird species richness and the density of total birds and SGCNs, suggesting that grassland bioenergy fields may be more beneficial for grassland birds if they are established near other grassland parcels. Predicted total bird density peaked below maximum biomass yields and predicted SGCN density was negatively related to biomass yields. Our results indicate that perennial grassland fields could produce bioenergy feedstocks while providing bird habitat. Bioenergy grasslands promote agricultural multifunctionality and conservation of biodiversity in working landscapes.
Faaborg, John; Holmes, Richard T.; Anders, A.D.; Bildstein, K.L.; Dugger, K.M.; Gauthreaux, S.A.; Heglund, P.; Hobson, K.A.; Jahn, A.E.; Johnson, D.H.; Latta, S.C.; Levey, D.J.; Marra, P.P.; Merkord, C.L.; Nol, E.; Rothstein, S.I.; Sherry, T.W.; Scott, Sillett T.; Thompson, F. R.; Warnock, N.
Migratory bird needs must be met during four phases of the year: breeding season, fall migration, wintering, and spring migration; thus, management may be needed during all four phases. The bulk of research and management has focused on the breeding season, although several issues remain unsettled, including the spatial extent of habitat influences on fitness and the importance of habitat on the breeding grounds used after breeding. Although detailed investigations have shed light on the ecology and population dynamics of a few avian species, knowledge is sketchy for most species. Replication of comprehensive studies is needed for multiple species across a range of areas. Information deficiencies are even greater during the wintering season, when birds require sites that provide security and food resources needed for survival and developing nutrient reserves for spring migration and, possibly, reproduction. Research is needed on many species simply to identify geographic distributions, wintering sites, habitat use, and basic ecology. Studies are complicated, however, by the mobility of birds and by sexual segregation during winter. Stable-isotope methodology has offered an opportunity to identify linkages between breeding and wintering sites, which facilitates understanding the complete annual cycle of birds. The twice-annual migrations are the poorest-understood events in a bird's life. Migration has always been a risky undertaking, with such anthropogenic features as tall buildings, towers, and wind generators adding to the risk, Species such as woodland specialists migrating through eastern North America have numerous options for pausing during migration to replenish nutrients, but some species depend on limited stopover locations. Research needs for migration include identifying pathways and timetables of migration, quality and distribution of habitats, threats posed by towers and other tall structures, and any bottlenecks for migration. Issues such as human
Faaborg, John; Holmes, Richard T; Anders, Angela D; Bildstein, Keith L; Dugger, Katie M; Gauthreaux, Sidney A; Heglund, Patricia; Hobson, Keith A; Jahn, Alex E; Johnson, Douglas H; Latta, Steven C; Levey, Douglas J; Marra, Peter P; Merkord, Christopher L; Nol, Erica; Rothstein, Stephen I; Sherry, Thomas W; Sillett, T Scott; Thompson, Frank R; Warnock, Nils
Migratory bird needs must be met during four phases of the year: breeding season, fall migration, wintering, and spring migration; thus, management may be needed during all four phases. The bulk of research and management has focused on the breeding season, although several issues remain unsettled, including the spatial extent of habitat influences on fitness and the importance of habitat on the breeding grounds used after breeding. Although detailed investigations have shed light on the ecology and population dynamics of a few avian species, knowledge is sketchy for most species. Replication of comprehensive studies is needed for multiple species across a range of areas, Information deficiencies are even greater during the wintering season, when birds require sites that provide security and food resources needed for survival and developing nutrient reserves for spring migration and, possibly, reproduction. Research is needed on many species simply to identify geographic distributions, wintering sites, habitat use, and basic ecology. Studies are complicated, however, by the mobility of birds and by sexual segregation during winter. Stable-isotope methodology has offered an opportunity to identify linkages between breeding and wintering sites, which facilitates understanding the complete annual cycle of birds. The twice-annual migrations are the poorest-understood events in a bird's life. Migration has always been a risky undertaking, with such anthropogenic features as tall buildings, towers, and wind generators adding to the risk. Species such as woodland specialists migrating through eastern North America have numerous options for pausing during migration to replenish nutrients, but some species depend on limited stopover locations. Research needs for migration include identifying pathways and timetables of migration, quality and distribution of habitats, threats posed by towers and other tall structures, and any bottlenecks for migration. Issues such as human
... include the Service, Reclamation, National Marine Fisheries Service (NMFS), DFG, State of California.... Managed wetlands provide valuable habitat for a variety of non- waterfowl birds, mammals, reptiles, and...
Douglas H. Johnson
Point counts of birds are made for many reasons, including estimating local densities, determining population trends, assessing habitat preferences, and exploiting the activities of recreational birdwatchers. Problems arise unless there is a clear understanding of what point counts mean in terms of actual populations of birds. Criteria for conducting point counts...
Considering the frequent nature of fires and resultant drastic change in habitat following fire, research on the effects of fire on birds in the grasslands of South Africa is surprisingly scarce. For at least five months after burns we followed the changes in bird species composition, species richness and densities of two controlled ...
Wayne J. Arendt; John Faaborg; Miguel Canals; Jerry Bauer
This research note compiles 43 years of research and monitoring data to produce the first comprehensive checklist of the dry forest avian community found within the GuÃ¡nica Biosphere Reserve. We provide an overview of the reserve along with sighting locales, a list of 185 birds with their resident status and abundance, and a list of the available bird habitats....
Reader, S.M.; Morand-Ferron, J.; Côté, I.; Lefebvre, L.
Field reports of new or unusual feeding behaviors may provide a valuable measure of behavioral flexibility in both birds and primates (Lefebvre et al. 1997, Reader and Laland 2002). In birds, many of these new behaviors are observed on islands and in urbanized habitats. We report here several
Zedler, Joy B.; Kus, Barbara E.
The value of natural wetlands to bird populations is well-recognized, and declines in waterfowl numbers are often attributed to losses in wetland area. if the destruction of wetland reduces bird populations, then adding wetland habitats might improve the situation. This idea was tested in Tijuana Estuary in the late 1980s.
Breaching events were associated with a change in feeding groups from waders to pursuit feeders, and a decrease in total bird numbers, most likely due to loss of potential littoral zone foraging habitat for waders resulting from reduced water levels. The highest bird numbers were recorded in winter reflecting the migration of ...
Brumm, H.; Naguib, M.
Any signal must get from a sender to a receiver if information is to be transmitted. In the case of bird song, the acoustic properties of the habitat may hinder this being achieved. However, birds as senders and receivers have evolved numerous adaptations to overcome the problem of getting the
Jun 5, 2012 ... These include staff training and retraining, developing good data bank based on .... wildlife is very important in bird control. Successful habitat ... Designated staff patrols the airside areas using chemical repellants, propane cannons, distress call. Birds/Wildlife Strikes Control for Safer Air .................Usman et ...
Tellería, J. L.
Full Text Available The Iberian dehesas are a man-made habitat composed of scattered oaks (Quercus spp. and extensive grass cover occupying three million ha in south-western Iberia. This paper compares the structure of the passerine bird communities in this region with other bird assemblages of Iberian woodlands. Although forest bird numbers in the southern half of the Iberian peninsula are decreasing, the dehesas show the highest richness in breeding birds, seemingly as the result of the increased presence of border and open-habitat birds. A low intra-habitat turnover of species was observed in the dehesas, with birds recorded at a sampling point accounting for a high percentage of the total richness of the community. This can be related to the low spatial patchiness of this habitat. In winter, the dehesas continued to maintain many bird species, but showed bird densities similar to other woodlands. This pattern, as well as the scarcity of some common forest passerines during the breeding period, could result from the removal of the shrub layer typical of Mediterranean woodlands.
The behaviour of birds in response to time of day was affected by temperature, as there was no difference between GUDs in open and covered habitats in the mornings at lower temperatures, but lower GUDs were recorded in cover (at higher temperatures) in the afternoon when birds may — due to thermoregulatory costs ...
Meredith J. Morris; Vincent H. Reld; Richard E. Pillmore; Mary C. Hammer
Seasonal occurrence, relative abundance, and habitat preference are listed for 90 bird and 41 mammal species that can be found at Manitou Experimental Forest. An annotated list is given also for an additional 70 casual or accidental bird species. Manitou Experimental Forest is located near Colorado Springs in the montane zone of the Colorado Front Range.
No one bird survey technique is perfect. Either the assumptions made by a technique are difficult to meet in the field, or there are biases due to the observer, the birds themselves, the landscape, or the nature of the habitat. These include survey effort, time of day, time of year, edge effects, vegetation structure, and variation ...
Kenneth V. Rosenberg; Jeffrey V. Wells
As part of the Partners in Flight (PIF) bird-conservation planning process, we assessed breeding land bird species according to seven categories of population vulnerability to derive a priority species pool in each of 12 physiographic areas that overlap the northeastern U.S. We then grouped species into the following habitat-species suites: (1) boreal-mountaintop...
Brown, Dexter W.; Turco, Michael J.
The U.S. Geological Survey (USGS), in cooperation with the Houston-Galveston Area Council and the Texas Commission on Environmental Quality, collected water-quality, stream-habitat, and biological data from two sites at West Fork Double Bayou, two sites at Cotton Bayou, and one site at Hackberry Gully in Chambers County, Texas, during July 2006-August 2007. Water-quality data-collection surveys consisted of synoptic 24-hour continuous measurements of water temperature, pH, specific conductance, and dissolved oxygen at the five sites and periodically collected samples at four sites analyzed for several properties and constituents of interest. Stream-habitat data were collected at each of four sites three times during the study. At each site, a representative stream reach was selected and within this reach, five evenly spaced stream transects were determined. At each transect, stream attributes (wetted channel width, water depth, bottom material, instream cover) and riparian attributes (bank slope and erosion potential, width of natural vegetation, type of vegetation, percentage tree canopy) were measured. Benthic macroinvertebrate and fish data were collected from the same reaches identified for habitat evaluation. A total of 2,572 macroinvertebrate individuals were identified from the four reaches; insect taxa were more abundant than non-insect taxa at all reaches. A total of 1,082 fish, representing 30 species and 13 families, were collected across all reaches. Stream-habitat and aquatic biota (benthic macroinvertebrates and fish) were assessed at the four sites to evaluate aquatic life use. Habitat quality index scores generally indicated 'intermediate' aquatic life use at most reaches. Benthic macroinvertebrate metrics scores indicated generally 'intermediate' aquatic life use for the West Fork Double Bayou reaches and generally 'high' aquatic life use for the Cotton Bayou and Hackberry Gully reaches. Index of biotic integrity scores for fish indicated generally
Schuler, C.A.; Rickard, W.H.; Sargeant, G.A.
This report provides information on te seasonal use of shrubsteppe vegetation by bird species at the RRL. Bird abundance and distribution were studied at the RRL to ensure that the DOE monitored migratory bird species pursuant to the Migratory Bird Treaty Act and to assess potential impacts of site characterization activities on bird populations. Birds were counted on two transects that together sampled an areas of 1.39 km/sup 2/. The relative abundance of birds, species richness, seasonal distribution, and the association of breeding shrubsteppe birds with major vegetation types were determined from Janurary through December 1987. Only 38 species were counted during 82 surveys. Total bird density during the nesting season (March-June) was 42.96 birdskm/sup 2/ and the density for the entire year was 26.74 birdskm/sup 2/. The characteristic nesting birds in shrubsteppe habitats were western meadowlark, sage sparrow, burrowing owl, mourning dove, horned lark, long-billed curlew, lark sparrow, and loggerhead shrike. Western meadowlark and sage sparrows were the most abundant breeding birds with an average density of 11.25 and 7.76 birdskm/sup 2/, respectively. Seasonal distribution of birds varied with species, but most species were present from March to September. Distribution and abunandance of nesting birds were correlated with habitat type. About 63% of the habitat surveyed was sagebrush, 26% was cheatgrass, and 11% was spiny hopsage. Sagebrush habitat supproted a greeater total bird density than cheatgrass or hopsage habitats. Sage sparrows were closely associated with sagebrush habitats, while western meadowlarks showed no strong habitat affinities. 22 refs., 9 figs., 6 tabs
... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Certificate for pet birds, commercial birds, zoological birds, and research birds. 93.104 Section 93.104 Animals and Animal Products ANIMAL... (INCLUDING POULTRY) AND ANIMAL PRODUCTS IMPORTATION OF CERTAIN ANIMALS, BIRDS, FISH, AND POULTRY, AND CERTAIN...
Total blood haemoglobin concentration is increasingly being used to assess physiological condition in wild birds, although it has not been explicitly recognized how reliably this parameter reflects different components of individual quality. Thus, I reviewed over 120 published studies linking variation in haemoglobin concentrations to different measures of condition and other phenotypic or ecological traits. In most of the studied avian species, haemoglobin concentrations were positively correlated with other commonly used indices of condition, such as body mass and fat loads, as well as with quality of the diet. Also, chick haemoglobin concentrations reliably reflected the intensity of nest infestation by parasitic arthropods, and haemoglobin was suggested to reflect parasitism by haematophagous ectoparasites much more precisely than haematocrit. There was also some evidence for the negative effect of helminths on haemoglobin levels in adult birds. Finally, haemoglobin concentrations were found to correlate with such fitness-related traits as timing of arrival at breeding grounds, timing of breeding, egg size, developmental stability and habitat quality, although these relationships were not always consistent between species. In consequence, I recommend the total blood haemoglobin concentration as a relatively robust indicator of physiological condition in birds, although this parameter is also strongly affected by age, season and the process of moult. Thus, researchers are advised to control fully for these confounding effects while using haemoglobin concentrations as a proxy of physiological condition in both experimental and field studies on birds.
James G. Dickson; Frank R. Thompson; Richard N. Conner; Kathleen E. Franzreb
Avian communities that are associated with forest habitat attributes are affected by silvicultural and other stand influences. Some species have specific habitat requirements, whereas others occupy a broad range of vegetative conditions. In general, bird species richness and density are positively related to stand foliage volume and diversity. Bird density and...
James T. Anderson; Karen A. Riesz
Wildlife habitats connected with forested islands and their back channels (areas where commercial traffic is prohibited) on the Ohio River are valuable to diverse species. However, quantitative data on the importance of these areas to cavity-nesting birds are lacking. We compared cavity-nesting bird use and habitat between back and navigational channel sides of islands...
Alexandre Marco da Silva
Full Text Available Soil loss expectation and possible relationships among soil erosion, riparian vegetation and water quality were studied in the São José dos Dourados River basin, State of São Paulo, Brazil. Through Geographic Information System (GIS resources and technology, Soil Loss Expectation (SLE data obtained using the Universal Soil Loss Equation (USLE model were analyzed. For the whole catchment area and for the 30 m buffer strips of the streams of 22 randomly selected catchments, the predominant land use and habitat quality were studied. Owing mainly to the high soil erodibility, the river basin is highly susceptible to erosive processes. Habitat quality analyses revealed that the superficial water from the catchments is not chemically impacted but suffers physical damage. A high chemical purity is observed since there are no urban areas along the catchments. The water is physically poor because of high rates of sediment delivery and the almost nonexistence of riparian vegetation.Expectativa de perda de solo e possíveis relações entre erosão, vegetação ripária e qualidade da água foram estudados na bacia do rio São José dos Dourados (SP. Através de recursos de geoprocessamento e da Equação Universal de Perda de Solos, os dados sobre expectativa de perda de solo foram levantados. Para a área de drenagem total e a faixa tampão dos corpos d'água de 22 sub-bacias aleatoriamente selecionadas, analisou-se a cobertura do solo predominante e qualidade do habitat. Devido principalmente à alta erodibilidade do solo, a área estudada é altamente suscetível ao processo erosivo. As análises de qualidade da água revelaram que as águas superficiais das sub-bacias estão quimicamente não impactadas, mas fisicamente degradadas. A alta pureza química deve-se, possivelmente, à ausência de áreas urbanizadas ao longo das sub-bacias e as alterações nas características físicas são, possivelmente, decorrentes das altas taxas de transfer
Full Text Available Tourist disturbance in semi–arid springs was analysed; birds and fish were selected as bioindicators. Media Luna spring is the biggest and most spatially complex system in the region, with the highest biodiversity levels and tourist use. Areas with the highest bird species richness and abundances showed highest structural heterogeneity and least direct human impact. No differences in species richness of fish were observed between sectors and the most abundant species were found in the sectors least perturbed by human activity. Factors that explained the bird distribution were the species´ tolerance to the effects of direct tourism (noise and direct presence of people and habitat quality, mainly riparian vegetation. Aquatic vegetation condition was very important for fish. Six bird species and two fish species were relevant as indicators of the habitat quality related to human impact. Anthropic disturbance such as tree plantation favoured some bird species, whereas aquatic vegetation removal was favourable for some fish species, such as the endemic Cichlasoma bartoni, however, both types of disturbance were unfavourable for other species; riparian vegetation removal was negative for both groups. Controlled tourism promotes good conditions for C. bartoni establishment. Efficient conservation measures such as limiting touristic distribution are necessary for all species, especially for the fish community, in order to conserve biodiversity in general.
Viana, D.S.; Gangoso, L.; Bouten, W.; Figuerola, J.
Long-distance dispersal (LDD) promotes the colonization of isolated and remote habitats, and thus it has been proposed as a mechanism for explaining the distributions of many species. Birds are key LDD vectors for many sessile organisms such as plants, yet LDD beyond local and regional scales has
R. Todd Engstrom; David J. Brownlie
Prescribed fire is being used extensively for habitat management of non-game birds, although the area burned today is small relative to the amount of land that burned historically. Results of a non-scientific questionnaire of public and private land managers in the eastern U.S. revealed prescribed fire is being used to provide winter, breeding season, and migration...
Yeung, Cynthia; Yang, Mei-Sun
The distribution and body condition of juvenile northern rock sole (NRS), Lepidopsetta polyxystra, and yellowfin sole (YFS), Limanda aspera, were studied in relation to prey availability across the coastal shelf at the Alaska Peninsula boundary of the eastern Bering Sea (EBS) to assess spatial variability in habitat quality. Juveniles of ≤ 20 cm and adults of ≥ 30 cm total length were collected from bottom trawl catch samples at stations located 10 to 120 km from the Alaska Peninsula coast, and in bottom depths of 28 to 85 m. Stomach contents and stable isotopes of carbon and nitrogen from muscle tissue were analyzed to describe diet composition. The quantity and quality of prey did not significantly affect the distribution of juvenile NRS and YFS. Spatial mismatch between the diet composition and the infauna prey assemblage suggested that prey availability was not limiting across the area, allowing fish to select for prey, presumably to maximize net energy gain. The body condition of juvenile NRS was higher in the eastern section of the area (Bristol Bay) - where they shared spatial and dietary niches with juvenile YFS, than in the west section (Unimak Island) where juvenile YFS were largely absent. A difference in body condition suggests that habitat quality may be higher in Bristol Bay. For NRS, stomach contents and stable isotopes in muscle tissue indicated an ontogenetic diet shift from amphipods to polychaetes from juvenile to adult stages. In contrast, for YFS, amphipods seemed to remain the primary prey and polychaetes the least important prey from juvenile to adult stage. Given that the high prey availability found in this south coastal area of EBS extends to areas across the EBS shelf, favorable habitat for juvenile flatfishes should be extensive. However, much of this potential juvenile habitat is underutilized by NRS, which were mainly limited to Bristol Bay and the Alaska Peninsula, whereas YFS did extend north over 500 km from Bristol Bay along
Árnason, Sighvatur S; Elbrønd (Bibs), Vibeke Sødring; Laverty, Gary
Dietary salt intake in domestic fowl affects epithelial transport and morphology of the lower intestine (colon and coprodeum). This study investigated lower intestinal morphology and transport activity in two wild bird species with natural diets containing either low or high salt. Tissues from ro...
Paul B. Hamel; Winston P. Smith; Daniel J. Twedt; James R. Woehr; Eddie Morris; Robert B. Hamilton; Robert J. Cooper
Current widespread concern for the status of neotropical migratory birds has sparked interest in techniques for inventorying and monitoring populations of these and other birds in southeastern forest habitats. The present guide gives detailed instructions for conducting point counts of birds. It further presents a detailed methodology for the design and conduct of...
Michael L. Morrison; Donald L. Dahlsten; Susan M. Tait; Robert C. Heald; Kathleen A. Milne; David L. Rowney
Seasonal differences in use of food and habitat have been shown for numerous bird species. Especially during winter, when insect food is often at its lowest availability, birds may be unable to secure enough food for survival. In earlier work in the mixed-conifer zone of the western Sierra Nevada (Blodgett Forest, El Dorado County), observers found that many birds...
Vashti (Tice) Supplee; Jennie MacFarland
The Important Bird Areas (IBA) Program is a worldwide program through BirdLife International that identifies sites considered to provide important habitats for avian species. Criteria for designation are species abundance, diversity, and range restriction. As the United States Partner of BirdLife International, the National Audubon Society administers the IBA Program...
M. F. Burger; D. J. Adams; T. Post; L. Sommers; B. Swift
The New York State Bird Conservation Area (BCA) Program, modeled after the National Audubon Society?s Important Bird Areas Program, is based on legislation signed by Governor Pataki in 1997. New York is the first state in the nation to enact such a program. The BCA Program seeks to provide a comprehensive, ecosystem approach to conserving birds and their habitats on...
Yvette K. Ortega; David E. Capen
Numerous studies have documented that forest edges affect habitat use and reproductive success of forest birds, but few studies have considered edges created by narrow breaks in the forest canopy. We compared predation rates on artificial nests placed within forest habitat along edge transects, 10 m from unpaved roads, and along interior transects, 300 m from forest-...
Fontúrbel, Francisco E.; Jiménez, Jaime E.
Birds are the most diverse vertebrate group in Chile, characterized by low species turnover at the country-size scale (high alpha but low beta diversities), resembling an island biota. We tested whether this low differentiation is valid at a local scale, among six forest habitat types. We detected 25 bird species; avifauna composition was significantly different among habitat types, with five species accounting for 60 % of the dissimilarity. We found a higher level of bird assemblage differentiation across habitats at the local scale than has been found at the country-size scale. Such differentiation might be attributed to structural differences among habitats.
Maria Angela Echeverry-Galvis
Full Text Available A temporal separation of energetically costly life history events like reproduction and maintenance of the integumentary system is thought to be promoted by selection to avoid trade-offs and maximize fitness. It has therefore remained somewhat of a paradox that certain vertebrate species can undergo both events simultaneously. Identifying potential costs of overlapping two demanding life history stages will further our understanding of the selection pressures that shape the temporal regulation of life history events in vertebrates. We studied free-living tropical Slaty brush-finches (Atlapetes schistaceus, in which individuals spontaneously overlap reproduction and moult or undergo both events in separation. To assess possible costs of such an overlap we quantified feather quality and flight performance of individuals in different states. We determined individual's life history state by measuring gonad size and scoring moult stage, and collected a newly grown 7(th primary wing feather for later analysis of feather quality. Finally, we quantified flight performance for each individual in the wild. Overlapping individuals produced lighter and shorter wing feathers than individuals just moulting, with females decreasing feather quality more strongly during the overlap than males. Moreover, overlapping individuals had a reduced flight speed during escape flights, while their foraging flight speed was unaffected. Despite overlappers being larger and having a smaller wing area, their lower body mass resulted in a similar wing load as in breeders or moulters. Individuals measured repeatedly in different states also showed significant decreases in feather quality and escape flight speed during the overlap. Reduced escape flight speed may represent a major consequence of the overlap by increasing predation risk. Our data document costs to undergoing two life history stages simultaneously, which likely arise from energetic trade-offs. Impairments in
Stofleth, J.; Andrews, E. S.; White, J. Q.
The floodplains of the Apalachicola River, Florida include an intricate network of sloughs, lakes and wetlands. These floodplain water bodies provide essential spawning and nursery areas for a diverse array of aquatic organisms. The frequency and duration of Apalachicola River flows sufficient to hydraulically connect and thereby activate these floodplain features has decreased over time due to upstream dams, diversions, and modification to the channel geometry (incision and widening). The main objective of this study is to characterize the relationship between a key water quality parameter, dissolved oxygen (DO), to the hydraulic connectivity of the ecologically-important large slough systems within the Apalachicola River floodplain over a range of flow conditions. When DO concentrations drop, the quality of habitat for fish, invertebrates and other aquatic organisms are impacted. Hydraulic connection between the river and the floodplain sloughs contributes markedly to DO levels in the sloughs. To characterize the relationship between hydraulic connectivity and water quality, water level, DO, and temperature data were continuously monitored within four (4) major floodplain sloughs, one (1) oxbow lake, and mainstem (control) from August 2009 to January 2011. A comparison was made between statistically representative DO concentrations (daily mean, diurnal range, daily minimum and maximum) for each site and in the river. River discharge was estimated at each site from nearby gages. By examining distinct changes in DO signatures with increasing flow, it was possible to determine the approximate flow at which the sloughs and oxbow lakes begin to become activated or hydraulically connected (flowing condition) to the mainstem of the Apalachicola River, and at what flow rates these floodplain wetlands become fully connected. Based on this data, we drew conclusions about the availability of suitable habitat for native fish species in these slough systems across a range of
Joyce, Hannah; Reaney, Sim
Catchment systems provide multiple benefits for society, including: land for agriculture, climate regulation and recreational space. Yet, these systems also have undesirable externalities, such as flooding, and the benefits they create can be compromised through societal use. For example, agriculture, forestry and urban land use practices can increase the export of fine sediment and faecal indicator organisms (FIO) delivered to river systems. These diffuse landscape pressures are coupled with pressures on the in stream temperature environment from projected climate change. Such pressures can have detrimental impacts on water quality and ecological habitat and consequently the benefits they provide for society. These diffuse and in-stream pressures can be reduced through actions at the landscape scale but are commonly tackled individually. Any intervention may have benefits for other pressures and hence the challenge is to consider all of the different pressures simultaneously to find solutions with high levels of cross-pressure benefits. This research presents (1) a simple but spatially distributed model to predict the pattern of multiple pressures at the landscape scale, and (2) a method for spatially targeting the optimum location for riparian woodland planting as mitigation action against these pressures. The model follows a minimal information requirement approach along the lines of SCIMAP (www.scimap.org.uk). This approach defines the critical source areas of fine sediment diffuse pollution, rapid overland flow and FIOs, based on the analysis of the pattern of the pressure in the landscape and the connectivity from source areas to rivers. River temperature was modeled using a simple energy balance equation; focusing on temperature of inflowing and outflowing water across a catchment. The model has been calibrated using a long term observed temperature record. The modelling outcomes enabled the identification of the severity of each pressure in relative rather
Reif, Andrew G.
Biological, chemical, and habitat data have been collected from a network of sites in Chester County, Pa., from 1970 to 2003 to assess stream quality. Forty sites in 6 major stream basins were sampled between 1998 and 2000. Biological data were used to determine levels of impairment in the benthic-macroinvertebrate community in Chester County streams and relate the impairment, in conjunction with chemical and habitat data, to overall stream quality. Biological data consisted of benthic-macroinvertebrate samples that were collected annually in the fall. Water-chemistry samples were collected and instream habitat was assessed in support of the biological sampling.Most sites in the network were designated as nonimpacted or slightly impacted by human activities or extreme climatic conditions on the basis of biological-metric analysis of benthic-macroinvertebrate data. Impacted sites were affected by factors, such as nutrient enrichment, erosion and sedimentation, point discharges, and droughts and floods. Streams in the Schuylkill River, Delaware River, and East Branch Brandywine Creek Basins in Chester County generally had low nutrient concentrations, except in areas affected by wastewater-treatment discharges, and stream habitat that was affected by erosion. Streams in the West Branch Brandywine, Christina, Big Elk, and Octoraro Creek Basins in Chester County generally had elevated nutrient concentrations and streambottom habitat that was affected by sediment deposition.Macroinvertebrate communities identified in samples from French Creek, Pigeon Creek (Schuylkill River Basin), and East Branch Brandywine Creek at Glenmoore consistently indicate good stream conditions and were the best conditions measured in the network. Macroinvertebrate communities identified in samples from Trout Creek (site 61), West Branch Red Clay Creek (site 55) (Christina River Basin), and Valley Creek near Atglen (site 34) (Octoraro Creek Basin) indicated fair to poor stream conditions and
Hadinoto; Suhesti, Eni
Bird is one component of the ecosystem which has an important role in supporting the occurrence of an organism's life cycle. Therefore, the presence of birds in an area is important, because it can affect the existence and distribution of plant species. The purpose of this study is to calculate the diversity of bird species and identify the source of bird feed in the compound. This study was conducted by field surveys in the residential complex. In addition to the birds as a research object vegetation as habitat / foraging birds were also observed. Data were analyzed by using the bird diversity index, richenes index, bundance index, dominance analysis, analysis of bird distribution and analysis of the level of meeting types, while vegetation will be analyzed based on the type and part of what is eaten by birds. In Pandau Jaya housing complex, found as many as 12 species of birds which consists of seven families. Bird species often present is Cucak Kutilang (Pycnonotus aurigaster) of 20 individuals, Bondol Peking (Lonchura punctulata) 14 individuals and Perkutut Jawa (Geopelia striata) 10 individuals. Bird species diversity (H ‘) in Pandau Jaya housing complex is still relatively moderate with a value of 2.27, while the Evenness Index (E) of 0.91 and Richenes Index (R) of 2.45. Types of vegetation as a food source, among others: mango, guava, cherry, jackfruit, ketapang, coconut, areca, palm, banana, papaya, flowers and grasses.
Williams, B.K.; Nichols, J.D.
Mathematical modeling of migratory bird populations is reviewed in the context of migratory bird management. We focus on dynamic models of waterfowl, since most management-oriented migratory bird models concern waterfowl species. We describe the management context for these modeling efforts, with a focus on large-scale operational data collection programs and on processes by which waterfowl harvest is regulated and waterfowl habitats are protected and managed. Through their impacts on key population parameters such as recruitment and survival rate, these activities can influence population dynamics, thereby providing managers some measure of control over the status of populations. Recent applications of the modeling of waterfowl are described in terms of objectives, mathematical structures, and contributions to management. Finally, we discuss research needs and data limitations in migratory bird modeling, and offer suggestions to increase the value to managers of future modeling efforts.
J.D. Wolfe; C.J. Ralph; P. Elizondo
The effects of habitat alteration and climatic instability have resulted in the loss of bird populations throughout the globe. Tropical birds in particular may be sensitive to climate and habitat change because of their niche specialization, often sedentary nature, and unique life-cycle phenologies. Despite the potential influence of habitat and climatic interactions...
Askia K. Wittern
Full Text Available Natal dispersal is an important component in bird population dynamics and can influence the persistence of local and metapopulations. We examined natal dispersal in the North Island robin (Petroica longipes, a sedentary bird species distributed in a fragmented forest habitat on Tiritiri Matangi Island, New Zealand. Earlier studies have shown that the only dispersal phase in this species takes place when juveniles leave their natal patch, and that juveniles who fail to find suitable habitat do not survive their first winter. These findings suggest that natal dispersal behavior in this species is important for population viability. We found that juveniles were highly affected by the fragmentation of the forest habitat, with patch occupancy being positively correlated with degree of connectivity of the landscape. Most juvenile movements (52.1% were observed between patches that were separated by less than 20 m. Juvenile North Island robins were found in all forest habitat types, including young and open stands. This suggests that the juveniles are not dependent on old forest stands during their dispersal phase. Based on these findings, we suggest that management of this regionally-threatened species should focus not only on maintaining populations in occupied patches and increasing the habitat quality of these patches, but also on protecting existing forest patches acting as corridors and creating new forest habitat among patches. This would greatly increase the viability of the species' metapopulations by increasing dispersal success between both unoccupied patches and subpopulations. Additionally, increased connectivity between forest patches could also be expected to increase the probability of successful dispersal of other threatened native species, many of which are also sensitive to the high degree of fragmentation of their habitats.
Banko, Paul C.; Hess, Steven C.; Scowcroft, Paul G.; Farmer, Chris; Jacobi, James D.; Stephens, Robert M.; Camp, Richard J.; Leonard, David L.; Brinck, Kevin W.; Juvik, J.O.; Juvik, S. P.
Under the multiple-use paradigm, conflicts may arise when protection of an endangered species must compete with other management objectives. To resolve such a conflict in the Critical Habitat of the endangered Hawaiian honeycreeper, palila (Loxioides bailleui), federal courts ordered the eradication of introduced ungulates responsible for damaging the māmane (Sophora chrysophylla) forest on which palila depend. During 1980–2011, a total of 18,130 sheep (Ovis aries and O. gmelini musimon) and 310 goats (Capra hircus) were removed from Palila Critical Habitat (PCH) primarily by public hunters (54%) and secondarily by aerial shooting. Nevertheless, our analysis indicates that ungulates have increased over time. Palila numbers have declined sharply since 2003 due to long-term habitat degradation by ungulates and drought. Although culling ungulate populations has allowed some habitat improvement, their complete removal is necessary for palila to recover, especially given the potential for continued drought. Introduced predators are being controlled to reduce palila mortality, māmane and other native trees are being planted to restore some areas, and fencing is being constructed to prevent ungulate immigration. Funds are recently available for more effective eradication efforts, which are urgently needed to eliminate browsing damage in PCH and protect the palila from extinction.
Paul C. Banko; Steven C. Hess; Paul G. Scowcroft; Chris Farmer; James D. Jacobi; Robert M. Stephens; Richard J. Camp; David L. Leonard; Kevin W. Brinck; J. O. Juvik; S. P. Juvik
Under the multiple-use paradigm, conflicts may arise when protection of an endangered species must compete with other management objectives. To resolve such a conflict in the Critical Habitat of the endangered Hawaiian honeycreeper, palila (Loxioides bailleui), federal courts ordered the eradication of introduced ungulates responsible for damaging...
California Department of Resources — This layer depicts areas designated for Chinook Critical Habitat as well as habitat type and quality in the California Coastal Evolutionary Significant Unit (ESU -...
Viana, Duarte S; Gangoso, Laura; Bouten, Willem; Figuerola, Jordi
Long-distance dispersal (LDD) promotes the colonization of isolated and remote habitats, and thus it has been proposed as a mechanism for explaining the distributions of many species. Birds are key LDD vectors for many sessile organisms such as plants, yet LDD beyond local and regional scales has never been directly observed nor quantified. By sampling birds caught while in migratory flight by GPS-tracked wild falcons, we show that migratory birds transport seeds over hundreds of kilometres and mediate dispersal from mainland to oceanic islands. Up to 1.2% of birds that reached a small island of the Canary Archipelago (Alegranza) during their migration from Europe to Sub-Saharan Africa carried seeds in their guts. The billions of birds making seasonal migrations each year may then transport millions of seeds. None of the plant species transported by the birds occurs in Alegranza and most do not occur on nearby Canary Islands, providing a direct example of the importance of environmental filters in hampering successful colonization by immigrant species. The constant propagule pressure generated by these LDD events might, nevertheless, explain the colonization of some islands. Hence, migratory birds can mediate rapid range expansion or shifts of many plant taxa and determine their distribution. © 2016 The Author(s).
Boulanger, Yan; Cyr, Dominic; Taylor, Anthony R.; Price, David T.; St-Laurent, Martin-Hugues
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
Silva, João P; Correia, Ricardo; Alonso, Hany; Martins, Ricardo C; D'Amico, Marcello; Delgado, Ana; Sampaio, Hugo; Godinho, Carlos; Moreira, Francisco
Few studies have assessed the effectiveness of the Protected Area networks on the conservation status of target species. Here, we assess the effectiveness of the Portuguese Natura 2000 (the European Union network of protected areas) in maintaining a species included in the Annex I of the Bird Directive, namely the population of a priority farmland bird, the little bustard Tetrax tetrax . We measured the effectiveness of the Natura 2000 by comparing population trends across time (2003-2006 and 2016) in 51 areas, 21 of which within 12 Special Protection Areas (SPA) that were mostly designated for farmland bird conservation and another 30 areas without EU protection. Overall, the national population is estimated to have declined 49% over the last 10-14 years. This loss was found to be proportionally larger outside SPA (64% decline) compared to losses within SPA (25% decline). However, the absolute male density decline was significantly larger within SPA . In spite of holding higher population densities and having prevented habitat loss, we conclude that Natura 2000 was not effective in buffering against the overall bustard population decline. Results show that the mere designation of SPA in farmland is not enough to secure species populations and has to be combined with agricultural policies and investment to maintain not only habitat availability but also habitat quality.
João P. Silva
Full Text Available Background Few studies have assessed the effectiveness of the Protected Area networks on the conservation status of target species. Here, we assess the effectiveness of the Portuguese Natura 2000 (the European Union network of protected areas in maintaining a species included in the Annex I of the Bird Directive, namely the population of a priority farmland bird, the little bustard Tetrax tetrax. Methods We measured the effectiveness of the Natura 2000 by comparing population trends across time (2003–2006 and 2016 in 51 areas, 21 of which within 12 Special Protection Areas (SPA that were mostly designated for farmland bird conservation and another 30 areas without EU protection. Results Overall, the national population is estimated to have declined 49% over the last 10–14 years. This loss was found to be proportionally larger outside SPA (64% decline compared to losses within SPA (25% decline. However, the absolute male density decline was significantly larger within SPA . Discussion In spite of holding higher population densities and having prevented habitat loss, we conclude that Natura 2000 was not effective in buffering against the overall bustard population decline. Results show that the mere designation of SPA in farmland is not enough to secure species populations and has to be combined with agricultural policies and investment to maintain not only habitat availability but also habitat quality.
Composicion de aves del Pacifico Sur de Nicaragua enfatizando las especies indicadoras dependientes de bosque [Community composition of Nicaragua's Pacific Slope forest birds, emphasizing forest quality-dependent species
M. Torrez; W.J. Arendt; M. Sotelo
Given the importance of biological corridors, it is necessary to evaluate their fauna especially those species are bioindicators of habitat quality, to determine patterns and extent of community diversity and how such factors reflect the level of conservation within and among green corridors in general. We investigated how selected landscape features within the Paso...
Dale M. Becker; Carolyn Hull Sieg
Home range size and habitat utilization of three breeding male Richardsonâs Merlins (Falco columbarius richardsonii) in southeastern Montana were studied using radio telemetry. Home ranges of these birds encompassed 13,23, and 28 km2. Each bird traveled up to 9 km from its nest. Each home range encompassed five habitats;...
Full Text Available Abstract There is little information about the status and ecology of the Eurasian otter (Lutra lutra in Iran. We assessed the habitat suitability for otters of the River Jajrood, Tehran province, measuring, or visually estimating, 12 environmental parameters along 16 600 m long river stretches (sampling sites. The downstream stretches of the river were found to be more suitable for otters with respect to the upper part of its course. Although the assessments of habitat suitability for the otter may be affected by several limits, the current distribution of the species on the river agrees with the results of this study. The preservation of the otter in Tehran province should involve the restoration of the ecosystem of the River Jajrood in order to improve the length of suitable river stretches.
Riassunto Stima dell’idoneità ambientale per la lontra (Lutra lutra del fiume Jajrood, Iran. Le informazioni relative alla lontra (Lutra lutra in Iran sono scarse. L’idoneità ambientale per la specie del fiume Jajrood, provincia di Tehran, è stata valutata, misurando o stimando 12 parametri ambientali lungo 16 stazioni di campionamento, coincidenti con tratti di fiume della lunghezza di 600 m. I tratti più a valle sono risultati più idonei rispetto al corso superiore del fiume. Malgrado i numerosi limiti del metodo di stima dell’idoneità ambientale adottato, i risultati sono in accordo con l’attuale distribuzione della lontra lungo il fiume Jajrood. La conservazione della lontra nella provincia di Tehran dovrebbe prevedere miglioramenti ambientali volti a incrementare lo sviluppo lineare degli habitat idonei lungo il fiume Jajrood.
Little is known of the nesting bird species in most of urban areas of East Africa. An investigation was made of the occurrence of breeding bird species in the fragmented thickets found in the Mwalimu Nyerere Campus of the University of Dar es Salaam, in the City of Dar es Salaam. The study examined how habitat ...
Martin, Thomas E.; Maron, John L.
The contribution of climate change to declining populations of organisms remains a question of outstanding concern. Much attention to declining populations has focused on how changing climate drives phenological mismatches between animals and their food. Effects of climate on plant communities may provide an alternative, but particularly powerful, influence on animal populations because plants provide their habitats. Here, we show that abundances of deciduous trees and associated songbirds have declined with decreasing snowfall over 22 years of study in montane Arizona, USA. We experimentally tested the hypothesis that declining snowfall indirectly influences plants and associated birds by allowing greater over-winter herbivory by elk (Cervus canadensis). We excluded elk from one of two paired snowmelt drainages (10 ha per drainage), and replicated this paired experiment across three distant canyons. Over six years, we reversed multi-decade declines in plant and bird populations by experimentally inhibiting heavy winter herbivory associated with declining snowfall. Moreover, predation rates on songbird nests decreased in exclosures, despite higher abundances of nest predators, demonstrating the over-riding importance of habitat quality to avian recruitment. Thus, our results suggest that climate impacts on plant–animal interactions can have forceful ramifying effects on plants, birds, and ecological interactions.
Millar, C. I.; Smith, A. T.; Hik, D. S.
Patterned-ground and related periglacial features such as rock-glaciers and fractured-rock talus are emblematic of cold and dry arctic environments. The freeze-thaw processes that cause these features were first systematically investigated in the pioneering work of Linc Washburn. Unusual internal and autonomous micro-climatic and hydrologic processes of these features, however, are only beginning to be understood. Such features occur also in temperate latitude mountains, often in surprising abundance in regions such as the Great Basin (NV, USA) and San Juan Mtns (CO, USA), where they occur as active as well as relict (neoglacial or Pleistocene) features. Rock-dwelling species of pikas (Ochotona) in temperate North American and Asian mountains and in North American high-latitudes have long been known for their preference for talus habitats. We are investigating geomorphic, climatic, and hydrologic attributes of these periglacial features for their role in habitat quality and thermal environment of pikas. PRISM-modeled and observed climatic conditions from a range of talus types for Ochotona princeps in California and the western Great Basin (USA) indicate that, 1) thermal conditions of intra-talus-matrix in summer are significantly colder than talus-surface temperatures and colder than adjacent slopes and forefield wetlands where pika forage; 2) near-talus-surface locations (where haypiles are situated) are warmer in winter than intra-talus-matrix temperatures; 3) high-quality wetland vegetation in talus forefields is promoted by year-round persistence of outlet springs, seeps, and streams characteristic of active taluses. The importance of snowpack to winter thermal conditions is highlighted from these observations, suggesting a greater sensitivity of habitat in dry temperate regions such as eastern California and Nevada USA to warming winter minimum temperatures than in regions or elevations where snowpacks are more persistent. In regions where warming air
Coverdale, Gregory A.
Explains forest fragmentation, the destruction of physical habitats for animals such as birds and points out the importance of studies on habitat and biodiversity. Introduces project ideas for songbird populations and their habitats which can be conducted in backyards or schoolyards. (YDS)
April A. Woodward; Alix D. Fink; Frank R. Thompson III
The effect of habitat edge on avian nesting success has been the focus of considerable debate. We studied relationships between habitat edges, locations of nests, and predation. We tested the ecological trap hypothesis for 5 shrubland bird species in the Missouri Ozarks. We compared habitat selection and daily nest predation rates among 3 distance-to-edge categories....
Fenu, Giuseppe; Bernardo, Liliana
Abstract Spatial shifts in insect fauna due to ecological heterogeneity can severely constrain plant reproduction. Nonetheless, data showing effects of insect visit patterns and intensity of mutualistic and/or antagonistic plant–insect interactions on plant reproduction over structured ecological gradients remain scarce. We investigated how changes in flower-visitor abundance, identity and behaviour over a forest-open habitat gradient affect plant biotic interactions, and quantitative and qualitative fitness in the edge-specialist Dianthus balbisii. Composition and behaviour of the insects visiting flowers of D. balbisii strongly varied over the study gradient, influencing strength and patterns of plant biotic interactions (i.e. herbivory and pollination likelihood). Seed set comparison in free- and manually pollinated flowers suggested spatial variations in the extent of quantitative pollen limitation, which appeared more pronounced at the gradient extremes. Such variations were congruent to patterns of flower visit and plant biotic interactions. The analyses on seed and seedling viability evidenced that spatial variation in amount and type of pollinators, and frequency of herbivory affected qualitative fitness of D. balbisii by influencing selfing and outcrossing rates. Our work emphasizes the role of plant biotic interactions as a fine-scale mediator of plant fitness in ecotones, highlighting that optimal plant reproduction can take place into a restricted interval of the ecological gradients occurring at forest edges. Reducing the habitat complexity typical of such transition contexts can threat edge-adapted plants. PMID:28775831
Full Text Available Most wildlife habitats and migratory routes are extremely threatened due to increasing demands on forestland and forest resources by burgeoning human population. Corridor landscape in Biligiri Rangaswamy Temple Tiger Reserve (BRT is one among them, subjected to various anthropogenic pressures. Human habitation, intensive farming, coffee plantations, ill-planned infrastructure developments and rapid spreading of invasive plant species Lantana camara, pose a serious threat to wildlife habitat and their migration. Aim of this work is to create detailed NDVI based land change maps and to use them to identify time-series trends in greening and browning in forest corridors in the study area and to identify the drivers that are influencing the observed changes. Over the four decades in BRT, NDVI increased in the core area of the forest and reduced in the fringe areas. The change analysis between 1973 and 2014 shows significant changes; browning due to anthropogenic activities as well as natural processes and greening due to Lantana spread. This indicates that the change processes are complex, involving multiple driving factors, such as socio-economic changes, high population growth, historical forest management practices and policies. Our study suggests that the use of updated and accurate change detection maps will be useful in taking appropriate site specific action-oriented conservation decisions to restore and manage the degraded critical wildlife corridors in human-dominated landscape.
Marchamalo, Miguel; Bejarano, María-Dolores; García de Jalón, Diego; Martínez Marín, Rubén
This study presents the application of LIDAR data to the evaluation and quantification of fluvial habitat in river systems, coupling remote sensing techniques with hydrological modeling and ecohydraulics. Fish habitat studies depend on the quality and continuity of the input topographic data. Conventional fish habitat studies are limited by the feasibility of field survey in time and budget. This limitation results in differences between the level of river management and the level of models. In order to facilitate upscaling processes from modeling to management units, meso-scale methods were developed (Maddock & Bird, 1996; Parasiewicz, 2001). LIDAR data of regulated River Cinca (Ebro Basin, Spain) were acquired in the low flow season, maximizing the recorded instream area. DTM meshes obtained from LIDAR were used as the input for hydraulic simulation for a range of flows using GUAD2D software. Velocity and depth outputs were combined with gradient data to produce maps reflecting the availability of each mesohabitat unit type for each modeled flow. Fish habitat was then estimated and quantified according to the preferences of main target species as brown trout (Salmo trutta). LIDAR data combined with hydraulic modeling allowed the analysis of fluvial habitat in long fluvial segments which would be time-consuming with traditional survey. LIDAR habitat assessment at mesoscale level avoids the problems of time efficiency and upscaling and is a recommended approach for large river basin management.
Virginia H. Dale
Full Text Available A computer simulation model, the Regional Simulator (RSim, was constructed to project how land-use changes affect the quality of water, air, noise, and habitat of species of special concern. RSim was designed to simulate these environmental impacts for five counties in Georgia that surround and include Fort Benning. The model combines existing data and modeling approaches to simulate the effects of land-cover changes on: nutrient export by hydrological unit; peak 8-h average ozone concentrations; noise caused by small arms and blasts; and habitat changes for the rare Red-cockaded Woodpecker (Picoides borealis and gopher tortoise (Gopherus polyphemus. The model also includes submodules for urban growth, new urbanization influenced by existing roads, nonurban land cover transitions, and a new military training area under development at Fort Benning. The model was run under scenarios of business as usual (BAU and greatly increased urban growth for the region. The projections show that the effects of high urban growth will likely differ from those of BAU for noise and nitrogen and phosphorus loadings to surface water, but not for peak airborne ozone concentrations, at least in the absence of associated increases in industry and transportation use or technology changes. In both scenarios, no effects of urban growth are anticipated for existing populations of the federally endangered Red-cockaded Woodpecker. In contrast, habitat for gopher tortoise in the five-county region is projected to decline by 5 and 40% in the BAU and high urban growth scenarios, respectively. RSim is designed to assess the relative environmental impacts of planned activities both inside and outside military installations and to address concerns related to encroachment and transboundary influences.
Wang, J.; Herricks, E.
The number of bird strikes on aircraft has increased sharply over recent years and airport bird hazard management has gained increasing attention in wildlife management and control. Evaluation of bird activity near airport is very critical to analyze the hazard of bird strikes. Traditional methods for bird activity analysis using visual counting provide a direct approach to bird hazard assessment. However this approach is limited to daylight and good visual conditions. Radar has been proven to be a useful and effective tool for bird detection and movement analysis. Radar eliminates observation bias and supports consistent data collection for bird activity analysis and hazard management. In this study bird activity data from the Naval Air Station Whidbey Island was collected by Accipiter Avian Radar System. Radar data was pre-processed by filtering out non-bird noises, including traffic vehicle, aircraft, insects, wind, rainfall, ocean waves and so on. Filtered data is then statistically analyzed using MATLAB programs. The results indicated bird movement dynamics in target areas near the airport, which includes (1) the daily activity varied at dawn and dusk; (2) bird activity varied by target area due to the habitat difference; and (3) both temporal and spatial movement patterns varied by bird species. This bird activity analysis supports bird hazard evaluation and related analysis and modeling to provide very useful information in airport bird hazard management planning.
The most prominent conservation concerns are typically habitat loss and habitat fragmentation. The role of habitat degradation has received comparatively little attention. But research has shown that the quality of habitat patches can significantly influence wildlife population d...
Full Text Available A study has been conducted with the purpose of knowing the type diversity of birds in various habitats (research sites and to identify which species of bird are dominant in a variety of selected habitat. This research lasted for 3 months from April to June 2015 located in the cluster are of Ternate Island. The sampling and collecting data are taken from five habitat types in the study site: Settlement, Plantation, River Basin, Secondary Forest and Primary Forest. 3 observation points taken randomly are made in each type of habitat, but the determination of the observation point is adjusted to the easily accessible field condition to make the observation so that the total number of points obtained 15 observation points. The data collection of the diversity of bird species is done using TSCs (Time Species Counts method which is the calculation of bird species by time and free exploration. In this method, the data is recorded in six columns with a time interval of ten minutes with a one-hour count of each survey. To calculate the diversity of bird species by using Shannon-Wiener Diversity Index according to Bibby et al, (2000 with the formula H’ = - Σ Pi. ln.Pi where: H’: Shannon- Wiener Diversity Index; In: Basic logarithm; Pi: ni/N; ni: i number of species; N: Number of all species. From the research result, it is found that 64 bird species, among the bird species that have been found, are relative of paruh bengkok bird such as Kakatua putih (Cacatua alba, Kasturi Ternate (Lorius garrulus, Nuri kalung ungu (Eos squamata, Betet-kelapa paruh-besar (Tanygnathus megalorynchos and Perkici dagu-merah (Charmosyna placentis. In which these birds occupy the height from the sea reaching to the 1000 m above sea level above the sea level and some are kept by the community during the research such as Kakatua putih (Cacatua alba, Kasturi Ternate (Lorius garrulus and Nuri kalung ungu (Eos squamata.
Weisberg, Peter J.; Dilts, Thomas E.; Becker, Miles E.; Young, Jock S.; Wong-Kone, Diane C.; Newton, Wesley E.; Ammon, Elisabeth M.
Ecological niche theory implies that more heterogeneous habitats have the potential to support greater biodiversity. Positive heterogeneity-diversity relationships have been found for most studies investigating animal taxa, although negative relationships also occur and the scale dependence of heterogeneity-diversity relationships is little known. We investigated multi-scale, heterogeneity-diversity relationships for bird communities in a semi-arid riparian landscape, using airborne LiDAR data to derive key measures of structural habitat complexity. Habitat heterogeneity-diversity relationships were generally positive, although the overall strength of relationships varied across avian life history guilds (R2 range: 0.03-0.41). Best predicted were the species richness indices of cavity nesters, habitat generalists, woodland specialists, and foliage foragers. Heterogeneity-diversity relationships were also strongly scale-dependent, with strongest associations at the 200-m scale (4 ha) and weakest associations at the 50-m scale (0.25 ha). Our results underscore the value of LiDAR data for fine-grained quantification of habitat structure, as well as the need for biodiversity studies to incorporate variation among life-history guilds and to simultaneously consider multiple guild functional types (e.g. nesting, foraging, habitat). Results suggest that certain life-history guilds (foliage foragers, cavity nesters, woodland specialists) are more susceptible than others (ground foragers, ground nesters, low nesters) to experiencing declines in local species richness if functional elements of habitat heterogeneity are lost. Positive heterogeneity-diversity relationships imply that riparian conservation efforts need to not only provide high-quality riparian habitat locally, but also to provide habitat heterogeneity across multiple scales.
Quinn, Nigel W.T.
The San Joaquin River Riparian Habitat Restoration Program (SJRRP) has recognized the potential importance of real-time monitoring and management to the success of the San Joaquin River (SJR) restoration endeavor. The first step to realizing making real-time management a reality on the middle San Joaquin River between Friant Dam and the Merced River will be the installation and operation of a network of permanent telemetered gauging stations that will allow optimization of reservoir releases made specifically for fish water temperature management. Given the limited reservoir storage volume available to the SJJRP, this functionality will allow the development of an adaptive management program, similar in concept to the VAMP though with different objectives. The virtue of this approach is that as management of the middle SJR becomes more routine, additional sensors can be added to the sensor network, initially deployed, to continue to improve conditions for anadromous fish.
Sumasgutner, Petra; Nemeth, Erwin; Tebb, Graham; Krenn, Harald W; Gamauf, Anita
Urbanization is a global phenomenon that is encroaching on natural habitats and decreasing biodiversity, although it is creating new habitats for some species. The Eurasian kestrel (Falco tinnunculus) is frequently associated with urbanized landscapes but it is unclear what lies behind the high densities of kestrels in the urban environment. Occupied nest sites in the city of Vienna, Austria were investigated along a gradient of urbanization (percentage of land covered by buildings or used by traffic). Field surveys determined the abundance of potential prey (birds and rodents) and the results were compared to the birds' diets. A number of breeding parameters were recorded over the course of three years. The majority of kestrels breed in semi-natural cavities in historic buildings. Nearest neighbour distances (NND) were smallest and reproductive success lowest in the city centre. Abundance of potential prey was not found to relate to the degree of urbanization but there was a significant shift in the birds' diets from a heavy reliance on rodents in the outskirts of the city to feeding more on small birds in the centre. The use of urban habitats was associated with higher nest failure, partly associated with predation and nest desertion, and with significantly lower hatching rates and smaller fledged broods. High breeding densities in urban habitats do not necessarily correlate with high habitat quality. The high density of kestrel nests in the city centre is probably due to the ready availability of breeding cavities. Highly urbanized areas in Vienna are associated with unexpected costs for the city dwelling-raptor, in terms both of prey availability and of reproductive success. The kestrel appears to be exploiting the urban environment but given the poor reproductive performance of urban kestrels it is likely that the species is falling into an ecological trap.
Ralston, Barbara E.; Lauretta, Matthew V.; Kennedy, Theodore A.
Glen Canyon Dam operations are known to affect mainstem Colorado River temperature and shoreline habitats for native fish. Options for ameliorating the impacts that operations have on young native fish include changing release volumes and/or changing the daily range of releases. Long-term alterations of operations that may produce a measurable biological response can be costly, particularly if the treatment involves reduced power generation. In September and October 2005, a series of two-week releases occurred that alternated between daily fluctuations that varied by 76 m3 s-1 and steady releases. The purpose of these short-term experiments was to study the effect of daily operations on water quality parameters and biotic constituents (phytoplankton, macroinvertebrates, and fishes) of associated shoreline habitats. Our results indicate that measured biological and physical parameters were, in general, unaffected by flow treatments. However, results should be interpreted cautiously as time within and between treatments was likely insufficient to affect measured parameters. These results lead to the recommendation that studies like this may be more amenable to laboratory experiments first and then applied to a large-scale setting, preferably for longer duration.
Chan, Jasper Fuk-Woo; To, Kelvin Kai-Wang; Chen, Honglin; Yuen, Kwok-Yung
Birds, the only living member of the Dinosauria clade, are flying warm-blooded vertebrates displaying high species biodiversity, roosting and migratory behavior, and a unique adaptive immune system. Birds provide the natural reservoir for numerous viral species and therefore gene source for evolution, emergence and dissemination of novel viruses. The intrusions of human into natural habitats of wild birds, the domestication of wild birds as pets or racing birds, and the increasing poultry consumption by human have facilitated avian viruses to cross species barriers to cause zoonosis. Recently, a novel adenovirus was exclusively found in birds causing an outbreak of Chlamydophila psittaci infection among birds and humans. Instead of being the primary cause of an outbreak by jumping directly from bird to human, a novel avian virus can be an augmenter of another zoonotic agent causing the outbreak. A comprehensive avian virome will improve our understanding of birds' evolutionary dynamics. Copyright © 2015 Elsevier B.V. All rights reserved.
Full Text Available The present paper acts as an introduction to a series that will describe the exploratory analyses of migration phenology and morphometrics of the most common passerine species at the Ócsa Bird Ringing Station. This station is situated in the Ócsa Landscape Protection Area that belongs to the Duna–Ipoly National Park, Hungary. The area is somewhat cooler and more humid than the surrounding agricultural fields and tree plantations, covered by a mosaic of diverse hygrophilous vegetation patches. Bird trapping is mostly based on Japanese mist-net lines crossing different plant communities. During the period of 1984–2015, a total of 422,862 birds were trapped and ringed here, while 202,739 local, 1,235 within country, and 443 foreign recaptures were also recorded. Each bird is characterized by the following data: location and time of capture, species, age, sex, scores of fat, pectoral muscle, wing tip abrasion, and moult, length of wing, 3rd primary, and tail, and body mass. After subjected to a rigorous quality check, digital data are deposited in the archive of the Hungarian Bird Ringing Centre, and the EURING data base. From time to time, other research projects also utilized the accessibility of wild birds captured here, thus collection of blood samples, ecto- and endoparasites was carried out at the station. The relatively long time span, large number of species and individuals, and the readily available environmental (weather, vegetation, etc. data makes the avian data collected here a suitable base for studies of various disciplines like capture methodology, habitat preferences, breeding, migration, and wintering, effects of weather and climate change, and epidemiology of viruses and parasites.
Status for investigations of birds and proposals for further investigations of birds in 2002 and 2003 for Horns Rev offshore wind farm; Status for fugleundersoegelser samt forslag til opfoelgende fugleundersoegelser i 2002 og 2003 for Horns Rev vindmoellepark
The purpose of the investigations of birds is to establish a knowledge and data base that can make possible to enlighten the extent and character of potential influences the offshore wind farm might have on the birds. The potential influences the offshore wind farm might have on birds include: a) modification of the habitat, b) collision effects, and c) disturbances. (BA)
number of ways from the natural environment: for example, in urban areas, wooded habitats are extensively fragmented, vegetation cover is very sparse and some vegetation layers are lacking (Gilbert 1989). Habitat fragmentation can result in population declines of birds by reducing adequate space for territories, nest sites, ...
Sabatier, R; Teillard, F; Rossing, W A H; Doyen, L; Tichit, M
In European grassland landscapes, grazing and mowing play a key role for the maintenance of high-quality habitats that host important bird populations. As grasslands are also key resources for cattle feeding, there is a need to develop management strategies that achieve the double objective of production and biodiversity conservation. The objective of this study was to use a modelling approach to generate recognisable patterns of bird dynamics in farms composed of different land use proportions, and to compare their production and ecological dimensions. We developed a dynamic model, which linked grassland management to bird population dynamics at the field and farm levels. The model was parameterised for two types of suckling farms corresponding to contrasting levels of grassland intensification and for two bird species of high conservation value. A viability algorithm was used to define and assess viable management strategies for production and ecological performance so as to draw the shape of the relationship between both types of performances for the two types of farms. Our results indicated that, at the farm level, there was a farming system effect with a negative and non-linear relationship linking performance. Improving bird population maintenance was less costly in extensive farms compared with intensive farms. At the field level, the model predicted the timing and intensity of land use, maximising either production or ecological performance. The results suggested that multi-objective grassland management would benefit from public policies that consider levels of organisation higher than the field level, such as the farm or the landscape.
Kellermann, Jherime L.; van Riper, Charles
Small-bodied songbirds replenish fat reserves during migration at stopover sites where they continually encounter novel and often unpredictable environmental conditions. The ability to select and utilize high quality habitats is critical to survival and fitness. Vegetation phenology is closely linked with emergence of insect prey and may provide valid cues of food availability for stopover habitat selection. Climate change is disrupting phenological synchrony across trophic levels with negative impacts on bird populations. However, whether synchrony or mismatch indicates historic or disrupted systems remains unclear. Many Neotropical migratory songbirds of western North America must cross arid regions where drought conditions related to climate change and human water use are expected to increase. We studied migrant abundance and the diversity (niche breadth) and proportional use of vegetation species as foraging substrates and their synchrony with vegetation flowering during spring migration along the lower Colorado River in the Sonoran Desert of the U.S. and Mexico.
Ruth, Janet M.; Barrow, Wylie C.; Sojda, Richard S.; Dawson, Deanna K.; Diehl, Robert H.; Manville, Albert; Green, Michael T.; Krueper, David J.; Johnston, Scott
Migratory birds face many changes to the landscapes they traverse and the habitats they use. Wind turbines and communications towers, which pose hazards to birds and bats in flight, are being erected or proposed across the United States and offshore. Human activities can also destroy or threaten habitats critical to birds during migratory passage, and climate change appears to be altering migratory patterns. The U.S. Fish and Wildlife Service (USFWS) and other agencies are under increasing pressure to identify and evaluate movement patterns and habitats used during migration and other times.
Martínez-Abraín, Alejandro; Jiménez, Juan
One speaks of ecological substitutes when an introduced species performs, to some extent, the ecosystem function of an extirpated native species. We suggest that a similar case exists for habitats. Species evolve within ecosystems, but habitats can be destroyed or modified by natural and human-made causes. Sometimes habitat alteration forces animals to move to or remain in a suboptimal habitat type. In that case, the habitat is considered a refuge, and the species is called a refugee. Typically refugee species have lower population growth rates than in their original habitats. Human action may lead to the unintended generation of artificial or semiartificial habitat types that functionally resemble the essential features of the original habitat and thus allow a population growth rate of the same magnitude or higher than in the original habitat. We call such areas substitution habitats and define them as human-made habitats within the focal species range that by chance are partial substitutes for the species' original habitat. We call species occupying a substitution habitat adopted species. These are 2 new terms in conservation biology. Examples of substitution habitats are dams for European otters, wheat and rice fields for many steppeland and aquatic birds, and urban areas for storks, falcons, and swifts. Although substitution habitats can bring about increased resilience against the agents of global change, the conservation of original habitat types remains a conservation priority. © 2016 Society for Conservation Biology.
Eugene S. Morton; Bridget J. M. Stutchbury
Migratory birds are birds of two worlds, breeding in the temperate zone then living as tropical birds for most of the year. We show two aspects of this unique biology that are important considerations for their conservation. First, habitat selection for breeding must include their need for extra-pair mating opportunities. Second, non-breeding distributions in tropical...
J. E. C. Figueira
Full Text Available Analysis of a three-year bird survey in the pantanal of Poconé revealed that most of the resident and seasonal birds are habitat generalists, using two or more habitats. In this study, previously sampled habitats were ranked in relation to species richness and stability (as measured by the ratio of seasonal to resident species. In all, nine habitats were grouped into three categories; results are as follows: 1 forests: more species-rich and more stable; 2 cerrado: intermediate levels; and 3 aquatic: less species-rich and less stable. The number of seasonal species remained relatively constant in forests throughout the year, while increasing in the other habitats during the dry season. The abundance of resident species seems to be related to species use of multiple habitats. Although many species were found to be habitat generalists, we discuss possible consequences of habitat loss and other human impacts on efforts to conserve this important bird community.
Roy, W. Kelly [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Giffen, Neil R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wade, Murray [CDM Smith, Inc., Knoxville, TN (United States); Haines, Angelina [Xcel Engineering, Inc., Oak Ridge, TN (United States); Evans, James W. [Tennessee Wildlife Resources Agency, Nashville, TN (United States); Jett, Robert Trent [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Bird data have been collected through surveys, environmental assessments, and other observations for decades in the Oak Ridge National Environmental Research Park, located on the US Department of Energy s Oak Ridge Reservation (ORR) in East Tennessee. Birds were recorded in a variety of habitats, including wetlands, interior forests, grasslands, ponds, corridors, forest edges, and more. Most of the information was gathered from waterfowl surveys conducted from 1990 to 2008, from Partners in Flight (PIF) breeding bird surveys conducted from 1995 to 2013, and from past publications and research on Reservation birds. We have also included our own observations and, in a few instances, credible observations of ORR birds of which we have been made aware through eBird or discussions with area ornithologists and bird watchers. For the period 1950 2014, we were able to document 228 species of birds on the ORR. Several of these species are known from historic records only, while others were not known to have ever occurred on the Reservation until recently. This report does not include PIF breeding bird data from the 2014 season or any records after July 2014. Twenty-two species approximately 10% of the total number of species observed have state-listed status in Tennessee as endangered, threatened, or in need of management. Of the 228 species we documented, 120 are believed to be breeding birds on the ORR.
Roy, W. K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Giffen, N. R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wade, M. C. [CDM Smith (United States); Haines, A. M. [Xcel Engineering, Inc.(United States); Evans, J. W. [Tennessee WIldlife Resources Agency (WRA), Nashville, TN (United States); Jett, R. T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Bird data have been collected through surveys, environmental assessments, and other observations for decades in the Oak Ridge National Environmental Research Park, located on the US Department of Energy’s Oak Ridge Reservation (ORR) in East Tennessee. Birds were recorded in a variety of habitats, including wetlands, interior forests, grasslands, ponds, corridors, forest edges, and more. Most of the information was gathered from waterfowl surveys conducted from 1990 to 2008, from Partners in Flight (PIF) breeding bird surveys conducted from 1995 to 2013, and from past publications and research on Reservation birds. We have also included our own observations and, in a few instances, credible observations of ORR birds of which we have been made aware through eBird or discussions with area ornithologists and bird watchers. For the period 1950-2014, we were able to document 228 species of birds on the ORR. Several of these species are known from historic records only, while others were not known to have ever occurred on the Reservation until recently. This report does not include PIF breeding bird data from the 2014 season or any records after July 2014. Twenty-two species--approximately 10% of the total number of species observed--have state-listed status in Tennessee as endangered, threatened, or in need of management. Of the 228 species we documented, 120 are believed to be breeding birds on the ORR.
Samuel A. Cushman; Kevin McGarigal; Kevin S. McKelvey; Christina D. Vojta; Claudia M. Regan
The primary objective of this chapter is to describe standardized methods for measurÂ¬ing and monitoring attributes of landscape pattern in support of habitat monitoring. This chapter describes the process of monitoring categorical landscape maps in which either selected habitat attributes or different classes of habitat quality are represented as different patch types...
Skoczylas, Daniel R.; Muth, Norris Z.; Niesenbaum, Richard A.
Predation of herbivorous Lepidoptera larvae by insectivorous avifauna was estimated on Lindera benzoin in edge and interior habitats at two sites in eastern Pennsylvania (USA). Clay baits modeled after Epimecis hortaria (Geometridae) larvae, the primary herbivore of L. benzoin at our study sites, were used to estimate predation by birds. In both habitat types, models were placed on uninjured L. benzoin leaves as well as on leaves that had prior insect herbivore damage. Rates of model attack were greater, and model longevity reduced, in forest edge plots compared to interiors. Naturally occurring herbivore damage on L. benzoin was greater in forest interiors. However, model attack was not significantly greater on leaves with prior herbivory damage, suggesting that birds do not effectively use this type of leaf damage as a cue in their foraging. Our findings are consistent with a contribution of bird predation towards top-down control of herbivory in this system. We further discuss these results in a broader context considering the possible effects of habitat type on leaf quality, leaf defense, and herbivore performance.
Krstolic, Jennifer L.; Johnson, Gregory C.; Ostby, Brett J.K.
Chemical, physical, and biological data were collected during 2009-2011 as part of a study of the Clinch River in Virginia and Tennessee. The data from this study, data-collection methods, and laboratory analytical methods used in the study are documented in this report. The study was conducted to describe the conditions of the Clinch River and to determine if there are measurable differences in chemical, physical, or biological characteristics in a segment of the river where freshwater mussel populations are in decline, have low density, richness, little to no recruitment, and lack endangered species (low-quality reach) compared to a segment of the river where mussel assemblages have relatively high density, richness, evidence of recruitment, and support endangered species (high-quality reach). Five continuous water-quality monitors were installed and operated on the mainstem of the Clinch River and two tributaries. Discrete water-quality sample sets were collected during base-flow and stormflow conditions two sites on the Clinch River and on the Guest River, a tributary to the Clinch River predominantly in the Appalachian Plateaus Physiographic Province. Base-flow water-quality samples were collected in July and August 2011 at 15 sites along the mainstem of the Clinch River. Other analyses included longitudinal sampling along the mainstem of the Clinch River at 10 sites to evaluate bed-sediment chemistry, habitat condition, and mollusk community status. In situ freshwater mussel growth and mortality experiments were conducted with hatchery propogated Villosa iris (rainbow mussels). Tissue from the V. iris as well as tissue from 16 Actinonaias pectorosa mussels were analyzed for trace metals, and V. iris mussel tissue was analyzed for organic compounds. Data collected during this investigation were analyzed by various U.S. Geological Survey or U.S. Fish and Wildlife Service laboratories.
Rodney B. Siegel; Peter Pyle; James H. Thorne; Andrew J. Holguin; Christine A. Howell; Sarah Stock; Morgan W. Tingley
In a rapidly changing climate, effective bird conservation requires not only reliable information about the current vulnerability of species of conservation concern, but also credible projections of their future vulnerability. Such projections may enable managers to preempt or reduce emerging climate-related threats through appropriate habitat management. We used NatureServe's Climate Change Vulnerability Index (CCVI) to predict vulnerability to climate change of 168 bird species that breed i...
Anna M Mangan
Full Text Available As the largest terrestrial biomes, crop and pasturelands can have very large positive or negative impacts on biodiversity and human well-being. Understanding how animals use and impact agroecosystems is important for making informed decisions that achieve conservation and production outcomes. Yet, few studies examine the tradeoffs associated with wildlife in agricultural systems. We examined bird use of organic apple orchards as well as how birds influence fruit production positively through control of an economically important insect pest (codling moth (Cydia pomonella and negatively through fruit damage. We conducted transect surveys, observed bird frugivory and assessed bird and insect damage with an exclosure experiment in small organic farms in western Colorado. We found that organic apple orchards in this region provide habitat for a large number of both human-adapted and human-sensitive species and that the species in orchards were relatively similar to adjacent hedgerow habitats. Habitat use did not vary as a function of orchard characteristics, and apple damage by both birds and C. pomonella was consistent within and across apple blocks that varied in size. A small subset of bird species was observed foraging on apples yet the effect of birds as agents of fruit damage appeared rather minor and birds did not reduce C. pomonella damage. Our results demonstrate that organic apple orchards have the potential to provide habitat for diverse bird communities, including species typically sensitive to human activities, with little apparent effect on production.
McCarthy, Sarah G.; Duda, Jeffrey J.; Emlen, John M.; Hodgson, Garth R.; Beauchamp, David A.
We examined invertebrate prey, fish diet, and energy assimilation in relation to habitat variation for steelhead Oncorhynchus mykiss (anadromous rainbow trout) and rainbow trout in nine low-order tributaries of the South Fork Trinity River, northern California. These streams spanned a range of environmental conditions, which allowed us to use bioenergetics modeling to determine the relative effects of forest cover, stream temperature, season, and fish age on food consumption and growth efficiency. Evidence of seasonal shifts in