2,224 research outputs found
A Snow-tracking Protocol Used to Delineate Local Lynx, Lynx canadensis, Distributions
Determining Canada Lynx (Lynx canadensis) distribution is an important management need, especially at the southern extent of the species range where it is listed as threatened under the U. S. Endangered Species Act. We describe a systematic snowtrack based sampling framework that provides reliable distribution data for Canada Lynx. We used computer simulations to evaluate protocol efficacy. Based on these simulations, the probability of detecting lynx tracks during a single visit (8 km transect) to a survey unit ranged from approximately 0.23 for surveys conducted only one day after snowfall, to 0.78 for surveys conducted 7 days after a snowfall. If the survey effort was increased to three visits, then detection probabilities increased substantially from 0.58 for one day after snowfall to about 0.95 for surveys conducted 7 days after a snowfall. We tested the protocol in the Garnet Range, Montana, where most lynx were radio-collared. We documented a total of 189 lynx tracks during two winters (2001-2003). Lynx distribution based on snow-track surveys was coincident with the area defined through radio telemetry. Additionally, we conducted snow-track surveys in areas of western Wyoming where lynx were believed present but scarce. We detected a total of six lynx tracks during three winters (1999-2002). In Wyoming , where lynx presence was inferred from a few tracks, we verified species identification by securing genetic samples (hairs from daybeds) along track-lines
Wolverine Reproductive Den Habitat in Glacier National Park, Montana
Wolverine reproductive dens occur in habitat not easily accessible to humans during the denning period (Feb â May) and can be challenging to find. As such, few den sites have been precisely described. From 2003 â 2007 we located and documented 14 natal and maternal dens of 3 reproductive female wolverine in Glacier National Park. Two females were known to have produced young in multiple years, using different den sites each year. Reproductive dens occurred at an average elevation of 1890m (range: 1805-1999m), on 9° slopes (range: 5-22o), within a variable range of aspects (  =263°), and with an average snow depth of 2.6m (range: 2.4-3.4m). Den structures included downed trees, large boulders, and rock caves associated with alpine cirques, ridges, and cliff bands at, or below, existing tree line. Distance to occupied human development averaged 6.4km, and distance between denning areas of the same female in different years averaged 5.8 km. Various climate change models predict less persistent snowpack in many areas of the conterminous United States, with a resultant potential for increased isolation of island populations of wolverines
Wolverine Food Habitats and Foraging Strategies in Glacier National Park, Montana
From 2003-2007 we captured and instrumented 28 wolverines (Gulo gulo) in Glacier National Park to investigate reproduction and recruitment. We collected 189 scat samples at reproductive den, forage and rendezvous sites, and documented 90 prey species through observation and prey remains found at similar sites. Seasonal scat analysis provided evidence of differences in prey species consumed during winter (n = 170), summer (n = 19), and reproductive den (n = 103) periods. Ungulates were the most frequently observed prey found in all scats (71%; N=135), with Cervid remains being observed most often (37%; n = 70). Hibernating rodents (ground squirrels and marmots) (36%; n = 68) were the next most utilized prey, with the third most documented prey being mice and voles (31%; n = 56). Vegetation (72%; n = 169), soil material (31%; n = 59), and bone (90%; n = 171) were also found in scats. Seasonal importance of prey was documented, with ungulates being the most observed prey in winter scats (75%; n = 128) and den period scats (79%; n = 81), and hibernating rodents being most observed in summer scats (47%; n = 9). A similar condition was found with analysis of all prey remains (n = 90); ungulates were consumed most often (69%; n = 63), with hibernating rodents as the second most documented prey (12%; n = 11). Wolverines exhibited seasonal dietary shifts in that ungulates were consumed most frequently during winter (77%; n = 55) and the den period (78%; n = 17), with hibernating rodents the most frequent prey documented in summer (50%; n = 9). Wolverine foraging strategies, including searching tree wells, fishing, decapitation, and food caching are also discussed
Recovery of Wolverines in the Western United States: Recent Extirpation and Recolonization or Range Retraction and Expansion?
Wolverines were greatly reduced in number and possibly extirpated from the contiguous United States (U.S.) by the early 1900s. Wolverines currently occupy much of their historical range in Washington, Idaho, Montana, and Wyoming, but are absent from Utah and only single individuals are known to occur in California and Colorado. In response, the translocation of wolverines to California and Colorado is being considered. If wolverines are to be reintroduced, managers must identify appropriate source populations based on the genetic affinities of historical and modern wolverine populations. We amplified the mitochondrial control region of 13 museum specimens dating from the late 1800s to early 1900s and 209 wolverines from modern populations in the contiguous U.S. and Canada and combined results with previously published haplotypes. Collectively, these data indicated that historical wolverine populations in the contiguous U.S. were extirpated by the early 20th century, and that modern populations in the contiguous U.S. are likely the descendants of recent immigrants from the north. The Cali1 haplotype previously identified in California museum specimens was also common in historical samples from the southern Rocky Mountains, and likely evolved in isolation in the southern ice-free refugium that encompassed most of the contiguous U.S. during the last glaciation. However, when southern populations were extirpated, these matrilines were eliminated. Several of the other haplotypes found in historical specimens from the contiguous U.S. also occur in modern North American populations, and belong to a group of haplotypes that are associated with the rapid expansion of northern wolverine populations after the last glacial retreat. Modern wolverines in the contiguous U.S. are primarily haplotype A, which is the most common and widespread haplotype in Canada and Alaska. For the translocation of wolverines to California, Colorado, and other areas in the western U.S., potential source populations in the Canadian Rocky Mountains may provide the best mix of genetic diversity and appropriate learned behavior
Climate Change Predicted to Shift Wolverine Distributions, Connectivity, and Dispersal Corridors
Boreal species sensitive to the timing and duration of snow cover are particularly vulnerable to global climate change. Recent work has shown a link between wolverine (Gulo gulo) habitat and persistent spring snow cover through 15 May, the approximate end of the wolverineâs reproductive denning period. We modeled the distribution of snow cover within the Columbia, Upper Missouri, and Upper Colorado River Basins using a downscaled ensemble climate model. The ensemble model was based on the arithmetic mean of 10 global climate models (GCMs) that best fit historical climate trends and patterns within these three basins. Snow cover was estimated from resulting downscaled temperature and precipitation patterns using a hydrologic model. We bracketed our ensemble model predictions by analyzing warm (miroc 3.2) and cool (pcm1) downscaled GCMs. Because Moderate-Resolution Imaging Spectroradiometer (MODIS)-based snow cover relationships were analyzed at much finer grain than downscaled GCM output, we conducted a second analysis based on MODIS-based snow cover that persisted through 29 May, simulating the onset of spring two weeks earlier in the year. Based on the downscaled ensemble model, 67% of predicted spring snow cover will persist within the study area through 2030â2059, and 37% through 2070â2099. Estimated snow cover for the ensemble model during the period 2070â 2099 was similar to persistent MODIS snow cover through 29 May. Losses in snow cover were greatest at the southern periphery of the study area (Oregon, Utah, and New Mexico, USA) and least in British Columbia, Canada. Contiguous areas of spring snow cover become smaller and more isolated over time, but large (.1000 km2) contiguous areas of wolverine habitat are predicted to persist within the study area throughout the 21st century for all projections. Areas that retain snow cover throughout the 21st century are British Columbia, north-central Washington, northwestern Montana, and the Greater Yellowstone Area. By the late 21st century, dispersal modeling indicates that habitat isolation at or above levels associated with genetic isolation of wolverine populations becomes widespread. Overall, we expect wolverine habitat to persist throughout the species range at least for the first half of the 21st century, but populations will likely become smaller and more isolated
Wolverine Gene Flow Across a Narrow Climatic Niche
Wolverines (Guio guio) are one of the rarest carnivores in the contiguous United States. Effective population sizes in Montana, Idaho, and Wyoming, where most of the wolverines in the contiguous United States exist, were calculated to be 35 (credible limits, 28 52) suggesting low abundance. Landscape features that influence wolverine population substructure and gene flow are largely unknown. Recent work has identified strong associations between areas with persistent spring snow and wolverine presence and range. We tested whether a dispersal model in which wolverines prefer to disperse through areas characterized by persistent spring snow cover produced least-cost paths among all individuals that correlated with genetic distance among individuals. Models simulating large preferences for dispersing within areas characterized by persistent spring snow explained the data better than a model based on Euclidean distance. Partial Mantel tests separating Euclidean distance from spring snow-cover-based effects indicated that Euclidean distance was not significant in describing patterns of genetic distance. Because these models indicated that successful dispersal paths followed areas characterized by spring snow cover, we used these understandings to derive empirically based least-cost corridor maps in the U.S. Rocky Mountains. These corridor maps largely explain previously published population subdivision patterns based on mitochondrial DNA and indicate that natural colonization of the southern Rocky Mountains by wolverines will be difficult but not impossible
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Human-made structures, vegetation, and weather influence ferruginous hawk breeding performance
Studies of anthropogenic impacts on wildlife may produce inconclusive or biased results if they fail to account for natural sources of variation in breeding performance and do not use probabilistic sampling at a scale functional for management. We used stratified random sampling and generalized linear mixed models to test hypotheses on relationships of daily nest survival rate (DSR) and fledgling production with anthropogenic and environmental factors that influence reproduction in the ferruginous hawk (Buteo regalis). We conducted the study across ferruginous hawk range in Wyoming, USA, 2010â2012. We performed extensive field surveys of prey, vegetation, and nest substrates, and used spatially explicit data to quantify weather, and the most widespread forms of anthropogenic infrastructure (i.e., roads, oil and gas well pads) in ferruginous hawk territories. We found strong evidence that DSR and productivity were greater for nests on anthropogenic structures (i.e., artificial nest platforms, gas condensation tanks, abandoned windmill platforms, power poles) compared to natural substrates (i.e., trees, cliffs, rock outcrops). Additionally, ferruginous hawks produced more fledglings at territories with greater shrub cover and fewer severe storms during the June broodârearing period. Amount of oil and gas development and prey was not associated with either measure of breeding performance. Our results suggest that artificial nest platforms are an effective tool to improve breeding success of ferruginous hawks and nesting on anthropogenic structures does not constitute an ecological trap for this species. Although ferruginous hawks nested in some areas with very little vegetative cover, territories with greater amounts of shrub cover produced more fledglings. The negative impact of severe spring storms on fledgling production illustrates the importance of including future weather scenarios in management planning for this species because storms are predicted to increase in frequency and intensity as a result of climate change. Published 2015. This article is a U.S. Government work and is in the public domain in the USA
Identification of PKD1L1 Gene Variants in Children with the Biliary Atresia Splenic Malformation Syndrome
Biliary atresia (BA) is the most common cause of endâstage liver disease in children and the primary indication for pediatric liver transplantation, yet underlying etiologies remain unknown. Approximately 10% of infants affected by BA exhibit various laterality defects (heterotaxy) including splenic abnormalities and complex cardiac malformations â a distinctive subgroup commonly referred to as the biliary atresia splenic malformation (BASM) syndrome. We hypothesized that genetic factors linking laterality features with the etiopathogenesis of BA in BASM patients could be identified through whole exome sequencing (WES) of an affected cohort. DNA specimens from 67 BASM subjects, including 58 patientâparent trios, from the NIDDKâsupported Childhood Liver Disease Research Network (ChiLDReN) underwent WES. Candidate gene variants derived from a preâspecified set of 2,016 genes associated with ciliary dysgenesis and/or dysfunction or cholestasis were prioritized according to pathogenicity, population frequency, and mode of inheritance. Five BASM subjects harbored rare and potentially deleterious biâallelic variants in polycystin 1âlike 1, PKD1L1, a gene associated with ciliary calcium signaling and embryonic laterality determination in fish, mice and humans. Heterozygous PKD1L1 variants were found in 3 additional subjects. Immunohistochemical analysis of liver from the one BASM subject available revealed decreased PKD1L1 expression in bile duct epithelium when compared to normal livers and livers affected by other nonâcholestatic diseases. Conclusion WES identified biâallelic and heterozygous PKD1L1 variants of interest in 8 BASM subjects from the ChiLDReN dataset. The dual roles for PKD1L1 in laterality determination and ciliary function suggest that PKD1L1 is a new, biologically plausible, cholangiocyteâexpressed candidate gene for the BASM syndrome
Identifying the domains of context important to implementation science: a study protocol
Background
There is growing recognition that âcontextâ can and does modify the effects of implementation interventions aimed at increasing healthcare professionalsâ use of research evidence in clinical practice. However, conceptual clarity about what exactly comprises âcontextâ is lacking. The purpose of this research program is to develop, refine, and validate a framework that identifies the key domains of context (and their features) that can facilitate or hinder (1) healthcare professionalsâ use of evidence in clinical practice and (2) the effectiveness of implementation interventions.
Methods/design
A multi-phased investigation of context using mixed methods will be conducted. The first phase is a concept analysis of context using the Walker and Avant method to distinguish between the defining and irrelevant attributes of context. This phase will result in a preliminary framework for context that identifies its important domains and their features according to the published literature. The second phase is a secondary analysis of qualitative data from 13 studies of interviews with 312 healthcare professionals on the perceived barriers and enablers to their application of research evidence in clinical practice. These data will be analyzed inductively using constant comparative analysis. For the third phase, we will conduct semi-structured interviews with key health system stakeholders and change agents to elicit their knowledge and beliefs about the contextual features that influence the effectiveness of implementation interventions and healthcare professionalsâ use of evidence in clinical practice. Results from all three phases will be synthesized using a triangulation protocol to refine the context framework drawn from the concept analysis. The framework will then be assessed for content validity using an iterative Delphi approach with international experts (researchers and health system stakeholders/change agents).
Discussion
This research program will result in a framework that identifies the domains of context and their features that can facilitate or hinder: (1) healthcare professionalsâ use of evidence in clinical practice and (2) the effectiveness of implementation interventions. The framework will increase the conceptual clarity of the term âcontextâ for advancing implementation science, improving healthcare professionalsâ use of evidence in clinical practice, and providing greater understanding of what interventions are likely to be effective in which contexts
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