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Full-Text Articles in Medicine and Health Sciences
Individual Trophic Niche Specialization In American Beaver (Castor Canadensis), Jimmy Taylor, Robert Francis, Scott Rush, Bronson Strickland, Guiming Wang
Individual Trophic Niche Specialization In American Beaver (Castor Canadensis), Jimmy Taylor, Robert Francis, Scott Rush, Bronson Strickland, Guiming Wang
USDA Wildlife Services: Staff Publications
The American beaver (Castor canadensis) has been described as a choosy generalist at the species/population scale, yet observational studies have shown little variation in diet among individuals. We compared isotopic values of δ13C or δ15N taken from hair of 32 beaver, representing seven colonies in northern Alabama, USA to determine 1) if colonies of beaver show overlap in isotopic niche width as a result of the similar use of food resources and 2) if individual trophic niche specialization occurs within colonies. Total Trophic Niche Width varied across the wetland with the widest being twice …
Dammed Water Quality—Longitudinal Stream Responses Below Beaver Ponds In The Umpqua River Basin, Oregon, John R. Stevenson, Jason B. Dunham, Steven M. Wondzell, Jimmy Taylor
Dammed Water Quality—Longitudinal Stream Responses Below Beaver Ponds In The Umpqua River Basin, Oregon, John R. Stevenson, Jason B. Dunham, Steven M. Wondzell, Jimmy Taylor
USDA Wildlife Services: Staff Publications
Beaver-related restoration (BRR) has gained popularity as a means of improving stream ecosystems, but the effects are not fully understood. Studies of dissolved oxygen (DO) and water temperature, key water quality metrics for salmonids, have demonstrated improved conditions in some cases, but warming and decreased DO have been more commonly reported in meta-analyses. These results point to the contingencies that can influence outcomes from BRR. We examined water quality related to beaver ponds in a diverse coastal watershed (Umpqua River Basin, OR, USA). We monitored water temperature 0–400m above and below beaver ponds and at pond surfaces and bottoms across …
An Evaluation Of Body-Grip Trap Trigger Configurations For Reducing River Otter Take Incidental To Beaver Trapping, Alec J. Sundelius, Nicholas Forman, Nathan M. Roberts, Shawn T. Rossler, David B. Ruid, Robert C. Willging
An Evaluation Of Body-Grip Trap Trigger Configurations For Reducing River Otter Take Incidental To Beaver Trapping, Alec J. Sundelius, Nicholas Forman, Nathan M. Roberts, Shawn T. Rossler, David B. Ruid, Robert C. Willging
USDA Wildlife Services: Staff Publications
River otter (Lontra canadensis) populations in North America have been the focus of significant restoration efforts. Wildlife management agencies, concerned about the unintentional take of river otters incidental to beaver (Castor canadensis) trapping, may recommend techniques to avoid capturing river otters. River otter avoidance techniques that are ineffective or diminish trap performance for beavers are undesirable. We conducted a field evaluation in 2015 and 2016 in Wisconsin to assess how two trigger configurations (offset and center) on body-grip traps would affect the incidental capture rate of river otters during beaver trapping. We also evaluated effects of …
Landscape Genetics Of American Beaver In Coastal Oregon, Clinton W. Epps, Vanessa M. Petro, Tyler G. Creech, Rachel S. Crowhurst, Matthew J. Weldy, Jimmy D. Taylor
Landscape Genetics Of American Beaver In Coastal Oregon, Clinton W. Epps, Vanessa M. Petro, Tyler G. Creech, Rachel S. Crowhurst, Matthew J. Weldy, Jimmy D. Taylor
USDA Wildlife Services: Staff Publications
American beaver (Castor canadensis) have been translocated for population restoration, reduction of human‐wildlife conflict, and enhancement of ecosystem function. Yet few studies have assessed dispersal of beaver, making it difficult to determine at what scale translocations are appropriate. Genetic studies can provide inferences about gene flow, and thus dispersal. We used a landscape genetic approach to evaluate whether landscape features influenced gene flow among beaver in the Coast Range of western Oregon, USA, using samples collected April–September 2014. We collected genetic samples from live‐captured (n=232), road‐killed (n=2) and trapper‐provided (n=58) tissue samples and genotyped them at 10 microsatellite loci. We …
Spatial Transferability Of Expert Opinion Models For American Beaver Habitat, Isidro Barela, Leslie M. Burger, Guiming Wang, Kristine O. Evans, Qingmin Meng, Jimmy D. Taylor
Spatial Transferability Of Expert Opinion Models For American Beaver Habitat, Isidro Barela, Leslie M. Burger, Guiming Wang, Kristine O. Evans, Qingmin Meng, Jimmy D. Taylor
USDA Wildlife Services: Staff Publications
Species distribution models and habitat suitability models (HSMs) have become a popular tool in the conservation of biodiversity. However, the ability to predict species spatial distributions at sites beyond the data source sites (i.e., spatial transferability) is critical for the applications of HSMs in the management and conservation of rare or endangered species. The main objective of our study was to assess the predictive performance and spatial transferability of expert opinion models (EOMs). To build EOMs, we identified through extensive literature reviews 17 key landscape variables to characterize habitat use by American beaver (Castor canadensis). We developed 31 pairwise opinion …
Relationships Between Survival And Habitat Suitability Of Semi- Aquatic Mammals, Isidro Barela, Leslie M. Burger, Jimmy Taylor, Kristine O. Evans, Ryo Ogawa, Lance Mcclintic, Guiming Wang
Relationships Between Survival And Habitat Suitability Of Semi- Aquatic Mammals, Isidro Barela, Leslie M. Burger, Jimmy Taylor, Kristine O. Evans, Ryo Ogawa, Lance Mcclintic, Guiming Wang
USDA Wildlife Services: Staff Publications
Spatial distribution and habitat selection are integral to the study of animal ecology. Habitat selection may optimize the fitness of individuals. Hutchinsonian niche theory posits the fundamental niche of species would support the persistence or growth of populations. Although niche-based species distribution models (SDMs) and habitat suitability models (HSMs) such as maximum entropy (Maxent) have demonstrated fair to excellent predictive power, few studies have linked the prediction of HSMs to demographic rates. We aimed to test the prediction of Hutchinsonian niche theory that habitat suitability (i.e., likelihood of occurrence) would be positively related to survival of American beaver (Castor canadensis), …
Habitat Selection By American Beaverat Multiple Spatial Scales, Guiming Wang, Lance F. Mcclintic, Jimmy D. Taylor
Habitat Selection By American Beaverat Multiple Spatial Scales, Guiming Wang, Lance F. Mcclintic, Jimmy D. Taylor
USDA Wildlife Services: Staff Publications
Background: Semiaquatic mammals require both aquatic and terrestrial habitats, particularly interfaces between the two habitats. As ecosystem engineers, American beaver (Castor canadensis) consume and fell a great amount of deciduous trees. We tested the prediction that open water and amounts of food resources, including hardwood forests (i.e., deciduous trees as the dominant form of vegetation), herbaceous and woody wetlands, and shrubs, would influence the second-order habitat selection (i.e., placing home ranges on the landscape) by American beaver, whereas the third-order habitat selection of American beaver would be associated with woody wetland and shrub edges. We investigated hierarchical habitat selection by …