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Full-Text Articles in Life Sciences
Spatial Analysis Of Factors Influencing Long-Term Stress In The Grizzly Bear (Ursus Arctos) Population Of Alberta, Canada, Mathieu Bourbonnais, Trisalyn Nelson, Mark Cattet, Chris T. Darimont, Gordon Stenhouse
Spatial Analysis Of Factors Influencing Long-Term Stress In The Grizzly Bear (Ursus Arctos) Population Of Alberta, Canada, Mathieu Bourbonnais, Trisalyn Nelson, Mark Cattet, Chris T. Darimont, Gordon Stenhouse
Physiology Collection
Non-invasive measures for assessing long-term stress in free ranging mammals are an increasingly important approach for understanding physiological responses to landscape conditions. Using a spatially and temporally expansive dataset of hair cortisol concentrations (HCC) generated from a threatened grizzly bear (Ursus arctos) population in Alberta, Canada, we quantified how variables representing habitat conditions and anthropogenic disturbance impact long-term stress in grizzly bears. We characterized spatial variability in male and female HCC point data using kernel density estimation and quantified variable influence on spatial patterns of male and female HCC stress surfaces using random forests. Separate models were developed for regions …
Stress And Reproductive Hormones In Grizzly Bears Reflect Nutritional Benefits And Social Consequences Of A Salmon Foraging Niche, Heather M. Bryan, Chris T. Darimont, Paul C. Paquet, Katherine E. Wynne-Edwards, Judit E. G. Smits
Stress And Reproductive Hormones In Grizzly Bears Reflect Nutritional Benefits And Social Consequences Of A Salmon Foraging Niche, Heather M. Bryan, Chris T. Darimont, Paul C. Paquet, Katherine E. Wynne-Edwards, Judit E. G. Smits
Physiology Collection
Physiological indicators of social and nutritional stress can provide insight into the responses of species to changes in food availability. In coastal British Columbia, Canada, grizzly bears evolved with spawning salmon as an abundant but spatially and temporally constrained food source. Recent and dramatic declines in salmon might have negative consequences on bear health and ultimately fitness. To examine broadly the chronic endocrine effects of a salmon niche, we compared cortisol, progesterone, and testosterone levels in hair from salmon-eating bears from coastal BC (n = 75) with the levels in a reference population from interior BC lacking access to salmon …