Stress and Reproductive Hormones in Grizzly Bears Reflect Nutritional Benefits and Social Consequences of a Salmon Foraging Niche

摘要: Physiological indicators of social and nutritional stress can provide insight into the responses species to changes in food availability. In coastal British Columbia, Canada, grizzly bears evolved with spawning salmon as an abundant but spatially temporally constrained source. Recent dramatic declines might have negative consequences on bear health ultimately fitness. To examine broadly chronic endocrine effects a niche, we compared cortisol, progesterone, testosterone levels hair from salmon-eating BC (n = 75) reference population interior lacking access 42). As predicted, was higher both sexes relative bears, possibly reflecting density coast mediated by We also investigated associations between amount individual consumed (as measured stable isotope analysis) cortisol hair. Also decreased increasing dietary after year low than high salmon. These findings at two spatial scales suggest that experience or response on-going declines, providing novel insights resource availability fitness-related physiology.