Life Sciences Commons^™

Salmonid Species Diversity Predicts Salmon Consumption By Terrestrial Wildlife, Christina N. Service, Andrew N. Bateman, Megan S. Adams, Kyle A. Artelle, Thomas E. Reimchen, Paul C. Paquet, Chris T. Darimont

Habitat and Trophic Ecology Collection

1. Resource waves—spatial variation in resource phenology that extends feeding opportunities for mobile consumers—can affect the behaviour and productivity of recipient populations. Interspecific diversity among Pacific salmon species (Oncorhynchus spp.) creates staggered spawning events across space and time, thereby prolonging availability to terrestrial wildlife.

2. We sought to understand how such variation might influence consumption by terrestrial predators compared with resource abundance and intra- and interspecific competition.

3. Using stable isotope analysis, we investigated how the proportion of salmon in the annual diet of male black bears (Ursus americanus; n = 405) varies with species diversity and density of spawning …

Stress And Reproductive Hormones Reflect Inter-Specific Social And Nutritional Conditions Mediated By Resource Availability In A Bear–Salmon System, Heather M. Bryan, Chris T. Darimont, Paul C. Paquet, Katherine E. Wynne-Edwards, Judit E. G. Smits

Physiology Collection

Food availability can influence the nutritional and social dynamics within and among species. Our investigation focused on grizzly and black bears in coastal British Columbia, Canada, where recent and dramatic declines in their primary prey (salmon) raise concerns about potentially negative effects on bear physiology. We examined how salmon availability relates to stress and reproductive hormones in coastal grizzly (n = 69) and black bears (n = 68) using cortisol and testosterone. In hair samples from genotyped individuals, we quantified salmon consumption using stable isotope analysis and hormone levels by enzyme immunoassay. To estimate the salmon biomass available to each …

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 …