Spatial factors related to mortality and population decline of endangered mountain caribou

摘要: Mountain caribou are an endangered ecotype of woodland (Rangifer tarandus caribou) that historically occurred throughout the high snowfall regions southeast British Columbia and northwestern United States. The decline in is thought to be due apparent competition where increases inearly-seral conditionsstimulateanumerical responseinprimaryungulate preyandtheir predators these incidentally kill unsustainable number caribou. Based on known location death 207 radio collared animals, we tested hypotheses pertaining relationships between landscape composition predator-specific mortality mountain at 2 ecologically based spatial scales. Relative conditions within subpopulation boundaries (level 1) or home ranges 2), were greater risk predation low elevations particularly otherwise complex terrain (i.e., valleys) with more variation overstory canopy closure road densities. Caribou vulnerability bears was also positively related age. Cougar not roads complexity but often landscapes warmer aspects proportions stands <120 years. Wolf primarily broader scale association finer scale. Our results indicate a function both static (e.g., terrain) dynamic conditions) factors, did find evidence localized habitat fragmentation forest harvest influenced This result inconsistent hypothesis suggests change largely functions scales involving can beyond those occupied by caribou, including winter primary ungulate prey. These changes season-dependent dispersion other ungulates their may influence Although interrelated, further contribute increasing efficiency movement some thereby encounter rates 2013 Wildlife Society.