The demographic consequences of partial migration among woodland caribou in fragmented landscapes

Partial migration behavior is common across taxa despite evolutionary logic that differential demographic consequences could fix for particular strategies in each system. Woodland caribou in the Canadian Rockies exhibit genetic evidence of mixed lineages of diverged Beringian-Eurasian migratory caribou and North American sedentary caribou subspecies. While both behaviors remain in Canadian Rockies populations, the selective balance between sedentary and migratory strategies may be subject to recent alteration by anthropogenic habitat fragmentation, as mediated by predation. We used Cox proportional hazards modeling to assess the relative impact of migratory behavior, genetic signature, and habitat fragmentation on survival of a sample of >300 radio-marked caribou from 1998-2008.