9th International Deer Biology Congress

AUTHORS: Mitchell J. Flowers, Evelyn H. Merrill – Department of Biological Sciences, University of Alberta, Canada; Mark Hebblewhite, W.A. Franke College of Forestry & Conservation, University of Montana

ABSTRACT: The success of different migratory strategies among the Ya Ha Tinda (YHT) elk herd has changed following two decades of population decline, with fewer animals summering in Banff National Park and more becoming year-round residents or migrating east onto industrial forest lands every year.1,2 Resident elk wintering at YHT are habituated to human disturbance affording them more foraging opportunities (via multi-tasking) in winter than western migrants not habituated to humans. If eastern migrants also are habituated to humans in summer because of high recreational use on forest lands, this may partially explain their recent increase. To investigate how elk respond to predation risk—and how these responses may influence each migratory strategy’s vulnerability to predation—we compare the fine-scale spatiotemporal responses of migratory herd segments to humans and predators using time-to-event (TTE) modeling4 with data from 44 remote cameras placed throughout the winter range of the YHT. Cameras were distributed evenly among open, closed, and edge habitats at various distances from human activity. Photographs document when elk, wolves, cougars, grizzly bears, and humans use each site and provide estimates of how many individuals were present. We used a mixed effects Cox proportional hazards model to determine how the time between elk visitations (TTE) is influenced by time of day, elk group size and composition, recent predator presence, and site characteristics (e.g. distance to roads, vegetative cover, and topography). Preliminary results indicate the time between elk visitations is longer after wolves have been detected and shorter with the presence of bulls, larger group sizes, and in predominantly open habitats. With camera traps becoming an increasingly common tool for wildlife research, this purpose-driven sampling design offers a novel and non-invasive approach for determining how landscape features and human disturbance can alter the relative importance of space and time in shaping predator-prey interactions.