Both predator and prey have numerous ways of sensing each other’s presence and it’s well known that prey alter their behaviour in response to predation risk across a variety of spatial and temporal scales. The level of fear experienced by prey may influence how strongly they respond to changes in predation risk and past experience with specific predators can greatly increase an individual’s chance of survival when entering novel environments – or when returning from seasonal migrations
While numerous studies equate mortality sites to areas of high risk, a prey animal’s perception of predation risk¾and the precautionary behaviours that follow ¾can be initiated long before a predator is directly encountered. In particular, many ungulates have been shown to alter their behaviour when faced with the immediate risk of predation, reducing visitation time and increasing vigilance when detecting fresh predator sign. Based on the assumption that a prey’s assessment of predation risk is partially informed by the detection of sign left by a predator’s passage, I will measure the local activity of wolves, cougars, and humans with remote cameras to investigate (i) how elk respond to local patterns of predator activity and (ii) how the intensity of these responses may differ between elk with different migratory strategies.
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 elk to humans and predators using time-to-event (TTE) modeling with data from 44 remote cameras placed throughout the winter range of the YHT. 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 near roads and after wolves and grizzlies have been detected, but shorter with larger group sizes in summer, 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.
Presentations:
Flowers, M., Hebblewhite, M. and E. Merrill. 2018. Using remote cameras to investigate how elk respond to predators in winter. Presentation. International Deer Biology Congress, Estes Park, Colorado, USA.
Flowers, M., Melsted, J., Hebblewhite, M. and E. Merrill. 2018. Using remote cameras to investigate elk responses to wolves across seasons. Poster Presentation. Alberta Chapter of The Wildlife Society Conference, Lethbridge, AB, Canada.
Technical Reports:
Martin, H., Hebblewhite, M., K. MacAulay, M. Flowers, J.E. Berg, E. Spilker, J. Killeen, and E. Merrill. 2016. Ya Ha Tinda elk and predator study: Annual report 2016–2017. Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada. 56 pp.
Funding Agencies:
Alberta Conservation Association
Safari Club International—Northern Alberta Chapter
Contact:
flowers@ualberta.ca