Oral presentation- Open Session 12th International Mammalogical Congress

Climate-mediated variability in predator-prey dynamics: Impacts of climate change on snowshoe hares (#212)

Michael J L Peers 1 , Yasmine N Majchrzak 1 , Charles J Krebs 2 , Rudy Boonstra 3 , Emily K Studd 4 , Allyson K Menzies 4 , Dennis L Murray 5 , Stan Boutin 1
  1. University of Alberta, Edmonton, Alberta, Canada
  2. University of British Columbia, Vancouver, British Columbia, Canada
  3. University of Toronto Scarborough, Scarborough, Ontario, Canada
  4. McGill Unversity, Montreal, Quebec, Canada
  5. Trent University, Peterborough, Ontario, Canada

Predicting the impacts of climate change on community structure remains challenging due to the complexities in understanding how climate disruption will alter predator-prey dynamics. Predator species may be increasingly favoured if consumption rates are increased under climate change through improvements in variables such as capture efficiency. In multi-predator systems, changes in risk may result in either additive or compensatory mortality on the prey species depending on whether climate change leads to similar or inverse relationships in the consumption rate of each predator. These intricacies of climate change remain largely unexplored, mainly because of the difficulties of monitoring detailed changes in climate conditions coupled with cause-specific survival of the target species. Snowshoe hares (Lepus americanus) are a keystone prey species of the boreal forest, and the numerical response of several predator species are associated with their fluctuating abundance. Hares have a lower foot load relative to other species, providing them with an advantage in soft, deep snow over their predators. Increased temperatures and the frequency of freeze-thaw events may increase susceptibility of hares to predation throughout their range by reducing snow depths and increasing snow hardness. Cause-specific survival of snowshoe hares in the Yukon, Canada was monitored for three winters along with daily climate conditions such as temperature, snow depth and hardiness. We demonstrate complexities of climatic drivers on hare mortality risk from their two main predators, Canada lynx (Lynx canadensis) and coyote (Canis latrans) and discuss the potential importance of these findings on hare population dynamics over time.