Oral presentation- Open Session 12th International Mammalogical Congress

Reexamining the role of food in the snowshoe hare cycle (#303)

Yasmine N Majchrzak 1 , Michael J.L. Peers 1 , Rudy Boonstra 2 , Charles J Krebs 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 Toronto Scarborough, Scarborough, Ontario, Canada
  3. University of British Columbia, Vancouver, British Columbia, Canada
  4. McGill University, Montreal, Quebec, Canada
  5. Trent University, Peterborough, Ontario, Canada

Understanding the causes behind population cycles is a fundamental issue in ecology. The primary objective of this project is to examine the effects of food limitation on the survival and reproduction of snowshoe hares (Lepus americanus) which undergo 10-year cycles. We work in the southwest Yukon where previous studies supplemented food for hares on large study grids with the net result being high immigration and limited improvement in survival. We radio-collared hares at Kluane Lake, Yukon, Canada, and selected individuals were fed throughout the winter with known amounts of commercial rabbit chow administered from selective feeders. We monitored daily survival using VHF telemetry from the fall through spring. Females from both treatment and control groups were placed in maternity cages just prior to giving birth. Food supplemented individuals experienced increased survival and reproductive output over controls. Fed females gave birth to larger offspring and had larger litter sizes in comparison to control females. These results demonstrate a potentially strong effect of food limitation on the snowshoe hare cycle, given that demographic parameters linked to the decline (i.e. adult survival, reproductive output) were significantly affected by food addition. Our current understanding of the fundamental drivers of the cycle may need to be re-evaluated given these findings.