Abstract

Topic: Predator-prey interactions


Variation in wolf predation on moose in Ontario: insight into predatory limitations on moose populations

Dani Freund1, Morgan Anderson2, John Benson3, Alex Bezzina4, John Fryxell5, Josh Holloway4, Karen Loveless4, Scott Moffatt5, Joseph Northrup4, Art Rogers6, Luke Vander Vennan7, Brent Patterson4

  1. Environment and Life Sciences Department, Trent University, Peterborough, Ontario , Canada
  2. Department of Integrative Biology, University of Guelph, Guelph, Canada
  3. University of Nebraska-Lincoln, School of Natural Resources, St. Lincoln, Nebraska, USA
  4. Trent University, Peterborough, Ontario, Canada
  5. Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada
  6. Centre for Northern Forest Ecosystem Research, Ontario, Ministry of Natural Resources and Forestry, Thunder Bay, Ontario, Canada
  7. British Columbia Ministry of Forests, NelsonBritish Columbia, Canada.

Understanding population growth patterns of moose under predation and harvest pressure is necessary for developing effective management strategies. This information is particularly pertinent in Ontario, Canada, where Indigenous communities, the provincial government, and non-government institutions have reported declines of moose populations since the early 2000’s. We investigated 379 wolf-killed moose during 51 wolf pack winters across five study areas in Ontario from 2006 to 2008 (Algonquin and Timmins) and 2010 to 2013 (Pickle Lake, Auden, and Cochrane). We found spatial and temporal variation in moose kill rates between and within study areas, some of which were attributable to both intrinsic (e.g. pack size) and extrinsic (e.g. distribution and abundance of moose and alternate prey) factors we were able to assess. Wolves generally killed more old and vulnerable moose than available in the populations at large. However, some packs killed relatively more prime-aged moose. Increased predation on prime age moose seemed to be related to low overall moose abundance, relatively high harvest of calves, and low abundance of alternate prey. From these findings we predict that 1) wolves appear to be highly selective for vulnerable moose overall, 2) in our study area, availability of vulnerable moose rather than moose density likely drives wolf kill rates; and 3) in areas where moose harvest is high, wolves may be forced to prey on more prime age moose in the winter, suggesting the impact of wolf predation on moose may be partially compensatory, additive, or even superadditive depending on local conditions.