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 Fryxell², Josh Holloway⁴, Karen Loveless⁴, Scott Moffatt⁵, Joseph Northrup⁴, Art Rogers⁶, Luke Vander vennan⁷, Brent Patterson⁴

Trent University, Environment and Life Sciences Department, Peterborough, ON, K9J 8M5, Canada
Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada
University of Nebraska-Lincoln, School of Natural Resources, 3310 Holdredge St., Lincoln, NE 68583, United States of America
Trent University, DNA Building, 2140 East Bank Drive, Peterborough, Ontario, Canada K9J 7B8
Department of Integrative Biology, University of Guelph, 50 Stone Road E., Guelph, Ontario, N1G 2W1 Canada
Centre for Northern Forest Ecosystem Research, Ontario Ministry of Natural Resources and Forestry, Thunder Bay, Ontario, Canada
British Columbia Ministry of Forests, #401-333 Victoria Street, Nelson, BC V1L 4K3, Canada.

Abstract
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.