YUKON MOOSE: I. SEASONAL RESOURCE SELECTION BY MALES AND FEMALES IN A MULTI-PREDATOR BOREAL ECOSYSTEM

Abstract

Moose (Alces alces) in Yukon experience an extreme range of thermal conditions, highly variable snow depths, natural and anthropogenic disturbances, predation by wolves and grizzly bears, and hunting pressure. Our objective was to identify variables that best explained habitat-selection patterns of moose in south-central Yukon for use in land-use planning and impact assessment. We evaluated selection of land-cover class, elevation, aspect, predation risk, and harvest vulnerability using resource selection functions. We created pooled models for males and females by averaging models for individuals by sex and season. Selection of shrub-dominated land cover highlighted the importance of forage accessibility throughout the year. Selection for elevation, aspect, and cover changed throughout the year, as influenced by climatic conditions. By selecting mixed cover types during calving and summer, female moose presumably balanced needs for both cover and forage. Males minimized harvest vulnerability during rut. Moose, in general, demonstrated highly variable habitat selection; however, consistent individual responses between sexes supported trends identified by pooled selection coefficients, as well as detected trends among males and females. The greatest amount of individual variation occurred during the growing season and the least amount during late winter, suggesting that climatic factors limited the options available to moose at a critical time of the year.