FINE-SCALE WINTER HABITAT SELECTION BY MOOSE IN INTERIOR MONTANE FORESTS

Abstract

Clarification of animal activity during habitat studies may facilitate understanding of the complexities of habitat selection. Animal activity is difficult to determine with remote monitoring (e.g., GPS collars). We used snow-tracking and vegetation sampling to examine site-level habitat selection by moose (Alces alces) within late-winter range in montane forests in southwestern British Columbia. We assessed vegetation characteristics within systematically placed available plots, and moose use plots, divided into foraging and travelling plots. Willow (Salix spp.), red osier dogwood (Cornus stolonifera), and saskatoon (Amelanchier alnifolia), together termed "moose shrubs", made up 83% of browse events recorded. Moose foraging plots had greater coverage of total shrub, moose shrub, and willow, lower canopy cover, and fewer trees than available and travelling plots; snow depth did not influence moose foraging activity. Moose foraging areas had 2.4 times more total shrub coverage, 3.8 times more moose shrub coverage, and 4.4 times greater willow coverage than available plots. Moose travelling plots had less snow depth and were located closer to seral edges than available and foraging plots. Multivariate modeling indicated moose selected foraging areas where cover of shrubs was higher; willow coverage alone explained a significant amount of model fit. Moose traveled in areas with shallower snow depth, decreased distance to seral edge, and lower amounts of moose shrub, although these variables explained little of the variation in the data. Managers wishing to provide high quality late-winter moose range in interior montane environments should manage habitats to promote both forage production and reduced travel costs. Only a few key forage species appear to be preferred by moose during late winter in any particular area. These species can be readily identified, and production of these preferred browse species enhanced.