Paul C. Paquet, Conservation Biology Institute, PO Box 150, Meacham, SK S0K 2V0, Canada; Steve Donelon, Alberta Department of Environment, 800 Railway Avenue, Canmore, AB T1W 1P1, Canada; Carolyn Callaghan, Zoology Department, University of Guelph, Guelph, ON N1G 2W1, Canada; Shelley Alexander, Department of Geography, University of Calgary, Calgary, AB T2N 1N4, Canada

Winter travel patterns of gray wolves (Canis lupus) living in snowy environments have not been studied extensively. We evaluated winter travel of wolves in four Canadian parks, where most packed and snow-free trails result from human activity. We examined the influence of snow conditions and human activities on winter movements and cover selection of wolves by tracking in snow during twelve winters. We postulated that wolves would use packed or snow-free travel routes rather than unmodified trails. We found wolves avoided travel routes where tracks penetrated > 40-50 cm. They also used established trails significantly more often than new or unbroken trails. Human use caused compaction of most established trails (77%). Travel in open habitats occurred most frequently on modified trails. Human-modified travel routes also allowed wolves to travel at higher elevations and in deeper snow than on natural trails. Wolves on modified trails often (40%) traversed areas where they would sink > 60 cm if forced to travel off-trail. In contrast, wolves on unmodified trails favored cover types at lower elevations with high snow-intercept values such as riparian areas and closed coniferous forest. The use of coniferous habitats increased as snow depth increased. We conclude that human-modified trails provide wolves winter access to areas that are otherwise unavailable. The influence of human activities on wolf movements may have implications for prey species, other predators, and wolf-human relationships. We caution managers to assess critically the effects of human activities that modify natural snow cover.