WINTER HABITAT USE BY PTARMIGAN, SNOWSHOE HARES, RED FOXES, AND RIVEROTTERS IN THE BOREAL FOREST - TUNDRA TRANSITION ZONE OF WESTERN QUEBEC

We investigated species-habitat relationships of the midsized fauna in habiting the transition zone between the boreal forest and forest tund ra of subarctic Quebec. Data were collected during a winter aerial tra ck survey of 46 randomly selected 25-km(2) plots. The presence of spec ies tracks and habitat variables were recorded for each 1-km section o f riparian edge habitat within a plot. Sections of non-riparian habita t were also surveyed. Logistic regression was used to construct habita t models for ptarmigan (Lagopus spp.), snowshoe hares (Lepus americanu s), red foxes (Vulpes vulpes), and river otters (Lutra canadensis). Sp ecies' habitat type selection was studied by comparing use and availab ility. Kendall's correlation coefficients were computed to analyze int errelations between variables. Significant logistic regressions were o btained for each species. The index of rank correlation between the ob served responses and predicted probabilities for all pairs of observat ions ranged from 0.67 for ptarmigan to 0.84 for river otters. Species abundance was negatively associated with latitude except for that of s nowshoe hare, which showed a stronger negative link with open habitat. For all species, distribution was not proportional to the frequency o f occurrence of habitat types. Non-riparian habitat was either avoided or not significantly preferred by all species. Herbivorous species an d river otter selected edge habitats along watercourses. Our study sug gests that differences presented by the forest tundra and boreal fores t are of importance for wildlife.