Temporal and spatial variation in home range size for two woodland caribou ecotypes in Ontario.

摘要

Woodland caribou (Rangifer tarandus caribou) are wide-ranging and sensitive to disturbance, making the conservation of this subspecies a priority. I investigated geographic and seasonal patterns, ecotypic differences, and potential ecological drivers of variation in home range size of woodland caribou in Ontario. Adult female caribou ( n = 131) were outfitted with GPS collars in 2009 and 2010. I applied three methods to quantify space use, including 95% minimum convex polygons. Using a mixed model approach, I examined the effects of ecological correlates on home range size at different temporal scales.;Caribou exhibited dramatic individual variation in range size at annual and seasonal scales. Annual ranges varied from 128 km2 to 98,337 km2. Summer emerged as the period with the greatest disparity in seasonal range size relative to annual range size between ecotypes, and the season with the most marked differences in land cover and meteorological predictors, suggesting differences in limiting factors. For both ecotypes, home range size appeared strongly influenced by land cover. Thus, for sedentary caribou, conifer-dominated landscapes with little edge and, for migratory caribou, sufficient spaces to provide forage and minimization of energetic costs appear critical to balancing predator avoidance and energetic requirements at the home range scale.;KEYWORDS: Rangifer tarandus, ecotype, home range, land cover, seasonal variation, ecological correlates, MCP, mixed model.