Winter distribution of woodland caribou in relation to clear-cut logging in west-central Alberta

The responses of a herd of migratory woodland caribou (Rangifer tarandus ca ribou) to timber harvesting that fragmented about 11% of their winter range in west-central Alberta were examined in this study. From 1981 to 1996, 45 caribou were radio-collared and monitored during the initiation and comple tion of first-pass timber harvest (50% removal). Variables examined were ho me-range size, daily movement rates, and distance to the nearest cut block for radio-collared individuals. Daily movement rates and individual winter range sizes decreased as timber harvesting progressed. Caribou avoided usin g recently fragmented areas by an average of 1.2 km. If fragmentation of th e winter range continues through timber harvesting and other industrial act ivities, the "spacing out" antipredator strategy used by caribou may be com promised. Based on these findings, timber-harvesting strategies are recomme nded that (i) ensure an adequate area of usable habitat to support the curr ent population, (ii) minimize the amount of fragmented area, and (iii) in t he short term avoid presently defined core use areas.