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

Abstract: The responses of a herd of migratory woodland caribou (Rangifer tarandus caribou) 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 completion of first-pass timber harvest (50 % removal). Variables examined were home-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 using recently fragmented areas by an average of 1.2 km. If fragmentation of the winter range continues through timber harvesting and other industrial activities, the “spacing out ” antipredator strategy used by caribou may be compromised. Based on these findings, timber-harvesting strategies are recommended that (i) ensure an adequate area of usable habitat to support the current population, (ii) minimize the amount of fragmented area, and (iii) in the short term avoid presently defined core use areas. Résumé: Nous avons étudié les réactions d’un troupeau de Caribous des bois (Rangifer tarandus caribou) en migra-tion à la coupe de bois qui a fragmenté environ 11 % de son ravage dans le centre ouest de l’Alberta. De 1981 à 1996, 45 caribous ont été munis de colliers émetteurs et suivis depuis le début de l’opération de coupe de bois jusqu’à la fin de la première coupe (coupe de 50 %). Nous avons examiné la taille du domaine, les taux de déplacement et la distance jusqu’au parterre de coupe le plus proche. A mesure que la coupe progressait, les taux de déplacement quoti