BROWN AND BLACK BEAR PREDATION ON MOOSE IN SOUTHCENTRAL ALASKA

Causes of moose (Alces alces) calf mortality were studied during 1984 in an area where brown bear (Ursus arctos), black bear (Ursus americanus), and gray wolf (Canis lupus) populations were sympatric. Predation by brown bears was the greatest cause of mortality. Brown bears averaged 1 calf and 1 adult moose kill/11.7 and 43.7 bear-days, respectively, during late May-late June, while black bears averaged 1 calf moose kill/40 bear-days during the same period. No adult mosoe were killed by black bears. There were no statistically significant differences (P > 0.05). in predation rates among sexes, ages, or family classes of either brown or black bears. Predation rates were highly variable among individual bears