A 5-year study of black bears (Ursus americanus) in Yosemite National Park commenced in 1974 to provide park managers with information necessary for professional stewardship of the species. At the time, both the public and the National Park Service were concerned about increasing property damage and personal injuries caused by bears, and that actions by visitors and park staff were inimical to a wild, healthy bear population. Black bear food habits were investigated to determine the role of food of human origin in bear diet. We found that plants comprised 75% of the diet of Yosemite black bears. Herbage, including grasses, sedges, and herbaceous dicots, was the principal food during spring and early summer. Nuts and berries, expecially manzanita (Arctostaphylos spp.) and oak acorns (Quercus spp.) predominated in the late summer and fall. Insects, especially ants (Formicidae), and deer (Odocoileus hemionus) were the principal animal foods. Foods of human origin constituted 15% of the bear diet. Great annual fluctuations in the proportions of the major food categories reflected varying weather patterns and efforts by the Park Service to eliminate human foods from black bear diets.
- Volume 5
- Issue
- Pages 1-10
- Publication Date 1 January 1983
- DOI 10.2307/3872514
- File Size 621.17 KB
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