Home range activities of 21 adult, 1 subadult, and 10 yearling black bears (Ursus americanus) in west-central Idaho were studied between March 1975 and December 1976. Adult males occupied significantly larger and less stable home ranges and ranged farther between radio-locations than adult females or yearlings. Habitat selection and movements were governed primarily by the distribution, availability, and phenology of key food plants. Home ranges overlapped extensively within and between sex-classes. Females separated from their yearling offspring about 1 June; however, occasional reassociations occurred shortly after the initial breakup. Dispersal appeared to occur primarily in the 2.5-year-old age group. The nondenning period extended from about the second week of April to about the last week of November. Time of entrance into and emergence from dens was highly variable among bears and between years. The minimum breeding age for females was 3.5 years; regular alternate-year breeding was not noted. Breeding began in late May, peaked in June, and extended through late July. Mean litter size was 1.9 cubs with a nearly even sex ratio. The reproductive rate was 0.782.
- Volume 4
- Issue
- Pages 181-190
- Publication Date 1 January 1980
- DOI 10.2307/3872865
- File Size 446.03 KB
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