Home range, daily movements, and reproductive biology of brown bear in southcentral Alaska
Ballard WB, Miller SD, Spraker TH. 1982. Home range, daily movements, and reproductive biology of brown bear in southcentral Alaska. The Canadian Field-Naturalist. 96(1):1-5
Twenty-three radio-collared adult brown/grizzly bears (U. arctos) were studied in the Nelchina Basin of south-central Alaska during 1978 and 1979. Radio-collared bears were seen on 85.4% of 644 radio locations. Home ranges of adult females averaged 408 km2, while those of adult males averaged 769 km2. Movement of males averaged 7.7 km/day, while females averaged 7.0 km/day. Most bears entered dens in late Oct. and emerged between April 9 and May 12 and thus were active for half of the year. Most females became reproductively mature at 4.5 yr; in 3 cases females bred successfully at 3.5 yr. A reproductive interval of 2 yr was reported in 1 case following loss of a yearling offspring. Typical breeding intervals were 3 yr. Average size of 17 cub and yearling litters was 1.9: high rates of cub loss were observed. Breeding activity was concentrated in May and June. Relative to most other North American brown bear populations, brown bears in interior Alaska had larger home ranges, females reached sexual maturity at young ages, and weaning of litters occurred earlier.
- Type
- Journal Article
- Authors
- Ballard, Warren; Miller, Sterling; Spraker, Ted
- Units
- CAKN , DENA , KATM , WRST
- Keywords
- Alaska Range, breeding season, Brown Bear, Copper River Basin, cub mortality, daily movements, Denning, Home Range, litter size, Marking Studies, Mortality, Movement, Nelchina Basin, Reproduction, reproductive interval, sexual maturity, Ursus arctos