ANWR progress report number FY83-8: Ecology of brown bears inhabiting the coastal plain and adjacent foothills and mountains of the northeastern portion of the Arctic National Wildlife Refuge
Published By US Fish and Wildlife Service, Department of the Interior
Issued almost 10 years ago
Summary
Description
Fifty brown bears were captured between 23 June and 3 July 1982 in the coastal plain and adjacent foothills and mountains of the northeastern portion of ANWR. Radiotransmitters were attached to 32 of the 50 bears and these bears were monitored through denning in October and early November. More females were captured in age classes 6.5 year old and less, while males were more abundant in 7.5 year old and older age classes. Survival of immature bears appears good from year to year based on the percentage of captured bears in each age class. No mortality was detected within the immature age classes. Preliminary data interpretation indicate that the coastal plain and foothills habitats may be used more often by younger age classes and females with young than older bear without young. Preliminary calculations of range size indicated that young bears moved over larger areas than adult bears. In all cases, range sizes determined in this study were less than recorded for brown bears in northwest Alaska and northeast Alaska. Brown bears were observed feeding on caribou Rangifer tarandus carcasses on 6 occasions during the study. These instances were the only recorded interactions between the 2 species, except one unsuccessful chase of a bull caribou by a bear on 23 August. Dens were located for 28 radiocollared bears and dens of 10 unmarked bears were located during aerial surveys for bear dens. Bears moved south into the foothills and mountainous habitats to den, except for 2 radiocollared bears. One brown bear denned in the coastal plain and one denned in the foothills of Marsh Creek. These 2 dens were the only bear dens located within the 1002c study area boundaries.