Information on 35 overwinter maternity dens of Alaskan polar bears (Ursus maritimus Phipps) and on 101 female polar bears with cubs, recently emerged from dens, was obtained by aerial and ground surveys, interviews with Arctic coast residents, and literature review. Pregnant females form snow dens in October and November and give birth in December and January. Females and cubs emerge from dens in late March and April. Factors necessary for continued successful denning in an area include ice movements that enable bears to reach the area in the fall; the availability of seals as a food source and ice conditions facilitating their capture during the predenning and postdenning periods; and suitable weather conditions (snowfall, wind, and ambient temperatures) and topography that combine to produce snowdrifts that do not thaw during the denning period. Dens consist of 1 or more chambers, connecting tunnels, and entrance-exit tunnels. Alaskan dens were found as far inland as 48 km from the coast, along the coast, on offshore islands, on shorefast ice, and on drifting sea ice. Bears denning in the coastal zone are subject to human disturbance and should receive protection.
- Volume 4
- Issue
- Pages 101-108
- Publication Date 1 January 1980
- DOI 10.2307/3872850
- File Size 303.26 KB
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