Polar Bear Maternity Denning in the Beaufort Sea

Site fidelity of Svalbard polar bears revealed by mark-recapture positions

“…Females do not reuse exact denning sites, but are often faithful to a denning area Stirling 1990, Zeyl et al 2010) and to substrate in regions where denning on land, fast ice and drift ice occur (Amstrup and Gardner 1994). Zeyl et al (2010) found a matrilineal structure within main denning areas, indicating that daughters are highly philopatric to the area where they were born, given that autumn sea ice conditions allow them to reach the islands.…”

Barents Sea polar bears (Ursus maritimus): population biology and anthropogenic threats

“…Early snow cover is also necessary in most areas, and the terrain is important for snow accumulation. In the Beaufort Sea, about half of the dens were on drifting pack ice, half on land and some few on land-fast ice (Amstrup & Gardner 1994). There has been no evidence of offshore denning in Svalbard (Lønø 1970;Larsen 1986), and the highly dynamic sea-ice conditions in the region may explain why this behaviour is not seen.…”

“…In Hudson Bay, polar bears den in earth dens that can be up to 80 km from the coast, but bears move into snow dens as snow accumulates in autumn (Jonkel et al 1972;Richardson et al 2005). Denning philopatry among female polar bears has been shown in Hudson Bay (Ramsay & Stirling 1990), in Svalbard (Zeyl et al 2010) and the Beaufort Sea (Amstrup & Gardner 1994). Andersen et al (2012) found that most maternity dens in Svalbard are close to the coast ( B10 km).…”

“…Polar bears typically den at low densities throughout the circumpolar Arctic, but concentrated denning areas exist at Wrangel Island, Russia (Belikov 1980), Kong Karls Land, Svalbard (Larsen 1985), and south-west Hudson Bay, Canada (Jonkel et al 1972). Most maternity dens are located on land, although a few are made in multi-year sea ice off the Alaskan coast (Harington 1968;Lentfer 1975;Amstrup & Gardner 1994;Fischbach et al 2007). In Hudson Bay, polar bears den in earth dens that can be up to 80 km from the coast, but bears move into snow dens as snow accumulates in autumn (Jonkel et al 1972;Richardson et al 2005).…”

Polar bears : proceedings of the 14th Working meeting of the IUCN/SSC Polar Bear Specialist Group, 20-24 June 2005, Seattle, Washington, USA

“…Dens are excavated in snow drifts on land or offshore pack ice. Amstrup and Gardner (1994) reported that 47% of maternal dens found in Alaska occurred on land. Bears denning on land are more likely to be exposed to industrial activities than bears denning on the offshore pack ice.…”