Den selection by barren-ground grizzly bears, Mackenzie Delta, Northwest Territories

Abstract

Animals living in highly seasonal environments such as the Arctic must cope with periods of reduced resource availability. During periods of food shortage, some resident mammals hibernate and rely on energy stores to overwinter. To conserve energy, hibernating grizzly bears (Ursus arctos) excavate dens that provide thermal insulation and safety. To determine the distribution and habitat characteristics used by grizzly bears for denning in the Mackenzie Delta, Northwest Territories, Canada, we used kernel density and resource selection function analyses based on 624 den locations collected in 1972–2014. We found that grizzly bear dens were broadly distributed with varying densities over the landscape. Our analyses showed that bears selected den sites with aquatic bed and low shrub land cover, with soil types composed of sand- , gravel- , and glacier-deposited rock, and southeastern- , southwestern- , and northern-facing slopes. Grizzly bears also selected for areas with sloped terrain. Open spruce forest was avoided. Information on grizzly bear denning habitat could be used to inform human land use planning and minimize human–bear conflicts.