Polar Bear Dens and Wapusk National Park
While most bears gather along the coast, some have other plans. Pregnant females remain inland in maternity dens in the heart of Wapusk National Park. Established in 1996, Wapusk National Park covers 11,475 square kilometres of the Hudson Bay lowlands.
Both Wapusk National Park and the surrounding Churchill Wildlife Management Area (established in 1978) protect one of the largest polar bear maternity denning areas in the world. This area supports approximately 100-150 denning females each year and produce on average 200-250 cubs.
The dens are unique to the polar bears of Hudson Bay. Most polar bear populations use dens made of snow or a combination of earth and snow within about 16km (10 miles) of shore. However, the western Hudson Bay population travels an average of 30-50km (20-30 miles) and some over 100+km (60 miles) inland in search of suitable denning habitat.
Their needs are quite specific in the Churchill area. They pick spots that gather ample snow, usually the south facing shores of small lakes or creeks. On the lea side of the prevailing winds, they dig into large banks of peat, hollowing out a den in the permafrost about 2-3 metres (6-9’) and one metre (3’) high.
A layer of black spruce will be found on top of these denning sites, their intertwined root systems providing strength to the ceiling and security in the winter. Forest fires, however, can destroy this ceiling, rendering the den unusable. With most fires started by lightning in this area, the hotter, dryer summers predicted with a changing climate present another potential threat to Churchill’s bears.