The idea of a polar bear residing inside a dome-shaped snow house is a widespread misconception. Polar bears do not build or inhabit igloos, which are structures created by humans. This common confusion stems from the fact that both the bear and the structure exist in the Arctic environment and both utilize snow for shelter.
Separating Fact from Fiction: Defining the Igloo
An igloo is a shelter constructed by people, specifically the Inuit and other indigenous communities of the Arctic. The word iglu is an Inuit term meaning “house” or “shelter,” but outside of the Inuit languages, it refers exclusively to a dwelling made of compacted snow blocks. These blocks are meticulously cut from hard, wind-packed snow and arranged in a self-supporting spiral dome shape.
The igloo’s dome relies on the blocks leaning inward to provide structural integrity without an internal frame. This design, combined with the insulating properties of the snow, is highly effective at trapping heat. Inside the structure, temperatures can remain near or above freezing, even when outside air drops far below zero. Igloos traditionally served as temporary shelters for hunters or as semi-permanent winter family dwellings.
The True Home of the Polar Bear
The polar bear, or Ursus maritimus, is classified as a marine mammal because its existence is intrinsically tied to the ocean environment. Its true habitat is not a constructed dwelling but the vast, shifting expanse of the Arctic sea ice. Polar bears spend the majority of their lives on this ice platform, which extends across the circumpolar region, including areas of Canada, Alaska, Russia, Greenland, and Norway.
This sea ice is the platform from which the bears hunt their primary prey, ringed and bearded seals. They rely on the ice to ambush seals surfacing at breathing holes or to stalk them near the ice edge. The annual cycle of sea ice formation and melt dictates the bears’ movements and their ability to build up the necessary fat reserves.
How Polar Bears Use Snow and Ice
While polar bears do not build igloos, they skillfully use snow and ice for shelter in a different manner. They create snow dens primarily through excavation, digging into deep snow drifts, often on land or on stable sea ice. These excavated structures are essentially snow caves, not block-built houses.
The most significant use of a snow den is by pregnant female polar bears, who enter them in autumn to give birth and hibernate through the winter. These maternity dens offer a stable, insulated environment, keeping the interior significantly warmer than the outside air. A typical den includes a tunnel entrance leading to an oval chamber where the mother and cubs remain for several months, living off the mother’s stored fat. Other polar bears may simply dig shallow pits or troughs in the snow for temporary relief from severe cold or strong winds while resting.