Polar bears are apex predators uniquely adapted to the challenging Arctic environment. They possess a thick white coat and a substantial layer of insulating fat, helping them endure extreme cold. Sea ice is a crucial platform for their survival and hunting activities.
Global Distribution of Polar Bears
Polar bears inhabit the circumpolar Arctic, with their global distribution spanning five primary countries. These “range states” include Canada, Russia, Greenland (an autonomous territory of Denmark), Norway, and the United States (Alaska). Their presence is not uniform, reflecting variations in habitat suitability and ice conditions.
Canada hosts the largest proportion of the world’s polar bear population, accounting for approximately 60%. These bears are found across Canada’s expansive northern territories, including significant populations in Hudson Bay. Russia, with its vast Arctic coastline, also supports substantial polar bear populations, though some groups are less extensively studied.
Greenland shares several polar bear subpopulations with neighboring Canada. Norway’s polar bears are primarily located around the Svalbard archipelago and within the Barents Sea region. In the United States, polar bears are found exclusively in Alaska, particularly within the Chukchi Sea and Southern Beaufort Sea subpopulations.
Essential Arctic Habitats
Polar bear existence in these countries is directly linked to specific environmental conditions defining their Arctic habitats. Sea ice is the most important component, serving as a dynamic platform for hunting their primary prey, seals. Polar bears hunt by waiting near seal breathing holes or stalking seals resting on the surface.
Beyond hunting, sea ice provides pathways for polar bears to travel vast distances in search of prey and mates, and serves as a resting place. They frequent areas where sea ice meets open water, such as polynyas and leads, as these locations are biologically productive and attract seals. Habitat quality is largely determined by the type and extent of sea ice, with a preference for annual ice over continental shelves where productivity is highest.
Pregnant female polar bears require specific denning sites for giving birth and raising cubs. These maternity dens are excavated in snowdrifts on land, often along coastal bluffs, riverbanks, or hillsides. Some populations also utilize stable, land-fast sea ice for denning. These dens offer insulation, maintaining warmer temperatures inside. When sea ice melts during summer, bears move onto land, relying on stored fat reserves due to food scarcity.
Status and Conservation Across Regions
The global polar bear population is estimated at 22,000 to 31,000 individuals across the Arctic. The International Union for Conservation of Nature (IUCN) classifies the species as vulnerable. While some subpopulations show stability or increases (e.g., Kane Basin, M’Clintock Channel), many others are declining (e.g., Western Hudson Bay, Southern Beaufort Sea).
The primary threat to polar bears is the loss of sea ice habitat, driven by climate change. Rising Arctic temperatures reduce sea ice availability, impacting their ability to hunt, travel, and reproduce. Other challenges include increasing human-wildlife conflicts, as bears are forced onto land longer and may approach settlements for food. Industrial development (e.g., oil and gas exploration) and environmental pollution also pose risks.
International cooperation is important for polar bear conservation. The five range states—Canada, Denmark (Greenland), Norway, Russia, and the United States—signed the 1973 Agreement on the Conservation of Polar Bears. These nations regularly coordinate conservation efforts, including a Circumpolar Action Plan. This plan addresses threats, from mitigating human-bear conflicts to managing climate change impacts. National initiatives, such as listing polar bears as a threatened species under the U.S. Endangered Species Act, also provide legal protections.