Physical Appearance and Size
Polar bears are the largest living land carnivores, with adult males typically weighing between 350 and 700 kilograms and measuring 2.4 to 3 meters in length, including the tail. Their fur appears white to yellowish and consists of a dense undercoat topped with hollow, transparent guard hairs that scatter light, giving the iconic white look. The skin beneath the fur is black, which helps absorb heat from sunlight. They have small, rounded ears and a long, streamlined head with a pronounced snout, strong curved claws, and large, paddle-like paws that aid in swimming and walking on ice Forbes.
Females are generally smaller than males, weighing 150 to 250 kilograms and measuring about 1.8 to 2.4 meters in length. Cubs are born blind and toothless, with soft grayish fur, and weigh around 0.5 to 0.7 kilograms at birth. By autumn, a healthy adult bear can accumulate a thick layer of blubber, sometimes exceeding 11 centimeters in depth, which provides insulation and energy reserves during periods of food scarcity National Park Service.
Current Population and Habitat Status
Global polar bear populations are estimated at 22,000 to 31,000 individuals, spread across 19 subpopulations in Arctic regions of Canada, Alaska, Greenland, Norway, and Russia. The International Union for Conservation of Nature lists the species as vulnerable, with several subpopulations showing declining trends due to sea ice loss. The Southern Beaufort Sea subpopulation, studied extensively near Alaska, has experienced measurable declines linked to reduced sea ice availability IUCN Red List.
Sea ice extent in the Arctic has been declining steadily, with recent satellite data showing record low winter maximum extents in multiple years. The U.S. Geological Survey tracks polar bear movements and body condition using satellite collars and aerial surveys, providing data on habitat use and survival rates. Changes in sea ice patterns directly affect hunting success for seals, the bears' primary prey, and influence migration routes and denning locations across the Arctic USGS.
Diet, Behavior, and Conservation Efforts
Polar bears are hypercarnivores, relying heavily on ringed and bearded seals for nutrition. They hunt primarily by waiting at seal breathing holes in the ice, using their acute sense of smell to detect prey from over a kilometer away. During summer months when sea ice retreats, bears may fast for extended periods, relying on stored fat reserves. Some populations have adapted by scavenging on whale carcasses or foraging on land, but these alternative food sources generally provide fewer calories World Wildlife Fund.
Conservation efforts focus on protecting critical habitat, managing human-bear conflicts, and reducing greenhouse gas emissions to slow Arctic warming. International agreements such as the 1973 Agreement on the Conservation of Polar Bears guide national policies across range states. Research institutions and wildlife agencies continue to monitor population health, reproductive success, and body condition to inform management decisions and assess the effectiveness of current protections USDA NRCS.