The polar bear (Ursus maritimus) is a carnivorous bear whose native range lies largely within the Arctic Circle, encompassing the Arctic Ocean, its surrounding seas and surrounding land masses. It is a large bear, approximately the same size as the omnivorous Kodiak bear (Ursus arctos middendorffi). A boar (adult male) weighs around 350–700 kg (770–1,500 lb), while a sow (adult female) is about half that size. Although it is the sister species of the brown bear, it has evolved to occupy a narrower ecological niche, with many body characteristics adapted for cold temperatures, for moving across snow, ice, and open water, and for hunting the seals which make up most of its diet. Although most polar bears are born on land, they spend most of their time at sea. Their scientific name means "maritime bear", and derives from this fact. Polar bears hunt their preferred food of seals from the edge of sea ice, often living off fat reserves when no sea ice is present.
A grizzly–polar bear hybrid (also pizzly bear, prizzly bear, or grolar bear) is a rare ursid hybrid that has occurred both in captivity and in the wild. In 2006, the occurrence of this hybrid in nature was confirmed by testing the DNA of a strange-looking bear that had been shot near Sachs Harbour, Northwest Territories on Banks Island in the Canadian Arctic.
Possible wild-bred polar bear-grizzly bear hybrids have been reported and shot in the past, but DNA tests were not available to verify the bears' ancestry.