page_title: Polar bear
section_title: Habitat
hierarchical_section_title: Polar bear / Habitat
caption_attribution_description: Čeština: Medvěd lední skáče mezi krami na ostrově Západní Špicberk, který spadá pod Norsko English: Polar Bear jumping, in Spitsbergen Island, Svalbard, Norway. Español: Un oso polar en pleno salto, en la isla Spitsbergen, Svalbard, Noruega. Français&#160;: Un ours blanc (Ursus maritimus) bondissant entre deux blocs de glace de la banquise fondante, sur l'île de Spitzberg, dans l'archipel norvégien de Svalbard. Polski: Niedźwiedź polarny (Ursus maritimus) skaczący między krami w pobliżu wyspy Spitsbergen, w archipelagu Svalbard należącym do Norwegii. Português: Um urso polar (Ursus maritimus) saltando entre dois blocos de gelo da banquisa em derretimento, na ilha de Spitsbergen, Svalbard, Noruega. Bosanski: Polarni medvjed (Ursus maritimus), na ostrvu Spitsbergen, Svalbard, Norveška Deutsch: Ein Eisbär (Ursus maritimus) auf Spitzbergen Magyar: Jegesmedve (Ursus maritimus) ugrik a Spitsbergen szigeten, a norvég Spitzbergákon Italiano: Orso polare (Ursus maritimus) sull'isola di Spitsbergen, Norvegia. 한국어: 노르웨이 스발바르 제도 스피츠베르겐 섬에서 도약 중인 북극곰(Ursus maritimus) Nederlands: Een springende ijsbeer op het Noorse eiland Spitsbergen. Русский: Белый медведь (Ursus maritimus) перепрыгивает со льдины на льдину. Западный Шпицберген, Норвегия.
context_page_description: The polar bear is a hypercarnivorous bear whose native range lies largely within the Arctic Circle, encompassing the Arctic Ocean, its surrounding seas and surrounding land masses. It is the largest extant bear species, as well as the largest extant predatory carnivore. A boar weighs around 350–700 kg, while a sow 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 seals, which make up most of its diet. Although most polar bears are born on land, they spend most of their time on the sea ice. 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. Because of their dependence on the sea ice, polar bears are classified as marine mammals.
  Because of expected habitat loss caused by climate change, the polar bear is classified as a vulnerable species.
context_section_description: The polar bear is a marine mammal because it spends many months of the year at sea. However, it is the only living marine mammal with powerful, large limbs and feet that allow them to cover kilometres on foot and run on land. Its preferred habitat is the annual sea ice covering the waters over the continental shelf and the Arctic inter-island archipelagos. These areas, known as the "Arctic ring of life", have high biological productivity in comparison to the deep waters of the high Arctic. The polar bear tends to frequent areas where sea ice meets water, such as polynyas and leads (temporary stretches of open water in Arctic ice), to hunt the seals that make up most of its diet. Freshwater is limited in these environments because it is either locked up in snow or saline. Polar bears are able to produce water through the metabolism of fats found in seal blubber, and are therefore found primarily along the perimeter of the polar ice pack, rather than in the Polar Basin close to the North Pole where the density of seals is low.
  Annual ice contains areas of water that appear and disappear throughout the year as the weather changes. Seals migrate in response to these changes, and polar bears must follow their prey. In Hudson Bay, James Bay, and some other areas, the ice melts completely each summer (an event often referred to as "ice-floe breakup"), forcing polar bears to go onto land and wait through the months until the next freeze-up. In the Chukchi and Beaufort seas, polar bears retreat each summer to the ice further north that remains frozen year-round.
caption: Polar bear jumping on fast ice in Spitsbergen Island, Svalbard Archipelago, Norway
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