Polar Bear

If current warming trends continue, they may disappear within 100 years

Common Name

Polar bear
Ours blanc; ours polaire (Fr);
Oso polar (Sp)

Scientific Name
Ursus maritimus

Habitat
Arctic

Location
Arctic (northern hemisphere)

Background

Majestic creature of the far north, the polar bear is the world's largest terrestrial carnivore. Its Latin name, Ursus maritimus, means "sea bear", reflecting the fact that the species spends much of its life in or around water, or actually mostly on the water as it usually found on sea ice. As the southern edge of the Arctic ice cap melts in summer, polar bears follow the retreating sea ice. Some bears are then stranded and spend their summers fasting on land, living off body fat stored from hunting in the spring and winter.

Increasing levels of carbon dioxide and other heat-trapping gases in the atmosphere from the burning of fossil fuels - oil, coal and gas - are causing global warming. As a result, annual sea ice in the Arctic is melting earlier in the spring and forming later in the autumn. Research funded by WWF has found that this leaves many polar bears with less time on the sea ice to hunt for food and build up their fat stores, and increased time on land where they must fast. As their icy habitat disappears, the survival of the polar bear is at risk.

Although the species is not currently endangered, its future is far from certain. If current warming trends continue unabated, scientists believe that polar bears may disappear within 100 years. WWF funds field research by the world's foremost experts on polar bears to find out how global warming will affect the long-term condition polar bear populations.

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Physical Description

Polar bears are the top predator in the arctic marine ecosystem. They evolved from brown bears during the Pleistocene, the time period that spanned from 1.8 million to 11,000 years ago.

The polar bear's coat, covering it completely except for the nose and foot pads, is superbly adapted to Arctic environments, where temperatures rarely exceed 10 °C (50 °F) in summer and typically hover around -30 °C (-22 °F) during winter.

Polar bears are excellent swimmers and can sustain a pace of 10 km/h by using their front paws like oars while their hind legs are held flat like a rudder.

They spend much of their time at or near the edge of the pack ice. This is where they are most likely to find food. As the southern edge of the arctic ice cap melts in summer, some bears will follow the retreating ice north to stay close to seals and other prey. Other bears spend their summers on land, living off body fat stored from successful hunting in the spring and winter. When the ice returns in the fall, the bears leave land to resume life on the sea ice.

Size
Adult males typically measure 200 to 250 cm (6.5 to 8 feet) from the tip of the nose to the tip of the tail and weigh 400-600 kg (880-1300 lbs). Females are about half this size.

Colour
It is the reflection of light that causes the fur to appear white, or yellowish white. In fact, the fur has no white pigment.

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Habitat

Major habitat type
Arctic

Biogeographic realm
Nearctic and Palearctic

Range States
Canada (Manitoba; Newfoundland; Northwest Territories; Nunavut; Ontario; Quebec; Yukon), Greenland, Norway (Svalbard), Russian Federation (Krasnoyarsk; Magadan; North European Russia; West Siberia; Yakutiya), United States (Alaska)

Geographical Location
Arctic

Ecological Region
Alaskan North Slope Coastal Tundra, Canadian Low Arctic Tundra, Taimyr and Siberian Coastal Tundra, Chukote Coastal Tundra, Bering-Beaufort-Chukchi Seas, Barents - Kara Seas, Grand Banks, Canada

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Why is this species important?

Large carnivores are sensitive indicators of ecosystem health. Polar bears are studied to gain an understanding of what is happening throughout the Arctic as a polar bear at risk is often a sign of something wrong somewhere in the arctic marine ecosystem.

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