Get To Know Polar Bears
The polar bear, or ursus maritimus, lives in the Arctic and is found in Alaska, Canada, Russia, Greenland, and Norway. The polar bear is well adapted to survive in its Arctic home, where winter temperatures average -30 degrees Fahrenheit. The polar bear’s fur helps it blend in to its snowy environment and keeps it warm. A thick layer of fat under its two layers of fur helps it withstand extremely cold temperatures, up to -50 degrees Fahrenheit. The polar bear’s small ears and tail help decrease heat loss. The polar bear’s paws are larger than other bears’ and are partially webbed to allow it to walk easily on snow and to swim well in order to hunt its food.
Male polar bears can weigh up to 1,700 pounds and stand 8 to 10 feet tall, making the polar bear the largest carnivore in the world. Female polar bears weigh between 200 and 700 pounds and are 6 to 8 feet tall. Polar bears primarily hunt ringed seals but will eat other animals as well, such as walruses, and beluga whales. Polar bears will also consume roots, berries, kelp, fish, and birds, especially if they are trapped on or near land in the southern part of their range.
An acute sense of smell allows polar bears to smell the holes in the ice that seals use to breath from miles away. Polar bears hunt most of their food in the spring and slow their metabolism to survive on their stored fat during the warmer months. Polar bears do not hibernate. Instead they travel south during the winter and north during the summer to stay near the ice that allows them to hunt seals. Polar bears eat the seals’ fat, or blubber, which the polar bear stores in its own body as fat. As the polar bear digests the fat, it releases enough water that the polar bear rarely if ever has to drink fresh water. Polar bears wash themselves off after eating by swimming. They dry off by shaking themselves and then rolling in the snow. Polar bears also nap after eating to conserve energy.
Female polar bears most commonly have litters of twin cubs and will have about five litters over their lifetimes. The cubs are born in December or January and weigh less than two pounds. The mother and cubs stay together in a den built in snowdrift or hill during the winter and leave in April. During this time the mother bear does not leave the den and does not eat. When the bears leave the den, the mother hunts seals to feed herself and her cubs. They stay together for two years while the cubs mature. The average life span of a polar bear in the wild is 15 to 18 years. There are approximately 20,000 polar bears in the Arctic.
Polar bears communicate vocally and through body language. They wag their heads to signal a desire to play. Polar bear play imitates fighting. Polar bears will ask to share food by touching noses. Polar bears show anger and warn other animals away by hissing, snorting, roaring, or growling.
The Arctic ice is necessary for polar bears to survive. There are two kinds of Arctic sea ice: annual and multi-year. Annual ice forms in the fall near the coastline and attaches to land. Warmer spring temperatures make this ice crack, forming narrow waterways that whales and other animals use to swim. The annual ice disappears completely during summer. Multi-year ice is thicker than annual ice and is found in the center of the Arctic rather than near the coasts. This ice shrinks in summer but does not disappear.
The biggest problem facing polar bears is the loss of sea ice, which polar bears need to hunt their food. Scientists have found that the Arctic sea ice is now 40 percent thinner and are concerned that the Arctic ice cover may disappear in summer. The ice is thinning because the Arctic is warmer than in the past. Some climate scientists believe that the average temperature in the Arctic will rise by seven to 12 degrees over the next 100 years. If ice forms later in the fall and disappears earlier in the spring, the polar bear has less time to hunt and store the fat it needs to survive during the summer months. The U.S. Geological Survey estimates that two-thirds of the polar bear population will die out over the next half century if polar ice thinning continues.
The polar bear has an important place in traditional folklore of the Arctic peoples. The Inuit call the polar bear “Nanuk” and believe Nanuk to be powerful and wise. In Inuit myths, human beings learned to hunt seals from the polar bear. In some legends, the polar bear is actually a man who transforms into a polar bear by wearing fur and teaches humans about how to hunt and survive in the Arctic. Some believed that hunters had to show respect to polar bears so that the dead bear would spread his fame to other polar bears, which would make them seek out the hunter. In other legends, the shamans or magicians take the form of polar bears and become spirit bears that cannot be killed. In one legend, a woman adopts a polar bear and raises it as her son. The bear protects her and feeds her. In another legend, Nanuk the bear tried to escape from Inuit hunting dogs and ran off the edge of the world and into the sky, where he became stars. The Great Spirit, Tuurngasuk, takes the form of a polar bear in the legends of the Labrador Inuit.
The Arctic Bear: Facts about the Arctic and polar bears’ adaptations to their cold environment.
Marine Mammals: Bibliography of printed resources for further study on the polar bear and marine and sea otters.
Polar Life: Information on arctic animals, including the polar bear. Also a link to a sister site on polar environments and environmental concerns.
Polar Bear Video: Information on polar bears and environmental challenges they face. Also includes a video of polar bears hunting seals.
Polar Bear Tracker: Tracks the movement of polar bears across the Arctic. Also includes information on polar bears, online games, and polar bear news.
Polar Bear Facts: Frequently asked questions about polar bears, polar bear facts, polar bear research, maps and tracking information and information on climate change and its effect on polar bears. Also includes videos and photos.
The Polar Bear: Facts on the polar bear as well as on the other seven species of bear.
Arctic Wildlife: Information on polar bears and other Arctic species.
Polar Bear Habits: Information on breading and denning. Also information on environmental threats facing the polar bear.
Polar Bear Legend: A legend of a woman who adopted a polar bear.
The Hunter and the Polar Bear: A legend from the Inuit.
Polar Bear Facts and Myths: Facts on polar bears and their habitat.
Polar Bears and Hunting: Information on how polar bears hunt, what they eat, and what animals attack them.
Polar Bear Info Book: Facts on polar bear habitat, characteristics, behavior, adaptations, and diet. Also includes a bibliography for further research.
Status of Polar Bears: Information on threats facing polar bears and their current status.
Polar Bear Facts and Conservation: Information on polar bear size, reproduction, behavior, and habitat.
The Evolution of Polar Bears: What the fossil record reveals about polar bear evolution.
Polar Discovery: Information on the Arctic ecosystem.
Polar Bear Pictures: Information on the polar bear and its geographic distribution. Includes picture section.