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Polar bear facts for kids

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Polar bear
Polar Bear 2004-11-15.jpg
Conservation status
Scientific classification
Domain:
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Binomial name
Ursus maritimus
Phipps, 1774
Polar bear range map.png
Polar bear range

The polar bear (Ursus maritimus) is a large bear which lives in the Arctic. It is also called white bear or northern bear. It has black skin under the white fur. They are strong and fast, and can run as fast as 25 miles (40 km) an hour for a short distance.

Appearance

Polarbearonice
Polar bear jumping on fast ice

Polar bear fur is made up of a layer of dense underfur and an outer layer of "guard hairs", which appear white to tan but are actually translucent. The fur keeps them very warm. The skin is not white; it is black. Therefore, they can absorb sunlight efficiently. They are strong and can swim very well. Polar bears are similar in size to a normal bear but have a slimmer neck, longer legs and fur.

The only other bear of comparable size to the polar bear is the Kodiak bear, which is a subspecies of brown bear. Adult male polar bears weigh 350–700 kg (770–1,500 lb) and measure 2.4–3 metres (7 ft 10 in – 9 ft 10 in) in total length. Around the Beaufort Sea, however, mature males reportedly average 450 kg (1,000 lb). Adult females are roughly half the size of males and normally weigh 150–250 kg (330–550 lb), measuring 1.8–2.4 metres (5 ft 11 in – 7 ft 10 in) in length. Elsewhere, a slightly larger estimated average weight of 260 kg (570 lb) was claimed for adult females. When pregnant, however, females can weigh as much as 500 kg (1,100 lb). The polar bear is among the most sexually dimorphic of mammals, surpassed only by the pinnipeds such as elephant seals. The largest polar bear on record, reportedly weighing 1,002 kg (2,209 lb), was a male shot at Kotzebue Sound in northwestern Alaska in 1960. This specimen, when mounted, stood 3.39 m (11 ft 1 in) tall on its hindlegs. The shoulder height of an adult polar bear is 122 to 160 cm (4 ft 0 in to 5 ft 3 in). While all bears are short-tailed, the polar bear's tail is relatively the shortest amongst living bears, ranging from 7 to 13 cm (2.8 to 5.1 in) in length.

Compared with its closest relative, the brown bear, the polar bear has a more elongated body build and a longer skull and nose. As predicted by Allen's rule for a northerly animal, the legs are stocky and the ears and tail are small. However, the feet are very large to distribute load when walking on snow or thin ice and to provide propulsion when swimming; they may measure 30 cm (12 in) across in an adult. The pads of the paws are covered with small, soft papillae (dermal bumps), which provide traction on the ice. The polar bear's claws are short and stocky compared to those of the brown bear, perhaps to serve the former's need to grip heavy prey and ice. The claws are deeply scooped on the underside which assists in digging in the ice of the natural habitat. Research of injury patterns in polar bear forelimbs found injuries to the right forelimb to be more frequent than those to the left, suggesting, perhaps, right-handedness. Unlike the brown bear, polar bears in captivity are rarely overweight or particularly large, possibly as a reaction to the warm conditions of most zoos.

Life

They are mostly carnivorous. They eat mostly seals and fish. When Polar bears hunt, they often wait at holes in the ice, where the seals come up to breathe. They can live off of one seal for many days, but it will make them hungry if they do.

Polar bears live alone. Polar bears are black with clear fur, so in daylight, they appear white; at night, they are invisible.

Young Polar bears stay with their mothers for 1–2 years, and they become mature when they are 5–6 years old. People think Polar bears can become 25–30 years old in nature, but in captivity (for example, in zoos), they can become up to 45 years old.

Polar bears live in countries in the Arctic Circle, including these:

Polar bear cubs

Ursus maritimus us fish
Cubs are born helpless and typically nurse for two and a half years
Ursus maritimus Polar bear with cub 2
Mothers and cubs have high nutritional requirements, which are not met if the seal-hunting season is too short

The breeding time is 8 months. The babies are born six weeks after their mother mates. At birth, a baby cub weighs less than 2 pounds (0.9 kilograms). The mother feeds the babies milk, which makes them grow fast, and after 10 weeks, the cubs weigh about 20 to 25 pounds (9.1 to 11.4 kilograms). Young polar bears wrestle in the snow to build their strength and skills. They practice using their strong paws, and they show off their big, sharp teeth.

Mother polar bears will do anything to protect their young. They can kill a predator with just one swat of their powerful front paws. Scientists have even seen a mother polar bear stand up and leap at a helicopter to keep it away from her cubs.

During the first year, the cubs begin to eat solid food but still nurse from their mother. They begin to learn to hunt and swim. But they cannot live on their own. By the time they are two years old, the cubs have grown into large bears. They leave their mother and strike off into territory of their own. They hunt and live alone. But they play with other bears they meet. Polar bears are ready to mate when they are five or six years old. They are adults by this time and weigh 330 to 660 pounds (150 to 300 kilograms).

Polar bear adults

Polar Bears Play fight
Subadult polar bear males frequently play-fight. During the mating season, actual fighting is intense and often leaves scars or broken teeth.

Both male and female polar bears live to be as much as 30 years old (in a zoo). Polar bears have 42 teeth.

As adults, male bears fight with each other over a female. Each male fluffs out his coat of fur to make himself look bigger. Then, he swaggers along, growling, to scare off his rival. Polar bear scientists call this "the cowboy walk." The polar bear eats seals, fish and fruits (berries). They can be up to 250cm long and 160cm tall and weigh up to 600kg.

When two polar bears meet, they have a special way of greeting each other. They circle around each other for a while, grunting. Then they come closer and touch noses.

History

The polar bear was the most dangerous animal to hunt. It was also greatly respected for its strength and spirit. The bear's blubber, meat, and fur all help the Inuit survive. The Inuit gave thanks and respect in turn. After a hunt, they held a celebration that lasted for several days. Then, a polar bear dance was held. Finally, the bear's skull was set on an ice floe to release its spirit back into the Arctic.

Paws

Polar Bear Eating
Polar Bear Eating

A polar bear's paws are perfect snowshoes for them. The bottoms are wide and covered with fur to help keep the bear from slipping. The sharp claws help grip the ice.

A polar bear can crawl across ice too thin for a human to walk on. They spread out their legs and lay their bellies flat on the ice. Then they use their claws to slowly push themselves across the ice.

Mating

Female polar bear (Ursus maritimus) with cub, Svalbard
Mother and cub on Svalbard
Ursus maritimus Steve Amstrup
A Polar bear mother with her babies

Polar bears mate in April or May. The cub is born in December, when the mother is hibernating. The cub stays in the den with the mother until March, then, they all come out. They eat immediately after hibernating. Sometimes, because of global warming, this is impossible and the cubs die before they have had a chance to live. The cub leaves its mother in 2-3 years.

Life expectancy

Polar bears rarely live beyond 25 years. The oldest wild bears on record died at age 32, whereas the oldest captive was a female who died in 1991, age 43. The causes of death in wild adult polar bears are poorly understood, as carcasses are rarely found in the species's frigid habitat. In the wild, old polar bears eventually become too weak to catch food, and gradually starve to death. Polar bears injured in fights or accidents may either die from their injuries, or become unable to hunt effectively, leading to starvation.

Liver

The polar bear's liver contains a lot of vitamin A. Inuit people knew that eating the liver could cause sickness and death. Several groups of European polar explorers were seriously ill after eating livers. The symptoms included drowsiness, wanting to sleep, being irritable, headaches, and vomiting. After 24 hours, people's skin began to peel off.

In culture

PolarBearWalrusTuskCarving
Engraving, made by Chukchi carvers in the 1940s on a walrus tusk, depicts polar bears hunting walrus

Indigenous folklore

For the indigenous peoples of the Arctic, polar bears have long played an important cultural and material role. Polar bear remains have been found at hunting sites dating to 2,500 to 3,000 years ago and 1,500-year-old cave paintings of polar bears have been found in the Chukchi Peninsula. Indeed, it has been suggested that Arctic peoples' skills in seal hunting and igloo construction has been in part acquired from the polar bears themselves.

The Inuit and Alaska Natives have many folk tales featuring the bears including legends in which bears are humans when inside their own houses and put on bear hides when going outside, and stories of how the constellation that is said to resemble a great bear surrounded by dogs came into being. These legends reveal a deep respect for the polar bear, which is portrayed as both spiritually powerful and closely akin to humans. The human-like posture of bears when standing and sitting, and the resemblance of a skinned bear carcass to the human body, have probably contributed to the belief that the spirits of humans and bears were interchangeable.

The Nenets of north-central Siberia placed particular value on the talismanic power of the prominent canine teeth. These were traded in the villages of the lower Yenisei and Khatanga rivers to the forest-dwelling peoples further south, who would sew them into their hats as protection against brown bears. It was believed that the "little nephew" (the brown bear) would not dare to attack a man wearing the tooth of its powerful "big uncle", the polar bear.

Symbols and mascots

GRE-10-Greenland-5 Kroner (1911)
Greenland's 1911 five kroner note depicting a polar bear
Coat of arms of the Chukotka Autonomous Okrug in the Russian Federation
Coat of arms of the Greenlandic Self-Rule government (Kalaallit Nunaat)

Their distinctive appearance and their association with the Arctic have made polar bears popular icons, especially in those areas where they are native. The Canadian two-dollar coin carries an image of a lone polar bear on its reverse side, while a special millennium edition featured three. Vehicle licence plates in the Northwest Territories in Canada are in the shape of a polar bear, as was the case in Nunavut until 2012; these now display polar bear artwork instead. The polar bear is the mascot of Bowdoin College, Maine; the University of Alaska Fairbanks; and the 1988 Winter Olympics held in Calgary. The Eisbären Berlin hockey team uses a roaring polar bear as their logo, and the Charlotte, North Carolina hockey team the Charlotte Checkers uses a polar bear named Chubby Checker as their mascot.

Coca-Cola has used images of the polar bear in its advertising, and Polar Beverages, Nelvana, Bundaberg Rum, Klondike bars, and Fox's Glacier Mints all feature polar bears in their logos.

Fiction

Polar bears are popular in fiction, particularly in books for children or teenagers.

Images for kids

See also

Kids robot.svg In Spanish: Ursus maritimus para niños

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