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Interesting Facts About The Polar Bear
Polar bears are the largest bears on earth. Males of the species weigh 900 to 1,200 pounds on average and females are approximately half that size. The largest polar bear ever recorded weighed over 2,000 pounds. Although the average weight of the species makes them the largest bears on the planet, the single largest bear ever recorded was actually a Kodiak bear, which is a subspecies of the grizzly.
Polar bears make their living on the ice at the top of the world. They are native to regions all around the Arctic Circle where the sea ice remains for most or all of the year. They are nomadic hunters that rely heavily on the ocean for their survival.
The adults of the species are solitary, with the only long-term groups consisting of a mother and her cubs. Adults tend to avoid each other, but they do not usually fight except in the case of males seeking to mate with a female. Polar bears are not territorial, so bears living in the same general area do tend to run into each other from time to time.
Seals are the main source of food for polar bears, and they are very adept at hunting them. When their mother is hunting, the cubs are expected to stay still and silent, or their mother will discipline them for failing to do so. During the summer, some bears come onshore and forage for berries and other edible plant matter.
Polar bears are good swimmers and spend considerable time in the water. During warmer periods of the year and in warmer regions, bears swim between ice floes regularly. Mother will allow young cubs to ride on their backs during these trips if they are not strong enough to make it on their own.
Non-reproductive females, adolescents, and adult male polar bears do not hibernate. They will build and use dens during bad weather, but they do not enter the typical winter period of inactivity that other bears do. Pregnant females are the only polar bears that appear to hibernate.
The Anatomy of a Polar Bear
The thick white fur of the polar bear is responsible for keeping them warm in the cold habitat they inhabit. Each individual hair is hollow, a feature that traps warm air against the bear's skin. The hairs are also colorless and only appear white or cream thanks to the reflection of the sun's rays. The coat of a polar bear is oily and water repellent, enabling them to shake dry after swimming.
Polar bears have small ears and a short tail compared to other bears. This is because any part of the body that sticks out too far could lose too much heat in the cold. Thanks to all of these survival mechanisms, polar bears actually overheat more readily than they get cold!
Polar bears also have massive feet that serve as snowshoes, and short, thick claws that act as crampons on the ice. In addition to their claws, polar bears have textured paw pads that are used to help maintain their footing on the ice. They are well-equipped for swimming too, with webbed toes that they can use to propel themselves through the water.
Polar Bear Reproduction and Growth
Female polar bears are sexually mature at 4 to 5 years of age. They mate in the spring and summer, but have a special ability to delay implantation of the fertilized eggs until the fall, when they den for the year. The one to three cubs are born in their mother's ice den during the middle of winter and weigh only around a pound each.
Polar bear milk is high in fat and protein, and the cubs grow quickly. They typically spend around three months in the den with their mother before emerging in the spring. The infant and juvenile period are the longest stretch of time that a polar spends with another of its own species. They will live with their mother for 2 to 2 1/2 years before finally going their own way.
Adolescent polar bear siblings sometimes stay together for a period of time after leaving their mother. They will not be sexually mature until the age of 4 or 5. Females will breed then, but males will not be large enough to compete with older males for access to females for several more years. Most breeding males are 8 to 10 years of age or older.