Polar Bears

 

This week we are looking at the polar bear, the polar bear is a large bear native to the Arctic and nearby areas. It is closely related to the brown bear, and the two species can interbreed. The polar bear is the largest extant species of bear and land carnivore, with adult males weighing 300–800 kg.

They are a powerful symbol of the strength and endurance of the Arctic. The polar bear's Latin name, Ursus maritimus, means "sea bear." It's an apt name for this majestic species, which spends much of its life in, around, or on the ocean–predominantly on the sea ice. In the United States, Alaska is home to two polar bear subpopulations.

They are good swimmers and can sustain a pace of six miles per hour by paddling with their front paws and holding their hind legs flat like a rudder. They have a thick layer of body fat and a water-repellent coat that insulates them from the cold air and water.

These bears spend over 50% of their time hunting for food. A polar bear might catch only one or two out of 10 seals it hunts, depending on the time of year as well as other things. Their diet mainly consists of ringed and bearded seals because they need large amounts of fat to survive.

They rely heavily on sea ice for traveling, hunting, resting, mating and, in some areas, maternal dens. But because of ongoing and potential loss of their sea ice habitat resulting from climate change–the primary threat to polar bears Arctic-wide–polar bears were listed as a threatened species in the US under the Endangered Species Act in May 2008. As their sea ice habitat recedes earlier in the spring and forms later in the fall, polar bears are increasingly spending longer periods on land, where they are often attracted to areas where humans live.

 They can run as fast as 40 kilometres per hour—but only for short distances. Younger, leaner bears are the best runners and are able to cover two kilometres’ without stopping. Older and larger bears, on the other hand, quickly overheat. However, they can only swim up to 10 kilometres per hour.

They have 42 razor sharp teeth: With jagged back teeth and canines larger than grizzly teeth, that would be quite the bite. Their paws are 30 cm wide which is big which act as a natural snowshoe that helps the bear trek across treacherous ice and deep snow. They also have 3 eyelids: The third helps protect the bear's eyes from the elements and they have 4 inches of fat under their skin to keep it warm. Their skin is black, and their fur is transparent, and they have a blue tongue.

During autumn pregnant polar bears make dens in earth and snowbanks, where they'll stay through the winter and give birth to one to three cubs. In spring the mother emerges from her den followed by her cubs. During that time, she will protect them and teach them how to hunt. They have a gestation period of between 195 and 265 days. They can live 20 to 30 years, but only a small percentage live past 15 to 18 years.

The oldest known polar bear in the Arctic lived 32 years. The oldest known polar bear in a zoological park lived 45 years.

When it comes to predator’s adult polar bears have no natural predators except other polar bears. Cubs less than one year old sometimes are prey to wolves and other carnivores.

Newborn cubs may be cannibalized by malnourished mothers or adult male polar bears.