Data from recent years show that that the polar bear (Ursus maritimus) embarked on the path of evolution about five million years ago. His ancestor was a brown bear. But, in contrast to his brown cousin, living on earth, the polar bear has adapted perfectly to life in the Far North of sea ice.
Today the world celebrates the International Day of the polar bear (International Polar Bear Day) or , in a more familiar Russian version, Day polar bear. The main aim of the Day is to spread awareness about polar bears and to draw public attention to the need for their protection. Also refers to the need to solve the problem of the melting of the polar ice cap — the root cause of the threat of extinction of populations of polar bears. Another cause of life-threatening polar bears, is the development of oil fields, followed by pollution.
According to rough estimates of scientists in the world today, there are about 20-25 thousand polar bears. The world's leading experts who study polar bears, have published evidence that of the 19 subpopulations of polar bear — eight decreased, three remained stable, and one rose. Data on the remaining seven subpopulations is difficult to collect.
Melting ice in the Arctic, which occurs as a result of global warming could lead to the disappearance of two-thirds of polar bears in 2050.
The first International Day of the polar bear is significant for the five countries, with populations of polar bears — Russia, Norway, Canada, Greenland and the United States (Alaska). In May 2008, the U.S. brought a polar bear in the Red Book of the status of a species threatened with extinction. Canada and Russia have determined the status of the polar bear as a "vulnerable species».
It is important to remember that polar bears can be found only in the Arctic latitudes, near the North Pole. In Antarctica, the South Pole, polar bears do not live.
Interestingly, the polar bears are very comfortable ambient temperature minus 45 degrees and below. Heat sohranaetsya through two layers of fur and a thick layer of subcutaneous fat. In addition, due to the small size of ears and tail also prevents heat loss. You could even say that polar bears are more affected by overheating of the body, especially while running after prey.
Usually adult polar bears weigh 350 to 550 pounds, but there are individuals with a mass of over 550 kilograms. The largest male polar bear, registered in the history of observations of these animals weighed one ton. Females weigh an average of 150 to 300 kilograms.
Usually the female polar bear with two cubs are born, but it happens that the conditions conducive environment bears the birth of three cubs, or vice versa — only one bear. Cubs remain with their mother to two and a half years, learning and acquiring hunting skills to survive in the harsh Arctic environment.