Polar bear – this is one of the few species-saving measures from which were effective extinction. The question of the preservation of the population nevertheless is still open. Why? Melting ice in the Arctic grows and threatens to turn into a real disaster for many native animals, including polar bears and…
Polar Bear (Latin ursus maritimus) – The largest land predator in the world. Some representatives reach 3 meters in length and weight up to 1 ton. However, the average male weighs only 400-450 kilograms with a body length of 2 – 2.5 meters and a height at the withers – 1.5 meters. Females are much smaller – 200-300 kg. It lives in the polar regions in the northern hemisphere of our planet. Roams in accordance with the seasonal changes in the polar ice boundaries. Carried mainly on the coast and on ice floes drifting and of fast.
Interestingly, the 100 – 250 thousand years ago on the ground trod a formidable predator, like a giant polar bear (ursus maritimus tyrannus) – up to 4 meters in length and 1.2 tons of weight. His remains were found in what is now England.
From the other bears is different (except for size and color coat) a long neck and flat head. The skin of a polar bear black. White fur may turn yellow in the summer due to exposure to sunlight. Shuba bear transmits only ultraviolet rays. Due to the structure of the hairs (they are hollow), the bear may temporarily “go green.” This happens in zoos in countries with hot climates, when the wool infest microscopic algae.
On the soles of the feet of the polar bear has a hard coat, so as not to slide on the ice. There is a swimming webbed fingers. The large claws are designed for something to hold in their paws even very powerful animals such as walrus.
Also walrus (which can handle only on land), polar bears prey are: bearded seal, ringed seal, fish, birds, eggs, chicks. It can eat carrion, algae, in places inhabited by man often “acquired in the trash.” Extremely curious, often try unfamiliar foods to taste. Able to rob a warehouse of food polar expedition.
One way to hunt polar bear: tipping the floes with seals located on it. Also bear is able to wait for hours near the seal hole. Once the victim pokes his head out to breathe fresh air, it covers the deadly force blow. Then the bear pulls the seal on the ice and begins to feast. Consumes only skins and seal oil, meat usually leaves polar foxes and birds of prey.
In hibernation 50-80 days lie pregnant females, while other females and males sleep much less and, moreover, not annually.
Polar bears may seem sluggishness, slow animals. In fact, they are very agile and fast developing on land speed up to 25 km/h. Few compared with a polar bear and under water. It comes easily to swimming (speed – 7 km/h) and diving. Under water can be up to 2 minutes. Thick hair does not get wet and freeze the body of a bear. Another important feature, which helps to survive in conditions of constant cold, is the presence of the layer of fat up to 10 cm thick. Well-developed sense of smell and sight. The potential production of the bear can see or smell for many kilometers.
Surprisingly, the bears are more inclined to overheating, rather than freezing. They can withstand temperatures of up to negative 80 degrees, while the warm weather brings bear serious discomfort and irritation.
Record swim recorded on the Beaufort Sea north of Alaska (685 km) made the white bear, losing his little baby, and 48 kg of weight (20% of the total weight). For the movement of animals was monitored by a body attached to a GPS-beacon.
Polar bears – solitary animals. Between themselves, as a rule, is not at war, except the mating season, when males are fighting over females.
The Courtship takes place between March and June. In October females dig dens in which are populated only in mid-November. There are several popular places for bears in puppies, for example, Franz Josef Land, Wrangel Island, and others. Pregnancy lasts 230-250 days. Little Bears appear near the end of the winter, even though their mother is still up to the April remains dormant. Three months later, the newly formed family leaves the den. Cubs stay with their mother’s milk and feed it to 1.5 years.
Over the life of a female polar bear gives birth to 10-15 pups. Mortality among the cubs reach 10-25%. The average life span of polar bears in the wild – 20-25 years (a record is considered to be a mark in 30 years), in captivity – 30-35 (record – 45 years).
Interestingly, polar bears can breed with brown, and the resulting hybrid (called polar or grizzly grolar) is able to produce fertile offspring. At the moment we know only three confirmed cases of hybridization in nature. Melting ice in the Arctic is forcing polar bears to explore new territory, moving away from the coast farther and farther to the south. Some researchers believe that for this reason the meeting of white and brown bears in the future will occur more often, so the number of polar grizzly in the world will grow.
Polar bear population worldwide is estimated at 20-30 thousand individuals. In Russia, listed in the Red Book (5-7 ths. individuals). In general, recently managed to not only stabilize, but also to increase the global population of polar bears. However, as mentioned above, the melting of Arctic ice could seriously affect the fate of the species. The question is, will the polar bears adapt to new climatic conditions on Earth.
However, the main factor in reducing the number of polar bears remains man. Other enemies in nature they do not. Besides poaching, the factors of anthropogenic impacts include pollution of the environment by developing industry (production of oil on the continental shelf) and the increased harvesting of fish and seals.