Описание презентации по отдельным слайдам:
Bears, like other carnivores, trace their pedigree back to the miacids, small, snouted, weasel like animals that lived 50 million years ago. Some 38 million years ago bears began to go their own evolutionary way. The first clearly bear like animals was Amphicynodon; the first true bear was Ursavus (both represented in the form of skulls, the only evidence available). The modern genus Ursus appeared between five and ten million years ago.
They (ursids) are the heavyweights of the land varnivores and generally omnivores (omnivores = an animal that is both vegetable and animal food necessary has to survive) , with a preference for vegetable food. After a period of eating meat more or less esclusively, they became omnivores for still not yet explained reason. The giant panda departed the furthest from a strictly carnivorous diet until recently they were thought to be strict vegatarians. The polar bear with scant choice of food in the Arctic became largely carnivorous and developed into an expert swimmer and stalker in order to hunt seals, its favorite prey. The bears maintained the talents of some early miacids for tree-climbing.
Brown Bear (Ursus arctos) is the most widespread member of the bear family, which is found throughout Europe, Asia and North America. Scientifically, more is known about brown bear than any of the other bear species escept for the American black bear. Despite its name, the brown bear ranges in color from black to yellow, reddish and even beige. In some areas, brown bears grow as large as polar bears and in other places they are less than half that size. Because of these differences in size and colour , people used to think there were many different species, not just on.
The term "grizzly" addresses in addition, Grizzlies on the white-grey speckled upper skin, which particularly animals in the Rocky Mountains exhibit, from yellow-brown to dark-brown or nearly black colored. The color depends particularly on the habitat, in the special one on the food and on the climate. The size decreases generally from the north to the south, while they can weigh in the north up to 680 kilograms, and in the south from 80 to 200 kilograms. The grizzly bear male is on average 1.8 times as heavy as the grizzly bear female. Despite its massive figure he can run with a speed of over 60 km/h. The legs before and the shoulders of the grizzly are particularly massive and powerful and allow him to dig.
Kodiak Bear (Ursus arctos middendorffi) is the largest terrestrial carnivore. It is a variety of brown bear living Alaska. The kodiak bear draws its name from the island Kodiak, one of the islands of the gulf of Alaska, but one also finds some on the peninsula and the close islands, like Afognak and Shuyak.
Contrary to popular belief, black bears have both a good sense of smell and good eyesight. Despite the fast that their lumbering gait (a result of having hind legs longer than forelimgs) gives them an awkward appearance, they are extremely intelligent. Black bear are found in variety of colors and there are 16 curently recognized subspecies, which is considered threatened. As a whole, though, the species is increasing in numbers after reaching a low point caused by human persecution. Black bears caught poaching outside a national wildlife refuge in Georgia, according to one refuge manager, show real sagacity. Although many people do not regard black bear as dangerous animal, they can unquestionably kill human beings as readily as their grizzly cousins.
Polar Bear (Ursus maritimus) is descended from brown bear ancestors that became permanently bleached and reshaped by the harsh environment north of the Artic Circle (polar bear habitat). The polar bear swim like be born in water and are indeed an excellent swimmer, with a long neck, powerful sloping shoulders, padling membranes that web half the length of its forepaws and a thick, oily fur that sheds seawater ad helps insulate the bear against the cold. The polar bear can without resting 80 km by ice-cold water to swim.
Since there are so few captive pandas, the Chinese government has officially banned hunting them and only rarely permits their export. The panda remains one of the world's most mysterious creatures, nearly as baffling a subject of investigation in captivity as it is when free. The giant pandas remote and nearly inaccessible HImalayan habitat and the protection provided by the Chinese government safeguard it from hunters guns. Signicificant studies of pandas in the wild does not exist. Almost all scientific knowledge of their behavior has of necessity been based on observations of captive animals in zoos.
The teddy bear, that cherrished companion of both the young and old, seems always to have been around, played with by generations of children as far back as anyone can remember. For collectors is difficult to believe that there was was ever a time before they existed. But surprisingly, their origin is relative modern and he is just 105 years old.
Номер материала: ДA-019787
Вам будут интересны эти курсы: