Презентація по 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.
In the northern hemisphere the brown bear was long feared, admired and even worshiped as the king of beasts, taking a special place in folk tales.
As with American black bear, brown bears (Ursus arctos) have been the subject of considerable taxonomic 'splitting' into subscpecies, the Grizzly and the Kodiak are probably the best known.
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.