Bear

General Info :

Bears are mammals of the family Ursidae. Bears are classified as caniforms, or doglike carnivorans, with the pinnipeds being their closest living relatives. Although only eight species of bears are extant. Common characteristics of modern bears include large bodies with stocky legs, long snouts, shaggy hair, plantigrade paws with five nonretractile claws, and short tails. Bears use shelters, such as caves and burrows, as their dens; most species occupy their dens during the winter for a long period (up to 100 days) of sleep similar to hibernation.

Physique :

Bears are generally bulky and robust animals with relatively short legs. Adult male Kodiak bears average 480 to 533 kg (1,100 to 1,180 lb) compared to an average of 386 to 408 kg (850 to 900 lb) in adult male polar bears, per the Guinness Book of World Records. The smallest bears are the sun bears of Asia, which weigh an average of 65 kg (140 lb) for the males and 45 kg (99 lb) for the females, though the smallest mature females can weigh only 20 kg (44 lb). All "medium"-sized bear species (which include the other five extant species) are around the same average weight, with males averaging around 100 to 120 kg (220 to 260 lb) and females averaging around 60 to 85 kg (130 to 190 lb), although it is not uncommon for male American black bears to considerably exceed "average" weights. Head-and-body length can range from 120 cm (47 in) in sun bears to 300 cm (120 in) in large polar and brown bears and shoulder height can range from 60 cm (24 in) to over 160 cm (63 in) in the same species, respectively. The tails of bears are often considered a vestigal feature and can range from 3 to 22 cm (1.2 to 8.7 in).

Diet :

Some bears will climb trees to obtain mast (edible vegatative or reproductive parts such as acorns); smaller species that are more able to climb include a greater amount of this in their diets. One exception is the polar bear, which has adopted a diet mainly of marine mammals to survive in the Arctic. The other exception is the giant panda, which has adopted a diet mainly of bamboo. Stable isotope analysis of the extinct giant short-faced bear shows it was also an exclusive meat-eater, probably a scavenger. The sloth bear, though not as specialized as the previous two species, has lost several front teeth usually seen in bears, and developed a long, suctioning tongue to feed on the ants, termites, and other burrowing insects they favour. At certain times of the year, these insects can make up 90% of their diets. All bears will feed on any food source that becomes available, the nature of which varies seasonally. When taking warm-blooded animals, bears will typically take small or young animals, as they are easier to catch. However, both species of black bears and the brown bear can sometimes take large prey, such as ungulates. Often, bears will feed on other large animals when they encounter a carcass, whether or not the carcass is claimed by, or is the kill of, another predator.

Distribution :

Bears are primarily found in the Northern Hemisphere, and with one exception, only in Asia, North America and Europe. A single species, the spectacled bear, is native to the Andean region of South America. The Atlas bear, a subspecies of the brown bear, was the only bear native to Africa. It was distributed in North Africa from Morocco to Libya, but has been extinct since around the 1870s. The most widespread species is the brown bear, which occurs from Western Europe eastwards through Asia to the western areas of North America. The American black bear is restricted to North America, and the polar bear is restricted to the Arctic Sea. All the remaining species are Asian. With the exception of the polar bear, bears are mostly forest species. Some species, particularly the brown bear, may inhabit or seasonally use other areas, such as alpine scrub or tundra.