The Brown Bear (Ursus arctos) is a species of bear that can reach weights of 130-700 kg (300 to 1500 pounds). The Grizzly Bear, the Kodiak Bear and the Mexican Brown Bear are North American subspecies of the Brown Bear.
Brown Bears have coats in shades of blond, brown, black, or a combination of those colours; the long outer guard hairs are often tipped with white or silver, giving a "grizzled" appearance. Brown Bears have a large hump of muscle over their shoulders which gives strength to the forelimbs for digging. Their heads are large and round with a concave facial profile. In spite of their size, they can run at speeds of up to 56 km/h (35 mph).
Once native to Asia, Africa, Europe and North America, Brown Bears are now extinct in some areas and have had their numbers greatly reduced in others. They prefer semi-open country, usually in mountainous areas. The Brown Bear ranges from Alaska east through the Yukon and Northwest Territories, south through British Columbia and through the western half of Alberta. Isolated populations exist in northwestern Washington, northern Idaho, western Montana, and northwestern Wyoming. The subspecies U. arctos horribilis (the Grizzly Bear) is the common Brown Bear of continental North America; the subspecies U. arctos middendorffi (Kodiak Bear) includes bears on the Alaskan islands of Kodiak, Afognak, and Shuyak. The range of the subspecies U. arctos nelsoni is in northern Mexico.
There are estimated to be about 200,000 Brown Bears in the world. The largest populations are in Russia, with 120,000, United States with 32,500 and Canada with 21,750. Brown Bears are found in small populations in much of Europe from Spain to Russia. There are 14,000 in ten separate population in Europe. 95% of Brown Bears in the United States are in Alaska.
The Brown Bear is primarily nocturnal and in the summer puts on up to 180kg (400 pounds) of fat, on which it relies to make it through winter, when it becomes very lethargic. Although they are not true hibernators and can be woken easily, they like to den up in a protected spot such as a cave, crevice or hollow log during the winter months.
Being omnivores, they feed on a variety of plant parts, including berries, roots, and sprouts; fungi; and fish, insects and small mammals. Brown Bears are largely vegetarian, deriving up to 75% of their dietary calories from vegetable matter. Interestingly, bears eat an enormous number of moths during the summer—sometimes as many as 20-40,000 in a day—and may derive up to one third of their calories from moths.
Normally a solitary animal, the Brown Bear congregates alongside streams and rivers during the salmon spawn. Every other year females produce 1 to 4 young which weigh only one pound at birth.
The subspecies of Brown Bear have been listed as follows; however, there is little agreement on classification:
The Grizzly Bear is listed as threatened in the coterminous United States.