Brown bear

Ursus arctos

SUBFAMILY

Ursinae

TAXONOMY

Ursus arctos Linnaeus, 1758, "sylvis Europaelig frigidaelig" assumed to be northern Sweden. Five subspecies.

OTHER COMMON NAMES

English: Grizzly, kodiak, coastal brown bear, Alaskan brown bear, Asiatic brown bear, Russian brown bear, European brown bear, Himalayan snow bear, Syrian bear; French: L'ours brun; German: Braunbär; Spanish: Oso pardo.

PHYSICAL CHARACTERISTICS

A large bear that varies in color from its typical brown to light tan or black. Large muscles create a noticeable shoulder hump that is further exaggerated in some geographic areas, particularly in North America, by a mane of long hairs with whitish-gray highlights. Its snout protrudes from a concave or "hollow" face. Females average from 250-450 lb (110-200 kg), and males from 350-850 lb (160-385 kg), although brown bears from some areas, including parts of Alaska, often reach 1,000 lb (450 kg) or more. Average adult size is about 3-4 ft (0.9-1.2 m) at the shoulder and 6-7 ft (1.8-2.1 m) when standing on the hind legs. Large bears may stand more than 8 ft (2.4 m) tall.

DISTRIBUTION

Widely distributed globally, with populations in North America from Alaska and northern Canada as far south as Wyoming, in Europe, in northern Asia, and in Japan.

HABITAT

Found in diverse habitats, particularly heavily wooded forests in Eurasia, and more open areas and tundra in North America.

BEHAVIOR

Other than females with their cubs, brown bears are mostly solitary animals. If food is plentiful, however, they will share one area. For example, it is not uncommon to see several brown bears along a shallow river during a salmon run. Brown bears are usually most active at dawn and dusk, but may be active at any time. A hierarchy of sorts often forms, with the largest males keeping smaller individuals from approaching them too closely.

FEEDING ECOLOGY AND DIET

Omnivores, brown bears mainly subsist on grasses and plant roots, but will also dig up and eat ants, catch fish using their jaws and paws, and take both small and large mammals, including moose, caribou, and even American black bears. They also occasionally eat carrion.

REPRODUCTIVE BIOLOGY

Polygamous. Breeding season is an occasion when bears abandon their solitary ways, with pairs forming for up to two weeks. How ever, a female may mate with more than one male, and have cubs in the same litter with different fathers. Mating occurs from mid-spring to mid-summer, with implantation of the embryo following in the fall. Females typically have two cubs, although a litter may range from one to four. Births occur in the winter. Weaned at about 5 months of age, the cubs stay under the protective care of their mother for at least two-and-a-half years, at which point she may breed again. Sexual maturity is attained at about 4-7 years of age, although competition for females may prevent a younger male from breeding as early as that.

CONSERVATION STATUS

Not listed by the IUCN, although it has diminished greatly from its historical range.

SIGNIFICANCE TO HUMANS

Hunted primarily as trophies, but once hunted for their meat and hides. Various organs and body parts are also currently sought by Asian markets. Brown bears can be aggressive and have been known to attack humans, although this is rare. ♦

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