American black bear

Ursus americanus

SUBFAMILY

Ursinae

TAXONOMY

Ursus americanus Pallas, 1780, type locality not given but assumed to be eastern North America. Up to 18 subspecies.

OTHER COMMON NAMES

English: North American black bear, cinnamon bear, kermode bear, glacier bear; French: L'ours noir; German: Amerikanischer Schwarzbär; Spanish: Oso negro, oso varibal, oso negro americano.

PHYSICAL CHARACTERISTICS

A relatively short-haired bear with curved claws; rather short tail; conspicuous, but not overly large ears; and fairly long, often tawny snout. Somewhat similar to the brown bear, but the American black bear's shoulders are lower than its rump when walking. Fur coloration can vary from brown to black, sometimes reddish, bluish black, and occasionally white, with geographically distinct subspecies typically tending toward one color pelage, although color can vary even among brothers and sisters. They often have a bit of white fur on the chest. Head and body length runs from about 5-6 ft (1.5-1.8 m), and shoulder height at about 2-3 ft (60-90 cm). Standing, a typical adult reaches about 5 ft (1.5 m). Weight differs among the sexes, with the males averaging 250-350 lb (110-160 kg), al

most twice the female's average weight of about 150-175 lb (70-80 kg). The largest males can reach up to 800-900 lb (360-400 kg) when they are at their heaviest just before hibernation, although these extreme weights are rare.

DISTRIBUTION

Northernmost Mexico, all but north-central Canada, and about half of the United States, especially Alaska and the western and eastern states, and the upper Great Lakes region.

HABITAT

Commonly woods with thick undergrowth, but also wetland areas, meadows, tundra particularly in Labrador, and sometimes disturbed sites near human activity.

BEHAVIOR

American black bears are commonly crepuscular and spend most of the day and night resting in a clump of leaves on the ground, although they may shift this schedule and become active during the day. Despite their typically lumbering gait, they can break into short 30 mph (48 kph) runs if necessary. They are also good swimmers and expert tree climbers, using their front claws to scale a trunk in very short order.

American black bears spend much of the winter dormant, but scientists do not consider them true hibernators, because they frequently awaken from deep sleep to leave their winter dens for short periods. Their dens may be caves; hollow, standing or fallen trees; or burrows.

American black bears are typically solitary, except for females with cubs, and maintain feeding territories of 8-15 mi2 (20-40 km2) throughout much of the year. At sites where food is abundant, such as garbage dumps, however, several adult males and females may share a small area. Males and females pair up for breeding for only a few days at most.

FEEDING ECOLOGY AND DIET

These omnivores eat almost anything, and are most frequently seen by humans scavenging for leftovers at campsites and garbage dumps. In the wild, they tend toward a vegetarian diet, eating everything from berries and nuts to grasses and roots, but will also dine on honey, salmon, ants and other insects, rodents, an occasional young ungulate, livestock, and carrion when the opportunities arise.

REPRODUCTIVE BIOLOGY

Polygynous. Mating occurs from late spring to early summer, but implantation of the embryo is delayed until late fall. Birth follows in mid-winter with typically two blind and naked cubs, although litters may range from one to four, rarely five, young. The young nurse while the female continues her winter rest and then leave the den in the spring. The family remains together with the mother providing milk until late summer or early fall, sometimes longer. After weaning, the cubs stay with the mother for one or two years. American black bears become sexually mature at about 3-6 years of age, with the females maturing on average about a year earlier than the males.

CONSERVATION STATUS

Not listed by the IUCN.

SIGNIFICANCE TO HUMANS

Hunted for meat, trophies, and hides, as well as various body organs and parts for cultural medicinal uses. American black bears are not normally aggressive, and only very rarely harm humans. They do, however, occasionally become pests to campers, beekeepers, farmers, and others who usually unintentionally furnish food sources. ♦

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