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Black Bear

Ursus americanus

Black Bear

Description

The black bear weighs up to 900 pounds, is up to 80 inches in length, and stands up to 6 feet or more. Males are considerably larger than females, with the largest males being almost twice as large as the largest females.

Although black bears in the eastern parts of North America are indeed black, western populations are usually lighter in color, ranging from creamy white or bluish gray to brown. The cinnamon bear (subspecies cinnamomum) of the Rocky Mountain region, for example, is rusty brown in color.

Cinnamon Bear

Regardless of the general body color, almost all black bears have a muzzle color that contrasts with the body color, and many have a white chest spot.

Black bears are distinguished from grizzly or brown bears by their longer, less heavily furred ears, smaller shoulder humps, shorter claws, and a straight (rather than concave) facial profile.

Distribution and Habitat

Black bears are found from northern Alaska east across Canada to Labrador and Newfoundland, and south through the Rockies and western United States into central Mexico, as well as through the Appalachians; scattered populations can also be found in the Ozarks, Florida, and around the Great Lakes. Although specific habitats vary somewhat by location, black bears generally prefer forested terrain that is relatively inaccessible.

distribution of the black bear

Diet

Although considered omnivorous, black bears prefer a more vegetarian diet of fruits, grasses, nuts, seeds, and honey. Most meat is consumed in the form of insects that happen to be on the vegetation they are eating, although they will occasionally consume carrion. Where black bear populations "mingle" with human populations, it is not uncommon to find individual bears helping themselves to human garbage.

Reproduction

Breeding usually takes place in June and July, but the embryo does not begin developing until autumn. Total gestation time is about 220 days, with actual embryonic development taking about 10 weeks. The female usually gives birth while in hibernation, with an average of 2 or 3 cubs being born per litter. Cubs snuggle close to the mother's fur for warmth and nurse while she sleeps, and the entire family emerges from the den in early spring. Cubs are weaned at 6 to 8 months, but stay with their mother until she is ready to breed again, which generally occurs every other year.

Behavior

Black bears are generally solitary, coming together only for mating. They may form into groups if food is plentiful, but those groups almost always break up as soon as the food supply dwindles.

Both males and females establish territories, and each male's territory usually overlaps the ranges of several females. While territories are scent marked, the black bear's preference for solitude generally prevents individual bears from intentionally intruding into another bear's territory.

Whether individual bears are more active during the morning, day, evening, or night depends primarily on geographic location, which affects seasonal food availability. Bears in the northermost portions of the range usually spend the entire winter season in deep hibernation, while those in milder climates may only hibernate part of the winter.

Although a black bear can inflict nasty injuries with its sharp claws, it will almost never attack unless seriously provoked. Even a mother black bear with cubs prefers to lure potential threats away from her cubs rather than directly confront them. Most "attacks" on humans are accidental, coming as the result of a bear being startled while digging through garbage or getting a little too anxious when being offered food by a well-meaning sightseer.

Scientific Classification

phylum Chordata
subphylum Vertebrata
class Mammalia
order Carnivora
family Ursidae
genus & species Ursus americanus

SOURCE
Animal Diversity Web animaldiversity.org/accounts/Ursus_americanus/

SEE ALSO
Brown Bear

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The Robinson Library >> Science >> Zoology >> Mammals >> Order Carnivora >> Family Ursidae

This page was last updated on June 17, 2017.