American Black Bear

SUBFAMILY URSINAE
Ursus americanus 

APPEARANCE This medium-sized bear is usually black with a brown muzzle, lacks a shoulder hump, and often has a white patch on the chest. Although black is the predominant color, chocolate and cinnamon brown color phases are also common, which often results in people confusing them with brown bears. Black bears with white and pale-blue coats (known respectively as Kermode and glacier bears) also occur in small numbers. Kermode bears are found along the north-central coast of British Columbia, and the Yukon Territory, Canada. Black bears have strong, highly curved claws and the profile of the face is convex when compared with the more concave profile of a brown bear.

SIZE Adult male black bears range from about 130 to 190 centimeters (50 to 75 inches) in length and weigh 60 to 300 kilograms (130 to 660 pounds). Females measure from 130 to 190 centimeters (50 to 75 inches) and weigh 40 to 80 kilograms (90 to 175 pounds). Black bears vary considerably in size, depending on the quality of the food available. Males may be from about 20 to 60 percent larger than females. At birth, cubs weigh 225 to 330 grams (7 to 11 ounces).

HABITAT Black bears are normally found only in forested areas, but within such habitat they are highly adaptable. They live in both arid and moist forests, from sea level to over 2,000 meters (6,560 feet). Historically, black bears are thought to have stayed away from open habitat because of the risk of predation by brown bears. Black bears have become established in the tundra of northern Labrador, a region where there are no brown bears.

DISTRIBUTION Black bears are widely distributed throughout the forested areas of North America although they have been totally driven out from some of their original range. They are presently found in northern Mexico, 32 states of the United States, and all the provinces and territories of Canada except Prince Edward Island.

REPRODUCTION Females reach sexual maturity at three to four years of age and males a year or so later. Mating takes place in June, July, and August, and pairs may remain together for only a few hours or for several days. Pregnancy last s about 220 days, and the cubs are born in a maternity den in January and February. Litter size ranges from one to five, but two is the average. Cubs may be weaned at six to eight months, but they remain with their mothers for a year and a half. Consequently, the most often that female black bears can mate, unless they lose their cubs prematurely, is every two years. Longevity in the wild is 20 to 25 years.

SOCIAL SYSTEM Except for females with cubs, black bears spend most of their time alone. During the breeding season, a male and female may remain together for several days at a time and groups of bears may feed in close proximity to each other if food is abundant, such as in berry patches or at dumps. Female home ranges are 3 to 40 square kilometers (1 to 15 square miles). While the home ranges of individual bears are usually exclusive from those of other bears of the same sex, male ho me ranges are larger and may overlap those of several females. A young adult female is often allowed to establish her territory within that of her mother, while sub adult males must disperse.

DIET Black bears are omnivorous and feed on a wide range of foods, depending on what is available. Insects (particularly ants), nuts, berries, acorns, grasses, roots, and other vegetation form the bulk of their diet in most areas. Black bears can also be efficient predators of deer fawns and moose calves. In some areas of coastal British Columbia and Alaska they also feed on spawning salmon.

Image by David Kirshner
From Ian Stirling, ed. Bears, Majestic Creatures of the Wild.
Emmaus, Pennsylvania: Rodale Press, 1993. 240 pages.