AMERICAN BLACK BEAR
Ursus americanus
STATUS:
The American black bear is distributed throughout North America, from Mexico to Canada and California to New York. They occupy a huge range of habitat types and this is reflected in their diet and behaviors. In the United States there are estimated to be over 300,000 individuals. Over most of their range in North America black bear populations appear to be stable or increasing and are classified as a game animal in thirty-three states and all the Canadian Provinces. At least two populations have had serious problems with their black bear populations and have initiated steps to restore these dwindling populations (Louisiana and Florida).
DESCRIPTION:
Black bears have short, non-retractable claws that give them an excellent tree-climbing ability. Black bear’s fur is usually a uniform color except for a brown muzzle and white markings that sometimes appear on their chests. Eastern populations are usually a black color phase while western populations often show brown, cinnamon, and blond color phases. Black bears with white-bluish fur are known as Kermode (glacier) bears and these unique color phases are only found along northwestern Canada’s Pacific coast.
SIZE:
Male black bears grow to be about twice the size of females. Occasionally males may weigh as much as 500-600 pounds, but average between 150 - 300 pounds and female average weights are between 90-150 pounds.
POPULATION:
It is estimated that there are at least 600,000 black bears in North America. In a 1993 survey, Canada had an estimated 327,000-341,000 (with no estimates for Saskatchewan, Nova Scotia, Northwest Territories, or New Brunswick). In the US there are an estimated 298,000-326,000, (includes an estimate of 100,000 from Alaska and excludes South Dakota, Texas and Wyoming). No estimates are known for Mexico but the bears are thought to be isolated in four relatively small populations that, in spite of some progress, are generally considered threatened due to increased pressure from human encroachment, poaching and habitat loss.
LIFESPAN:
In the wild, black bears live 20-25 years, however there has been increased mortality around 10 years of age.
RANGE:
American black bears are found in Mexico, 32 states in the US, and Canada. They historically occupied nearly all of the forested regions of North America but in the US they are now restricted to the forested areas less densely occupied by humans. In Canada black bears still inhabit most of their historic range except for the intensively farmed areas of the central plains. In Mexico black bears were thought to have inhabited the mountainous regions of the northern states but are not limited to a few remnant populations.
HABITAT:
Black bears are extremely adaptable and show a great variation in habitat types, though they are primarily found in forested areas with a thick ground vegetation that have an abundance of fruits, nuts, and vegetation. Wetland and stream areas often provide more lush vegetation, while wooded areas with trees larger than 20 inches in diameter can be used for climbing. In the northern areas, they can be found in the tundra, and they will sometimes forage in fields or meadows.
FOOD:
Food habits of black bears are as varied as their habitats. Bears will consistently use hard and/or soft mast crops (nuts and/or berries) when seasonally available as an important food source. They also eat a variety of plants, insects, small mammals, and carrion when available. In northern regions, they will eat spawning salmon out of streams. They will also occasionally kill young deer or moose calves.
BEHAVIOR:
Black bears tend to be solitary animals, with the exception of mothers and cubs. The males and females come together to mate for either a few hours or a few days. The bears will forage alone unless there is an incredible abundance of food in one area, then they will tolerate each other and forage in groups. Most black bears hibernate dependant upon local weather conditions and whether or not there is a lack of food during the winter months. Hibernation allows mammals to conserve energy during seasons with no food and water. Once they enter hibernation, they may remained denned for as long as 8 months (northern populations) without eating, drinking, urinating, or defecating. In regions where there is a consistent food supply and warmer weather throughout the winter, bears may not hibernate at all or do so for a very brief time. Pregnant females give birth and usually remain denned throughout the winter, but males and non-pregnant females may leave the dens from time to time.
OFFSPRING:
Females become reproductively mature around the age of three to four, with males usually maturing at the age of five. Mating occurs during the summer, and the cubs are born in January or February. The litter size can vary from one to four cubs, however it is most common that two cubs will be born. Cubs remain with the mother for a year and a half or more, even though they are weaned at a six to eight months of age. Females only reproduce every second year (or more) and thus black bear populations have a slow rate of growth. Should the cubs die for some reason, the female may then reproduce after only one year.
THREATS:
In Canada there no major large scale threats to the black bear population, though there are some locally important problems related to habitat loss (logging, human encroachment), and poaching or depredation kills. In the US most states reported that habitat loss and habitat fragmentation were the major threats, though a few also thought poaching, depredation kills, road-kills, and over-harvesting were potential threats. In Mexico substantial habitat loss and poaching are probably the main factors threatening the bears. The bears are unprotected and a poor economy makes it difficult for the government to enforce existing rules. Wealthy private landowners have taken steps to encourage the black bear populations to supplement their incomes with tourism or hunting and it is here that black bears are recovering.
Highways, homes and other developments built through bear habitat can bisect and isolate large areas of habitat that bears depend on for food, water and shelter. Habitat fragmentation also makes it difficult for bears to find mates and limits their chances to move into more suitable habitat. There is a misconception that black bears are vicious animals, and as humans move ever deeper into the bears’ habitat, the number of bear-human interactions increases, often resulting in lethal control actions.