The black bear (Ursus americanus) is a species of bear found in North America. They are also called American black bears. They are the smallest and most widely distributed type of bear in North America.
Black bears have a brownish-black coat with a lighter patch on their chest and muzzle. The fur is soft, with dense underfur and long, coarse, thick guard hairs. They have small ears, short tails, and long claws that they use to climb trees and catch prey.
There are around 16 sub-species or types of black bear, including:
- Olympic black bear (Ursus americanus altifrontalis) – habitat is the Pacific Northwest coast from central British Columbia through northern California and inland to the tip of northern Idaho and British Columbia
- New Mexico black bear (Ursus americanus amblyceps) – habitat is Colorado, New Mexico, western Texas and the eastern half of Arizona into northern Mexico and southeastern Utah
- Eastern black bear (Ursus americanus americanus) – habitat is eastern Montana to the Atlantic coast, from Alaska south and east through Canada to Maine and south to Texas
- California black bear (Ursus americanus californiensis) – inhabits mountain ranges of southern California, north through the Central Valley to southern Oregon
- Haida Gwaii black bear (Ursus americanus carlottae) found in the Queen Charlotte Islands and Alaska
- Cinnamon bear (Ursus americanus cinnamomum) – habitat is Colorado, Idaho, western Montana and Wyoming, eastern Washington and Oregon and northeastern Utah
- Glacier bear (Ursus americanus emmonsii) found in Southeastern Alaska
- East Mexican black bear (Ursus americanus eremicus) – a critically endangered subspecies found in Northeastern Mexico and U.S. borderlands with Texas
- Florida black bear (Ursus americanus floridanus) – Florida, southern Georgia, Alabama, and Mississippi
- Newfoundland black bear (Ursus americanus hamiltoni) found in Newfoundland
- Kermode bear (Ursus americanus kermodei) – habitat is the central coast of British Columbia
- Louisiana black bear (Ursus americanus luteolus) is found in eastern Texas, Louisiana and southern Mississippi.
- West Mexican black bear (Ursus americanus machetes) found in north-central Mexico
- Kenai black bear (Ursus americanus perniger) – inhabits the Kenai Peninsula of Alaska
- Dall Island black bear (Ursus americanus pugnax) – found on Dall Island in the Alexander Archipelago, Alaska
- Vancouver Island black bear (Ursus americanus vancouveri) you guessed it: found on Vancouver Island, British Columbia
How Much Does A Black Bear Weigh?
The size and weight of black bears vary depending on age, sex, and geographic location. American black bears on the East Coast are typically heavier on average than those on the West Coast.
The average weight of a male black bear is about 400 pounds. The average weight of a female black bear is about 200 pounds.
The North American Bear Center, in Ely, Minnesota, claims the title of the world’s largest captive male and female American black bears. Ted, the male, weighed 950–1,000 lb in the fall of 2006. Honey, the female, weighed 484 lb in the fall of 2007.
Black bears have a small, vestigial tail usually around 4.8 inches long. They will hibernate for up to 7 months in the northern reaches of their habitat.
Feeding, Hunting & Foraging Behaviour of the Black Bear
Black bears on the Pacific Coast frequent beaches, estuaries, and streams where they live largely on berries, intertidal invertebrates, and fish. They hunt salmon returning to spawning streams during the day and night and take their prey into the forest to be eaten.
Estimates put the total weight of salmon transported into the forest by an average bear at about 1600 kilograms. Bears prefer the eggs and brains of salmon so that much of the carcass is left uneaten to decay in the forest.
The nitrogen released from the decaying salmon carcasses is recycled back into the trees as they grow. The decaying trees release the nitrogen into the streams to be used by young salmon.
American black bears mostly forage at night, though they may actively feed at any time. Up to 85% of the American black bear’s diet consists of vegetation, though when coming out of hibernation they will seek to feed on carrion from winter-killed animals.
American black bears are also fond of honey and will gnaw through trees if hives are too deeply set into the trunks for them to reach it with their paws.
Courtship And Breeding Behaviour
Every second year, the females will mate, with a gestation period of 210-220 days. In the south, pregnant females hibernate whereas in the north, both sexes hibernate for up to 7 months. Bears do not eat, move around, drink or urinate during hibernation. Small quantities of feces are produced and metabolic rates drop by 50%. Pregnant females lose up to 40% of their weight during hibernation.
Young male bears disperse from the natal territory of their mothers at 1-3 years of age to seek out their own territories. They begin to mate at about 3 or 4 years of age and continue to grow until they are about 10 years old. Females raise the cubs alone, without the father.
Mating occurs in early summer and delayed implantation of the fertilized egg is delayed until autumn resulting in birth in January. Newborns weigh 200-450 gms. No other placental mammal gives birth to such relatively small young. The cubs suckle from the mother while she is in hibernation although she is alert to their needs.
Families emerge from hibernating dens in spring when the cubs weigh about 2-5 kg. They remain with their mothers through the next winter or until the cubs are about 17 months old and their mother enters estrus.
Yearlings weigh up to about 50 kg at this time but some can be as little as 7 kg. The range in weight is thought to be an adaptation to high and low-quality habitats by Black Bears
References:
Bauer, E. and P. Bauer. 1996. Bear: behaviour, ecology, and conservation. Voyageur press, Stillwater MN.
Cowan, I. McTaggart and C. J. Guiguet. 1965. The mammals of British Columbia. BC. Provincial Museum Handbook No. 11, Victoria, BC.
Craighead, Lance (2003) Bears of the World, Voyageur Press
Puckett, Emily E.; Etter, P.; Johnson, E.; Eggert, L. (2015). Phylogeographic Analyses of American Black Bears (Ursus americanus) Suggest Four Glacial Refugia and Complex Patterns of Postglacial Admixture. Molecular Biology and Evolution. 32 (9): 2338–2350.
Wilson, D. E. and S. Ruff. 1999. The Smithsonian book of North American mammals. Smithsonian Institution, Washington, D.C.