American black bears (Ursus americanus), often simply called black bears, are the most common bears in North America. They live in northern Mexico, the U.S. and Canada. Black bears are smaller than brown bears (Ursus arctos) and polar bears (Ursus maritimus), making them the smallest of the three species of bears in North America.
Black bears are excellent climbers and use their curved claws to scale trees and access food, such as nuts and honeycombs. On the ground, they are powerful runners and can reach speeds of up to 35 mph (56 km/h), according to the U.S National Park Service (NPS).
Black bears are usually black, as their name suggests, but their coats may also be brown, cinnamon-colored or even white, according to the International Association for Bear Research and Management (IBA). This coat variation means they're occasionally mistaken for brown bears, especially where the ranges of the two species overlap in the northwest of the U.S. and Canada.
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A black bear's size and weight vary depending on its age and the time of year. Male black bears are up to 60% bigger than females, weighing up to 660 pounds (300 kilograms), while females only reach 175 lbs. (80 kg), according to the IBA. In contrast, male brown bears can weigh up to 860 lbs. (390 kg) and females up to 455 lbs. (205 kg).
Although brown bears are bigger than black bears and usually have lighter-colored coats, the NPS suggests that other characteristics, such as the shape of the bear's body and their tracks, are a more reliable way to identify each species. Black bears do not have a pronounced shoulder hump, and their shoulders are lower than their rump when standing on all fours. Brown bears, on the other hand, have a clear shoulder hump that is higher than their rump.
KEY FACTS
Size: 3 feet (0.9 meters) tall at the shoulder (all fours)
Life span: Up to 39 years
Conservation status: Least concern
Black bears also have straighter faces than brown bears when viewed from the side, and have taller, more oval-shaped ears, according to the NPS. Their front claws are less than 2 inches (5 centimeters) long and are shorter than brown bear claws, which are 2 to 4 inches (5 to 10 cm) long. Black bear claws are also more curved than brown bear claws and appear in bear tracks less often. Toe prints are more separated and arced in black bear tracks than brown bear tracks, and claw marks are closer to the foot pad (when they are visible).
Brown bears live in the western region of the black bears' range, including western Canada and U.S. states such as Alaska, Washington and Idaho. Black bears also live so far north that their range overlaps with polar bears along the northern coastlines of Canada, such as in Ontario and Québec, according to the International Union for Conservation of Nature (IUCN).
A black bear with a freshly caught salmon in its mouth in Alaska. (Image credit: Shutterstock)
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The NPS recommends that people keep their distance from wild bears and avoid surprising them. If attacked by a black bear, a victim should fight back. Playing dead doesn't fool black bears (although it might work with brown bears), so if a victim is unable to escape to a car or another secure location, they should use whatever objects are available and strike the bear in its face and muzzle.
Black bears are not active predators and only hunt when an opportunity for prey presents itself. Most of the vertebrates they eat are already dead, according to the University of Michigan's Animal Diversity Web (ADW). If they do decide to hunt, black bears will go after young, hoofed mammals, such as elk, moose and other deer species, according to The National Wildlife Federation. Black bears in Canada and Alaska also feed on salmon.
Bears usually fatten up in late summer and fall as they prepare to hibernate through the winter months, from about November to March. They may feed for up to 20 hours, consuming up to 20,000 calories per day during this period, according to the Pennsylvania Game Commission.
Black bears create their dens in the ground, under a windfall or in a hollow tree or cave, or use a previously occupied animal den, according to the NPS. The hibernation length varies across the black bears' range. Black bears in Mexico, for example, may not need to hibernate at all as the climate is mild and food remains available through winter. In contrast, black bears living in the colder environment of northern Alaska hibernate for about 7 months, according to Alaska Department of Fish and Game.
During hibernation, black bears lower their body temperature and heart rate and suppress their metabolism by 75% to reduce their energy needs, Live Science previously reported. They survive off fat reserves built up in late summer and fall but maintain much of their muscle mass so they don't become weak.
Three black bear cubs with their mother. (Image credit: Mark Moore via Getty Images)Female black bears typically give birth to two or three offspring in February during hibernation. Baby black bears, called cubs, weigh just 7 to 11 ounces (200 to 310 grams) at birth, according to the Arizona-Sonora Desert Museum. Black bear cubs stay in the den with their mothers until spring. The cubs are weaned before they reach 8 months old, but they won't leave their mothers until they are about 17 months old, after hibernating with her during their second winter, according to ADW.
Black bears can live more than 30 years in the wild. The oldest black bear on record was a female in Minnesota that reached 39, according to the Florida Fish and Wildlife Conservation Commission (FWC). However, most black bears only live to be about 10 years old and die well short of their maximum lifespan, according to ADW. The main causes of death for adult black bears are vehicle collisions, hunting and starvation due to a lack of available food, according to the Florida Fish and Wildlife Conservation Commission.
BLACK BEAR TAXONOMY
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Ursidae
Genus & species: Ursus americanus
Source: ITIS
The Integrated Taxonomic Information System (ITIS) recognizes 16 different subspecies of American black bear, often named after the parts of North America they inhabit. For example, there are Florida black bears (Ursus americanus floridanus) and California black bears (Ursus americanus californiensis), although these bears are not just confined to these states. Cinnamon bears (Ursus americanus cinnamomum) get their name because they often have cinnamon-colored coats.
A white Kermode bear, or spirit bear, on Princess Royal Island in Canada. (Image credit: Natalie Fobes via Getty Images)Kermode bears (Ursus americanus kermodei) are a subspecies of black bear in British Columbia, Canada that are sometimes white. White Kermode bears are also known as spirit bears, although they are part of the Kermode population and are not a separate subspecies. The highest concentration of spirit bears is found on Gribbell Island, off the north coast of British Columbia, where one-third of the black bears on the island are born white, according to The National Wildlife Federation.
Spirit bears' white coats are caused by a mutation in a gene called mc1r. The gene is recessive, which means a bear cub will only be white if both of its parents carry the gene, according to The National Wildlife Federation. If only one parent carries the recessive gene then the cub will have a normal, black coat.
A 2009 study published in the Biological Journal of the Linnean Society found that white black bears are better at catching salmon than normal black bears during the day. This could be because the fish find it harder to see the white bears overhead as lighter coats blend in better with a bright sky background than black coats.
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However, black bears are threatened in some parts of their range. Black bears are considered nationally endangered in Mexico due to deforestation, hunting and other human activities. Hunting black bears was banned in Mexico in 1985, and the population is now recovering and expanding thanks to conservation efforts, according to the IUCN.
Bears are regularly hunted and killed in the U.S. and Canada, but this is controlled and managed by state and provincial agencies. Other common threats to bears include residential and commercial development, agriculture, road building and high traffic densities.