Black bears are not necessarily black. Their coarse fur can be white, cinnamon, or a nearly golden brown, often with a white patch on throat or belly. They are large, stout and almost tailless, with heavy blunt claws. They once ranged almost all of the United States, but are now confined to remote forest regions.
Black bears are huge when they stand up,more than five feet tall, but on all fours they can resemble a large dog, perhaps three feet tall at the shoulder.
The average female weighs about 230 pounds and the average male around 300. Large males can weigh a fearsome six hundred pounds.
Black bears have rounded heads, round ears and small dark eyes. Their tan or brown noses thrust forward like a dog's snout, but they are equipped with 42 strong teeth, including two pointed canines.
They walk plantigrade. That is, they stand on the palms of their feet as people do, rather than on their toes like felines. This stance is very stable, and they can run up to thirty miles an hour. They usually move on all fours, but stand up to scout, to reach or to fight. Their claws are not retractable, but they can swipe fish out of streams, dig out grubs, or climb trees rapidly.
Range and diet
They live in mountain forests and forested wetlands, from Canada to Mexico and from the tree line to sea level. They live in the Rockies, the Alaska Range, the Coast Ranges, the Ozarks and the Appalachians, and in dense swampy southern forests.
In California, they have been seen on empty beaches, swiping fish out of rivers that run into the sea. They raid commercial beehives. In autumn, bears preparing for hibernation may invade orchards, knocking down apples and stuffing themselves.
They are true omnivores, eating what they find. They eat berries, nuts and acorns, and dig up underground fungi. They eat insects, especially ant and beetle larvae, but also rodents and ground-nesting birds.
People who feed bears are endangering themselves, and shortening bear's lives. Bears habituated to humans live half as long as other bears. They are hit by cars while begging; they eat toxins or plastic packaging in garbage; they are vulnerable to poachers who sell their gall bladders as folk medicine. Feeding bears trains them to associate with humans.
Male bears scent mark territories in spring, to invite females. Female bears come into heat when they are three to five years old. They choose a mate and stay with him for three to five weeks, but both partners may also choose other mates. One, two or more cubs are born in winter, and the female nurses them in hibernation.
Cubs are tiny, about eight inches long. They open their eyes at about a month, and begin to walk at five weeks. They nurse for 30 weeks, and strike out on their own at about 18 months. Black bears live about 18 years on average, but often much longer in captivity.
Not all black bears hibernate. Southern bears experience lethargy, but leave their dens frequently. In deep-snow regions, black bears may remain in their dens for seven months.
Dens are hollow tree trunks, spaces under logs, alcoves or caves. In autumn, bears rake leaves into their dens to make a nest. Their activity level slowly drops until they enter hibernation.
Hibernating bears are not deeply asleep, though they curl in a tight ball and barely move. Some biologists call their state winter lethargy. Their respiration and heart rates do slow down, and they do not eat or defecate. The hormone leptin takes away their appetite. Bears may lose up to 40 percent of their body weight in winter.
With spring, the bears emerge. They eat winter-killed carrion, and feed hungrily on the first green shoots. They take two weeks to wander their territory, climbing and swimming and coming alive again.