Bear is a large, powerful, and solitary mammal. Mammals are animals that feed their young on mother’s milk. Bears belong to an order (group) of mammals called carnivores, or meat-eaters. Bears may eat meat and sometimes prey on other animals. But most species (kinds) of bear rely mainly on foods other than meat, including fruit, nuts, insects, and vegetation. Because bears are so large, they must feed heavily when food is abundant, packing on weight to survive months when food is scarce. Wild bears can live from 15 to more than 30 years, depending on the region and species. In captivity, bears can live as long as 47 years.
Loading the player...Bear
The Alaskan brown bear is the largest carnivore that lives on land. It grows about 9 feet (2.7 meters) long and may weigh up to 1,700 pounds (770 kilograms). The sun bear is the smallest bear. It is 3 to 5 feet (90 to 150 centimeters) long and weighs only 60 to 150 pounds (30 to 70 kilograms). Most bears are terrestrial—that is, they live on land. The polar bear, however, is considered a marine mammal because it spends most of its time on the Arctic sea ice.
Most wild bears live north of the equator. They are found in Asia, Europe, and North America and into the Arctic. Only the spectacled, or Andean, bear lives south of the equator in South America.
The body of a bear
Most bears have a heavy body with thick fur, a large head, a long muzzle, and a short tail. They have small eyes in the front of the head and cannot see as well as other large mammals. Their rounded ears stand straight up, helping them to hear. However, bears rely mostly on their excellent sense of smell, which helps them to find food.
Bears have strong shoulders, which help them to climb and swim and to catch prey. They have somewhat short, strong legs and large feet. Each foot has five toes, and each toe ends in a long, heavy claw. Some species of bear have especially long claws, which they use to dig for squirrels, roots, and insects or to hold and tear at prey. Other bears have shorter claws, helping them to climb trees in search of fruits and nuts. Loading the player...
Black bear cub climbing
The hind feet of a large bear may average 12 to 16 inches (30 to 40 centimeters) long. The front feet are wide and strong. Bears may walk slowly as they look for food, but they are agile and can move fast when necessary. Some bears can run more than 40 miles (64 kilometers) an hour.
The life of a bear
Bears are solitary and usually live alone. They do not like being with other bears and need plenty of space. When food is plentiful in a particular area, bears can gather in large numbers for weeks at a time. But when food is hard to find, they tend to stay away from one another to avoid fighting.
Most bears are shy and avoid humans. But bears are curious and are opportunistic feeders—that is, they take advantage of nearly every chance to eat. As a result, bears sometimes come into fairly close contact with people. Bears that grow accustomed to feeding near people can lose their fear of humans, becoming dangerous. Bears normally do not behave aggressively unless they are bothered or are protecting their cubs or food sources. But when angered, a bear can move quickly in spite of its great size.
Denning and winter sleep.
A bear may spend part of the year in a shelter called a den. Bear dens vary by species. They are made with whatever materials are easiest to find. For example, in areas that have plenty of large, hollow trees, bears will make their dens in tree trunks or even under roots. In rocky, mountainous areas, bears will den under large rocks or in small caves. In some cases, bears even make “nests” using brush, leaves, or grass. Female polar bears dig dens in the snow.
In the den, some bears may enter into winter sleep. This state of reduced activity helps them to survive when food is hard to find. Winter sleep is similar to hibernation in some ways, but it is not true hibernation. For example, true hibernators reduce their body temperature until they are very cold, and they have difficulty waking up. In winter sleep, however, a bear’s temperature lowers only by a few degrees, and the bear can easily be awakened.
Pregnant females will always seek the shelter of a den to give birth to cubs. Black and brown bears can stay in their dens for months at a time. In some places and for some species, however, male bears and females that are not pregnant may not den. Instead, they may simply reduce their activity during winter months. Male and non-pregnant female polar bears stay active throughout the year. They spend the cold months hunting for seals and other marine mammals. Little is known about the denning habits of wild spectacled bears, sun bears, Asiatic black bears, sloth bears, and pandas. But most biologists agree that they all must den or nest to have cubs.
Reproduction.
Bears have an unusual reproduction cycle. When the egg of a female bear is fertilized, it will not begin to develop until later in the season, sometimes several months after fertilization. Most bear species breed in the spring or summer, and cubs are born in the winter. Some species, such as the sun bear, may reproduce throughout the year.
Cubs.
Bear cubs are born during the mother’s winter sleep or nesting period. A female bear usually has two cubs at a time, but the number in a litter (group of newborns) may vary from one to four. The cubs are tiny and hairless at birth, weighing only 1/2 to 1 pound (0.25 to 0.5 kilogram). Their eyes open about a month after birth, and by that time the body is covered with thick, soft fur. A healthy mother’s milk is very rich, helping the cubs to grow quickly.
The cubs stay in the den with their mother for about two to four months after birth. They become active in the spring but still stay close to the den with their mother. She takes them farther when they are old enough to walk for long distances and escape danger. The cubs may weigh from 20 to 80 pounds (9 to 36 kilograms) by autumn. After their first year, the cubs become yearlings. They may continue to stay with the mother for one to three years until she breeds again. While they are together, the mom teaches her cubs to look for food and to climb trees to escape danger. When the cubs are old enough, young males will wander off to new areas, while young females may live close to their mothers.
Food.
Bears must gain as much weight as possible to survive the winter months or other periods when food is scarce. Therefore, they must eat a lot of food and will eat almost anything. Wild bears spend most of their time getting nourishment from acorns, pine seeds, berries, fruits, nuts, and the leaves and roots of plants. They will also turn over rocks to look for bugs or dig to find roots or squirrels. Some bears wade into streams and catch fish with their front paws or strong jaws. Bears are fond of sweet things such as honey and will rip apart beehives. Their thick fur and thick skin help protect them from bee stings.
Bears also like the same foods as humans and other animals. This taste attracts them to human garbage, grease on barbeque grills, hummingbird feeders, dog food, and other unprotected food sources. Bears sometimes prey on such livestock as sheep, goats, and young calves. They also eat carrion (dead and decaying animal flesh).
Loading the player...Bear catching and eating salmon
Land use.
Bears often wander far in search of food, particularly during drought or after large wildfires. Bears will also wander in search of a mate. They do not have territories, but instead live in a general area called a home range, which they share with other bears. However, bears leave scents and markings on trees so that other bears know to keep their distance. Female bears generally have smaller ranges unless pressured to wander in search of food. Males have much larger home ranges that can vary from a few to thousands of square miles or kilometers.
Kinds of bears
There are eight species of bears: (1) brown bears, (2) American black bears, (3) Asiatic black bears, (4) polar bears, (5) sun bears, (6) sloth bears, (7) spectacled or Andean bears, and (8) giant pandas. Scientists formerly placed giant pandas in the raccoon family or in a family with red pandas. For information about giant pandas and red pandas, see Panda.
Brown bears
are the most widespread species. They are found in Asia, Europe, and North America. They vary widely in size depending on the region. Brown bears may average from 100 to 1,500 pounds (45 to 680 kilograms). They vary in color from yellowish to almost black. They have a hump on their back. Brown bears occupy such famous high mountains as the Pyrenees of Europe and the Himalayas of Asia, all the way down to the Gobi Desert of Mongolia.
The brown bears of coastal Alaska are called Kodiaks. They are named after an Alaskan island where they are numerous. They also live on other Alaskan islands. Kodiaks, as well as brown bears in the coastal areas of Russia, are larger than other brown bears, because they eat plenty of fish, which is high in protein.
Loading the player...Alaskan brown bear
Grizzly bears live mainly in Alaska and western Canada. They are also found in the mountains of Idaho, Montana, Washington, and Wyoming. The bears may grow up to 8 feet (2.4 meters) long and generally weigh from 250 to 600 pounds (110 to 270 kilograms). Grizzly bears can be angered quickly, but they usually do not attack unless threatened or surprised.
Grizzlies get their name from the white hairs that grow in their brown coats, making them look grizzled (streaked with gray). For the same reason, they may also be called silvertips. A grizzly has long, curved claws that it uses chiefly to dig out ground squirrels, roots, and insects to eat. The claws can also be used as weapons.
Loading the player...Grizzly bear
American black bears
are the most numerous of all eight bear species. They are found only in North America. American black bears grow 5 to 6 feet (1.5 to 1.8 meters) long. The average black bear ranges from 100 to 400 pounds (45 to 180 kilograms), but some weigh up to 880 pounds (400 kilograms).
American black bear colors vary widely. Most have black coats with tan muzzles. Others are very dark brown. The cinnamon bear has a light, rusty brown coat. A bear’s coat color can also change within seasons. In coastal areas of British Columbia, there lives a unique black bear called the spirit bear, or Kermode bear. It has brown eyes, creamy white fur, and white claws. Only about one in four bears in this region have this color. The blue bear, also called the glacier bear, lives in southeastern Alaska. It has gray hairs mixed with the black ones, giving the animal a bluish appearance. Some American black bears have white patches, called blazes, on their chests.
Black bears live in many large wooded areas. It is estimated that there are nearly a million of them in the national forests of North America. Many states allow people to hunt these bears.
Asiatic black bears
are sometimes called moon bears because they often have a large, cream-colored chest blaze shaped like a crescent. Most Asiatic black bears are black, with some white hairs on the chin. They are about the same size as American black bears. Asiatic black bears measure from 4 to 6 feet (1.2 to 1.8 meters) in length and may weigh from 110 to 440 pounds (50 to 200 kilograms).
Asiatic black bears live in forests and brush regions throughout southern and eastern Asia. They can live in a wide range of habitats, such as high mountains or tropical forests. Asiatic black bears feast on oak acorns, beechnuts, walnuts, chestnuts, hazelnuts, and pine seeds. They also eat juicy plants, such as bamboo shoots, in the spring, and fruits and insects in the summer. They will also eat carrion.
In the northern part of their range, both female and male Asiatic black bears will enter winter sleep. In the tropical forests of their southern range, only pregnant females will den, to have their cubs. Asiatic black bears make beds of twigs in the snow so they can sun themselves. In summer, they build nestlike beds of sticks in trees, where they sit and eat, or sleep.
Asiatic black bears have been known to attack livestock and people. In Japan, bears sometimes raid fruit orchards and come into conflict with people. In countries such as China and Vietnam, people hunt the bears for their bile (a fluid produced by the liver) and other body parts. They believe these parts have special healing powers. Some countries have tried to farm bears as an easy way to produce the bile. See Asiatic black bear.
Polar bears,
sometimes called ice bears or sea bears, live in regions bordering the Arctic Ocean. Their habitat covers parts of Canada, Greenland, Norway, Russia, and the United States. Polar bears have very large home ranges, because they can wander for thousands of miles on the sea ice to find food. They even sometimes ride floating chunks of ice.
Polar bears are excellent swimmers. They can swim for long distances, sometimes for days at a time. If they swim too far, they will lose too much energy and starve. Polar bears will swim between ice floes and under the ice, even diving for kelp. They can run for short bursts at speeds up to 35 miles (56 kilometers) an hour.
Generally, polar bears are a little larger than brown bears. They have a smaller head, but a longer, thinner neck, which helps them to swim better. The thick, heavy fur is creamy white, but it can sometimes turn yellow from seal oils. The hairs of the fur are hollow, which helps to reflect light and to insulate the bear when it is swimming in cold water. Polar bears have black skin and a very thick layer of fat, even on their feet. They also have thick pads of fur on the soles of the feet. The fur helps keep the feet warm and also helps the animal walk on ice.
Polar bears are excellent hunters. They depend almost completely on seals for their food. These bears require high amounts of protein and fat to survive. They also hunt walruses and beluga whales. Polar bears may also eat dead whales that have washed ashore. When the sea ice has melted, they will eat vegetation, such as grass and berries.
Traditionally, Arctic tribes, such as the Inuit people, hunted polar bears. They ate the meat, used the bones for many kinds of utensils, and made products from the hides. Some Inuit still hunt polar bears for these purposes. Unregulated sport hunting had greatly reduced the number of polar bears in the past. But numbers have since recovered to healthy levels and are managed carefully. However, the main threat to these bears is a dwindling amount of sea ice in the summer, thought to result from global warming. See Polar bear.
Sun bears,
sometimes called Malayan bears, are the smallest species of bears. They grow only about 3 to 5 feet (1 to 1.5 meters) long, and weigh 60 to 150 pounds (30 to 70 kilograms). Most sun bears have a black coat and a tan, gray, or orange nose. Some have light brown feet. Sun bears have large paws with no hair on the soles. The claws are more curved and have sharper points than those of other kinds of bears. The bear gets its name from the white or yellow marks on its chest. Each sun bear has its own unique chest blaze. Many people of ancient times believed the marks represented the rising sun.
Sun bears eat mostly fruits, honey, and insects. They especially like figs. They have a very long tongue, which helps lap up insects and honey. Their curved claws help them climb trees and tear apart insect mounds. Sun bears usually hunt only at night. They spend the day sleeping and sunbathing in trees. They build nestlike beds in trees by bending or breaking the branches. Sun bears live in the forests of Borneo, Indochina, the Malay Peninsula, Myanmar, Sumatra, and Thailand. Like the Asiatic black bear, sun bears are also hunted for their valuable body parts. See Sun bear.
Sloth bears
get their name from an Old English word meaning slow. Sloth bears move very slowly except when disturbed. These bears are so fond of honey that they are sometimes called honey bears.
Sloth bears grow about 5 feet (1.5 meters) long and weigh about 250 pounds (110 kilograms). They have shaggy black fur and a white or yellow chest mark shaped like a U, V, or Y. Sloth bears have big, furry ears.
Sloth bears live in Bhutan, India, Nepal, and Sri Lanka. They sleep in the grass, under shrubs, or in shallow caves. Sloth bears are known to behave aggressively, but perhaps they do so because they live in areas where they often come into contact with people. Sloth bears hunt chiefly at night. These bears eat primarily ants and termites. Sloth bears pull apart the termites’ nests with their long claws, blow away the dust, and use their mouth like a vacuum to suck up the insects. See Sloth bear.
Spectacled bears,
also commonly known as Andean bears, are the only South American bears. This bear got its name from the cream-colored rings around its eyes, which look like reading glasses. The bear grows about 3 to 6 feet (0.9 to 1.8 meters) long and weighs 75 to 350 pounds (34 to 160 kilograms). It has shaggy black or blackish-brown fur.
The spectacled bear lives in the cool mountain forests and high grasslands of Bolivia, Colombia, Ecuador, Peru, and Venezuela. Little is known about the habits of this bear, but it eats such tough, fibrous food as bamboo, tropical plants called bromeliads and palms. Spectacled bears also eat fruits, insects, and small animals. Occasionally, they will attack livestock. Overhunting and destruction of its forest home have made the spectacled bear scarce throughout much of the area.
