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A bear's walk differs from that of most other animals. Most animals walk
and run on their toes. A bear, like a human being, puts the entire sole
of its foot on the ground with each step and the heel of the foot strikes
the ground first. The hind feet of a large bear may be 12 to 16 inches
(30 to 41 centimeters) long. The large feet, the short legs, and heel-first
way of stepping make bears look slow and clumsy. But bears are agile and
can move fast. Polar bears can run at speeds of up to 35 miles (56 kilometers)
an hour.
The life of a bear
Bears usually live alone and never gather in groups. During the mating
season in the summer, a male and a female bear may live together for about
a month. Then the male wanders away and the female prepares a place for
her cubs to be born.
Winter Sleep. Some bears spend much of the winter in a state similar
to sleeping. Many scientists consider the bear's winter sleep to be an
example of hibernation. Many other scientists, however, do not consider
bears to be true hibernators. They point out that a bear's body temperature,
unlike that of other hibernating mammals, does not drop greatly during
winter sleep. In addition, a bear awakens easily and may become fairly
active on mild winter days. These scientists use such terms as "winter
lethargy" or "incomplete hibernation" to describe the bear's
sleep period.
A bear prepares for its winter sleep by eating large amounts of food
during late summer and storing fat within its body for energy. When food
becomes scarce, the bear goes to its den. The den may be a cave or a brush
pile, or a burrow that the bear has dug under the roots of a large tree.
Some kinds of bears may build shelters of twigs or dig shallow holes in
hillsides. Female polar bears find ice caves or dig dens in the snow.
Brown bears and black bears, both of which live in regions that have
harsh winters, almost always have a period of winter sleep. Species found
in areas with milder winters may enter dens for only brief periods. Tropical
species, such as sun bears and sloth bears, do not have a winter sleep
period. Although polar bears live in the Arctic, they normally remain
active during the winter. These bears spend the winter wandering the polar
ice near open water and preying on seals and other marine mammals that
come ashore.
Cubs. Most bear cubs are born during the mother's winter sleep
period. A female bear usually has two cubs at a time, but the number may
vary from one to four. The cubs weigh only 1/2 to 1 pound (0.23 to 0.5
kilogram) at birth. Their eyes are closed, and they have no fur. The eyes
open about a month after birth, and by that time the body is covered with
thick, soft fur. The cubs stay in the den with their mother for about
two months. In spring, they come out, frisky and playful. They grow rapidly
and may weigh 40 pounds (18 kilograms) by autumn. Cubs stay with the mother
for one or two years. She teaches them to hunt for food.
Food. Bears are meat-eating animals, but they also eat many other
kinds of food. They hunt mice, ground squirrels, and other small animals
in fields and forests. They may wade into streams and catch fish with
their front paws or strong jaws. Favorite foods of bears include ants,
birds' eggs, and grubs (see GRUB). Bears sometimes prey on livestock,
especially lambs and young pigs. Their diet also may include acorns, berries,
fruits, nuts, and the leaves and roots of plants. Bears are fond of honey
and will rip apart beehives or the nests of wild bees to get it. Their
long, thick fur helps protect them from bee stings.
Habits. Bears often wander far in search of food. A grizzly bear
may claim an area of 10 to 12 square miles (26 to 31 square kilometers)
as its private hunting ground. Polar bears swim well and are often found
living on islands of ice drifting more than 200 miles (320 kilometers)
from land.
Bears are usually peaceful animals. They try to avoid a fight and run
from danger. They have few enemies except other bears and humans. Bears
show no fear of people and often wander into camping areas looking for
food. However, all bears are short-tempered and get angry quickly. They
are fierce fighters and will attack anything that seems to threaten them
or their cubs, food, or homes. An angry bear moves quickly in spite of
its great size. One blow from its powerful front paws can kill even large
animals, such as cattle and deer. The long, thick claws are also dangerous
weapons. Few bears lose a fight with another kind of animal.
Wild bears live from 15 to more than 30 years. In zoos, a brown bear
has lived as long as 47 years, and a polar bear for 34 years.
Kinds of bears
Zoologists traditionally recognize seven species of bears: (1)
big brown bears, (2) American black bears, (3) Asiatic black bears, (4)
polar bears, (5) sun bears, (6) sloth bears, and (7) spectacled bears.
In addition, some zoologists classify pandas as bears. But other zoologists
place pandas in the raccoon family or in a family of their own.
Big brown bears include the world's largest bears. Among them
are the brown bears of Europe and Asia; Alaskan brown bears, such as the
Kodiak bear and peninsula brown bear; and the grizzly bears of western
North America. Big brown bears vary in color from yellowish to almost
black.
Alaskan brown bears are found chiefly on the mainland of Alaska and on
Kodiak and Afognak islands off the southeastern coast of Alaska. They
also live on other Alaskan islands.
Grizzly bears may grow up to 8 feet (2.4 meters) long, and they
generally weigh from 350 to 500 pounds (160 to 230 kilograms). They get
angry quickly, but usually do not attack unless they are threatened.
Grizzlies get their name from the white hairs that grow in their brown
coats, making them look grizzled (streaked with gray). Grizzlies may also
be called silvertips. A grizzly has long, curved claws that it uses chiefly
to dig out ground squirrels and mice to eat. The claws are also used as
weapons.
Grizzlies live mainly in Alaska and western Canada. They also are found
in the mountains of Idaho, Montana, Washington, and Wyoming. About 200
grizzlies live in Yellowstone National Park.
American black bears are among the most common species. They grow
about 5 feet (1.5 meters) long and are the smallest bears of North America.
Most black bears are from 200 to 300 pounds (91 to 140 kilograms), but
some weigh up to 500 pounds (230 kilograms).
Not all black bears are completely black. Some have black coats with
brown noses and white patches on the chest. Others, called cinnamon bears,
have a rusty brown coat. The island white bear, or Kermode's bear, has
creamy white fur and white claws. It lives in the coastal areas of British
Columbia. The blue bear, also called the glacier bear, has gray hairs
mixed with the black ones, giving the animal a bluish color. The blue
bear lives in the mountains of the St. Elias Range in southeastern Alaska.
Black bears can run as fast as 25 miles (40 kilometers) per hour when
they chase prey, and they are skillful tree-climbers. These bears become
troublesome around camps and cabins if food is left in their reach. Black
bears have severely injured and sometimes have even killed campers or
travelers who feed them.
Black bears live in many large wooded areas of North America. There are
about 75,000 of them in the national forests of the United States. Many
states allow people to hunt these bears, and hunters kill about 25,000
a year.
Polar bears are the best swimmers of all bears. They are only
a little smaller than big brown bears. They have a smaller head, but a
longer, thinner neck than most other kinds of bears. The thick, heavy
fur is creamy white, with a hint of yellow. A polar bear has pads of fur
on the soles of its feet. The fur helps keep the feet warm and also helps
the animal walk on ice.
Polar bears can move quickly in spite of their size. These bears can
run up to 35 miles (56 kilometers) per hour--fast enough to catch reindeer.
They can swim 3 to 6 miles (5 to 10 kilometers) per hour. Polar bears
are excellent hunters, and when they are very hungry in winter, they may
attack humans. Their usual prey consists mostly of sea animals, including
fish, seals, and walruses. Polar bears also eat grass and dead whales
that have been washed ashore. The Inuit (sometimes called Eskimos) hunt
polar bears. They eat the meat, use the bones for many kinds of utensils,
and make clothes from the hides.
Polar bears live in regions bordering the Arctic Ocean. Sometimes they
ride floating chunks of ice as far as the Gulf of St. Lawrence, 750 miles
(1,210 kilometers) south of the Arctic Circle. Many people have traveled
to the Arctic to hunt polar bears for sport and for their hides. Such
activities have greatly reduced the number of polar bears.
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