The polar bear or the sea/ice bear are the world's
largest land predators. They can be found in the Artic, the
U.S. (Alaska), Canada, Russia, Denmark (Greenland), and
Norway. Each of these countries either banned hunting or
established rules for how many polar bears could be hunted
within its own boundaries. These rules help keep polar bear
populations stable. Today, 25,000 to 40,000 polar bears roam
the Arctic.
Around the age of four or five the female polar bear can
start having babies. They usually only have two cubs and they
have these babies in a cave they've dug in a large snow drift.
They stay there over winter and come out in spring with the
babies.
The babies are much smaller than human babies when
they're born. They are the size of a rat and weigh little more
than a pound. They can grow to full man size in a year if they
have lots of food.
Despite what we think, a polar bear's fur is not white.
Each hair is clear hollow tube. Polar bears look white because
each hollow hair reflects the light. On sunny days, it traps
the sun's infrared heat and keeps the bear warm at 98 degrees
F (when they're resting).
Polar bear fur is oily and water repellent. The hairs
don't mat when wet, allowing the polar bears to easily shake
free of water and any ice that may form after swimming.
Polar bears have wide front paws with slightly webbed
toes that help them swim. They paddle with their front feet
and steer with their hind feet. Paw pads with rough surfaces
help prevent polar bears from slipping up on the ice.
Polar bears have been known to swim 100 miles (161
kilometers) at a stretch.
Polar bears primarily eat seals. They often rest
silently at a seal’s breathing hole in the ice, waiting for
a seal in the water to surface. Once the seal comes up, the
bear will spring and sink its jagged teeth into the seal’s
head.
Sometimes the polar bear stalks its prey. It may see a
seal lying near its breathing hole and slowly move toward it,
then charge it, biting its head or grabbing it with its
massive claws. A polar bear may also hunt by swimming beneath
the ice.
Humans are the polar bears only predator. Baby polar
bears often starve. In fact, 70 percent do not live to their
third birthday. Sometimes seals are hard to find, especially
in the summer when the ice has melted. All across the Arctic,
man is moving in to mine oil and coal and there is less space
for the polar bear to live. Oil spills can be very dangerous.
A bear with oil on its coat cannot regulate its body
temperature properly. If the bear eats the oil while grooming
it could die.
Man made pollution is also a cause of death. At each
stage of the food chain, pollutants get more concentrated. By
the end when the polar bear eats the seal and it could be
lethal.
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