A female polar bear will go into a
hibernation type state in the fall, if she is pregnant. A female
polar bear can become pregnant in April or May. If this happens then
she needs to eat lots and build up her fat deposits. A pregnant
female polar bear will not go out to the ocean and the pack ice, the habitat
that polar bears are most suited to, instead she will build a
maternity den. The mother polar bear will build her den in a snow
hill, or an icy slope. The female polar bear will go into her den in
the fall and will not emerge until spring. Polar bears can have a
varied gestation period. Anywhere from 190 to 260 days. Female
polar bears may not become pregnant the moment of copulation, instead the
female polar bear may store the male sperm inside her. She does this
to enable that the sperm will fertilize the egg at the ideal time.
When conditions are just right.
While she is in the den, the female polar bear will give birth to a
litter of cubs. Usually the female will have 1-3 cubs. When
the polar bears are born they weigh less than a kilogram about 1 to 1 ½
pounds. Baby polar bears are born with their eyes shut and with very
little fur. While inside the maternity den, the baby polar bears
feed on the mother polar bears milk, which is rich in fat protein.
Polar bear cubs usually arrive in November or December. They remain
in the den with their mother until she breaks through the snow and ice
that has covered the door. At this time the polar bear cubs are
about three months old. When the family emerges, they stay close together.
A mother polar bear will nurse and protect her young for up to 2 1/2
years. Once the polar bear cub leaves it's mother, it will not
become sexually mature until about the age of 5.
