Common Name: Polar
Bear
Class: Mammalia
Order: Carnivora
Family: Ursidae
Genus: Ursus
Species: Ursus
maritimus
|
 |
Taxonomy/Description
Polar bears belong
to the bear family, Ursidae, which also includes black bears, brown
bears, and spectaled bears, in the Mammalian Order Carnivora. Its
scientific name is Ursus maritimus, which means "sea bear". The
polar bear is the largest land carnivore on the planet, and the only
other member of Carnivora, along with the sea otter, that is a
Marine Mammal.
They are the only
bears that have fur on their feet. This helps them grip the ice.
Males are 7-9ft long and can weigh 700-1600lbs. Females are smaller
weighing 330-550lbs. Their bodies are built to survive in the
extreme cold of an icy environment and freezing water. These
conditions reach temperatures as low as -50ºF. Their blubber can be
4.5 inches thick. Extremely dense fur covers black skin. Black skin
absorbs all available sunlight, warming the bear during daylight
hours. The fur is hollow to help insulate against the cold.
Although the bear's fur looks white, it is actually pigment free.
It looks white because it reflects light like snow does. They have
wide webbed front feet, and are powerful swimmers. Their long
streamlined bodies help them swim 20-30 miles at a time.
Habitat/Diet
The polar bear's
range extends throughout the Arctic circle, including Alaska,
Canada, Russia, Denmark, and Norway. Polar bears are omnivores
eating mostly other marine mammals including seals, young walruses
and even whales. A beluga was attacked and killed while breathing
at an ice hole by a polar bear. They will also take advantage of a
carcass and eat vegetation during the summer months. The species of
seal commonly hunted by polar bears are the ringed seal and bearded
seal. Polar bears are known to hunt and eat humans. Only a small
handful of animals, including tigers, lions, great white sharks,
Komodo dragons, Australian saltwater crocodiles and anacondas are
known to hunt, kill and eat humans.

Behavior/Reproduction
Polar bears are
solitary animals coming together only to mate, rear their young and
if there happens to be a large kill around the vicinity. Although
mating takes pace in April or May, the fertilized egg does not
implant until the fall. This is known as delayed implantation.
During the winter, pregnant females will build a den in the snow to
give birth to two cubs. Each cub weighs slightly more than a
pound. The cubs will stay with their mother for 18 months learning
how to hunt.

Conservation
Polar bears are
potentially threatened. Their lives are affected by the any
increase in global climate. Such a climate change may be caused by
humans introducing carbon dioxide and other greenhouse gases. Polar
bears require the large amounts of ice present in the arctic for
survival. Although most polar bears live far from heavily populated
human areas, pollution still has adverse effects. Chemical
pollutants travel by wind and precipitation, eventually reaching
even the most remote arctic regions. These pollutants will then
carry through the food chain and accumulate within predators like
polar bears, resulting in disease and eventually death. Drilling,
mining, fishing, hunting and the broad spectra of other human
interactions also threaten the lives of polar bears.