Marine Mammals

Polar Bear Ursus maritimus Nanoq



image courtesy of: en.wikipedia.org/wiki/



Distribution:
image courtesy of: en.wikipedia.org/wiki/



Status:

image courtesy of: en.wikipedia.org/wiki/



Media:
 
Watch a video of a Polar Bear
 
Watch a video of a Polar Bear
 
Watch a video of a Polar Bear
 


Polar Bear Extras:
 
Play a Polar Bear Game
 
View a Status Map of the 19 Arctic
Polar Bear Populations

View a Polar Bear Status Table
 
Agreement on Polar Bear Harvest
between Greenland & Canada
 
Scientific Methods used in polar
bear studies
 
Conservation Issues
 
Click on the image for a larger view of a
Polar Bear in a den on a coastal snow bank:
image courtesy of: alaska.usgs.gov/science
/biology/polar_bears/denning.html


Description:

The polar bear is the world's largest carnivore species found on land. It is native to the Arctic Circle and everything encompassing it. It is tied for the largest bear with the omnivorous Kodiak bear which is approximately the same size. Although most polar bears are born on land, it spends most of its time at sea.

An adult male weighs around 350-680 kg (770-1,500 lb), while an adult female is about half that size. It is closely related to the brown bear but it has evolved ecological niches to adapt to cold temperatures, moving across snow, ice, and open water.

Polar bears have a coat that is yellowish white all year round. They have large feet and short, stocky claws, these are adaptations to there environment. The polar bear has a more elongated body build and a longer skull and nose. The 42 teeth of a polar bear reflect its highly carnivorous diet. The cheek teeth are smaller and jagged than in the brown bear, and the canines are larger and sharper. The white coat usually yellows with age. The long muzzle and neck of the polar bear help it to search in deep holes for seals, while powerful hindquarters enable it to drag massive prey.

The polar bear's hearing is about as acute as that of a human, and its vision is also good at long distances.

The polar bear is usually wary of people. However, some can be extremely curious, and starving bears can be dangerous. Polar bears are rarely seen along the central west coast, which is the area most visited by tourists.

The ringed seal is the polar bear's most important prey. However, the polar bear also hunts other seal species and birds. Bears 'stranded' at ice-free shores may move inland during the summer to eat various plants. Polar bears depend on sea ice as a platform for hunting seals. The Arctic is home to millions of seals, which become prey when they surface in holes in the ice in order to breathe, or when they haul out on the ice to rest.
Polar bears hunt primarily at the interface between ice, water, and air; they only rarely catch seals on land or in open water.

Still-hunting is the polar bear's most common hunting method. The polar bear has an extremely well-developed sense of smell and uses it to locate seal breathing holes. When it finds a hole it crouches nearby in silence for a seal to appear. When the seal exhales, the bear smells its breath, reaches into the hole with a forepaw, and drags it out onto the ice. The polar bear kills the seal by biting its head to crush its skull. The polar bear also hunts by stalking seals resting on the ice. The prey usually has no idea that the polar bear is around and is about to attack.

The polar bear is an excellent swimmer and have been seen in the open Arctic waters being 200 miles out. With its body fat providing buoyancy, it swims by dog-paddling. Polar bears can swim 6 miles/hour. When walking, the polar bear tends to have a lumbering gait and maintains an average speed of around 5.5 km/h (3.5 m.p.h.).

It remains active all year round under normal weather conditions, but can hibernate for short periods. However, pregnant female leaves sea ice in November to December to find a solid snow bank, where she digs a den. One to three cubs are born around the turn of the years. These remain in the den until approximately April first after which they follow their mother out on the ice. Polar bear cubs usually stay with their mother until 30 months old. Therefore females only give one birth every three years.

The polar bear for thousands of years has been a key figure in the material, spiritual, and cultural life of Arctic indigenous people. The hunting of these bears has also remained important in their cultures.

Global warming as become the polar bears most significant threat to survival. The melting of its sea ice habitat reduces it ability to find sufficient food. The IUCN is predicting that if the weather continues to change we won't have any polar bear in 100 years. The polar bear is listed as a threatened species under the Endangered Species Act in May of 2008.


















Source courtesy of: The Nature and Wildlife Guide to Greenland, Benny Gensbøl (2005) and wikipedia.org