Alaska - Polar Bear (Ursus maritimus)

The polar bear evolved from the brown bear and is the largest member of the bear family.

 

Adaptations by polar bears to life on sea ice include: translucent fur with water repellent guard hairs and dense underfur, short furred snout, small ears, teeth specialized for a carnivorous rather than omnivorous diet, and hair on the bottom of their feet. Polar bears are the most nomadic of all bears, some of which travel an average of 5,500 miles a year or about 15 miles a day.

Males measure from 8 to 11 feet from nose to tail (2.4 - 3.4 m) and generally weigh from 600 to 1,200 pounds (272 - 543 kg), but may weigh up to 1,500 pounds (679 kg). Females measure from 6 to 8 feet (1.8 - 2.4 m) and weigh from 400 to 700 pounds (181 - 317 kg). Polar bears generally live alone except when mating or rearing cubs.
Exceptions occur when polar bears gather at food sites such as a whale carcass or when they are concentrated on land during the open water season in parts of Canada.
Female polar bears will reach breeding maturity between the ages of 4 and 6. Pregnant female bears seek out denning areas in late fall on land or sea ice.
Dens are made in snow along bluffs and rough ice where snow drifts accumulate. The female digs out a small chamber in the snow drift to serve as a maternity den.
A litter of 1 to 3 cubs is born in December or January.
The cubs will not leave the den until March or early April and will stay with the mother for about two and a quarter years. Female polar bears will have a litter every 3 or 4 years. Polar bears can live up to 32 years but most probably do not live past 25 years in the wild.
Polar bears can be found in Greenland, Norway, Russia, Canada, and in north and northwest Alaska.

Polar bears travel on sea ice which expands and shrinks during annual cycles. In the winter, they will travel as far south as St. Lawrence Island or even St. Matthew Island. During summer months, they are more commonly found near the edge of the ice in the Beaufort Sea and the Chukchi Sea.
It is estimated that their are 22,000 - 28,000 polar bears worldwide and approximately 3,000 - 5,000 in Alaska.

Ringed seals are a favorite food of polar bears. They capture the seals by waiting by breathing holes and at the edges of leads and cracks in the ice. Bears may also stalk seals resting on the top of the ice and catch young seals by breaking into pupping chambers in the spring. Polar bears also hunt bearded seals, walrus and beluga whales. They will feed on carrion also, including whale, walrus and seal carcasses found along the coast.