Polar Bear
Status: Vulnerable.
Description:The
largest four-footed carnivore, unique in color and lifestyle. The exceptionally thick,
water-repellent coat is white, or sometimes yellowish-white. The entire body is furred
except for the nose and foot pads, the latter being lightly "haired" and
partially webbed (for swimming). The ears are short and the head and neck elongated. Claws
are extremely sharp and useful in grabbing prey.
Size:Males range
from 8-9 feet in body length and weigh 750-1400 pounds. Females are smaller, measuring 6
1/2 feet long, and weigh 350-650 pounds.
Habitat:Sea ice and
waters, islands, and coasts. Favored habitat is the annual ice which lies next to the
continental arctic coastlines such as those in northern Canada, Greenland and the former
Soviet Union.
Range: Circumpolar
Arctic. Each bear has its own home range (or territory). A polar bear will not usually go
past its home range, but will migrate within its range. The size of a home range varies --
much depends on the volume of pack ice and the number of seals available.
Food Source: Polar
bears mostly feed on ringed seals, and sometimes bearded, harp, and hooded seals. They
will also scavenge on walrus and whale carcasses.
Behavior: The two
main focuses of this solitary creature's life is to conserve energy and to hunt. Only
females (especially when pregnant) hibernate for long periods of time. Males make
temporary dens in severe weather, but do not hibernate. Polar bears depend mostly on their
sense of smell to guide them through their travels and to determine the location of their
prey. Polar bears use two hunting methods: stalking and still-hunting. Stalking is the
method used by most carnivores, where prey is stalked (followed) and them ambushed
(attacked by surprise). Polar bears are able to stalk both on land and in water.
Still-hunting, frequently used by polar bears, is when a bear sits beside a breathing hole
and waits for a seal to come up for air. Once the seal is in range, the bear grabs it with
his powerful forepaws and claws. An adult bear eating its kill will often share it with
another bear rather than fighting for sole possession.
Reproduction: Females
are able to breed at the age of five years. They have a relatively long gestation period
of 195-265 days before a litter of 1-3 cubs is born. The cubs are born in December and
January, and remain with the mother inside the den until March or April. The cubs stay
with the mother for 28 months.
Population: About
20,000 in the wild.
Longevity: Polar
bears can live in the wild up to 20-25 years.
Survival Threats: Habitat
destruction due to oil and gas exploration and development. Sport hunting and fur trade
also pose serious threats.
Legal Protection: CITES,
Appendix II, U.S. Marine Mammal Protection Act, Agreement on the Conservation of Polar
Bears (an international treaty between five countries, and ratified by the U.S. Senate in
1976).