Classification Kingdom Animalia Phylum Chordata Class Mammalia Order Carnivora Family Ursidae Genus Ursus Species maritimus
Common Name Polar Bear
Morphology The polar bear is the largest living land carnivore, with adult males growing up to 2.6 meters in length. The most well known of all bears, the polar bear is immediately recognisable from the distinctive white color of its thick fur. The only unfurred parts of the body are the foot pads and the tip of its nose, which are black, revealing the dark color of the skin underneath the pelt. Polar bears have large strong limbs and huge forepaws which are used as paddles for swimming. The polar bear has bilateral symmetry. The toes are not webbed, but are excellent for walking on snow as they bear non-retractable claws which dig into the snow like ice-picks. The soles of the feet also have small projections and indents which act like suction cups and help this bear to walk on ice without slipping. Females are about half the size of males, although a pregnant female with stored fat can exceed 500 kilograms in weight. Polar bear cubs weigh up to 0.7 kilograms at birth. They look similar in appearance to adults, though they have much thinner fur.
Distribution Map
Economical Importance A new study, The Economics of Polar Bear Trophy Hunting in Canada, jointly released by Humane Society International and International Fund for Animal Welfare, reveals that polar bear hunts provide little economic benefit to Canada's Inuit communities. The study shows that the income derived from polar bear trophy hunting amounts to only a small fraction of Northern Canada's economy and is concentrated in few hands. A coalition of wildlife groups including Humane Society International and International Fund for Animal Welfare is calling for an international ban on the trade in polar bear parts — such as rugs — at the upcoming meeting of the Conference of the Parties to the Convention on International Trade in Endangered Species of Wild Fauna and Flora, set for March 13-25 in Doha, Qatar. "No country wants to be known as the one that put the last nail in the coffin of the polar bear," said Teresa Telecky, Ph.D. and wildlife department director for Humane Society International. "We implore CITES member countries to eliminate the threat that international commercial trade poses to this rapidly declining species." Polar bears in the wild live entirely within five countries: Canada, Greenland (Denmark), Norway, Russia and the United States. There are presently between 20,000 and 25,000 polar bears, and the number is decreasing. Leading polar bear scientists believe that two-thirds of the world's polar bears will be lost by mid-century because of habitat loss due to climate change. Canada is the only country that allows international commercial sale of hides of polar bears killed by indigenous hunters and is the only country that allows polar bear trophy hunting.
Biology -Polar bears are solitary mammals throughout most of the year, with the exception of breeding pairs and family groups. Populations, or stocks, of polar bears are distributed throughout the Arctic and have overlapping home ranges which are not defended, and may vary in size from a few hundred to over 300,000 square kilometers. -The main food source is ringed seals and, to a lesser degree, bearded seals. The polar bears capture seals when they surface to breathe, or hunt them in their lairs, where young seals are nurtured. Polar bears show some amazing adaptations to their Arctic life and are able to detect prey that are almost a kilometer away and up to a meter under the compacted snow, using their heightened sense of smell. They also feed opportunistically on walruses, belugas, narwhals, waterfowl and seabirds. -When food is available these bears have a remarkable ability to devour large amounts of food rapidly, and are also metabolically unique in their ability to switch from a normal state to a slowed-down, hibernation-like condition at any time of year when there is less food available. For example, in Hudson Bay the ice melts completely by mid-July and, as it does not re-freeze until mid-November, pregnant females do not feed for eight months. During this fasting time, they metabolise their fat and protein stores and recycle metabolic by-products. During periods of particularly cold weather polar bears may also fast, and are known to conserve energy by occupying temporary dens. -Polar bears breed from late March to late May. Females nurse and care for their cubs for 2.5 years and are therefore only available for mating once the cubs are independent, every three years. As this means that only a third of females can breed each season there is intense competition by the males for females, which may explain why males are so large in size. Females must mate many times over a period of several weeks before ovulation and fertilisation are stimulated (induced ovulation), and breeding pairs remain together for one to two weeks to ensure successful mating. If the female’s partner is displaced she may mate with more than one male at this time. Implantation of the fertilised egg is delayed until mid-September to mid-October, and the female gives birth to the young in a snow den some two to three months later.
Interesting Facts
-Polar bears have black skin and although their fur appears white, it is actually transparent. -It is the largest carnivore that lives on land. -Polar bears use sea ice as a platform to hunt seals. -Seals make up most of a polar bears diet. -Male polar bears can weigh up to 680 kg (1500 lb). -Female polar bears usually only weigh about half as much as males. -Polar bears spend most of their time at sea. -Scientists estimate that there are around 20000 polar bears. -Polar bears have 42 teeth.
Ecological Importance 1. As one of the largest land carnivores in the world along with grizzly bears, polar bears are known as a keystone species, the apex of the ecosystem. They keep biological populations in balance, a critical component to a functioning ecosystem. 2. They’re also a sign of health for the ecosystem. If the keystone species is unhealthy, that’s a sign the entire ecosystem is in trouble. In the case of the Arctic, the health of that ecosystem is a sign for what’s in store for the rest of the world. 3. Polar bears eat almost exclusively seals, but if they can’t hunt for that food source due to lack of a sturdy ice platform or pure exhaustion, they’ll quickly move on to others. This could threaten the existence of other Arctic species, like the Arctic fox or the walrus, as they compete for food resources. 4. Scavengers like the Arctic fox and Arctic birds like the snowy owl depend on big kills from polar bears as sources for food as well. If they’re not killing seals, they’re cutting out another food source for wildlife