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Polar bear
Ursus maritimus
| Size |
Polar bears are usually 7-8.5 feet (2-2.6 meters) long. |
| Weight |
They can weigh up to 1,200 lbs (545 kg). |
| Conservation Status |
On the 2010 IUCN Red List of Threatened Species, the Polar bear is listed as Vulnerable. |
| Diet |
In the wild, these large bears hunt ringed seals, Arctic foxes, birds and baby walruses. They can easily kill a ringed seal with just one blow and can consume up to 200 lbs (90 kg) of food at one time.
At the Zoo, just one of our polar bears can consume one to five pounds of mackerel and ground meat and four pounds of omnivore biscuit (a chow specially formulated for bears) a day.
Forage foods are also provided and can include apples, raisins, peanut butter, honey and dehydrated fruit. They are also offered meaty shank bones as enrichment. |
| Geographic Range |
Primarily on arctic coasts, islands and adjacent sea ice of Norway and Russia, North America (Alaska, Canada) and Greenland. |
| Where to find me in the Zoo |
Bear Country |
Note: Description below should include Longevity, Behavior, and Reproduction information
Polar bears have very good eyesight and hearing although their sense of smell is their most highly developed sense. These remarkable bears have a transparent eyelid (nictitating membrane) that work like a pair of sunglasses filtering out the excessive brightness of snow and sun. They also work as waterproof goggles underwater.
Polar bears have 42 teeth and are well adapted to their carnivorous diet. Their canines are the largest and longest of any other bear. They use their extremely sharp carnassials and molars for shearing and biting food.
Longevity
In zoos, polar bears may have a life expectancy of 23 years.
Behavior
Polar bears are solitary animals and mating occurs during the summer season. At the end of the Polar winter, which is in March or April, females give birth to between one and four cubs who stay with their mother for one or two years.
Because of the Arctic or midnight sun, polar bears are active any time of the day or night. On bitterly cold days, they might dig a hole, curl up and even cover their noses with their paws to keep warm. In warmer weather they might also burrow into the earth to keep cool.
Adaptations
Polar bears have adapted well to life in cold climates. Their fur is transparent and because it is hollow, can transmit the sun's warmth down to the layer of skin where it is converted to heat.
The skin of a polar bear is black, as well as its nose, footpads and claws. The layer of fat beneath their skin acts not only as insulation, but also as a food reserve. The rough leather pads on the bottom of their feet help them keep their balance on slippery surfaces.
Considering their large size, polar bears are surprisingly fast. On land, they can outrun a reindeer for short distances, moving at speeds of 25 mph. In water, polar bears can swim for considerable distances at a speed of up to six miles per hour. They paddle with their front feet and use their back feet as rudders.
Klondike: Female, born November 23, 1980 at the Bronx Zoo in New York. She arrived at the Zoo on October 1, 1981. She weighs over 475 lbs.
Coldilocks: Female, born December 13, 1980 at Seneca Park Zoo in Rochester, NY. She arrived at the Zoo on October 6, 1981. She is slightly smaller than Klondike, but still weighs over 450 lbs.
Enrichment
Adoption Information
Featured Foster Parent
Conservation at a Glance
 Wrangel Island, Arctic Russia: Polar Bears International (PBI)
- Polar bears live on Arctic coasts including northern Alaska and Russia, historically hunting on ice masses, which extend from the land.
- Arctic regions are directly affected by global warming. The increase in temperature melts ice and has the potential to dramatically change the landscape as the bodies of water that separate the land masses increase.
- The Philadelphia Zoo supports Dr. Nikita Ovsyanikov through Polar Bears International (PBI). For over a decade he has spearheaded research based on Wrangel Island, documenting the effects of global warming on this polar bear population.
- Dr. Ovsyanikov’s research has shown that polar bear predation behavior has recently changed. Where before polar bears hunted on the ice masses, in 2006, 60% of the bears on Wrangel Island moved farther inland and shifted towards scavenging on reindeer carcasses.
- Some bears appear to have adapted to life farther inland. But more bears are showing signs of being malnourished or are even drowning as they try to swim the increasingly longer distances between ice masses in search of prey.
- The Zoo collaborated with PBI to support 2008 as “The Year of the Polar Bear.” Zoo staff was instrumental in planning this year-long event to increase awareness of polar bear conservation.
- In October 2009, two Zoo staff traveled to Churchill, Manitoba, to help lead a program on polar bear conservation in conjunction with PBI. Churchill, know as the ‘Polar Bear Capital of the World’, is a town where polar bears congregate as they wait for the ice to freeze so they can begin hunting.
To learn more about the conservation efforts at the Philadelphia Zoo, click here.
Did you know the Philadelphia Zoo offers opportunities to travel around the world and get up close with certain animals? Learn more.
Zoo Research
Fun Facts
- Polar bears are inactive about 87% of the time, living off stored fat. They can go into a "walking hibernation" as a survival mechanism when food sources become scarce.
- They keep their eyes open, their nostrils shut and their ears flattened to their heads while swimming and they can stay underwater up to two minutes. They're capable of leaping out of the water seven to eight feet to catch seals or other prey.
Conservation
Introductions
Animal Lingo
Want More?
Sources:
(1) Domico T. 1988. Bears of the World. New York (NY): Facts on File., p. 65-89,
(2) Stirling I. 1993. Bears –Majestic Creatures of the World. Emmaus (PA): Rodale Press, Inc., p. 98-106,
(3) Nowak RM. 1999. Walker’s Mammals of the World, Volume I, 6th Edition. Baltimore (MD): The Johns Hopkins University Press., p. 688-691.
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