Polar Bear FAQs

Photo copyright Dick & Val Beck/Polar Bears International. Details...

Where do polar bears live?
Are polar bears endangered?
How many polar bears are there?
What is the polar bear's scientific classification and name?
How big are polar bears?
How do polar bears survive in the arctic environment?
What do polar bears eat?
What is the polar bear's place in the food chain?
What is a polar bear's life span?
How many cubs do female bears have?
When and where are the cubs born?
What do newborn cubs look like?
When does the family emerge from the den?
How long do the cubs remain with their mother?
Do polar bears hibernate?
Are there different populations of polar bears?
Does the polar bear have any predators?

Where do polar bears live?
Polar bears live In the Arctic in areas where they can hunt seals at openings in the sea ice called leads. There are five nations with polar bears: U.S. (Alaska), Canada, Russia, Greenland, and Norway. Polar bears do not live in Antarctica. Penguins do.

Are polar bears endangered?
Experts in polar bear science believe they are. They predict that as the Arctic continues to warm due to climate change, two-thirds of the world's polar bears could disappear by mid-century—although hope remains if action is taken to greatly reduce greenhouse gas emissions.

Rapid loss of sea ice is their major threat. Others include pollution, poaching, and industrial impact. Hunting will become a threat if not well regulated.

In 2005, the IUCN Polar Bear Specialist Group (PBSG) classified polar bears as vulnerable on the IUCN World Conservation Union's Red List of Threatened Species noting that extinction could occur due to sea ice changes.

In May 2008, U.S. Department of the Interior listed the polar bear as a Threatened Species under the Endangered Species Act. Canada and Russia list the polar bear as a species of concern.

At the 2009 meeting of the PBSG, the world's leading polar bear scientists reported that of the 19 subpopulations of polar bears, eight were declining, three were stable, and one was increasing. They lacked sufficient data about the remaining seven.

How many polar bears are there?
Scientists can only provide informed estimates. In 2008, scientists estimated that there might be 20,000 to 25,000 of them.

What is the polar bear's scientific classification and name?
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Ursidae
Genus: Ursus
Species: Ursus maritimus (sea bear)

A polar bear's closest relative is the brown bear, Ursus arctos.

How big are polar bears?
Very big! Adult males normally weigh 351 to more than 544 kilograms (775 to 1,200 pounds). Adult females are smaller, normally weighing 150 to 295 kilograms (330 to 650 pounds). The largest polar bear ever recorded was a male weighing 2,209 pounds. Wow!

Scientists usually refer to how tall bears are by measuring them at the shoulder when on all fours. Those heights are typically 3.5-5 feet for adult polar bears, both male and female. An adult male may reach over 10 feet when standing on its hind legs.

How do polar bears survive in the arctic environment?
They're built for it! Polar bears love the arctic climate, where winter temperatures can plunge to -45º C (-50º F). Polar bears are insulated by two layers of fur that help keep them warm. They also have a thick fat layer. In addition, their compact ears and small tail also prevent heat loss. In fact, polar bears have more problems with overheating than they do from the cold—especially when they run.

Polar bear feet are furred and covered with small bumps called papillae to keep them from slipping on ice. Their sense of smell is powerful for detecting seals. And their powerful claws can haul out a 40-90 kg (150-200 lb) seal from the water for dinner.

What do polar bears eat?
Polar bears have evolved to feed on seals, specifically seal fat, the highest calorie food source possible. The bears prey on both ringed and bearded seals. Ringed seals, which are smaller, are the most accessible, especially to younger bears and females. Male polar bears also hunt bearded seals, which are larger. When hunting is good, polar bears eat only the blubber in order to build up the fat reserves they need to sustain themselves between meals. They leave the carcass for scavengers, such as arctic foxes, ravens, and younger bears.

All the other foods that polar bears may eat are opportunistic feedings. Most of these foods, with the exception of beached whales, don't provide enough calories to sustain the polar bear's massive body size or to build up the bear's own fat reserves.

What is the polar bear's place in the food chain?
Right at the top of the arctic food chain. Polar bears balance nature by preventing an overpopulation of seals.

What is a polar bear's life span?
In human terms, not very long. In the wild, polar bears live an average 15 to 18 years, although biologists have tagged a few bears in their early 30s. In captivity, they may live until their mid- to late 30s. Debby, a zoo bear in Canada, lived to be 42.

How many cubs do female bears have?
Twins
are most common, but they can bear singlets or triplets depending on their condition. They give birth to their first litter when they are between four and eight years old—most frequently at five or six. Polar bears have the one of the slowest reproductive rates of any mammal, typically producing only five litters in their lifetime.

When and where are the cubs born?
In November or December in snow caves called maternity dens. After feeding heavily in April or May, females that have mated dig a den in late October or early November. Most choose den sites in snowdrifts along mountain slopes or hills near the shore. Some dig their dens in snowdrifts on the sea ice.

What do newborn cubs look like?
Like a big, white rat. At birth, cubs are 30 to 35 centimeters (12 to 14 inches) long and weigh little more than half a kilogram (about one pound). They are blind, toothless, and covered with short, soft fur. They are completely dependent on their mother for warmth and food.

When does the family emerge from the den?
In March or April. During her time in the den, the mother does not eat, drink, or defecate. Cubs grow rapidly, thanks to the calories in their mother's rich milk, which is about 31% fat. In their first year of life, cubs are called coys, which stands for cubs of the year.

How long do the cubs remain with their mother?
Until they're about 2-1/2 years old—although some bears in the Hudson Bay area wean their young at age 1-1/2. During this time with mom, they learn how to hunt and survive in one of the earth's harshest environments. Between the time they leave their mother and they are mature enough to mate, they are called subadults.

Do polar bears hibernate?
Pregnant female polar bears dig a snow den, give birth, and emerge three months later. During this time, they live off their fat reserves. But they don't hibernate in the strict sense of the word. True hibernators experience a marked drop in heart rate and body temperature and generally stay for a long period in a den. Adult males and non-pregnant females don't den up at all.

Are there different populations of polar bears?
Yes. Scientists recognize 19 distinct populations of polar bears, but no subspecies.

Does the polar bear have any predators?
Only humans, and on rare occasions, other polar bears. Some scientists believe that food stress is increasing acts of cannibalism, which has historically been a natural, but infrequent event.