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 enemies?
Where do polar bears live?
In the circumpolar north 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 (Denmark), 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 2030.
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, 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. Russia lists the polar bear as "a species of concern."
At the 2009 meeting of the IUCN Polar Bear Specialist Group (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 to say what is happening to 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 measure 2.5 to 3 meters (8 to 10 feet) tall and can weigh 250 to 770 kilograms (550 to 1,700 pounds). Adult females measure 1.8 to 2.5 meters (6 to 8 feet) tall and weigh 90 to 320 kilograms (200 to 700 pounds). The largest polar bear ever recorded was a male weighing 2,209 pounds. Wow!
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 and a layer of blubber that can measure 11.5 cm (4.5 inches) thick. 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 covered with small bumps called papillae to keep them from slipping on ice. Their sense of smell is so powerful they can detect a seal under ice miles away. 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?
Anything they want! But ringed seals are their favorite food. They eat bearded seals, too. When there are plenty of seals, polar bears like to eat only the fat. They leave the carcass for scavengers, such as arctic foxes, ravens, and younger bears.
Sometimes, polar bears kill and eat walrus and beluga whales. They’ve even been known to hunt short-legged reindeer and snack on birds, bird eggs, kelp, and beached whales. On Norway's Svalbard Islands, polar bears were once found feasting on a 350-year-old bowhead whale carcass uncovered by a retreating glacier.
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 average15 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?
Not 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. Polar bears instead enter a state of walking hibernation where their metabolism slows. Only pregnant polar bears enter a den, give birth, and emerge three months later.
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 enemies?
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.
