Polar Bear - Ursus maritimus - facts and video

Polar bears are among the largest carnivores in the world, rivaled only by the Kodiak brown bears of southern Alaska. As its scientific name, Ursus maritimus, suggests, the polar bear is primarily a marine bear. 

Numerous adaptations uniquely suit polar bears to life in icy habitats. Their fur is thicker than any other bears’ and covers even their feet, for warmth and traction on ice. A thick layer of blubber beneath their fur provides buoyancy and insulation. 

The long neck and narrow skull of the polar bear probably aid in streamlining the animal in the water, and the front feet are large, flat and oarlike. The polar bear is an excellent swimmer and individuals have been seen in open Arctic waters as far as 200 mi (320 km) from land. 

Diet

Staples: Polar bears feed almost exclusively on ringed seals and, to a lesser extent, bearded seals.
Polar bears travel great distances in search of prey.  They are also known to eat walrus, beluga whale and bowhead whale carcasses, birds, vegetation and kelp. 

Population

The World Conservation Union (IUCN) estimates that there are between 20,000-25,000 polar bears in the world.

Range

Polar bears are only found in the Arctic region and are highly dependant on the pack ice there since they spend much of their time hundreds of miles from land. The most important habitats for polar bears are the edges of pack ice, where currents and wind interact with the ice, forming a continually melting and refreezing matrix of ice patches. These are the areas of greatest seal abundance and accessibility.

Individual polar bears can travel thousands of miles per year following the seasonal advance and retreat of sea ice. Polar bears are distributed throughout the Arctic region in 19 subpopulations. Alaska, Canada, Russia, Greenland and Norway have polar bear populations. See a polar bear range map >>

Behavior

Polar bears are highly dependant on older stable pack ice in the arctic region, where they spend much of their time on the ice hunting, mating, and denning. They are generally solitary as adults, except during breeding and cub rearing.

Unlike brown bears, non breeding polar bear females and males do not hibernate or den in the winter. Pregnant polar bears need to eat a lot in the summer and fall in order to build up sufficient fat reserves for surviving the denning period, during which time they give birth to one-pound cubs and then nurse them to about 20-30 pounds before emerging from the den in March or April.

Reproduction
Mating Season: Late March through May
Gestation: About 8 months with delayed implantation
Litter size: 1-4 cubs; 2 cubs most common
Female polar bears locate denning sites in October on thick stable pack ice or on land. The young are born from November through January while the mothers are hibernating. Cubs will remain with their mothers for at least 2 ½ years. Female polar bears can produce five litters in their lifetime, which is one of the lowest reproductive rates of any mammal.

Global Warming and Other Threats

Polar bears could be extinct by 2050 as their habitat melts away due to global warming. The loss of snow pack, thinning and disappearing sea ice all reduce essential habitat. Loss of sea ice leads to higher energy requirements to locate prey and a shortage of food.

Polar bear survival is entirely dependant on sea ice as a platform for hunting the marine mammals that provide their nutritional needs. Polar bears stalk the seals using their breathing holes in the ice, as the total ice diminishes it will vastly decrease successful hunts and their overall food source. Though polar bears are excellent swimmers they are not adept at catching seals in open water.

Female polar bears require soft deep snow for dens to keep their cubs insulated from the harsh weather, and sufficient fat reserves to survive denning after giving birth to their cubs. Seals, a primary source of prey for polar bears, also require icy habitat to breed and raise their young. Changing ice conditions have forced the seals to move and give birth in different areas, making them more difficult to find.

Yet another threat to polar bears is human-caused mortality. Some bears are attracted by unsecured garbage and animal carcasses. This can eventually lead to conflicts between people and bears and lethal removal of the bear. Illegal killing (poaching) of bears also remains another factor causing their decline

Defenders At Work

In August 2009, Defenders of Wildlife, along with Humane Society International, International Fund for Animal Welfare urged the United States to lead the way to end international commercial trade in polar bears, including hides, trophies, rugs and other polar bear parts, by transferring polar bears from CITES Appendix II, which allows regulated international commercial trade, to Appendix I, which prohibits all international commercial trade in the listed species.

In 2008, Defenders' Executive Vice President Jamie Rappaport Clark testified at the January 17, 2008 U.S. House of Representatives hearing titled "On Thin Ice: The future of the Polar Bear." Read her testimony >>

Defenders is working to develop local and regional bear-awareness programs to help minimize conflicts between people and polar bears. Bear-human interactions are increasing in Alaskan and Canadian coastal villages. Consequently, the number of bears taken in defense of life and property is also increasing.

By educating people about options to minimize conflicts with bears, the need to resort to lethal control of problem polar bears can be minimized. Such bear-awareness programs have been quite successful in many areas with other bear species. Learn more about what Defenders of Wildlife is doing to protect polar bears >>

Reasons For Hope

The polar bear is an iconic symbol of global warming, and among the first species to be so affected by it. More and more countries around the world, in particular those that incorporate Arctic landscape like the United States, Russia, Canada, and Greenland, are pledging to fight global warming in order to preserve the polar bear.

Legal Status/Protection

• Endangered Species Act: The polar bear was listed as threatened under the federal Endangered Species Act on May 14, 2008. This move officially recognizes that polar bears are threatened with extinction from global warming, which is melting the Arctic sea ice where polar bears hunt for ringed and bearded seals, their primary food source.
• IUCN Red List: Vulnerable. In May 2006, the International Union for the Conservation of Nature (IUCN) added the polar bear to its Red List of the world’s most imperiled animals, predicting a 30% reduction in the polar bear population in the next 45 years.
• CITES: Polar Bears are currently protected under Appendix II, which allows regulated international commercial trade. In August 2009, Defenders of Wildlife was part of a proposal to transfer polar bears to Appendix I, which prohibits all international commercial trade in the listed species. Read the press release >>
• Learn more about legal status and protection of polar bears >>

How You Can Help

• Help polar bears and other wildlife by adopting a polar bear today at our Wildlife Adoption Center.
• Take Action for Wildlife at our Wildlife Action Center.

For additional information

Visit Defenders' Imperiled Species: Polar Bear pages for more information about what Defenders is doing to help.

Alaska Conservation Solutions
National Wildlife Federation
Pacific Environment
Polar Bears International
Sierra Club Alaska

Watch SeeMoreHD.com's high definition video footage of polar bears.