Polar Bear (Ursus maritimus)


CITES Status | Taxonomy | Description | Habitat | Distribution | Threats | Conservation Efforts

 

CITES Status

polar-bears

Credit: USFWS

Appendix II since 1975.  Proposed pdf for transfer to Appendix I by the United States at CoP16.

Taxonomy

Class: Mammalia
Order:  Carnivora
Family: Ursidae
Genus: Ursus
Species: maritimus

Description

Polar bears are large stocky animals with long hair, a short tail, rounded ears, and large paws that live in the Arctic region surrounding the North Pole.  Polar bears have a whitish appearance, while the skin and nose are black in color.  The polar bear is one of the largest terrestrial carnivores, being more than twice as large as the Siberian tiger.  A polar bear can weigh up to 800 kg (about 1762 pounds) and measure up to 250 cm (about 98 inches) in total length.  In order to survive in harsh Arctic conditions, polar bears have evolved unique features such as large furry feet and short, sharp, stocky claws giving it good traction on ice.

Polar bears are carnivores and feed primarily on seals, especially the ringed seal (Pusa hispida), but also consume sea birds and their eggs, small mammals, fish, and the meat of dead animals found along the shore.  Seals are especially important to the polar bear’s diet because they are rich in fat (also called blubber) and protein, which enable polar bears to withstand long fasting periods lasting several months.

 

Habitat

The primary habitat of the polar bear is sea ice.  Polar bears use sea ice as platforms to capture their main prey, the ringed seal.  A marine mammal, polar bears are excellent swimmers and are able to swim great distances between blocks or patches of ice, called ice floes, as they hunt.  During the summer when most of the sea ice has melted, polar bears remain along the edges of the ice pack, as well as on islands and along the coast.  Pregnant females construct dens in the snow along the coast where they give birth to one or two cubs during the winter (November-January).  A typical litter consists of two cubs, but litter size may also be three or four.  These cubs will remain with the mother for 2–3 years.


Distribution

Polar bears range throughout the Arctic region along the northern portions of the United States, the Russian Federation, Norway, Greenland (a territory of Denmark), and Canada.  During the summer, polar bears occur mainly along the coastlines in the southern portions of their range, while during the winter they range widely onto the sea ice at great distances from land.

Threats

  • Habitat loss due to global warming
  • Restricted access to prey due to habitat loss due to global warming
  • Over-harvest and commercial trade
  • Pollutants, tourism, and oil development that facilitate bear-human conflicts and habitat loss

The primary conservation threat is the loss (decrease in area) of sea ice due to global warming, as well as a decrease in the quality of sea ice as it melts and refreezes.  Habitat loss restricts the access of polar bears to seals, their main prey items.
Sea-ice has been reduced by 8 percent in the past 30 years alone, while summer sea-ice has been reduced by 15-20 percent.  An additional decline of 10-50 percent of annual average sea-ice extent is predicted by 2100.  A half dozen climate models, the best at predicting observed changes in sea-ice to date, predict the complete loss of summer sea-ice in the Arctic in about 30 years.  According to some scientists, this would mean the loss of ≈ 2/3 of the world’s current polar bear population by mid-century.
Commercial trade is a secondary impact that can compound the effects of habitat loss.

Conservation Efforts

At the international level, polar bears are managed under the Agreement on the Conservation of Polar Bears, signed in 1973 by the five range States.  Under this Agreement, range States coordinate the research, management, and harvest of polar bears.  The United States has additional agreements with Canada and the Russian Federation to manage shared polar bear populations.

In the United States, the polar bear in 2008 was designated as a threatened species under the Endangered Species Act of 1973, as amended.  This listing was based on the best available science, which shows that loss of sea ice threatens and will likely continue to threaten polar bear habitat.  The U.S. Fish and Wildlife Service is currently developing a Conservation/Recovery Plan for polar bears.

Polar bears are also managed under domestic legislation in the other range States.  Canada has a regulated subsistence take, while hunting or export of polar bears is prohibited in Greenland, Norway, and the Russian Federation.

Additional Information