Polar Bear

Polar bears make their home on the islands, coastlines and floating ice blocks of the Arctic. They spend most of their time in the water in search of seals, walrus and fish. Their webbed paws and streamlined body form help make them expert swimmers. Their white coat helps hide them in their snowy white world, an advantage when they want to sneak up on prey.

Polar bears are also well adapted to the cold. A thick coat with hollow hairs, black skin and furred footpads protect them against frigid weather.

As is the case with most bears, polar bears are not  very social animals.  Adults spend little time together, except during breeding season.  The closest bond is between a mother and her young.  Mother bears are very attentive to their cubs.  They often stay in their birthing den for up to six months without taking in any food or water.

The Crisis of Melting Sea Ice

Sadly,  polar bears are facing a relatively new threat to their survival --  loss of their sea ice habitat.  Sea ice is essential to the bears for feeding, mating, and maternal denning.  But over the last 20 years, scientists have noticed a marked reduction in Arctic sea ice.  Recent modeling of future sea ice trends predicts dramatic reductions in sea ice coverage over the next 50 to 100 years 

In Canada’s Hudson Bay, for example, the sea-ice season has been shortened by several weeks, limiting the time that polar bears can prey on seals.  This could be why scientists are finding thinner bears, lower female reproductive rates and higher death rates among young polar bears in that region.

Many biologists blame global warming for the melting of sea ice.  IUCN predicts that polar bear populations will drop more than 30 percent in the next four decades without a reversal of global warming trends.  In May 2006, this world conservation organization reclassified the species as vulnerable (which our Zoo calls threatened) -- which means polar bears face a high risk of extinction in the wild.  In addition, the U.S. Fish and Wildlife Service is considering a petition to list the polar bear as a threatened species under the Endangered Species Act.

Scientists are particularly concerned that polar bears may be less able to adapt to environmental changes than other bear species.  Not only are they highly specialized for life in the Arctic marine environment, but they have low reproductive rates. This, combined with the current greater speed of global warming, makes it unlikely that the bears will be able to adapt to the current warming trend in the Arctic.