Global warming is stressing polar bear populations by depleting sea ice in their Arctic habitat. Now, the U.S. Fish and Wildlife Service is proposing to list the polar bear as a threatened species under the Endangered Species Act. The listing will only be official after public comment and more scientific review.
Polar bears use sea ice as a platform to breed, travel, and hunt their main prey, seals. In Hudson Bay, summer sea ice is melting three weeks earlier than it did in the 1970's. Western Hudson Bay's polar bear population declined 22 percent between 1987 and 2004 because they have less time to catch seals before the summer ice melts. The shortening of the bears' hunting period is worsening their physical condition during the late summer and fall period where they typically rely on their fat reserves for survival.