How is climate change affecting polar bears?
The major threat to the western Hudson Bay population of polar bears is global warming. The increase in temperature leads to changes in the sea ice, which is the preferred habitat of polar bears. It is on the ice that bears are able to kill seals. Changes in the ice which affect the seal population or the bear’s ability to kill seals would adversely affect the bear population. When the ice melts, they move ashore and survive on stored fat until the following winter when they can hunt seals on the ice once again. Most bears fast for about four months, however pregnant females remain on land to give birth and fast for about eight months. Early ice break-up cuts short their time to hunt and build up their body condition, and longer ice-free periods extend the time that the bears fast on shore. Studies have shown that for each week early that break up occurs, the bears come ashore ten kilograms lighter and thus in poorer condition. Warmer weather for Hudson Bay can have other catastrophic
