LiveScience: Polar bears, the iconic victims of climate change, are shifting their migration patterns because of changes in sea ice. The bears are arriving on land earlier and departing later, a new study found, and it's threatening their access to food.
A team of researchers studied the migration patterns of polar bears (Ursus maritimus) in Hudson Bay, Canada, using satellite-tracking data collected between 1991 and1997 and 2004 and 2009. They found that the rate at which sea ice melts and re-freezes, as...