Polar bears are the iconic animals of climate change. For years, we've watched them struggle as the sea ice they live on melts. Now, scientists can see the effects: Polar bears are swimming themselves to the brink of starvation.
Polar bears mainly eat seals, and while they can swim to hunt prey, they're more successful and burn fewer calories when they stalk unsuspecting seals on the ice. Scientists tracking bears' hunting patterns have concluded as sea ice disappears, the bears will have fewer easy kills and will spend more time swimming.
During the test, researchers saw about half of hunting bears lost 10 percent of their body weight in just over a week. That's four times the weight they would've lost if they were on land not going after seals.
In other words, polar bears were burning more energy from hunting than they were gaining energy from food. In many instances, bears now either risk starvation or the dangers of raiding human-populated areas to eat trash.