large carnivores need to eat 60 percent more than anyone had realized. Turns out they are high-energy beasts, burning through 12,325 calories a day
Polar bears rely almost exclusively on a calorie-loaded diet of seals
In the late spring, the ice is breaking up sooner and forming later in the fall, forcing bears to burn huge amounts of energy walking or swimming long distances to get to any remaining ice.
polar bears aren’t made for walking,
The farther the bears have to travel to get on the ice to hunt the more weight they lose. Eventually they start losing muscle, hurting their chances of hunting success, which can lead to a downward spiral. Bears are also doing a lot more swimming as the sea ice declines, said Derocher.