To survive, the polar bear must keep its body at the right temperature and store enough energy to last between meals that could be a few days or a few months apart.
Patterns of freeze-up and breakup influence the distribution and number of seals, the polar bear's main prey.
Take a moment to imagine what the polar bear's environment is like.
Polar bears live in the Arctic.
The polar bear, which lives on the polar ice-cap, will lose its home and die out.
In fact, to move at any speed the polar bear uses twice as much energy as do most other mammals.