At birth, polar bears are blind, nearly hairless and weigh just over a pound—about the same as a loaf of bread. But they spend their first few months snuggled inside a snowy den, fattening up on ...

Then, the family emerges together in the spring. Wolfgang Kaehler / LightRocket via Getty Images At birth, polar bears are blind, nearly hairless and weigh just over a pound—about the same as a ...