How does a polar bear become pregnant?

Female bears can have cubs when they are four or five years old. Males are sexually mature by six years, but typically don't mate till they are 8 or 10.

Males fight between themselves and the strongest then mates with the female. They stay together about a week. Males may mate with several females during the mating season (April and May) and with different females each year.

Eight months later a cub is born.