The two main focuses of this solitary creature's life are to conserve energy and to hunt. Only pregnant females dig dens and hibernate in the traditional sense for extended periods. Polar bears depend mostly on their sense of smell to determine the location of prey. Their white coats make great camouflage for hunting seals, and they will wait patiently for hours next to a seal s air hole waiting for the seal to take a breath. Once the seal arrives, the polar bear will use its immense strength and sharp claws to clutch the seal and drag it through the small blowhole.
Females are able to breed at the age of five years.
They dig dens either on the coastal mainland or out on the drifting pack ice in late October or early November, and then remain denned until the next spring. An average of two cubs are born, each weighing about 1 pound at birth and growing to about 15 pounds by the time they emerge in the spring. The cubs have much to learn and usually remain with their mothers for more than two years. The primary threat facing polar bears today may be global warming. Scientists have already documented measurable effects in the body sizes and reproductive success of bears at Hudson s Bay.