Do Cubs Hibernate Like Adult Bears?

Bear cubs enter the world during hibernation, typically toward the end of January or the beginning of February, according to the Yellowstone website for the National Park Service. At this point the bears are still very small, typically 8 inches long and 8 to 12 ounces. The cubs lack vision, they're devoid of fur, and they are 100 percent reliant on their hibernating mothers' care and assistance.

The fast-growing young ones remain alongside mom, while nursing and resting themselves. Though the mother bears are usually asleep, they wake up occasionally to manage the needs of their cubs, whether by nursing them or by grooming them through licking. The wee cubs keep warm by staying close to their mother's stomach, indicates Peter Tyson of the Public Broadcasting Service's Nova program. The mother bear positions her back legs and paws to provide a comfortable "shelter" for the cubs.

Mother bears hibernate very lightly compared with other bears. Because of the responsibility of taking care of the cubs, a mother bear needs to be able to easily move in and out of sleep. Apart from mother-and-cub situations, black bears fly solo when it comes to winter hibernation.

Mother bears and their offspring usually leave their cozy dens when spring begins toward the end of March or the start of April. The cubs typically stay with their mothers for another year and a half or so to learn self-defense, how to track down food and tree climbing. Once the cubs are gone, the mothers resume the breeding process.