Besides their infamous appetite, Great Smoky Mountain National park bears are also known for their ability to hibernate during the winter months. Most park bears make their winter dens high above the forest floor in the cavities of large trees.

Surprisingly, many scientists say Smoky Mountain bears don’t hibernate at all. To them the park bears simply experience dormancy or deep sleep instead of true hibernation. Their conclusions are based on comparisons of bears, for this is true of all bears, with other hibernating mammals whose temperature and heart rates drop more dramatically than the Black bears. Southern bears, especially those in lowlands perhaps support their theory best, as they hibernate for such a short time in comparison to northern bears. Adding support to the theory of non-hibernation, Black bears can waken during the wintertime. They may even go out of their dens during warmer winter days. Still, the American Black bear population stays in their dens as much as six months in northern climates. In fact all bears stay in their state of semi-hibernation according as the climate in their territory dictates. Brown and grizzly bears, semi-hibernation can last as long as seven months, depending upon the severity of the winter and the location of their territory.

Setting the hibernation debate aside for a moment, for the purpose of this article, we will call the Black bears winter snooze hibernation.

Black bears prepare for hibernation by eating large amounts of food, especially in the late summer and early fall. A black bear in the Smoky Mountains may gain as much as 30 pounds a week while their food supply is sufficient to support them. But, as the food supplies dwindles, the bears become very tired and begin to look for a place to sleep through the winter. Although, hibernation dens vary, most Black bears in the Smoky Mountains prefer hibernating high in the cavities of trees. There are some park bears however, that prefer to dig out a den in the earth and line it with dried leaves or grass. Still others may chose a hollow log for their winter snooze, while others may have a preference for a particular cave. A den can be reused from the year before or it can be made new.

During hibernation, a Smoky Mountain Black bear’s metabolism slows to about half the normal rate, or approximately ten beats per minute. Their temperature drops as well, but as mentioned, does not lower as much as other animals that hibernate. Black bears only lose about six to seven degrees of body heat. Perhaps this is due to their unusually warm coat and the layers of fat stored for the winter. During hibernation, bears use up the body fat they so carefully stored the year before. Mother bears who give birth in the den can lose up to forty percent of her weight over the winter while others lose twelve to thirty percent. As the winter warms into spring, the bears of the Smoky Mountains waken with renewed appetite.