West Virginia is home to a thriving population of black bears, the only bear species found within the state. The current black bear population is estimated between 12,000 and 14,000 animals. These adaptable creatures undergo a period of dormancy known as hibernation during colder months, a survival strategy that allows them to conserve energy when food is scarce. This winter sleep helps them endure colder temperatures and reduced food sources.
Typical Hibernation Periods
Black bears in West Virginia generally begin to enter their dens for hibernation in late October through early December, re-emerging between March and April. The exact timing can vary based on environmental factors. For instance, abundant food or unseasonably warm winter temperatures may delay denning or keep some bears active.
Pregnant female bears often enter their dens earlier and emerge later, as they give birth during this dormant period. Black bear cubs are typically born in mid-winter, usually in January or February, while the mother is still in her den. These cubs nurse and grow within the den until they are large enough to emerge with their mother.
The Physiology of Bear Hibernation
Black bear hibernation differs from the deep hibernation of smaller mammals. While bears enter a state of reduced activity, they do not experience the extreme drop in body temperature of true hibernators. Their body temperature typically decreases to a range of 30 to 36 degrees Celsius, allowing them to remain somewhat responsive. This physiological adaptation means black bears can wake up and react relatively quickly if disturbed.
During this period, a bear’s metabolic rate can drop to 25% of its normal summer rate, and its heart rate significantly slows, sometimes to 9 to 21 beats per minute. Bears rely on their accumulated fat reserves for energy, avoiding eating, drinking, urinating, or defecating for several months. This efficient use of stored energy also helps them minimize muscle and bone degradation, allowing them to emerge from their dens in good physical condition.
Where Bears Den
Black bears in West Virginia select a variety of locations for their winter dens, prioritizing safety, insulation, and concealment from potential disturbances. Common den sites include hollow logs, rock crevices, and brush piles. They may also excavate dens under tree roots or utilize natural formations such as caves. Occasionally, bears will choose less conventional sites, such as standing hollow trees, which offer elevated protection. The selection of a den is a crucial step in their annual cycle, providing a secure environment for bears to undergo their winter dormancy.