Louisiana black bears start to den from late November to early January. Activity, movement, and home range generally decrease rapidly during this period as bears enter “pre-dens” or nests, or enter the den where they will spend the winter.

Louisiana black bears are not true hibernators. They go through a winter dormancy period termed “carnivorean lethargy”, or torpor, which helps them survive food shortages and severe winter weather. During the winter “sleep” bears do not eat, drink, urinate, or defecate. Waste products are recycled through unique metabolic and physiological processes and there is no degenerative bone loss during dormancy. Black bears exhibit varying degrees of lethargy while denning, but most can easily be aroused if disturbed.

Denning activity is influenced by a number of factors: food availability, age, gender, reproductive condition, photoperiod, and weather conditions. Generally, pregnant females are the first to den and males the last. Factors contributing to interruption of the denning period or the changing of den sites during a given winter include human activity, rapidly fluctuating water levels, fluctuating extremes in weather conditions, and the lack of concealment of ground dens. Data collected by monitoring denning behavior indicate bears are more active in winter months in the lower Mississippi River Valley than at more northern latitudes. Recent observations indicate that some females with cubs, especially in the coastal Louisiana population, actively forage in the area near the den, leaving their cubs for short periods and returning to care for them.

For some bears, usually males, winter inactivity may be nothing more than bedding for a few days or weeks in one area before moving to new bedding sites. Pregnant females, the first to seek den sites, usually choose sites that are more secure and inaccessible than those typically selected by males. Females prefer large, hollow trees, as these provide dry, secure, and well-insulated cover, but will also den in brushpiles and thickets (see Habitat Requirements section).