Movement Ecology and Activity Behavior of Black Bears in the Great Smoky Mountains National Park

Movements and activity behavior of 29 radio-collared black bears (Ursus americanus) were monitored between July 1976 and December 1977 in the Great Smoky Mountains National Park. Many bears exhibited home ranges with abrupt seasonal changes, especially between summer and fall. The timing and extent of these range shifts were influenced by sex, age and food availability. During good mast years, the fall ranges of many males overlapped considerably in an area of abundant oaks, while during poor mast years, social intolerance may force many subordinate males outside the Park boundaries in search of food. Fall movements increased the size of annual home ranges above previously reported estimates based strictly on summer data. Mean annual range size was 42 km² for adult males and 15 km² for adult females. Bears were generally more active in the summer, but traveled greater distances in a day during the fall. This was attributable to extended nocturnal activity in the fall probably associated with increased foraging in preparation for denning. A strictly crepuscular pattern was observed in the spring. Females with cubs were equally active throughout the year and were more active than any other sex-age group. Temperatures above 25 C or below freezing, and precipitation in the form of rain or snow apparently depress the level of activity.