Daily Activity Patterns of Female Black Bears in a Northern Mixed-Forest Environment

Activity patterns of 15 female black bears ( Ursus americanus ) were studied using motion-sensitive radiotransmitters during late summer and autumn of 1990 and 1991 in La Mauricie National Park, Quebec. Female black bears primarily were diurnal during this period, and no difference in activity patterns was detected between solitary females and females with young. Onset of activity followed sunrise by an average of 30 min, and cessation occurred on average 141 min after sunset. Activity and resting periods averaged 245 and 57 min, respectively. The proportion of active bears was highest during the ripening time of berries ( Rubus idaeus , Vaccinium myrtilloides , and Prunus virginiand ) in late August and of beechnuts ( Fagus grandifolid ) in early October. Bears denned earlier in 1991 than in 1990, probably because of the poor beechnut crop.