Activity patterns of black bears in relation to sex, season, and daily movement rates

Activity patterns of animals can vary depending on both endogenous and environmental factors. Although black bears exhibit substantial variation in activity across the year, relatively little is known about how daily activity patterns and associated movement rates differ among sex and age classes across seasons. We used fine-scale movement data from black bears fitted with GPS collars to evaluate movement and activity patterns across sex and age classes for daily and seasonal time periods in relation to mating and foraging behavior. Black bears were most active during crepuscular time periods, moderately active during the day, and least active at night, which is consistent with previous research on black bear activity patterns in areas where bears were not greatly influenced by human activities. However, during spring and early summer, adult males moved significantly more during the crepuscular time period than they did during late summer and fall. Female and subadult males exhibited very similar activity patterns between seasons; and during late summer and fall, all bear classes exhibited similar activity patterns across daily time periods. Differences in activity patterns of males between seasons were potentially related to extensive movements undertaken during the mating season. Although adult males exhibited lower movement rates in late summer and fall compared to spring and early summer, females and subadult males did not appear to reduce movement rates during the late-summer berry season. Our research reveals that, although bear classes exhibit similar temporal patterns of daily activity and inactivity, the magnitude of movement rates revealed differences in activity patterns among bear classes, which allowed us to better understand factors influencing activity in animal populations.