Scent-marking investment and motor patterns are affected by the age and sex of wild brown bears

Members of the Carnivora employ a wide range of postures and patterns to mark their scent onto objects and thereby communicate with conspecifics. Despite much anecdotal evidence on the marking behaviour of ursids, empirical evidence of scent-marking motor patterns displayed by wild populations is lacking. Analysing the time that different age and sex classes spend at scent-marking trees and the behaviours involved at different times of year could provide further insight into the function of marking. We used camera traps stationed at scent-marking trees to investigate scent-marking behaviour by wild brown bears, Ursus arctos. Through image-based data, we found evidence to support the hypothesis that time investment and scent-marking motor patterns are dictated by the age and sex of the bear. Adult males spent more time scent marking and displayed a more complex behavioural sequence of marking than adult females and juveniles. Adult male behaviour at marking trees was consistent throughout the year, indicating a continued benefit of chemical signalling outside of the breeding season. Juvenile bear behaviour at marking trees changed with age. Young dependent cubs were more likely to imitate their mother's behaviour, whereas older dependent cubs were more likely to engage in marking behaviour independently. The marking motor patterns of independent subadults were more simplistic than those of younger dependent cubs, suggesting a change in behaviour with independence. We suggest that these findings further support the hypothesis that scent-marking behaviour by brown bears functions in intrasexual competition between adult males. Cub behaviour at marking trees suggests an influence of social learning.

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