Bears - Sounds Wild
Bear Scent Marking

Audio

Download Episode: Bear Scent Marking (MP3 file 1,408 kB)

Transcript

Bear Scent marking

A black bear in the lush rainforest of Prince of Wales Island in Southeast Alaska is investigating a rub tree. He smells the base of the tree, then stands on his hind legs and stretches to sniff a scratched patch of bark exposing bare wood bleeding sap. The entire encounter is captured on a motion-triggered trail camera nearby.

Bears have an acute sense of smell. It's important for finding food and it also helps them keep track of each other. Bears tend to have overlapping home ranges and they're very interested in the status and dominance hierarchy of their neighbors. Bears use scent marking in many ways, including rubbing against trees, biting and clawing, urinating, and depositing anal gland secretions. Bears also mark the ground while walking, leaving scent in their tracks, using scent glands in their feet.

Researchers studying scent communication behavior in bears, also called chemical signaling, found that brown bears are very deliberate in where they place scent marks, how often they engage in marking behavior, and how much time and energy they invest in scent marking. They select trees located in regularly visited areas where the defense of a resource is needed. Bears place their scent marks strategically to increase the likelihood that the message is received.

Adult males use signals to communicate dominance to other males; females do not appear to use marking trees to advertise their availability (or estrous state) during breeding season.