Brown bears found to manipulate signals to appear larger

A scientific study published in the Journal of Mammalogy has documented that a small percentage of brown bears are capable of manipulating visual and olfactory signals to appear larger than they actually are. This behavior, intended to avoid physical confrontations with rivals, marks the first time such deceptive communication has been recorded in this species.

Researchers from an international team, including the National Museum of Natural Sciences (MNCN-CSIC) in Spain, monitored 164 bears in the Cantabrian Mountains between 2021 and 2024. Using 117,000 hours of camera trap footage, the team observed that seven bears—approximately 4.3% of the group—used platforms near trees and posts to leave marks at heights higher than they could naturally reach.

Investigator Vincenzo Penteriani noted that while this is an exceptional behavior, it demonstrates that bear communication is more complex than previously understood. Previously, the height of visual and olfactory marks was considered a reliable indicator of body size and dominance that could not be falsified.