Thanks to a study it has been discovered that, in addition to communication through chemical signals, brown bears also perform visual signals by tearing the bark of certain trees to communicate with each other. In addition, it has been possible to show that these signals are made exclusively by adult males and are only related to the reproductive needs of the species.
The research has been led by the National Museum of Natural Sciences (MNCN), with the participation of the Doñana Biological Station (EBD) and the Mixed Institute for Biodiversity Research (IMIB), all part of the Higher Council for Scientific Research (CSIC). ).
The study, which has been published in the Journal of Mammalogy, has consisted of analyzing the brown bear population of the Cantabrian mountain range using photo and video trapping. Working with the images has allowed them to study the behavior of several dozen individuals, including 13 adult males responsible for leaving marks on the trees.
Vincenzo Penteriani, a researcher at the MNCN, states that “communication between mammals has long been considered to be essentially limited to chemical and acoustic signaling.” “This experimental work provides, for the first time, evidence for the existence of a new communication channel for this species: visual signaling by removing part of the bark from the trunk of particularly visible trees,” he added.
Brown bears, Ursus arctos, make these marks by scratching and biting the bark of trees, which seems to have a very specific meaning, since they are only made by adult males during the mating season. The team that carried out the research believes that they could provide information such as the size of the individual, which would be a way of making explicit the dominance status of each male in search of mating.
These visual signals provide information that complements what they already provide with chemical signals. “Understanding the meaning of this form of communication not only represents an advance in our understanding of animal communication, but can also be used to easily locate areas frequented by bears during the mating season. Crucial information for conservation plans and management of the species”, explains Penteriani.
