Sex-, age-, and time-specific visual communication in brown bears

Area of Science:

• Ethology
• Behavioral Ecology
• Mammalian Communication

Background:

• Intraspecific communication in mammals typically relies on chemical and acoustic signals.
• Visual signaling is an often overlooked communication channel in mammals.

Purpose of the Study:

• To investigate a novel visual communication channel in brown bears (Ursus arctos) through trunk debarking.
• To document temporal patterns and behavioral aspects of this visual signaling behavior.

Main Methods:

• Experimental manipulations and camera traps were used on brown bear rubbing trees.
• Observed 13 focal trees in the Cantabrian Mountains, Spain.

Main Results:

• Visual marking via trunk debarking is exclusive to adult males during the mating season (April-June).
• This behavior is always associated with chemical marking, suggesting complementary roles.
• Visual marks may indicate individual size and dominance status for mating purposes.

Conclusions:

• This is the first evidence of visual signaling in a large carnivore being exclusive to adult males and linked to reproductive needs.
• Brown bear visual signaling advances understanding of animal communication and can help locate mammal mating areas for conservation.