The function of teeth chattering in male Barbary macaques (Macaca sylvanus)

Area of Science:

• Primatology
• Ethology
• Behavioral Ecology

Background:

• Teeth chattering is a common behavior observed across various primate species.
• Previous research suggests diverse social functions for teeth chattering, but specific roles remain debated.

Purpose of the Study:

• To investigate the specific social functions of teeth chattering in male Barbary macaques (Macaca sylvanus).
• To test hypotheses that teeth chattering signals submission, appeasement, affiliation, or reassurance.

Main Methods:

• Observational study utilizing focal watches of male Barbary macaques in a semi-free-ranging group.
• Comparison of outcomes in male-male dyadic social interactions with and without teeth chattering.
• Analysis of interaction outcomes to test predictions of four distinct functional hypotheses.

Main Results:

• Evidence supported all four tested hypotheses: teeth chattering functions as a signal of submission, appeasement, affiliation, and reassurance.
• In certain social contexts, reciprocal teeth chattering between males had a more significant impact on interaction outcomes than unilateral signaling.
• The presence and exchange of teeth chattering were associated with specific social dynamics and resolutions.

Conclusions:

• Teeth chattering plays a multifaceted role in the social behavior of male Barbary macaques.
• This vocalization is crucial for managing social relationships, conflict resolution, and maintaining group cohesion.
• The findings highlight the importance of teeth chattering in coordinating complex social interactions within primate communities.