Trade-offs between vocal accommodation and individual recognisability in common marmoset vocalizations

Area of Science:

• Primate vocal communication
• Animal behavior
• Bioacoustics
• Vocal learning

Background:

• Vocal accommodation, where individuals adjust their vocalizations to match partners, is increasingly observed in nonhuman primates.
• Convergent vocal accommodation signals social closeness but can threaten individual recognizability, particularly in calls where identity is crucial.

Purpose of the Study:

• To investigate how vocal accommodation varies across different call types with distinct functions in common marmosets.
• To test the hypothesis that accommodation extent and consequences depend on a call's function and its reliance on individual identity.

Main Methods:

• Quantified vocal accommodation in three call types (trill, phee, and food calls) during pair formation in 20 common marmosets.
• Analyzed how initial vocal distance and call function influenced accommodation.
• Assessed the impact of accommodation on statistical individual recognizability for each call type.

Main Results:

• Marmosets showed the most vocal convergence in trill calls (close contact), and less in phee and food calls where identity is more critical.
• Initial vocal distance predicted accommodation in two of the three call types.
• Accommodation reduced individual recognizability in trill calls but not in phee or food calls.

Conclusions:

• Vocal accommodation patterns differ significantly based on call function in marmosets.
• Findings suggest a trade-off between signaling social closeness and maintaining individual recognizability in primate vocalizations.