Local variation in Barbary macaque shrill barks

Area of Science:

• Ethology
• Bioacoustics
• Primate Behavior

Background:

• Vocal communication is crucial for social interactions in many species.
• Understanding population-specific variations in vocalizations can reveal insights into social structure and adaptation.
• Barbary macaques (Macaca sylvanus) exhibit complex social behaviors and vocal repertoires.

Purpose of the Study:

• To investigate acoustic differences in Barbary macaque vocalizations between two distinct populations.
• To determine the perceptual salience of these acoustic differences through playback experiments.
• To explore evidence for vocal plasticity in this primate species.

Main Methods:

• Recording and acoustic analysis of macaque vocalizations in response to a dog in France and Germany.
• Conducting playback experiments using calls from both local and foreign populations.
• Analyzing macaque behavioral responses to auditory stimuli.

Main Results:

• Significant acoustic differences were found in calls between the Rocamadour (France) and Salem (Germany) macaque populations.
• Macaques showed a slightly, but significantly longer response duration to calls from the other population.
• While general response patterns were similar, macaques could discriminate between calls from different origins.

Conclusions:

• Barbary macaques exhibit a degree of vocal plasticity, with subtle but detectable differences in call production between populations.
• These findings suggest that while call function is primary, macaques can perceive and react to population-specific acoustic variations.
• The study highlights the potential for localized adaptation in primate vocal communication.