Experimental playbacks show vocal mediation of intergroup avoidance in a forest monkey

Abstract

DISTINCTIVE vocalisations, audible over long distances, have been reported among many forest primate species, ranging from prosimians to apes^1–5. Such loud calls have often been hypothesised to mediate territorial or other forms of spacing between conspecific groups, and indeed audibility over distances sufficient to serve in intergroup communication is one of their defining characteristics. Nevertheless, evidence in support of such hypotheses is primarily indirect (but see ref. 1), and investigation of the responses of animals to these calls is generally lacking.