Pitheciid vocal communication: What can we say about what they are saying?

Abstract

The variation in ecological traits in pitheciids allow investigation of vocal communication across a range of social and acoustic circumstances. In this review, we present a summary of the history of pitheciid vocal studies, and review i) the status of current knowledge of pitheciid vocal repertoire sizes, ii) how much we understand about the context of different acoustic signals, and iii) how can we potentially use our knowledge of vocalizations in animal welfare practices. The repertoires described for titi monkeys and sakis have the expected sizes for these genera, considering their relatively small social group sizes. However, uacari groups can contain over 100 individuals, and a larger vocal repertoire than the ones described would be expected, which could be a consequence of the fissionfusion social system where the large group divides into smaller subgroups. Nevertheless, vocal repertoires exist for only about 12% of the pitheciid species and nothing is known, for example, concerning call ontogeny. We hope that this study will act as a reference point for researchers interested in investigating vocal behaviour in pitheciids, thus, optimising both funding focus and, researcher's time and effort. Also, we hope to help defining methodologies and strategies for the conservation and management of pitheciid monkeys.