Background & Main Question

Vocal exchanges in human and nonhuman primates has become a promising avenue of research in understanding the evolution of human language1,2.

Turn-taking – short, flexible, reciprocal exchanges between two or more interactants – seem to develop early in ontogeny (before even gestural or linguistic competence), are used universally across languages and cultures in humans, and have been recently identified in some branches of primates3,4.

Here, we examine the vocal communication and turn-taking behaviors of wild woolly monkeys at the Tiputini Biodiversity Station in Amazonian Ecuador.

Previous research with this population has shown that woolly monkey calls are individually recognizable and that the frequency of vocalizations and number of vocalizers increase early in the morning prior to departure, during significant changes in travel trajectories, at large feeding trees, and when settling down for the night.

Main Question:

Do woolly monkeys follow the temporal rules of vocal turn-taking?