Population-specific call order in chimpanzee greeting vocal sequences

Cédric Girard-Buttoz; Tatiana Bortolato; Marion Laporte; Mathilde Grampp; Klaus Zuberbühler; Roman M Wittig; Catherine Crockford

doi:10.1016/j.isci.2022.104851

Population-specific call order in chimpanzee greeting vocal sequences

iScience. 2022 Aug 6;25(9):104851. doi: 10.1016/j.isci.2022.104851. eCollection 2022 Sep 16.

Authors

Cédric Girard-Buttoz^{1

2

3}, Tatiana Bortolato^{1

2

3}, Marion Laporte^{4

5}, Mathilde Grampp^{1

2

3}, Klaus Zuberbühler^{6

7

8}, Roman M Wittig^{1

2

3}, Catherine Crockford^{1

2

3}

Affiliations

¹ The Ape Social Mind Lab, Institut des Sciences Cognitives Marc Jeannerod, UMR 5229, CNRS, 67 Boulevard Pinel, Bron, Lyon 69675 France.
² Department of Human Behavior, Ecology and Culture, Max Planck Institute for Evolutionary Anthropology, Leipzig 04103, Germany.
³ Taï Chimpanzee Project, Centre Suisse de Recherches Scientifiques, Abidjan, Ivory Coast.
⁴ Histoire naturelle de l'Homme préhistorique, UMR 7194, PaleoFED, Muséum National d'Histoire Naturelle, 17 place du Trocadéro et du 11 Novembre, 75116 Paris, France.
⁵ Institut des Sciences du Calcul et des Données, Sorbonne Université, Paris, France.
⁶ Universite de Neuchatel, Institut de Biologie, Cognition Compare, Neuchatel, Switzerland.
⁷ School of Psychology and Neuroscience, University of St Andrews, St Andrews, Scotland.
⁸ Budongo Conservation Field Station, Masindi, Uganda.

Abstract

Primates rarely learn new vocalizations, but they can learn to use their vocalizations in different contexts. Such "vocal usage learning," particularly in vocal sequences, is a hallmark of human language, but remains understudied in non-human primates. We assess usage learning in four wild chimpanzee communities of Taï and Budongo Forests by investigating population differences in call ordering of a greeting vocal sequence. Whilst in all groups, these sequences consisted of pant-hoots (long-distance contact call) and pant-grunts (short-distance submissive call), the order of the two calls differed across populations. Taï chimpanzees consistently commenced greetings with pant-hoots, whereas Budongo chimpanzees started with pant-grunts. We discuss different hypotheses to explain this pattern and conclude that higher intra-group aggression in Budongo may have led to a local pattern of individuals signaling submission first. This highlights how within-species variation in social dynamics may lead to flexibility in call order production, possibly acquired via usage learning.

Keywords: G social interaction; linguistics.