Pant-grunts in wild chimpanzees (Pan troglodytes schweinfurthii): the vocal development of a social signal
Abstract
While the gestural communication of apes is widely recognised as intentional and flexible, their vocal communication still remains considered as mostly genetically determined and emotionally bound. Trying to limit the direct projections of linguistic concepts, that are far from holding a unified view on what constitute human language, this thesis presents a detailed
description of the pant-grunt vocalisation usage and development in the chimpanzees (Pan
troglodytes schweinfurthii) of the Budongo forest, Uganda.
Pant-grunts are one of the most social vocalisations of the chimpanzee vocal repertoire and are always given from a subordinate individual to a dominant. The question of how such a signal is used and develops is critical for our understanding of chimpanzee social and vocal complexity in an ontogenetical and phylogenetical perpective. Results suggest that pant-grunt
vocalisations can be used in a flexible way, both in their form and usage within a social group.
More specifically, chimpanzees seemed to take into account the number and identity of
surrounding individuals before producing these vocalisations. At the acoustic level, pant-grunts seem to be very variable vocalisations that corresponded to different social situations commonly encountered. Grunts are one of the first vocalisations produced by babies but they are not first produced in social contexts. Although some modifications of the social grunts
form and usage could not entirely be attributed to maturation only, the role of the mother seemed to be restricted. Her direct influence was perhaps more visible in the rhythmic patterns of chorusing events. Taken together, this thesis suggests that chimpanzee vocalisations are more flexible in their usage, production and acquisition than previously thought and might therefore be more similar to gestural communication.
Type
Thesis, PhD Doctor of Philosophy
Rights
Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported
http://creativecommons.org/licenses/by-nc-nd/3.0/
Collections
Except where otherwise noted within the work, this item's licence for re-use is described as Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported
Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.