Year: 2016
Type: dissertation
Abstract: Comparisons between animal and human communication are invaluable for \nunderstanding the evolution of language and, as our closest living relatives, \nchimpanzees can provide particularly important insights into this. Here I examined \nunimodal (UM) and multimodal (MM) communication in wild chimpanzees, in an \nintegrated manner. I found that although MM signals were produced infrequently, and \nat lower rates compared to captivity, the vast majority of adult and sub-adult \nindividuals did freely combine vocal, gestural and facial signals to produce MM signals. \nA total of 48 free MM signal combinations were observed, incorporating a wide range \nof different signal types from different modalities. Focusing on one specific vocalgestural \nMM signal, I found that MM combinations and UM gestural signals were more \nsuccessful in eliciting responses compared to UM vocal signals. \nTo investigate signal function more systematically I focused on one common grooming \ngesture, the big loud scratch (BLS), and tested several competing functional \nhypotheses. I found little evidence to support the hypotheses that this signal operates \nas an attention-getter, or as a referential signal. In contrast, my data suggested that in \nthis community of chimpanzees, the BLS facilitates the negotiation of roles within a \ngrooming bout. Groomers used BLSs to request grooming during grooming bouts and \nthe BLS seemed to show willingness to groom, both to initiate a grooming bout, and \npotentially during a bout when groomees intend to start grooming their partner. \nFinally, to explore the theoretical link between the evolution of communication and \ncooperation I tested whether, on an individual level, there was a positive relationship \nbetween communicativeness and cooperativeness in chimpanzees. In contrast to \ntheoretical predictions, I found a significantly negative relationship between these two \ndomains, indicating that more communicative chimpanzees were less cooperative. I \nexplore several potential explanations for this highly unexpected finding.
Author: Claudia Wilke
Language: English
Topic: Primate Behavior and Ecology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W2618967376