The ontogeny of vocal sequences: insights from a newborn wild chimpanzee (Pan troglodytes schweinfurthii)
Abstract
Observations of early vocal behaviours in non-human primates (hereafter primates) are important for direct comparisons between human and primate vocal development. However, direct observations of births and perinatal behaviour in wild primates are rare, and the initial stages of behavioural ontogeny usually remain undocumented. Here, we report direct observations of the birth of a wild chimpanzee ( Pan troglodytes schweinfurthii ) in Budongo Forest, Uganda, including the behaviour of the mother and other group members. We monitored the newborn’s vocal behaviour for approximately 2 hours and recorded 70 calls. We categorised the vocalisations both qualitatively, using conventional call descriptions, and quantitatively, using cluster and discriminant acoustic analyses. We found evidence for acoustically distinct vocal units, produced both in isolation and in combination, including sequences akin to adult pant hoots, a vocal utterance regarded as the most complex vocal signal produced by this species. We concluded that chimpanzees possess the capacity to produce vocal sequences composed of different call types from birth, albeit in rudimentary forms. Our observations are in line with the idea that primate vocal repertoires are present from birth, though fine acoustic structures likely undergo ontogenetic processes. Our study provides rare and valuable empirical data on perinatal behaviours in wild primates.
Citation
Soldati , A , Muhumuza , G , Dezecache , G , Fedurek , P , Taylor , D , Call , J & Zuberbühler , K 2022 , ' The ontogeny of vocal sequences: insights from a newborn wild chimpanzee (Pan troglodytes schweinfurthii) ' , International Journal of Primatology . https://doi.org/10.1007/s10764-022-00321-y
Publication
International Journal of Primatology
Status
Peer reviewed
ISSN
0164-0291Type
Journal article
Description
Funding: The study was funded by Swiss National Science Foundation awarded to KZ (310030_185324), the St Leonard College Inter-University scholarship awarded to JC and KZ, the Swiss universities cotutelle grant and the Santander Mobility Grant awarded to AS.Collections
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