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 development. However, observations births perinatal behaviour wild rare, the initial stages behavioural ontogeny usually remain undocumented. Here, we report birth a chimpanzee ( Pan troglodytes schweinfurthii ) Budongo Forest, Uganda, including mother other group members. We monitored newborn’s approximately 2 hours recorded 70 calls. categorised vocalisations both qualitatively, using conventional call descriptions, quantitatively, cluster discriminant acoustic analyses. found evidence acoustically distinct units, produced isolation combination, sequences akin to adult pant hoots, utterance regarded as most complex signal by this species. concluded that chimpanzees possess capacity produce composed different types from birth, albeit rudimentary forms. Our line with idea repertoires largely present fine structures undergoing ontogenetic processes. study provides rare valuable empirical data on primates.