A multinational team of scientists from France, Germany, and Côte d’Ivoire documented that chimpanzees from different communities used distinctive gestures to attract mates. The researchers interpret this as evidence of dialect like variation in chimpanzee communication. The findings appeared in Current Biology.
The study tracked four chimpanzee communities in Tai National Park, Côte d’Ivoire, over more than a decade, from 2013 to 2024. Field teams observed social behavior, gestural communication, and mating rituals while carefully recording data across groups with similar settlements and differing social structures.
Researchers catalogued four gesture types used by males to attract females: ‘hit the heel’, ‘shock with the joints of the fingers’, ‘leaf cutting’, and ‘branch shaking’. The frequency and preference for these gestures differed across communities, revealing clear cultural variation among groups.
The researchers note that chimpanzees across groups share the same core movements but apply them at different rates, a pattern that resembles dialects in humans and points to social learning shaping communication in this species.
In a notable turn, after a 2004 incident involving illegal hunting, one chimpanzee community stopped using the gesture described as articulated fingers altogether. The change followed the loss of a key social exemplar and illustrates how an external event can shift the expressive repertoire of a community.
Scientists propose that removing influential adults who model gestures can erode the spread of a gesture and its maintenance within a group. This case demonstrates how human activity can influence animal culture and the persistence of traditional behaviors.
Earlier work showed that humans sometimes misread ape signals and underestimate the subtleties of nonhuman communication, underscoring the need for careful observation rather than assumptions about intent.
These findings highlight the cultural plasticity of chimpanzees, where social structure, ecological pressures, and external threats interact to shape communication and shared practices over time.