Great apes communicate cooperatively

The research team of Marlen Fröhlich and Simone Pika of the Humboldt Research Group at the Max Planck Institute for Ornithology together with colleagues from the Max Planck Institute for Evolutionary Anthropology in Leipzig, the Ludwig- Maximilians-University in Munich and the Kyoto University in Japan, conducted the first systematic comparison of communicative interactions in mother-infant dyads of two different bonobo and two different chimpanzee communities in their natural environments.

The bonobos were studied over the duration of two years in the Salonga National Park and Luo Scientific Reserve in the Democratic Rebublic of Congo. The chimpanzees were observed in the Taï National Park, Côte D'Ivoire, and Kibale National Park in Uganda.

The results showed that communicative exchanges in both species resemble cooperative turn-taking sequences in human conversation. However, bonobos and chimpanzees differ in their communication styles. "For bonobos, gaze plays a more important role and they seem to anticipate signals before they have been fully articulated" says Marlen Froehlich, first author of the study.

In contrast, chimpanzees engage in more time-consuming communicative negotiations and use clearly recognizable units such as signal, pause and response. Bonobos may therefore represent the most representative model for understanding the prerequisites of human communication. "Communicative interactions of great apes thus show the hallmarks of human social action during conversation and suggest that cooperative communication arose as a way of coordinating collaborative activities more efficiently," says Simone Pika, head of the study.