Franco-Japanese and other collaborative contributions to understanding chimpanzee culture at Bossou and the Nimba Mountains.

The Japanese approach to science has permitted theoretical leaps in our understanding of culture in non-human animals and challenged human uniqueness, as it is not embedded in the Western traditional dualisms of human/animal and nature/culture. This paper highlights the value of an interdisciplinary approach and combining methodological approaches in exploring putative cultural variation among chimpanzees. I focus particularly on driver ants (Dorylus sp.) and oil palm (Elaeis guineensis) consumption among the Bossou and Nimba chimpanzees, in south-eastern Guinea at the border with Côte d'Ivoire and Liberia, and hand use across different tool use tasks commonly witnessed at Bossou, i.e. ant-dipping, nut-cracking, pestle-pounding, and algae-scooping. Observed variation in resource use was addressed across differing scales exploring both within- and between-community differences. Our findings have highlighted a tight interplay between ecology, social dynamics and culture, and between social and individual learning and maternal contribution to tool-use acquisition. Exploration of hand use by chimpanzees revealed no evidence for individual-level hand or community-level task specialisation. However, more complex types of tool use such as nut-cracking showed distinct lateralization, while the equivalent of a haptic manual action revealed a strong right hand bias. The data also suggest an overall population tendency for a right hand preference. As well as describing these sites' key contributions to our understanding of chimpanzees and to challenging our perceptions of human uniqueness, this paper also highlights the critical condition and high levels of threats facing this emblematic chimpanzee population, and several questions that remain to be addressed. In the spirit of the Japanese approach to science, I recommend that an interdisciplinary and collaborative research approach can best help us to challenge perceptions of human uniqueness and to further our understanding of chimpanzee behavioural and social flexibility in the face of local social, ecological and anthropogenic changes and threats to their survival.