Distance-decay effect in stone tool transport by wild chimpanzees

Research on chimpanzees in Taï National Park, Ivory Coast, reveals a 'distance-decay effect' in stone tool transport, where the weight of hammerstones decreases with distance from raw material sources over ranges exceeding 2 km. This pattern emerges despite short-term tool transport appearing undirected and lacking deliberate movements away from sources. The study analyzed millennia-old tool sites, including Noulo, demonstrating consistency between modern and ancient behaviors. These findings suggest that chimpanzees' complex short-term planning can produce landscape-wide patterns over long periods, offering insights into similar processes in other stone-tool-using primates, including hominins.

Luncz, L. V., Proffitt, T., Kulik, L., Haslam, M., & Wittig, R. M. (2016). Distance-decay effect in stone tool transport by wild chimpanzees. Proceedings of the Royal Society B: Biological Sciences, 283(1845), 20161607. https://doi.org/10.1098/rspb.2016.1607