During fieldwork to document the use of stone tools by a group of wild chimpanzees in the Taï forest in Côte d’Ivoire in early 2022, researchers identified and 3D digitized a variety of stone tools used to crack different kinds of nuts.
Various groups of chimpanzees have long been shown to possess different tool-use cultures involving wooden and stone tools, however, only certain groups in West Africa use stone tools for cracking nuts. By comparing 3D models of different stone tools used by chimpanzees in the Taï forest with those of another group in Guinea, the researchers showed that there are notable differences between the two groups in terms of material culture.
The study shows that this particular group of Guinean chimpanzees use stone hammers that vary in stone type and size, and very large stone anvils, sometimes over a meter long. These durable stone tools are widespread throughout the landscape; preserve varying levels of damage associated with their use and represent a lasting record of chimpanzee behaviors.
Stone tools used to crack nuts may differ between chimpanzee groups
This study highlights the fact that, although several groups of chimpanzees practice the nutcracker, the tools they use can differ significantly from each other, potentially leading to group-specific material signatures. These differences are driven by a combination of stone choice, stone availability, and nut species consumed.
Previous research has shown that by using stone tools, some groups of chimpanzees develop their own archaeological records dating back at least 4,300 years. “The ability to identify regional differences in the culture of stone tool materials in primates opens up a range of possibilities for future primate archaeological studies,” says Tomos Proffitt of the Max Planck Institute for Evolutionary Anthropology. , who conducted the research.
It has been speculated that simple technology, such as nut cracking, was a precursor to more complex stone technologies during the early stages of our own evolution over three million years ago. Proffitt continues, “By understanding what this simple stone tool technology looks like and how it varies between groups, we can begin to understand how to better identify this signature in early hominid archaeological records.