Ant Fishing in Trees: Invention and Modification of a New Tool-Use Behavior

Wild chimpanzees are known to have a different repertoire of tool-use unique to each community. For example, “ant-dipping” is a tool-use behavior known in several chimpanzee communities across Africa targeted at army ants (Dorylus spp.) on the ground, whereas “ant-fishing,” which is aimed at carpenter ants (Camponotus spp.) in trees, has primarily been observed among the chimpanzees of Mahale in Tanzania. Although the evidence for differences between field sites is accumulating, we have little knowledge on how such “cultural” tool-use behaviors appear at each site and on how these are modified over time. In this chapter, we report “ant-fishing” by a young male chimpanzee at Bossou, Guinea, a behavior never before observed in this community during the past 27 years. This chimpanzee went on to modify this novel tool technology over the course of the following 2 years. At the age of 5, he employed wands of similar length to those used in ant-dipping on the ground, which is a customary tool-use behavior of this community. However, 2 years later, at the age of 7, his ant-fishing tools were shorter and the efficiency in obtaining carpenter ants was improved. This observation is a rare example of innovation in the wild and does provide some insights into the emergence and the learning process of a cultural behavior in chimpanzees