Even though I’ve been posting a lot on tool use lately, I’m sure you will appreciate this new study. The new study, “Invention and modification of a new tool use behavior: ant-fishing in trees by a wild chimpanzee (Pan troglodytes verus) at Bossou, Guinea,” has been published in the most recent issue of the American Journal of Primatology. The writeup is very simple and informative, which is great because I consider this a very important paper in figuring out the origins of tool use and the intricacies of primate behavior.
The scope of this paper is a report on tool use seen in a male chimpanzee from Guinea. Tool use has been documented in several other wild chimpanzee societies, most notably was Goodall’s observations of Gombe chimps using tools. Since then other researchers have seen other wild chimps use tools, particularly using rocks to crack nuts open, and using twigs and sticks to fish or dip for ants. Ever so recently, we read and saw a Fongoli chimp hunt with a makeshift spear.
The clincher behind chimpanzee tool use in the wild use has been that it seems to be localized within the group that the behavior is observed in. This has gotten many researchers to hypothesize that this is some group specific behavior, a cultural trait per say. Researchers had no idea how tool use behaviors emerged in these respective groups, nor how long they have been practicing tool use.
In this new study, JJ, the male chimpanzee was the only chimpanzee in his group seen selecting for sticks used to fish for ants in a two year time period. This group of chimpanzees from Bossou has been studying for 27 years and this behavior has never been observed before. So his tool use tendencies seem to be novel amongst this group. Throughout the two years of observation, JJ progressively modified the optimal fishing stick, selecting for shorter and shorter ones. This indicates that JJ learned the characteristics of the best tool, one that would yield more ants.
Unfortunately, no observation has been made of JJ transmitting this behavior to other Bossou chimps. But it does indicate several thing… tool use can independently arise in chimpanzees, regardless of the fact that the group as a whole practices tool use or not. Also, it provides an insights into the cognitive capacity of wild chimps, like JJ, to problem solve and modify their behavior.
Yamamoto, S., Yamakoshi, G., Humle, T., Matsuzawa, T. (2008). Invention and modification of a new tool use behavior: ant-fishing in trees by a wild chimpanzee (Pan troglodytes verus) at Bossou, Guinea. American Journal of Primatology DOI: 10.1002/ajp.20544