From dipping to fishing
Scientists retool thinking about chimp innovation
Chimpanzees not only share our ability to use tools. They also share our ability to create tools for a specific purpose. A group of Japanese scientists recently witnessed this inventiveness in action.
The researchers watched a 5-year-old chimp named JJ use a long twig to capture ants in a new way. At first meeting with only limited success, the innovative chimp then refashioned his tool for better results.
Tool use among chimpanzees is well documented. Chimps in some communities, for example, plunge long sticks into anthills and then eat the clumps of ants that cling to the sticks. This behavior is called ant-dipping.
Chimp groups elsewhere use shorter sticks to “fish” carpenter ants out of tree trunks. Each behavior relies on different tools and techniques.
In the current study, the Japanese scientists followed a group of chimps in a forested region of Guinea in West Africa. Studies had shown that chimps in this region used tools for ant-dipping, but no observations of ant-fishing had been reported.
In 2003, the researchers watched as JJ sat in a tree holding a long twig similar to those used for ant-dipping. He then tried using the tool to fish ants from a nearby tree trunk.
After 14 attempts, JJ wound up with only three ant snacks. He also got a series of painful ant bites in the process.
This time, when the researchers observed JJ, he was using a shorter, thinner stick to fish for ants. The new tool proved much more successful. JJ captured ants in half his trials and avoided getting any painful ant bites.
Shinya Yamamoto of Kyoto University, who led the study, says there is a difference between using a tool which comes to hand and creating one for a purpose.
“This is a rare case of the invention and modification of a new tool-use behavior by a wild chimpanzee,” Yamamoto says. “We do not yet know whether it will disappear or spread among other members of the community.”
The researchers say the findings provide new insights into problem-solving and learning processes in chimpanzees. JJ’s first, unsuccessful attempts at ant-fishing were likely based on what he knew about ant-dipping, they suggest. In ant-dipping, poking a long, thick stick into an anthill can reap great results.
The scientists now propose that JJ figured out how to fashion a new instrument based on trial-and-error. Not to mention many painful ant bites.
Watch JJ fish for ants: