Tool-Making Chimps Live in Rainforest Saved From Logging

NEW YORK, New York, October 27, 2004 (ENS) - A population of innovative chimpanzees that make tools to fish for termite dinners has been discovered in a rainforest in Central Africa that was saved from logging by a unique collaboration among a scientific organization, a timber company, and government officials. If the logging had gone ahead, these chimps likely would not have survived.

The New York based Wildlife Conservation Society, the Swiss timber company CIB, and the Republic of Congo have cooperated over the past four years to protect the forest.

Four years ago, CIB had planned to establish a logging operation in the 100 square mile Goualougo Triangle, which the Wildlife Conservation Society says would have irreparably harmed this unique population that may have had no contact with humans.

Efforts by the Wildlife Conservation Society to work with CIB and the Republic of Congo led to protection of the forest, which is now an integral part of Nouabalé-Ndoki National Park, a protected area the the Wildlife Conservation Society helped create in 1993.

"Had the Wildlife Conservation Society not helped to save the Goualougo from being logged, this discovery would not have been made and the forest and the chimps would have been lost," said Steve Gulick of Wildland Security. "At the same time, this study makes one wonder about the unnamed and never to be known Goualougos now threatened before the saw."

Researchers, funded in large part by the Wildlife Conservation Society (WCS) and National Geographic, used remote video cameras to record the chimps to minimize human disturbance to the animals.

Chimpanzee using a stick to puncture a termite mound (Photo courtesy The American Naturalist)

Earlier studies have documented tool use among chimps in eastern Africa and other regions, but still authors Crickette Sanz of Max Planck Institute for Evolutionary Anthropology, WCS researcher David Morgan of Cambridge University, and Gulick say that the Goualougo chimps use tools in different and more complex ways than ever seen before.

Their study is published in the November issue of the journal "The American Naturalist."

Tool kits, made up of more than one type of tool, were used. The researchers explained that to make use of a tool kit, an individual chimp has to understand the associative role of each tool to perform a specific task.

In addition, they observed that the tool kit used by chimpanzees in the Goualougo Triangle for fishing termites from their nests differs from tools used in East and West Africa.

"Although multiple tool use in wild chimpanzees is rare, we have clearly differentiated two tool sets that are frequently used by chimpanzees in the Goualougo Triangle when preying on termites," the researchers write.

Different stick tools were used for different functions. Goualougo chimpanzees consistently fashioned tools made of specific materials that had uniform lengths and diameters suitable for distinct tasks in termite predation, the researchers found.

Research focused on the Moto chimpanzee community, which consisted of 54 animals - 10 adult males, 18 adult females, seven subadults, and 19 juveniles. Tools from five other chimpanzee communities in the study area were also collected.

Tools were collected along an established termite nest circuit from December 2001 through December 2002. In addition, they were collected during daily reconnaissance surveys in the study area - January–June 2001, October 2001–December 2002, August–November 2003.

"With the aid of a remote video monitoring system," the researchers write, "we observed chimpanzees in the Goualougo Triangle arriving at nests with appropriate tool materials, manufacturing brush-tipped fishing probes, using puncturing sticks in combination with fishing probes to access subterranean termite nests, and using perforating twigs to open the surface of epigeal termite mounds before extracting termites with probes."

Chimpanzee in the Congo's Nouabalé-Ndoki National Park (Photo by David Morgan courtesy WCS)

"By retracing the travel path of chimpanzees, we were often able to find the location where raw materials for tools had been gathered, which showed that they had been specifically selected and transported to specific nests," the researchers write.

Some trees that were sources of stick materials were tens of meters from the termite nest, not visible from the tool-using location, and visited by chimpanzees on several occasions for gathering raw materials for tool making, they found.

Different plants were the source of material for perforating sticks.

Now researchers in the Goualougo Triangle are planning to conduct long-term remote monitoring of termite nests in several chimpanzee communities to compare technological traditions within the region.

"The Sangha River Trinational protected area in northern Congo provides one of the last opportunities to document the natural differences in material culture among several intact social groups and processes of technological diffusion within a wild ape population," they write.

To these researchers, the opportunity to observe the original behavior of wild chimps is priceless. They conclude, "These results of this study emphasize the importance of continuing to protect the remaining forests of the Congo Basin, their ape inhabitants, and the unique and largely undocumented cultures that reside within them."