Photos Reveal First Tool Usage In Wild Gorillas

"This is a truly astounding discovery," said Thomas Breuer of theWildlife Conservation Society. "Tool usage in wild apes provides uswith valuable insights into the evolution of our own species and theabilities of other species. Seeing it for the first time in gorillas isimportant on many different levels."

According to the study published in the open access journalPLoS Biology, on two separate occasions in the northern rain forests ofthe Republic of Congo, researchers observed and photographed individualwestern gorillas using sticks as tools. The observations were made inMbeli Bai--a swampy clearing located in Nouabalé-NdokiNational Park where monitoring has been ongoing since February 1995.The first instance occurred when a female gorilla nicknamed Leah byscientists attempted to wade through a pool of water created byelephants, but found herself waist deep after only a few steps.Climbing out of the pool, Leah then retrieved a straight branch from anearby dead tree and used it to test the depth of the water. Keepingher upper body above water, she moved some 10 meters out into the poolbefore returning to shore and her wailing infant.

Then another female gorilla named Efi used a detached trunkto support herself with one hand while digging for herbs with theother. As she moved from location to location, she used the stick forone last job, a bridge over a muddy patch of ground.

In the past, gorillas have been observed using tools in zoos,but not in the wild. And, while most other observed instances oftool-usage in great apes are related directly to processing food (i.e.the cracking of nuts with rocks or extracting termites with longsticks), these two examples of using tools for postural support weretriggered by other environmental factors.

The Wildlife Conservation Society has been studying gorillasand other wildlife in the Republic of Congo since the 1980s. In 1993,the Congolese Government, working in tandem with technical assistancefrom WCS, establishedNouabalé-Ndoki National Park. The Mbeli Bai site is being managed to meet long-term gorilla research and ecotourism objectives.

"These protected areas are not only important for theconservation of species they contain, they also hold the key tocomparing our own development as a species with our next of kin," addedBreuer. "Places likeNouabalé-Ndoki, and the nearby Goualougo Triangle, are places where we see the process unfolding before our very eyes."

An exclusive look at this scientific discovery, includingnever-before-seen photographs and interviews in Africa with the fieldscientists who observed and documented the behavior for the first time,will be broadcast as the lead segment in the launch episode of "WildChronicles," a brand new series airing nationally on PBS stationsbeginning October 1, 2005 (check local listings). Hosted by BoydMatson, the weekly, half-hour, science and nature adventure TV serieswill be presented nationally by PBS member station WLIW New York.

The Mbeli study appears in PLoS Biology, a peer-reviewed, highlycited journal published by the Public Library of Science (PLoS), anon-profit organization committed to the goals of open access, makingscientific and medical literature a public resource. This study isimmediately available online at http://www.plosbiology.orgwithout cost to anyone, anywhere to read, download, redistribute,include in databases, and otherwise use--subject only to the conditionthat the authors and source are properly cited.

Citation: Breuer T, Ndoundou-Hockemba M, Fishlock V (2005) Firstobservation of tool use in wild gorillas. PLoS Biol 3(11): e380.