Tooling Around: Wild Chimpanzees Use Branches to Fish for Algae

Man is known to possess reason and intellect, traits that motivate us to observe if other organisms in the world might be similar to us. Researchers at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany shared their recent discovery after observing wild chimpanzees in Bakoun, Guinea: they go fishing for algae with long and hefty tools.

Chimpanzees have been recorded as using tools to acquire or eat food. But scientists have observed that the tools they use vary depending on their habitat or where they feed. In 2010, researchers at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, initiated the "Pan African Programme: The Cultured Chimpanzee" (PanAf) to characterize and understand the differences in chimpanzee behaviors across Africa.

To better understand the ecological and evolutionary drivers of behavioral diversification in chimpanzees, The PanAf has followed a unique standardized protocol. Data on chimpanzee behavior, demography, and resource availability have been collected from over 40 different temporary research sites across Africa.

"The PanAf project represents a new approach to studying chimpanzees and will provide many interesting insights into chimpanzee demography and social structure, genetics, behavior, and culture," said Hjalmar Kuehl of the Max Planck Institute for Evolutionary Anthropology and the German Centre for Integrative Biodiversity Research. "The PanAf is only possible due to the numerous collaborations with chimpanzee researchers, field workers, and national wildlife authorities in 15 countries across Africa."

Human presence is extremely minimal at the PanAf sites, where the researchers rely on a wide spectrum of non-invasive sampling methods, including remote camera traps. After discovering conspicuously placed sticks along some of the bodies of water in Bakoun, PanAf site manager Anthony Agbor placed camera traps along these bodies of water.

"The tool-use appears quite different from what is known from a nearby long-term chimpanzee site at Bossou, Guinea and also differed from previous reports of rare algae scooping in Congo," said Ammie Kalan of the Max Planck Institute for Evolutionary Anthropology. "All age and sex classes of Bakoun chimpanzees were seen in the camera trap videos to successfully fish for algae in a river, stream or pond using woody branches or twigs as fishing rods. The tools were on average longer and sturdier than the algae fishing tools that are known from Bossou. Some Bakoun tools were more than 4 meters long!"

In Bakoun, the algae grow on the bottom of the stream beds and do not collect on the surface as it does at Bossou. "The ecology of the particular algae growing at each site may drive the types of tools necessary to harvest the algae," said Christophe Boesch, director of the Primatology Department at the Max Planck Institute for Evolutionary Anthropology. "We suggest that the algae probably provide an important nutritional benefit to the chimpanzees at Bakoun, especially during the dry season when chimpanzees were observed to fish algae for up to an hour at the same spot."