LEIPZIG, GERMANY―A new study of chimpanzee behavior could shed light on the origin of ritual sites in hominin evolution. Chimpanzees are known to use tools to extract and consume food, and the ways in which they use tools can vary depending upon where they live. A new standardized protocol for collecting data on chimpanzee behavior, called the “Pan African Programme: The Cultured Chimpanzee,” has thus been initiated by the Max Planck Institute for Evolutionary Anthropology at 39 research sites across Africa. Camera traps in West Africa caught chimpanzees throwing stones at trees. “The PanAf cameras filmed individual chimpanzees picking up stones from beside, or inside trees, and then throwing them at these trees while emitting a long-distance pant hoot vocalization,” Ammie Kalan of the Max Planck Institute for Evolutionary Anthropology said in a press release. This behavior is usually performed by adult males, in the context of ritualized displays. “As the stone accumulation behavior does not seem to be linked to either the abundance of stones or the availability of suitable trees in the area, it is likely that it has some cultural elements,” added Christophe Boesch, director of the Max Planck Institute’s Department of Primatology. To read about the discovery of the first known chimpanzee archaeological site, go to "Ancient Chimpanzee Tool Use."