Mysterious stone-throwing behavior of chimpanzees observed in the heart of West Africa may signify a form of sacred ritual, a new study has found.
The reason for this behavior is not yet clearly known, but at this point, researchers say that it may possibly have to do with cultural elements — belief in God, maybe.
Chimpanzees are known to be ingenious such that it uses different tools to hunt down food or carry out a task that needs to be done. The choice of which tools to use depends mainly on the location where the species live.
Scientists have been studying chimpanzees for nearly 60 years now, mostly in long-term researches. Despite the seemingly vast studies about chimps, researchers cannot clearly say that studies in small number of sites can represent chimpanzee populations in other locations.
Trying to solve this challenge are researchers from Max Planck Institute who started Pan African Program: The Cultured Chimpanzee (PanAf). The project aims to enhance knowledge about the ecological and evolutionary factors that influence the varied behaviors of chimpanzees.
"Here we present the first evidence of a previously undocumented, chimpanzee stone tool-use behaviour arising from the data collection of the PanAf," the authors write.
Chimpanzees Ritual Display
In their investigations, PanAf researchers discovered prominent piles of stones near trees in four study locations. To determine what caused this, the team set up camera traps next to the trees.
The videos confirmed that the chimpanzees were indeed responsible for the stack of stones. The interesting thing is there is an unusual ritual that comes along with it.
Study author Ammie Kalan says the cameras captured chimpanzees getting stones around trees and throwing it back while making panting-hooting-sounds.
Although the ritual is mostly practiced by males, researchers were also able to note females and juvenile chimps doing the said ritual.
The said behavior was observed in West Africa only. The ritual appears to have nothing to do with food hunt.
Implications Of Stone-Throwing Behavior
The study presents a previously unknown behavior of chimpanzees. Study author Christophe Boesch says that because the behavior looks like it is unrelated to the great amount of stone supply or the availability of conducive trees, cultural elements may probably be involved.
Chimpanzees have been used as study subjects to study early hominins. The study then raises questions about other stone accumulations in early archeological structures as well. The researchers say this stone-throwing behavior may suggest the roots of ritual locations in hominin evolution.
Boesch also says that the study emphasizes the potential of PanAf to uncover more information about chimpanzees.
The study was published in the journal Scientific Reports on Feb. 29.