Scientists Records Chimpanzees Performing a Bizarre Ritual (Video)
Chimpanzees in three West African countries Guinea Bissau, Côte d’Ivoire (the Ivory Coast), and Liberia, have been observed taking part in strange behavior. They store a great number of rocks in the hollows of trees. Then, usually, a male, takes one of the rocks, walks a distance away, grunts an utterance, and hurls the rock at the tree, leaving a mark on it. The rock is then placed back in the hollow to be reused in this manner again.
No chimps east of these countries have been observed doing this. What is more, there seems to be no reason for it tied to survival. It has nothing to do with acquiring food, mating, or furthering one’s status. Researchers say it might be a unique display of male power, marking the border of their troop’s territory, or even a spiritual ritual.
A team of 80 international scientists, led by Hjalmar S. Kuhl and Ammie K. Kalan, conducted the study. Kuhl and Kalan hail from the Max Planck Institute in Germany. The team set up camera traps in four remote locations in West Africa, where they caught footage of chimps taking part in this unusual and so far, unexplained behaviour. Their findings were published in Scientific Reports, part of the journal Nature.
The authors write, “We found four populations in West Africa where chimpanzees habitually bang and throw rocks against trees, or toss them into tree cavities, resulting in conspicuous stone accumulations at these sites.” Chimps have been known to use rocks as tools, to bash open fruits or nuts for instance. Certain groups have even been seen using sticks removed of leaves and sharpened as spears, for hunting.
But they’ve never been observed taking part in behavior outside of that tied to survival. Over time, researchers found that this so-called ritualistic practice caught on in troops where males had taken part in it, with even a few females doing so. So could it be a spiritual ritual? Researchers on Kuhl and Kalan’s team have likened the rock pilings to the types of Cairns the indigenous people of these areas make.
Cairns are piles of rocks that serve many purposes. People have been making them since the Stone Age. They can signify where a battle took place or as a memorial, as a marker for a grave site, a demarcation of territory, a signpost on a path, to denote a sacred site, and much more. This discovery transformed these four places from chimpanzee viewing areas to primate archaeological sites.
Study co-author Laura Kehoe made a statement that has caused something of an uproar. She mused, “Maybe we found the first evidence of chimpanzees creating a kind of shrine that could indicate sacred trees.” It wll take a long time to prove such a thing, should it be true. The first major hurdle, there’s great debate in the archaeological community over what counts as a ritual, or even how to define one.