Scientists were fascinated and also shocked to find chimpanzees seemingly worshiping trees like idols, just like we have done for thousands of years across all civilizations. The primates were filmed walking up to specific trees, staring at them, then throwing stones at them and adding to a stone pile at the tree’s base.
All these bizarre behaviours had nothing to do with challenging rivals, foraging, or courtship, an international team of scientists wrote in the academic journal Scientific Reports.
After carefully studying the video recordings and stone piles, Hjalmar Kuehl, from the German Centre for Integrative Biodiversity Research and the Max Planck Institute for Evolutionary Anthropology, and colleagues said that the animals appeared to be performing some kind of ritual, using the tree as the idol – their object of reverence or worship.
Are chimpanzees really capable of seeing certain trees as idols? Are they building shrines out of piles of stones. (Image: nature.com)
Chimpanzees perhaps more evolved than we realised
If these are really cases of adoration rituals, then the common chimpanzee (Pan troglodytes) must be much closer to us up the evolutionary ladder than previously thought.
After the video was placed on YouTube, some viewers suggested that rather than worshipping behaviours, perhaps the animals were engaged in some kind of sport, a chimpanzee-equivalent of shooting the hoops (basketball) or target practice.
We have known for a long time that chimpanzees (chimps) are skilled tool users, which they utilize for getting at food. What kind of tools they select varies, depending on where they live.
When the scientists saw the videos of chimpanzees seemingly making a shrine at the base of a tree, they were both fascinated and shocked. (Image: nature.com)
According to Max Planck Institute scientists, these fascinating rituals were recorded during the activities within the PanAf (Pan African Programme: The Cultured Chimpanzee) project.
No explanation for chimp behaviour
The research team, which included zoologists, animal psychologists and evolutionary anthropologists, are unable to explain why the chimps were throwing stones at trees and building piles at their bases. They suspect their actions likely have some cultural elements.
Since the middle of the last century, chimps have been studied extensively at a number of long-term field sites located in West and East Africa.
After human beings, chimps are probably the most proficient and sophisticated tool users. They are used by them for getting at termites, scooping ants out of holes and cracks, fishing, and prodding for honey.
Chimps have also been observed using stones and wooden blocks as hammers to crack open nuts.
Sometimes chimps may use tools in non-foraging situations. Males will occasionally throw stones and branches about during displays or confrontations with rivals, or leaf-clip as a way of letting a female know that they want to mate.
Several nature photographers have reported having stones thrown at them by unfriendly chimps.
We know chimpanzees use tools to get food.
Dr. Kuehl said:
“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.”
“The Pan Af is only possible due to the numerous collaborations with chimpanzee researchers, field workers and national wildlife authorities in 14 countries across Africa.”
As the chimpanzees they wanted to study had never had contact with humans, they had to use non-invasive sampling methods, including placing hidden camera traps.
Cameras showed chimps were the culprits
Some of the cameras that had been strategically placed at the Chimbo Foundation site in Guinea Bissau recorded episodes of chimps visiting the trees where the piles of stones were, throwing stones at them, and adding to the piles.
If this chimpanzee sees the tree as a temple and brings sacred stones to it, our closest primate is much closer to us in the evolutionary ladder than we had thought. (Image: nature.com)
The mystery of the stone piles was solved – the chimps were the culprits!
Regarding what the cameras recorded, Dr. Ammie Kalan, from the Max Planck Institute for Evolutionary Anthropology, a postdoctoral researcher investigating chimpanzee communicative behaviour within a cultural framework, said:
“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.”
The video footages suggested that most of the seemingly ritualistic behaviours were done by the adult males, although there were some cases of juveniles and females also participating.
Cheeta, the chimp who appeared in several Tarzan movies, enjoying a 75th birthday message from Jane Goodall on 9th April, 2007. If chimps are closer to us than we think, will they be directing movies within the next, say, 1 million years? (Image: mentalfloss.com)
Stone hurling not related to foraging
Nobody in East or West Africa or in the scientific community had ever witnessed this kind of behaviour before. It was evident, the authors emphasized, that what they were doing was in no way related to foraging.
Prof. Dr. Christophe Boesch, Director of the Max Planck Institute for Evolutionary Anthropology’s Deptartment of Primatology, said regarding the chimps:
“This study reports a new chimpanzee behavior not known previously and highlights the potential of the PanAf project to uncover unknown facets of the life of chimpanzees, our closest living relative.”
“As the stone accumulation behavior does not seem to be linked to either the abundance of stones or the availability of suitable trees in an area, it is likely that it has some cultural elements.”
Since prehistoric times, humans have been making rock stacks (cairns) as offerings to Gods and idols. (Image: cairnway.net)
Is chimp behaviour what we used to do?
Scientists and psychologists often use chimps as models of hominins in their studies. After discovering that these enigmatic stone piles were the result of chimp ritual behaviours, the authors believe we could gain some insight into how stone piles in archaeological sites were formed.
Might the ritualistic behaviours of chimps today shed some light on the origin of ritual sites in our own evolution? The authors think so.
The researchers wrote the following in an Abstract in the journal:
“This represents the first record of repeated observations of individual chimpanzees exhibiting stone tool use for a purpose other than extractive foraging at what appear to be targeted trees.”
“The ritualized behavioural display and collection of artefacts at particular locations observed in chimpanzee accumulative stone throwing may have implications for the inferences that can be drawn from archaeological stone assemblages and the origins of ritual sites.”
Citation: Ammie K. Kalan, Hjalmar S. Kühl, Christophe Boesch et al. “Chimpanzee accumulative stone throwing.” Scientific Reports. 29th February, 2016. DOI: 10.1038/srep22219.
Video – Chimp filmed in ‘sacred ritual’
The ritual on this video has simularities with the building of cairns or shrines, a human trait that has been happening for thousands of years across civilisations.