Jun 26, 20202 min read

Why do Chimpanzees Throw Rocks at Trees? Is there any Psychology Behind It?

Well, there is a mystery why these chimps like to throw rocks at trees. Isn’t it? Here, you are going to know why chimps do that. Now we are going to tell an interesting fact about chimps.

Chimpanzees have very similarity to human beings - taste, hearing ability. They have tool kits that they use to access something. For example, they use stone tools to crack open nuts.

There is another part we are going to tell that is Chimps throw rocks at trees which is a non-foraging strategy. There are many observations and theories on it. You may go through the article to know about the interesting facts. For that, you should know the other activities of chimps firstly.

Activities of Chimps

Primatologists have known some behaviour of chimps for a long time. Chimpanzees use stones as hammers to crack open hard-shelled nuts, throw stones to male display. All chimpanzee populations use tools, modified sticks, rocks, grass, leaves and for hunting and collecting honey, ants, nuts, water, they use these.

But now scientists are explaining another activity which is very strange. That is, chimps (most of the chimps are adult male) throw rocks at trees and accumulate them at the base or in hollow grooves. Now the question is why do they do so? Isn't it very mysterious?

Reason

Scientists had previously suggested that Chimps do strange and mysterious activities because they like the sound. Chimps hit trees with stones which is a part of an unexplained ritual. But now, scientists have said that Chimps actually communicate with others rather than any ritual. Also, they choose the trees based on their acoustic properties.

Research

The behaviour of chimps is similar to the four chimpanzees communities in West Africa. In 2016, a team of scientists researched it and published it in “Scientific Report”. Another team of scientists, led by Ammie Kalan, from the Max Planck Institute for Evolutionary Anthropology, Germany published their research in “Biology Letters”.

The team led by Ammie Kalan left a conspicuous visual signal in the chimpanzee localities. Then they saw that the chimps repeatedly revisit to throw rocks at the trees. Also, stone tool use which is a non-foraging related behaviour caught the team’s attention.

Chimpanzees choose the trees based on their acoustic properties. The sounds produced had energies concentrated at lower frequencies. This means the sounds would be longer in the environment. In spite of the similarity between surrounding trees bark and size, the produced sound was different. That was the evidence that the Chimps were choosing trees based on their acoustic properties.

Result

All activities, theories show that the strange behaviour of chimps are for interacting. Though researchers cannot completely certify this. That is all we have for now. Keep watching at our site and study our articles to know more.