Humans have been the most ingenious species to ever live on this planet; at least, as far as we have been able to discern. However, we continue to learn more and more about our ape cousins and how they came to understand and develop tools.
Cashew nuts are naturally protected by a thick shell which contains irritating, toxic chemicals evolved to discourage animals from eating them. The capuchin monkeys, however, have learned how to bypass this shell, to get to the nut inside.
Basically, these tiny primates set up a kind of hammer and anvil system near a tree. They use a flatter rock most of the time but a log or branch can work too. Then they use another rock as the hammer, placing the cashew on the “anvil” and using the “hammer” to crack it open.
University of Oxford primate archaeologist Michael Haslam has led this study which investigates how capuchin monkeys, for example, have used tools. He says, “From a human perspective, capuchin stone tool use appears quite simple.” But, he says, these primates actually do put a great deal of care and consideration into their work.
He goes on to say, “The capuchins are carefully selecting their hammer and anvil stones, and adjusting their striking behaviour, to efficiently open the nuts. It takes the monkeys years to learn how to do this properly, so even though it appears simple, there are actually a lot of parts to the process that need to be learned and practiced.”
Basically, Haslam argues that while humans are still the greatest tool users in history, we are getting a deeper understanding of how our “primate relatives” daily used tools. He also adds that this gives us a better appreciation of the way we, as organisms, use tools in today’s world and how that is still quite similar to the way humans used tools in the ancient world.
In addition, study co-author Tiago Falótico—a postdoctoral research fellow from the University of Sao Paulo—notes, “We thought that this behavior could be happening for a long time, but this is the first time that we have hard evidence for that.”
Similarly, evolutionary biologist Robert Shumaker notes, “This is really a first. This is the first time that non-great-ape tool use has been documented in the archaeological record.” Also the vice president of conservation and live sciences with the Indianapolis Zoo he was not part of this study.