BOB HIRSHON (host):
Monkey archaeology. I’m Bob Hirshon and this is Science Update.
Brazilian capuchin monkeys crack open cashew nuts by placing them on a large flat stone and pounding them with a smaller, harder stone. University of Oxford researcher Michael Haslam explains that the monkeys select the best stones for the task and leave them at what he calls “cashew processing sites”.
MICHAEL HASLAM (University of Oxford):
In the same way that we can find tools lying around, they can find the tools lying around cashew trees. Others are bringing them there; leaving them there. It becomes like a set of cutlery at a restaurant: it’s just sitting there for you.
Now, In the journal Current Biology, he and his colleagues report excavating near these sites and finding centuries-old stones underground that bore the unmistakable signs of nut processing. That suggests capuchins have been using tools for at least 700 years. The scientists are trying to understand how tool use develops and gets passed down through generations. I’m Bob Hirshon, for AAAS, the science society.
Story by Bob Hirshon