If you’re anything like me, a tin of mixed nuts will become completely cashew-less within 24 hours of being opened. The curvy little tree nuts are incredibly satisfying snacks, probably because of their high protein, fat and caloric value. No wonder, then, that our primate relatives also turn to cashews to as part of their diet. But while we humans have the benefit of industrial processing to pick, hull and roast our cashews for us, Brazil’s capuchin monkeys (you know, like the ones from Friends and Night at the Museum) must work a little harder for their supper.
A team of researchers at Oxford have been studying capuchin eating habits and found that not only do the monkeys enjoy a good cashew, they actually took to developing stone tools to harvest them hundres of years ago which they still use to this day. The first usage of rocks to smash open the tougher husk of the cashew seed date back to 700 years ago, and quite possibly earlier as the tools were from a site of more recent capuchin colonization. While the species migrated to and thrived in the region half a million years ago, it’s thought that food became scarce, thus prompting the smartest of the bunch to figure out how to access food in hard to open (and toxic) shells like the cashew fruit. The finding represents the oldest known non-human use of tools outside of Africa to date. So the next time you grab a can of cashews from the supermarket, just be glad you didn’t have to bang two rocks together just get one lousy nut.