It seems like everyone, at some point, has made a joking comment about monkeys throwing their feces. It certainly has happened. I know, because I’ve watched the videos online. But WHY do they do it?
The first thing to consider is that primates don’t usually do it at all. In the wild, it rarely happens.
It never happens with many kinds of primates. Karen Strier is a professor of anthropology at the University of Wisconsin. She studies the most peaceful primates around, the Northern muriqui. They live in Brazil. They have no social hierarchy, so they are all on equal footing. Therefore, there is no need for aggression.
Chimpanzees, though, have a rigid hierarchy in their groups. When they want to display dominance, they will of ten drag around branches or throw rocks. It’s part of their communication. Some research has found that chimps who are good at throwing stuff have more developed brains.
So in a zoo, a chimp might get frustrated, and might want to communicate this to us, the audience. The problem is that there aren’t a lot of suitable branches or rocks to throw. Hence, they throw their poop. (That’s why we keep plenty of branches and rocks here at KFI. For Bill mostly.)
Some scientists even think you should be flattered by this poop throwing, because it means that the animal wants to communicate with you. Dude, just send me an email!