Who talks about the past? Not just us.

Other than humans, there is only one animal that we know about that talks about events that have already happened (the past): Orangutans. Orangutans make a certain sound to signal that there is a predator nearby. Scientists have observed orangutans seeing a predator, quietly climbing to safety while carrying her infant, and waiting until it was safe to give the warning.

This delayed warning makes it safer for the infant, and indicates a greater intelligence than only communicating about events that are currently happening.

 “The mother saw the predator as most dangerous to her youngster and chose not to call until it was gone,” he says. Then, and only then, did she provide information, letting the infant learn about the danger that had passed, the team reports today in Science Advances.