Orang-utans communicate intelligently using gestures, researchers have found.
British scientists who spent nine months observing the great apes in three European zoos identified 40 frequently used body language signals. These were employed repeatedly to send messages such as "I want to play", "give it to me", "go away", "follow me", or "stop doing that".
"Play" gestures involved a range of clowning antics, including back rolls, placing objects on the head, and blowing raspberries.
"Nudge and shoo" movements meant an ape wanted to be left alone, while a hand to mouth "begging" gesture requested food.
Other gestures included hitting the ground, hair pulling, biting the air and grabbing.
This was the first study of great ape body language to focus on the intentional meanings of specific gestures. Two scientists from the University of St Andrews observed 28 orang-utans at Twycross Zoo in the UK, Apenheul Primate Park in the Netherlands, and the Durrell trust in Jersey. Their study is reported in the journal Animal Cognition.