WHEN children blow raspberries at you it usually means they’re feeling playful – and new research suggests the same is true for the orang-utan.

Long celebrated for their intelligence and sense of humour, the study suggests that great apes employ a variety of different gestures to signal that they want to play – including back rolls, placing objects on their heads and swinging upside down.

British scientists identified and translated up to 40 gestures used by the primate, which are employed to send messages such as “I want to play,” “Give it to me” and “I’m hungry.”

Similarly, they also use “nudging and shooing” gestures to indicate that they want to be left alone, or a hand-to-mouth movement to tell you that they’re hungry.

The latest research into orang-utan behaviour was conducted by British scientists, who spent nine months observing orang-utans in three European zoos.

Professor Richard Byrne and Dr Erica Cartmill reported their findings in the journal Animal Cognition.

“Orang-utan gestures are made with the expectation of specific behavioural responses,” they wrote, “and thus have intentional meaning as well as functional consequences.”

Dr Alison Cronin, director of Monkey World at Wool, said it showed that orang-utans, which spend much of their time in the wild alone, could adapt.

She added: “What’s interesting about this study is that they’re observing orang-utans in an unnatural environment.

“It’s an unnatural environment because in the wild they are semi-isolated, only meeting up to mate.

“It goes to prove what we and everybody else in the zoological world tends to acknowledge – that, in captivity, they can benefit and work out ways and means of existing together.”

Dr Cronin added: “Orang-utans are the most intelligent of the non-human primates.

“It goes to show that, put in unnatural circumstances, they evolve and adapt their behaviour to suit their environment.”