Chimps FLIRT with each other by ripping up leaves - and it's most common in randy teenagers
It's a rite of passage for awkward teenagers.But learning how to flirt is not a uniquely human trait, an expert has revealed.Professor Cat Hobaiter, who has studied primates for over 20 years, says adolescent chimps also chat each other up.And they do it in the most adorable way – by carefully ripping leaves in front of the individual they fancy.Professor Hobaiter, from the University of St Andrews, has spent her career carefully studying ape communication, including the use of gestures.'One of the ones we've looked at recently is leaf clipping, where they basically are tearing or plucking leaves,' she said.'This is basically chimp flirting. It's like a chimp pick–up line – you tear a little leaf at someone to show you like them.'She explained the gesture is mostly carried out by males to attract females, but 'it can go both ways'. Professor Hobaiter said chimps flirt by carefully ripping leaves in the vicinity of the individual they fancy. This chimp used his mouth to strip the small branch of leaves Descriptions of four forms of leaf–modifying gestures including leaf clipping, pulling and tearing'You certainly get some females who will use it,' she said. 'It's almost like when teenage girls are trying to work out how to get attention.'You get lots of lovely examples of it as everyone's trying to work out the rules for this new phase of life.'Professor Hobaiter said the ripping or tearing of leaves makes a very distinct sound, which can be heard from quite far away.However, some individuals carefully pluck leaves off a branch instead.'It's silent, like plucking daisy petals,' she explained. 'Like a "She loves me, she loves me not" pile of leaves.'Some chimps might use this tactic – instead of the louder ripping method – to be discreet with their romantic intentions.'Maybe you don't want to give the game away to the big guy around the corner that might out–compete you,' she added.Professor Hobaiter and colleagues published a study on chimp leaf clipping behaviours, which analysed the practice in two neighbouring communities of East African chimpanzees in Uganda. This chimpanzee was captured 'flirting' at a female, who was sitting in the tree just above him, through the act of leaf clipping Professor Hobaiter said the ripping or tearing of leaves makes a very distinct sound, which can be heard from quite far awayWhile both appeared to use the gesture as a method of flirting, the researchers observed distinct differences in their technique – indicating cultural differences between the groups.One community were more likely to use the 'leaf–clip' technique, which involved ripping apart individual leaves using the mouth, while the other preferred the 'leaf tear–pull' method, which involved tearing or pulling leaves, one by one, away from a twig.The study, published in the journal Scientific Reports, reads: 'Across communities, this behaviour primarily occurs in sexual contexts and is argued to function as a courtship behaviour to solicit copulations, particularly by young males toward females in oestrus (heat).'We found that while both communities used multiple forms, primarily within sexual solicitation, they showed a strong preference for a single, different gesture form.'The observed variation in form preference between these neighbouring communities within the same context suggests that these differences are, at least in part, socially derived.'Professor Hobaiter explained there are now 150 known ape gestures, several of which bear striking resemblance to human hand movements.'If they want to ask for something, they will reach with their palm out the way that we would,' she explained.'And if a chimpanzee wants to say 'go away', they make that little shoo movement we all do with our hands.'A light nudge with the back of the hand means 'budge up', while a big loud scratch is used to initiate grooming.Others are not quite so obvious and have taken years of analysis to decode. For example, a chimpanzee spinning around is likely saying 'stop that', while raising an arm is thought to mean 'let's travel'.Professor Hobaiter made her comments at the American Association for the Advancement of Science (AAAS) conference in Phoenix, Arizona.
