Young chimps learn how to flirt by ripping up leaves in front of their crush, a study has found.
The apes show affection and flirt by carefully tearing leaves in front of the chimp they like, with the ritual described as “a chimp pick-up line”.
Scientists have compared the behaviour to children’s playground games, in which they pluck the petals from a daisy repeating “she loves me, she loves me not”.
Prof Cat Hobaiter, a primate expert at the University of St Andrews, discovered the ritual as a result of ongoing work to understand chimp communication and gestures.
“One of the ones we’ve looked at recently is leaf clipping, where they basically are tearing or plucking leaves,” she said at the annual conference of the Association for the Advancement of Science.
“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 that the gesture is mostly carried out by males to attract females, but can also be adopted by females trying to woo a male.
The exchange of leaf clippings resembles the playground behaviour of human children where small gifts, sometimes flowers as well, can be given to crushes.
Prof Hobaiter said some chimps chose to declare their intentions by loudly ripping leaves, but that some opted for a discreet and reserved method, ripping them gently “like plucking daisy petals”.
She said there were now 150 known ape gestures, several of which bore a 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 said at the event in Phoenix.
“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 probably saying “stop that”, she said, while raising an arm is thought to mean “let’s travel”.
The study, which examined how different communities of East African chimpanzees interacted with leaves as part of their dialect, was published in the Scientific Reports journal.