A team of researchers managed to capture the bizarre ᴍᴀᴛing ritual of the capuchins while filming in the dry, arid region of Caatinga in north eastern Brazil. The recording was made during filming for a BBC and Discovery Channel documentary called Wild Brazil.
They were helped by Professor Camila Galheigo Coelho from the University of Durham who has spent the last two years studying the social interactions of the monkeys.
They have observed that female capuchin monkeys throw rocks at their desired males to communicate their readiness to ᴘʀᴏᴄʀᴇᴀᴛᴇ. Although this behaviour may seem ᴀɢɢʀᴇssɪve, it is actually the female’s attempt to grab the attention of a nearby male.
First, the female will stalk about the male, looking all nervy and excited and checking in with her girlfriends. Then she’s like screw it and she just flings the rock at her favorite cutie. After she throws the rock, she scurries the ʜᴇʟʟ out of there! So, embarrassed, but also a little self-satisfied? Some of these lady-monkeys even run up trees — and the male monkeys follow them.
Researchers reported that the stone doesn’t usually make contact with the male, but the two times that they did see the male monkey get ʜɪᴛ, he ᴍᴀᴛᴇᴅ with the female that threw the rock at him.
Capuchins (like humans) must perform some sort of ᴍᴀᴛing ritual, since they don’t display physical indicators of ꜰᴇʀᴛɪʟɪty. But this sort of behavior has never been witnessed in the wild before, say the scientists observing the monkeys. Previously, they reported, females would pout or whine loudly or touch males and run away in order to show their affections. But, as every dating book tells the girl monkeys, the game has changed. If these girl monkeys really want to snag a suitable monkey-ᴍᴀᴛe, they’re going to have to pick up the rock.