First impressions count, so aspiring bachelors must stand out from the crowd if they're to get a gal. But boasting with elegant plumage might not tip the balance with some females, so male manakins have added another talent to their list of attractive attributes; ear-catching percussive wing clicks. Manakins have modified their feathers and even their wing structures to produce the crackling sound effects! Yet no one knew how the birds' customised wings made the strange rattling sounds, until Kimberly Bostwick began following the manakins' noisy courtship routines on high-speed video(p. 3693).
Armed with a camera, Bostwick headed into the Costa Rican rainforest, where she was lucky enough to stumble across a group of Pipra mentalismales, just as a female flew into view. `The males went berserk' she remembers, and within 15 minutes Bostwick had gathered enough footage to realise that instead of using a single snapping technique, the males had a repertoire of snapping methods. In some displays birds dragged their wings down their tail feathers, while in other displays they beat their sides or flicked their wings, generating distinctive sounds at different stages of the courtship ritual.
If one species could be so creative, what was there to stop other species evolving their own snapping themes? At the end of filming a courting Manacus duo's high-speed chase, Bostwick heard a loud cracking sound from the male sitting alone on his perch. But when she replayed the high-speed footage, she saw that this sound effect was produced by the male clapping his wings together in rapid succession, vibrating them as fast as a hummingbird's wings; none of the Pipra males had done anything like that.
Bostwick admits that she was surprised to find such a variation in the bird's attractive wing-rattling repertoire, she says `I had assumed there was only one way [to wing snap]'. She adds that a Manakin's beauty is much more then skin deep because of the lengths they have gone to catch a female's favours, even modifying their wings to pitch the best click.