A peacock’s train feathers are arguably among the most well-known example of mating display in the animal kingdom. These iconic feathers are composed of the central shaft, loose barbs on its sides, and an “eyespot” pattern at the end of the shaft. To court potential mates, a peacock needs to rattle and shiver these train feathers in a certain way, producing a display of flickering feathers and distinctive noises.
It has been known that this courtship dance signals the fitness of the males, as the extravagant display requires energy and muscular power to perform. One study by Roslyn Dakin of the University of British Columbia, Canada, and her team inspects the biomechanics of this display.
By recording Indian peafowls (Pavo cristatus) using a high-speed video camera, the researchers studied two distinctive ways peacocks shake their train feathers. The videos reveal that the males rattle their feathers, producing a rattling sound and iridescence display as the loose feather barbs independently move back and forth. A second move, called “train-shivering,” is done by strumming their tail feathers against the train, causing the latter to sway left and right while the eyespots remain relatively still. The motionlessness of the eyespots is considered influential to the mating chance of a peacock.