Male peacocks shake their brilliantly-hued, long tail feathers to attract females in a courtship display known as “train-rattling.” But scientists had never closely examined the biomechanics behind this behavior—until now. A new paper in PLOS One concludes that the frequency at which those feathers vibrate can enhance this iridescent display—even as the eyespots remain almost perfectly still.
The courtship behavior of peacocks is well known, and until quite recently, scientists had assumed that the female of the species (peahens) simply preferred males with longer feathered trains and more eyespots—the more brightly colored, the better. Precisely how the males produced those shaking displays wasn’t deemed an important factor, which might be why nobody bothered to investigate the matter.
More recent research indicates the peacock courtship process might be quite a bit more complicated than this. For instance, the displays do seem to capture peahens’ visual attention, but eye-tracking studies showed that they aren’t spending much time gazing at the edges of the male trains, or at those brilliantly hued eyespots. Some other factor could be at work.