Peacocks' Special Feather Structure Creates Trippy, Hypnotizing 'Dance'

Peacocks, perhaps nature's most trippy bird, shake their tail feathers when it's time to attract a new mate. Why? Shaking those feathers — called "train-rattling" — causes an illusion where the eye-like circles on the feathers become more prominent, seemingly floating outward and hanging in the air. Those circles exist to lure in peahens, but have fascinated more than a few humans, too. Now a new study has taken a closer look at this 'train-rattling' dance and uncovered a few equally fascinating secrets about how it works.

According to a new study by University of British Columbia zoologist Roslyn Dakin, Haverford College biological physicist Suzanne Amandor Kane, and a team of researchers, peacocks rattle their feathers near (or at) resonance — about 25.6Hz. The tail feathers are largely composed of floaty, wispy strands, but the colorful 'eyes' are different — those strands are tightly locked together via micro-hooks, making them dense and less able to sway when the feathers rattle.

Because of this combination of dense-and-wispy feather strands, the rattling dance produces an illusion where the eyes appear static and unmoving while the rest of the features shimmy and shake. The prominence of these eyes attract mates, but may do so in more ways than one. Researchers found that the train-rattling dance produces sound waves that can be heard by peahens.

Whether those sounds also serve to attract mates is unknown. The sound waves could help draw a peahen's attention toward the feathers, at which point it may become entranced with the floating colorful eyes — or the sound itself may play a role in attracting a mate.

SOURCE: Discover