Why do peacocks show their feathers?

Peacocks, the male peafowl, show their feathers to court peahens, the female peafowl. Fanning and displaying the tail is part of their mating routine and determines which peacock a hen mates with. She chooses her mate based on the quality, size and colors of his tail feathers.

Peacock tail feathers are brightly colored in reds, blues and golds and have a distinctive eye, or circle, on them. When fanned, the tail feathers arch across the peacock's back and can touch the ground on both sides. These feathers make up 60 percent of the peacock's body length. When his tail train is included, the peacock is one of the largest flying male birds on Earth.