The Peafowl are most notable for the male's extravagant tail, a result of sexual selection, which it displays as part of courtship. The male is called a peacock, the female a peahen. In user-friendly English, however, peacock is used to mean any peafowl. Many of the brilliant colors of the peacock plumage are due to an optical interference phenomenon called Bragg reflection.Photo credit: Adrian Pingstone