JPG

This picture was taken on May 25, 2008 at Point Defiance Zoo.

Scientific Name : Pavo cristatus

Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Galliformes
Family: Phasianidae
Genus: Pavo

Color in nature occurs due to two basic processes: pigmentation and structural coloring. Pigment is a substance that, like a dye, gives color to living and inanimate objects. Peacocks and other structurally colored animals and things, such as rainbows, soap bubbles and the blue sky, instead get most of their color from light reflection. As a result, while human hair can look shiny clean, it can never achieve the brilliance and radiant coloration of a peacock's tail feather. In human hair, color is due to pigment. If you change the view angle, color is not altered. In peacock feathers, color is produced by the reflection of light with frequencies within the partial photonic band gap. If you change the view angle, the partial photonic band gap will shift to short wavelengths for oblique incidence.

Each peacock tail feather possesses a central stem with an array of barbs on each side. Each barb, in turn, possesses an array of smaller, flat barbules.

The outer layer of the barbules consists of a two-dimensional crystal framework made of melanin rods connected by keratin — a fibrous protein — in a lattice pattern. The number and spacing of the rods controls how light reflects which produces different colors. For peacocks, the colors are green, golden yellow, brown and a very bright blue.

Male peacocks display their iridescent feathers for prospective female mates. Females may check out the feathers of a number of different males before deciding on a suitor. The length and quality of a male peacock's feathers can indicate his age, vigor, and status.