Wednesday, September 28, 2005

Plumage


Many of the brilliant colors of the peacock plumage are due to an optical interference phenomenon (Bragg reflection) based on (nearly) periodic nanostructures found in the barbules (fiber-like components) of the feathers. Different colors correspond to different length scales of the periodic structures. For brown feathers, a mixture of red and blue is required one color is created by the periodic structure, while the other is a created by a Fabry-Perot interference peak from reflections off the outermost and innermost boundaries of the periodic structure. Such interference-based structural color is especially important in producing the peacock's iridescent hues (which shimmer and change with viewing angle), since interference effects depend upon the angle of light, unlike chemical pigments. In captivity, the peafowl has produced many plumage colour variations. Those are mutations that have been secured by selective breeding. They included: white bodied, barred winged, white eyed, pied, cameo, charcoal, bronze, opal, peach, midnight, purple, and any combination of these variations.
© 2004 onwards by Dr Himanshu Tyagi. All the photographs in this blog are copyright protected and can not be reproduced or stored in any medium without the written permission from Dr Himanshu Tyagi.

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