For those interested, there is an interesting article in the February issue of "The Scientist" describing how colors in the natural world are derived from colorless nano-structures. Among other colorful things, they talk about how the physical structure of the feather barbs imparts that brilliant blue to the Easter Bluebird. http://www.the-scientist.com/?articles.view/articleNo/34200/title/Color-from-Structure/ ______________________________________________________________________ Ohio-birds mailing list, a service of the Ohio Ornithological Society. Our thanks to Miami University for hosting this mailing list. Additional discussions can be found in our forums, at www.ohiobirds.org/forum/. You can join or leave the list, or change your options, at: http://listserv.muohio.edu/scripts/wa.exe?LIST=OHIO-BIRDS Send questions or comments about the list to: [log in to unmask]