Scientists have published their explanation for why some large species of bird, like the Lammergeier, have a silvery sheen in their wings.  The scientists, led by Dr. Ismael Galvan of the National Museum of Natural Sciences in Madrid, had suspected that there was a difference in how the feathers were put together rather than a difference in pigment, and, sure enough, major differences in the barbules of the feather were found (barbules grow from the barbs, which grow from the shaft of the feather, the rachis, and barbules link together with each other and pretty much make a feather a feather).  The differences in the barbules are described here.

Written by Corey
Corey is a New Yorker who lived most of his life in upstate New York but has lived in Queens since 2008. He's only been birding since 2005 but has garnered a respectable life list by birding whenever he wasn't working as a union representative or spending time with his family. He lives in Forest Hills with Daisy and Desmond Shearwater. His bird photographs have appeared on the Today Show, in Birding, Living Bird Magazine, Bird Watcher's Digest, and many other fine publications. He is also the author of the American Birding Association Field Guide to the Birds of New York.