Magpie Feather Coloration

April 29, 2020



Photography: George Seielstad 
Summary Authors: George Seielstad; Jim Foster

One's first view of a magpie is that of a black-and-white bird (a member of the crow family). But when a magpie feather lay on a trail I frequently walk, and the angle between the Sun and the feather with my eyeline was just right, I observed a multi-colored rainbow. The photo at bottom shows a closeup. These iridescent colors are caused by the diffraction of sunlight by the barbules at the tips of the bird's feather, which contain tiny platelets. The platelets interfere with the light rays to produce the metallic coloration. Because these platelets are likely all close in size, the colors that result are particularly bright. Photos taken on April 15, 2019, from Arlee, Montana.