At first glance the male Anna’s Hummingbird (Calypte anna) is solidly green. Then with a twist of his head he reveals a flash of shiny red brilliance. This color show is made possible by the way the feather microstructure reflects light differently as the viewing angle changes. During his spectacular aerial courtship displays, he advertises this red badge to female spectators by orienting toward the sun. This colorful element of surprise is key to his mating success.

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