Hummingbirds change colour.....How?

#juan

Hall of Fame Member
Aug 30, 2005
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This year is apparently a good year for hummingbirds. We seem to have dozens. Last night
and again this morning, I watched a hummingbird sit on a fence and change colour., The bird
went from a greeny/brown colour to the most brilliant red I have ever seen. The colour change
involved the bird's head and shoulders, neck, and his back and he could go from the dark green colour
to the bright red in a couple seconds. Any biologists around?