When is a blue bird NOT blue???

Well I found out after some research online that the answer to this question is ALWAYS. There actually is no such thing as a blue bird. Scott Sillett, a wildlife biologist at the Smithsonian Migratory Bird Center states, “Red and yellow feathers get their color from actual pigments, called carotenoids, that are in the foods birds eat,” Sillett explains. “Blue is different…no bird species can make blue from pigments. The color blue that we see on a bird is created by the way light waves interact with the feathers and their arrangement of protein molecules, called keratin. In other words, blue is a structural color. Different keratin structures reflect light in subtly different ways to produce different shades of what our eyes perceive as the color blue. A blue feather under ultraviolet light might look uniformly gray to human eyes.” I had no idea! I was convinced that the bluebird building the nest in my camera nest box was a male because it was just SO blue. Then the “real male” came in and he was even bluer yet, almost royal blue. So the light in the camera nest box was reflecting very strongly I see now. And incidentally, at night when the female bluebird sits on her three eggs, the image is actually in black and white because of the lack of reflected light. Mystery solved!