SCIENCE

There’s more to color than meets the eye. (Smithsonian)

Use our lesson plan to introduce students to the science of color.

Teachers, scroll down for a quick list of key resources in our Teachers’ Toolkit.

Is this mountain bluebird a blue bird? Magritte? Photograph by Elaine R. Wilson, courtesy Wikimedia. CC-BY-SA-2.5

Steller’s jays like this one are just one species identified as “blue jays.” But are they really “blue frauds”? Photograph by Alan D. Wilson, courtesy Wikimedia. CC-BY-SA-3.0

This beautiful indigo bunting is a bunting, but is it indigo? Photograph by Gareth Rasberry, courtesy Wikimedia. CC-BY-SA-3.0

Polly want a pigment? Photograph by Hank Gillette, courtesy Wikimedia. CC-BY-SA-3.0

Male purple martins are the only North American swallow with such seemingly deep-blue coloration. Photograph by JJ Cadiz, courtesy Wikimedia. CC-BY-3.0

Peacocks not blue? Poppycock! Photograph by Albinfo, courtesy Wikimedia. Public domain.

Discussion Ideas

• What do you mean, there’s no such thing as a blue bird? Those avian lovelies in the photo gallery look pretty blue to me!
  • Those birds look blue, but they’re not. They’re posers. Frauds. Impersonators. (Impigmentators?)
  • Birds usually get their color from pigments in the foods they eat. That gorgeous pink that gives flamingoes their signature color, for instance, is a result of their shrimp-heavy diet.
  • But blue is different. “Blue pigments, like those in blueberries, are destroyed whey they’re digested. No bird species can make blue from a pigment.”

• OK, so why do blue birds look blue?
  • Blue on bird feathers is a “structural color.” It is created by the 3-D structure of proteins on the birds’ feathers. The structures are called nanochannels and the proteins are called keratins.
    • “When white light strikes a blue feather, the keratin pattern causes red and yellow wavelengths to cancel each other out, while blue wavelengths of light reinforce and amplify one another and reflect back to the beholder’s eye … [D]ifferent shapes and sizes of these air pockets and keratin make different shades of blue.”

• Are there any other examples of nature feeding us blue-faced lies?
  • Oh yes. Structural colors are abundant in nature:
    • butterflies!
    • sea worms!
    • berries!
    • bugs!
    • cephalopods!
    • moles!

• Try adapting the color collage activity developed by one of our educators to display structural coloration vs. pigment coloration in nature. Use this good article from Wikipedia or this one from the Cornell Lab of Ornithology to get you started.

TEACHERS’ TOOLKIT

Smithsonian: When is a Blue Bird Not Blue?

Smithsonian: Why Are Some Feathers Blue?

Nat Geo: Galapagos Islands Through the Lens of Color activity

Cornell Lab of Ornithology: How Birds Make Colorful Feathers

Wikipedia Good Article: Structural Coloration