Today National Public Radio aired a story about how difficult it is for
organisms to make blue pigment. As it turns out, the vast majority of
"blue" animals you may encounter are actually taking advantage of the
prism effect, rather than having blue feathers, scales, and skin. A Steller's
jay's blue feathers, when backlit, actually look black. The barbs of the
feather are able to absorb every color except blue, which gets scattered back
to the viewer. This is known as a "structural color." As it turns out, very few birds actually have the
physiology to make blue pigments.
Click
here for that story.
This got us thinking about all of the blue animals we encounter on Tejon
Ranch- from western fence lizards (
Scleporus occidentalis) to blue
butterflies, to birds. In the wintertime, there are at least five species of
birds that exhibit blue plumage by reflecting only the blue portion of the
spectrum:
Mountain bluebird (Sialia currucoides)
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Photo by Elaine R. Wilson, accessed from Wikimedia Commons http://commons.wikimedia.org/wiki/File:Mountain_Bluebird.jpg |
Western bluebird (Sialia mexicana)
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Photo courtesy of Greg Smith, accessed from his Flickr account: https://www.flickr.com/photos/slobirdr/8304331232/in/set-72157603539054704 |
Western scrub-jay (Aphelocoma californica)
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Photo courtesy of Chuck Noble |
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Note how different angles of light change the quality of the blue. Photo courtesy of Chuck Noble. |
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Photo by Ingrid Taylar. Accessed from Wikimedia Commons: http://commons.wikimedia.org/wiki/File:Western_Scrub_Jay.jpg |
Steller's jay (Cyanocitta stelleri)
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Photo courtesy of Chuck Noble |
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Photo by Outriggr on Wikimedia Commons: http://commons.wikimedia.org/wiki/File:Steller%27s_Jay.jpg
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Pinyon jay (Gymnorhinus cyanocephalus)- Rare winter visitor based on pinyon pine production
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Photo by US Fish and Wildlife Service. Accessed through Wikimedia Commons: http://commons.wikimedia.org/wiki/File:Gymnorhinus_cyanocephalus1.jpg |
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Photo courtesy of Chuck Noble |
Blue Grosbeak (Passerina caerulea)- Not a winter bird, but striking nonetheless
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Photo courtesy of Chuck Noble |
If you're interested in learning more about bird feathers and structural colors in nature, consider following some of these links: