Last week, while driving my local backroads admiring the spring landscape, I caught a flash of brilliant turquoise that made me stomp on the brakes. About 30 yards out in a greening pasture, a male Lazuli Bunting lit on a stem, blue and gleaming as a semi-precious gemstone.
The sight of that small blue songbird brought a moment of transcendence; the complete bliss, delight, and peace one feels when seeing a lake sparkling in the morning sun, or a field of blooming lupines, or the clear sky itself. Blue birds can have that effect — they’re both dazzling and restful to the eye and soul.
Blue birds are relatively rare in North America, with only about 2% of species being predominantly blue in color. So when we spot a bird decked out in shades of lapis lazuli, indigo, turquoise, sapphire, or azurite, we really SEE it.
So it may come as a bit of a surprise that there is actually no such thing as a “blue” bird. Unlike many other bird colors, blue is not a pigment but is instead a color produced by the structure of feathers. The blue is created by the way light waves interact with the arrangement of keratin molecules in feathers. Feathers contain an intricate matrix of tiny air pockets and interlocking barbules that scatter and amplify blue light outward while absorbing other wavelengths. Different shapes and sizes of air pockets and keratin structures result in different shades of what our eyes perceive as the color blue. It’s all a trick of the light.
You can see for yourself how “structural color” works in different lighting conditions. In the shade or back-lit, a Blue Jay’s feather (or feather of your choice of blue-colored bird) will appear gray or brown because the gray-brown color of melanin pigments is visible. When light falls directly on the feather and is reflected to your eye, the feather will appear blue.
Another type of structural color in birds is iridescence, with perhaps the best known example being the gorget (throat feathers) of many hummingbird species. Iridescent colors are the result of the refraction of light caused by the protein structure of the feather barbules. The refraction splits the light into rich, component colors like a prism. As viewing angles change, refracted light becomes visible in a shimmering iridescent display. Although most “blue” birds have non-iridescent structural color in their feathers, a few blue species exhibit iridescent colors, including the Purple Gallinule, Tricolored Heron, and Tree Swallow.
I’ve gathered photos — some mine, some public domain — of many of our “blue” birds of North America. By no means is this an exhaustive list, but it does hit most of the bird families with blue members. Enjoy and take inspiration in their diverse expressions of blueness. After all, we here at Daily Kos have a real affinity to the color blue!
What is your favorite “blue” bird?
Which “blue” birds are found in your neck of the woods?
Is there a “blue” bird on your bucket list?
Grab a perch and share your birdy observations, photos, and musings!