Science in School: Fancy Feathers: Crazy Pretty!


Aarna Pal-Yadav

Throughout India, peacocks run wild. There are dozens of stories that try to explain the existence of these vibrant birds, but my favorite has to do with disease: when the Hindu Lord Indra, King of the Heavens, was cursed with a thousand ulcers, he transferred his illness into a blessing, giving a plain bird a thousand divine eyes across its tail feathers. And so, the first peacock was born. Besides the legends, truely, why do some birds have such pretty feathers?

In Fancy Feathers: the Basics, we discussed the basic types and structure of feathers as well as their purpose. As a recap, the main types of feathers are wing feathers for flight, tail feathers for steering, contour feathers, semiplume feathers, and downy feathers for insulation. All feathers have a rachis, the stiff central staff, with the hollow calmus base; barbs are the main branches off the rachis and barbules are the secondary branches off the barbs. The pennaceous region is smooth, while the plumaceous region is more fluffy. Birds use their feathers for flight, insulation, waterproofing, camouflage, or even display—in this article, we’ll further discuss how birds use their feathers to create crazy pretty displays.

If you think about it, having brightly-colored feathers isn’t the best idea: most birds are prey—to angry jungle cats or larger birds—so wearing the most vibrant of feathers. . . not the best idea. Predators can more easily identify birds with brightly-colored feathers as prey from further distances, and camouflage isn’t an option for these guys. So why would evolution lead to so many crazy-colored birds?

Although vibrant birds have a lower average survival time, they are more likely to find a mate and spread their genes to the next generation. Remember, the goal of natural life is to spread one’s genes to the next generation and there are two main ways to improve your chances of succeeding: live a long time or mate more often. The idea of “survival of the fittest” follows the process of natural selection, in which birds that have longer lives are able to pass on their genes and those genes become more prominent in each successive generation. The idea of “survival of the prettiest” follows the process of sexual selection, however, in which prettier birds are able to mate more often and spread their genes more that way. So, birds with crazy feathers are the result of generations of sexual selection as they evolved to be prettier and mate more, rather than live longer lives.

If you are interested in learning more about crazy pretty birds, I recommend the Netflix documentary Dancing With the Birds. It is absolutely beautiful to see the various Birds of Paradise in their habitat of the mountainous forest of New Guinea and the narrator excellently explains the lives of these birds. While the birds you’ll see in this documentary are undeniably pretty, there are so many other beautiful birds in your everyday life—including Cardinals, Eastern Bluebirds, and more—so go outside and look!