The Multiple Miracles of Bird Feathers
Other animals fly, make nests, chirp, lay eggs, and do all sorts of things birds do. But only birds have feathers, among the most magical creations in all of nature.
The flight computer attached to Frightful's tail coverts has revealed some amazing statistics. She once dove after a lure dropped from 3,000 feet, accelerating to 157 miles per hour before neatly catching it and pulling up from her stoop a mere 57 feet above the ground. The gravitational force on her body in that moment has been calculated as high as 27 Gs. Fighter pilots typically lose consciousness at anything over nine.
Before passing out completely, pilots often report a loss of color vision--something unthinkable for a bird. Birds live in a world of vivid color, where the brilliance of their plumes can signal everything from gender and maturity to their prospects as a spouse. Traces of feather color have been found on the earliest known feather fossils, suggesting that the evolutionary impulse to adorn and impress has been around for a long, long time.
For many male birds, their semi-annual molt provides the opportunity for adornment, the chance to don a set of elaborate breeding plumes they will later lose in favor of more cryptic colors to pass the off-season. But even the drabbest birds must molt, growing new feathers to replace those worn thin or damaged by parasites and constant use. It can be a precarious time: Growing new feathers takes a huge investment of energy. For those who raise their own chickens, it's a hard reality: Common barnyard hens molt once a year, a frustrating period when chicken owners find themselves feeding their flock every day, yet buying eggs at the grocery store. The birds can't help it--in the ordered priorities of survival, maintaining one's feathers takes clear precedence over reproduction.
Molting also results in the happy occurrence of discarded plumes, offering a fleeting reminder of the countless ways in which birds and their plumage touch our everyday lives. My wife remembers her grandmother saying, "You're never more than three feet from a spider." Even the best-kept home hosts scores of them, tucked into dark nooks and corners or hiding behind the walls. Well, you're never far from feathers, either. If they're not stuffing your pillows and parkas, they're covering every bird in every forest, field, backyard, suburb, and cityscape. You'll find feathers and their influence in fashion magazines, airplane wings, fishing lures, ballpoint pens, and fine art, but above all, in the birds--those commonest of creatures so casually adorned with miracles.
Adapted from Feathers: The Evolution of a Natural Miracle (Basic Books, 2011)