“Pick up a feather and run it between your fingers. It feels light and soft, yet sturdy, the hollow quill tapering upward to a graceful vane. Whether it slipped loose from a gull's wing or escaped a down pillow, the design is unmistakable. We know immediately that it came from a bird – nothing else is so uniquely avian. Birds fly, but so do bats and mosquitoes. Birds lay eggs, but so do fish, newts, and crocodiles. Gorillas make nests, cats and crickets chirp, and squid have beaks. Of all the conspicuous traits and behaviors that make a bird a bird, only feathers are theirs alone.”
Thus begins a most fascinating book that both your writers read recently. Titled Feathers: The Evolution of a Natural Miracle, it's written by conservation biologist Thor Hanson and reveals the amazing story of an object that is at once familiar yet completely mysterious, a story that has not, until now, been fully told.
“If you've ever flown in a window seat, you may have admired the silvery shine of an airplane wing and watched its several flaps raise and lower at different times during the flight. It's a precise and beautifully designed instrument, but must look terribly crude to a bird, whose own wings can flap and flex, extend and contract, spread, narrow, tuck, and twist, responding instantly to ever-changing conditions. Taken together, the overlapping flight feathers create a single dynamic airfoil. But they can also move independently and are themselves shaped like airfoils, acting as individual winglets within the greater whole. Vultures, eagles, and other soaring birds use small adjustments of their spread wing-tip 'fingers' to manipulate air currents or change speed and orientation, and all birds utilize feather movements to instinctively alter the turbulence patterns around their wings. Slots can be opened or closed to direct air between primaries; covert feathers can be raised or lowered like tiny flags – the possibilities are endless.”
Feathers is an incredible work about what may seem to many to be very commonplace articles. But feathers are an evolutionary marvel, at the root of the enduring debate about whether birds are dinosaurs. Hanson points out that feathers have been used to fly, protect, attract, and adorn, through time and place. It's an amazing subject and a wonderful book – be sure to read all about it!
Copyright © 2012, S. Halversen.
All Rights Reserved.