Everyone knows that birds sing, but what about the ones that play instruments? After to listening to half an hour of recordings of the snipe’s winnowing tailfeather sounds the other night, my mind turned to all the other birds I know who produce music with their feathers instead of their voices. The first to come to mind was the Mourning Dove, whose whistling wingbeats I have often welcomed as the first notes of an early morning as they shoot like a volley of arrows over the empty street. The choppy whistling of a startled dove seems to act as a predator warning alarm to other doves, as well as any other birds in the immediate area; cardinals and chickadees that hear recordings of dove wing-whistles are much slower to return to a feeding ground than if surprised in any other way.
The second birds I thought of were the hummingbirds; back in my California days, I would watch Anna’s Hummingbirds performing mating displays over the San Francisco heath, their flared tail feathers vibrating stiffly to produce a distinctive chirp as they divebombed the ground like young show-off stunt pilots.
The third birds I considered were the goddamn grouses. Yes, I grouse about grouses. After all, while most birds simply fly away when they sense something threatening approaching, it is a grouse’s defensive strategy to hide until you almost step on it before exploding into the air like a goddamn land mine, providing the casual hiker with at least a modest helping of severe cardiac arrest.Their wings have a helicopter-like “THUP-THUP-THUP” which ensures maximum surprise by producing maximum ruckus, enough to give any Nam vet a good flashback. But scare tactics aren’t the only use for their percussive wingbeats; males “drum” their wings against the air to create the sound of a slow-starting motorcycle revving up, which drives the lady grouses wild.
Charles Darwin called it “instrumental music,” but less romantically, we now call it “sonation:” sounds made by animals via anything but the syrinx. By this definition, the woodpecker’s drum solo and the cassowary’s unsubtle tap-dancing are considered part of the larger symphony of bird communication and, in fact, an extension of song. But the most extreme examples of bird sonation belong to those bright baubles of a neotropical bird family, the manakins. The golden-crowned manakin can make a series of loud popping sounds with its wings so that it seems to mimic a string of firecrackers going off; indubitably, one of the better attention-getters for young males of any species. Other manakins create whooshing sounds with their wing feathers during mating display dives. But even among the musical manakins, there is one that really excels at instrumentation. It has turned its wings into violins.
The club-winged manakin, as you’ve just seen, can vibrate its specially-shaped wing feathers 100 times a second to produce a high-pitched whine. The males — and only the males — have secondary wing feathers which have a series of ridges which compliment differently shaped feathers on the opposite wings. One is the violin, the other the bow. Since the seven ridges of the violin feather can make fourteen sounds during each shake — once when the bow feather strikes it, and once again when they move past each other — the manakin’s feathers can produce 1,400 individual sounds per second. Even the non-specialized flight feathers on the manakin’s wing play a part; though they do not vibrate when struck, they vibrate sympathetically when the sonating feathers do, both harmonizing with and amplifying the sound.
The effect is the only avian example of stridulation, or sound produced by rubbing body parts together. The most famous example of stridulation is the chirping of crickets, produced by rubbing wings and finely ridged legs together, but it also happens to be the mechanism of violins and their family of bowstring instruments, not to mention vinyl records. When a DJ scratches an album, what you’re hearing is the human equivalent of a cricket’s love song.
My primary question is this: born with a voice, why use an instrument? Unlike woodpeckers, hummingbirds, and grouses, manakins belong to the Passerine, or perching bird, family. It is also known as the songbird family — slightly misleading, as non-passerine birds are capable of singing, and some passerines, like the crow, can’t hold a tune to save their lives, but in the bird world certainly none have more beautiful songs than the passerines. Thrushes, bluebirds, canaries… all of your favorite voices belong to this clan. Passeriformes is a uniquely successful order as well, accounting for half of all bird species. The argument could be made that it’s their perching ability that have made the passerines so successful, but I have a hunch that it’s their songs that have split the passerines into so many diverse sub-orders and classes. Two male wrens with slightly different songs might attract female wrens with different musical tastes. Singing in a different dialect, or improvising a new riff, or even botching a high note might actually win or lose you a mate, which can waterfall into genetic divergence and the origin of an entirely new species. In the high-stakes arena of sexual selection, mere musical preference might divide an entire species in half, thereby setting the stage for adaptive radiation and biodiversity. The birds, in a way, don’t just create the songs; they are created by the songs.
What does this have to do with our fiddling manakins? It would seem that long ago, an ancestor of the manakin developed a unique form of singing that didn’t use his voice. It might have been a simple buzz, or a whinny, created by shivering its wing feathers together during a visual courtship display. However exactly it started, the ladies liked the sound of it. In a tropical paradise full of chattering, whistling, and booming, the airwaves might have become so saturated with birdsong that this new form of communicating stood out starkly against the white noise.
We call it sonation now, but in a way, Darwin’s “instrumental noise” is more apt. Imagine, if you will, an anarchist orchestra in which each musician is trying not to complete a harmonious symphony but rather to become top chair. Playing as loudly as possible only makes the chamber hall an unintelligible din in which no one is heard. So the musicians specialize; some take up piccolos to try to raise their voices above the clamor, some take bassoons. Rather than playing continuously, they vary their musical patterns; some play allegro, some adagio. Some in 2/4 time, some in 4/4. Some take major-key melodies; others, finding that niche filled, are better heard by playing minor-key counterpoint. All around the amphitheatre of the pond at night, the bullfrogs pluck their basses, the green frogs twang their banjos, the woodfrogs quack like oboes, and the spring peepers punctuate the concerto with flutes. Upon waking, the mourning doves sing low, the robins twist a melody from the tops of the trees, and the ravens simply talk. Soon, without any conductor, there is music happening, a wild and accidental symphony — part Beethoven, part Mingus, part Cage. It is an opera about war, greed, lust and power, and every singer believes himself to be the prima donna. And it is a masterpiece.
And eventually, there is no way to stand out but to invent new instruments. Perhaps the saturation of the symphony was what led to the percussion of the woodpecker and cockatoo, the reedy chirp of the hummingbird’s tail, and the violin of the manakin. Bills, feet, and feathers joined the orchestra. The body becomes an instrument. So diversity of sound rounds out what has become a global concert, making the harmony grander and more complete, though the symphony is emergent and unwritten and, thankfully, unfinished.