SINGING WINGS

The sparkle of a bird's song often outshines its other audio signatures, the gentle whistle of an overhead V of ducks, each bird contributing a position cue to every other member of the flock, or the huffing wingbeat of the oropendola and hornbill, heavy tropical air whining through ventages where degenerate wing coverts fail to seal the gaps between primary shafts: signals to other members of their forest species. The male oropendola embellishes his courtship song with percussive wing flapping, as do many others: the geology hammer-clacks of New Guinea's birds of paradise, the firecracker in a bug-zapper snaps of the neotropical manakins, and of course the accelerando floor tom of the Ruffed Grouse (Bonasa umbella).
It's those noisy wings of the grouse and his kin that posed a conundrum for me as a young falconer. There is nothing more attractive to a bird of prey than that explosive whir. At first blush it seems silly for a bird to carry the sound of a dinner bell, but there are benefits that balance out being the object of a hawk’s lust. The really noisy galliform birds like quail and grouse crouch low and freeze in cover when threatened. There they are only vulnerable to raptors with human assistants. When flushed, that explosive wingbeat startles most terrestrial predators enough to stop them in their tracks for a moment; it often leaves this mammal clutching his chest like Fred Sanford. I once flushed a turkey-sized Great Curassow (Crax rubra) from her nest at close range, an experience as close to stepping on a landmine as I care to get.

All of these birds have precocial young that leave the nest and follow their mother within hours of hatching. A flashy takeoff is useful in distracting trouble away from vulnerable chicks. I’ve seen several grouse species engage in “broken-wing” acts, and those noisy wings add much to the effect. Many pigeon species will do the same thing to lure a threat away from their nest, laying upon the ground like an invalid, while revving that peculiar whistling, wing-clapping takeoff. A number of nightjars and owls use similar devices. I've watched Common Poorwills (Phalaenoptilus nuttallii) and Madagascan Nightjars (Caprimulgus madagascariensis) try to lure me from their nests with broken-wing displays augmented by wing-clapping. Protective males of the former species have flown about my head, clapping their wings. It's likely that these birds use such “applause” in courtship displays, as well. I've seen their distant cousins, the Long-eared Owls (Asio otus), wing clap during nuptial flights, as well as in distraction and intimidation displays around the nest.
The nuptial regalia of several African and South American nightjar species feature extremely long tail or wing feathers. So far I haven't lucked into seeing their displays, but when imagining them, I hear the long shafts make lascivious ruffling sounds appropriate for the occasion.
The spectacular courtship of the Common Nighthawk (Chordeiles minor) can be heard through much of the United States. The hen perches on the ground while the male circles overhead, calling to her and making long, periodic stoops at the Earth. Each time he pulls out of a dive, his wings emit a howl that can be heard from a mile away. It's a sound I've heard scores of times, but expend great effort each year to re-experience. The similar sound of a falcon coming out of a stoop at close range is one of the many lures that keeps falconers engaged in that sport, often against their better judgment.

The flight of many swifts is almost a perpetual, transverse stoop, and the primaries of the faster species buzz like an arrow's fletching. Few experiences are as exhilarating as perching high on the side of a cliff, with dozens of swifts rushing by within inches, rendering a harmony something like the last sound heard by George Armstrong Custer*.
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upper: MONTEZUMA OROPENDOLA DISPLAYING(1993) acrylic 20" x 15"
second: GREAT HELMETED HORNBILL (1998) acrylic 30" X 19"
third: PENNANT-WINGED NIGHTJAR (1998) ink wash 23" x 17"
fourth: TWO STORIES--COMMON NIGHTHAWK (1994) acrylic 22" x 30"
lower: WHITE-THROATED SWIFTS (1993) (detail) acrylic 22" X 30"
*Yeah, I know...Custer was killed by bullets, not arrows.