Thursday, 19 March 2015

B.O.T.D. Common Nighthawk

Common Nighthawk (Chordeiles minor)


Wonderfully evocative names have been attached to the common nighthawk. Like all members of its family, it is known as a goatsucker, a bizarre term based on European folklore. Because its old world cousin, the nightjar, has a wide, gaping mouth and a fondness for pastures and other open places, the peasants long ago concluded that the mysterious night flyer sucked milk from their animals.

Two popular names for our common nighthawk - pork-and-beans and bull-bat - derive from characteristic sounds it makes. Beans resembles the nasal note the bird repeats emphatically during its jerky-jerky insect-hunting flights. Bull refers to to an odd nonvocal noise. During courtship, the male frequently interrupts his foraging flights with dramatic vertical plunges, swinging back upward just before hitting then ground. As its wings sweep into braking position, air rushing through the feathers produces a kind of sonic boom that has been likened to everything from a bass trumpet note to a whirring spinning wheel. Bull, a shorthand reference to the booming of bullfrogs, is imaginatively suggestive of the sound.