From the book

“See the nighthawks overhead, gliding sporadically, changing speeds and direction as they pursue flying ants, beetles, and bugs, all the while uttering their signature sound, a raspy, nasal peent . . . More spectacular is the male’s territorial booming. From thirty or more yards in the air, he dives steeply downward, and just before pulling up, sometimes within just a few yards of the ground, he flexes his wings down and forward, the tips of his outstretched flight feathers now meeting the rushing wind head on and vibrating loudly.”

Hear the peenting of this male overhead. Every half minute or so he dives and booms, the sound sometimes “likened to a bellowing bull or a (very) short freight train . . .” He booms loudly in the first second, for example, and throughout this recording other birds can be heard peenting and booming on neighboring territories.