The eastern whip-poor-will’s haunting, insistent repetition of its name has been iconic of spring and summer nights in the U.S. and the subject of literature and song since colonial times. Naturalist John Burroughs once heard a whip-poor-will make 1,088 vocal repetitions before pausing, according to the National Audubon Society (birds.audubon.org).
To find out more about whip-poor-wills, I dug out my copy of “Life Histories of North American Cuckoos, Goatsuckers, and Hummingbirds and Their Allies,” a Dover collection of papers from the “Smithsonian Institution United States National Museum Bulletin.” It includes one from 1940 on whip-poor-wills by Winsor Marrett Tyler, a fellow of the American Ornithologists’ Union, that has richly detailed observations dating back to colonial times (also available online at birdsbybent.netfirms.com – search on the site for “whippoorwill”).
The eastern whip-poor-will (Caprimulgus vociferus) likes open forest or forest bordering on open land, where it can hunt at night and easily retreat to cover to sleep and raise its young. It is an odd-shaped bird, heavy in the chest with a flat, rounded head and wide mouth.
“The head seems to be all mouth,” noted American ornithologist Charles Emil Bendire in 1895. These birds are built to hunt at night, flying fast through the forest or over fields, scooping bugs out of the air or diving down on them from above. Tyler and a colleague observed one hunting one night:
“At times it increased its speed and executed the most intricate maneuvers, appearing and disappearing among the branches, ever changing its direction, either sailing or flapping its wings, swerving sharply from side to side, heeling over till one wing pointed nearly to the zenith and the other to the earth, then snapping back to an even keel. It shot straight upward, dived head downward and doubled back, tumbling in the air . . . Although there was the appearance of a lack of caution in these mad dashes among the network of branches, we were convinced, as we watched, that the bird governed its movements with perfect precision, with the acme of coordination.”
John J. Audubon’s first drawing of a bird in flight, in 1812, was of a whip-poor-will. (See in the Harvard Library collection, oasis.lib.harvard.edu.)
The whip-poor-will belongs to the Caprimulgidae, or “goatsucker,” order of birds, which comprises 70 species around the world. The name came from the misplaced notion that these birds suck the milk from goats at night. Goatsuckers – or nightjars, as they are more elegantly called – do hunt at night, but for insects, not livestock.
Whip-poor-wills mostly go after large insects, including moths, crickets and grasshoppers, but also eat mosquitoes. Tyler recounts a story of an observer of the bird waking up in the woods to a whip-poor-will picking mosquitoes off and around the netting he was using for protection against the insects.
Along with its large mouth, the eastern whip-poor-will has large eyes and forward-facing “whiskers” (rictal bristles) around its mouth to help in its hunting. While this bird may locate insects by seeing their silhouettes against the sky, its eyes also have a reflective structure behind the retina that is probably an adaptation to low light conditions, according to AllAboutBirds.org. Theories vary as to the purpose of the bristles, from sensing prey to funneling prey into the bird’s mouth and protecting its eyes from large insects.
The eastern whip-poor-will is 9 to 10 inches long. Other local nightjars are the common nighthawk (Chordeiles minor), which is smaller and hunts at dusk rather than night, and the chuck-willow’s-widow (Caprimulgus carolinensis), which is larger and has a call that sounds like its name. (AllAboutBirds.org has recordings of all three species.)
Whip-poor-wills spend their winters as far south as Central America, arriving here around April to breed. Bendire’s description of their courtship ritual, which has rarely been observed, “is the best in the literature,” writes Tyler. Here’s part of it:
“Their entire love-making looked exceedingly human, and the female acted as timid and bashful as many young maidens would when receiving the first declarations of their would-be lovers, while the lowering of her head might easily be interpreted as being done to hide her blushes. Just about the time I thought this courtship would reach its climax, a dog ran out of the house and caused both to take flight.”
“Ornithologists still deplore the regrettable incident that interrupted the observation,” Tyler dryly comments.
Mated female whip-poor-wills usually lay two eggs in April or May on bare ground. According to AllAboutBirds.org, the laying is timed so that the young will hatch out during a full moon, when the bright nights make it easier for the adults to hunt for food for the hatchlings.
Whip-poor-wills’ defense against predators is camouflage, with the eggs, chicks and adults being a mottled mix of brown to black coloring. If the nest is disturbed, the chicks tend to bounce out of it, often kicked out by the mom as she flees. They run briefly in opposite directions, then go still, blending into the litter on the forest floor. Adults often perch lengthwise on branches to lower their profile.
As a kid growing up in the suburbs of Fairfax, I went to sleep at night hearing the whip-poor-will’s call in the woods bordering our backyard. Those woods have gone to development – and the whip-poor-wills with it. They are now on the decline in parts of their range, mostly from habitat loss. The 2005 Virginia Wildlife Action Plan lists the eastern whip-poor-will among the commonwealth’s “species of greatest conservation concern.”
At my last house, in Castleton, I regularly had the pleasure of hearing not just one but two whip-poor-wills doing a call-and-answer from about a mile apart. I haven’t heard one since I moved to my current house, but I keep listening.