The Eastern Whippoorwill (Antrostomus vociferus) is a medium-sized, strictly nocturnal bird of the Nightjar family, often heard but rarely seen due to its highly camouflaged plumage. This species is an icon of North American summer nights, known almost exclusively for its distinct vocalizations that echo through open woodlands. The song is loud and unique, securing the bird a permanent place in local folklore and literature. Listeners are most likely to encounter this characteristic sound during warm months when the bird is actively establishing territories and mating.
The Signature Song
The Whippoorwill’s song is a loud, three-syllable phrase that sounds remarkably like its own name, “Whip-poor-will,” which is the source of its onomatopoeic designation. The song has a rhythmic cadence, lacking a clear starting or ending note, which contributes to its chant-like quality when heard in the dark. The entire phrase is delivered with a brief pause before the first syllable. The middle syllable sometimes contains a subtle, split sound, making the phrase slightly more complex than a simple three-note repetition.
The volume of the call is substantial, allowing the sound to carry over long distances through the stillness of the night air. The most striking feature of the song is its rapid repetition, which can be sustained for long periods without a break. One documented observation recorded a single bird repeating the call 1,088 times without pausing.
The tone of the song is often described as insistent and slightly high-pitched, sometimes conveying an eerie or haunting quality. While the three main syllables are prominent, a listener close to a singing bird may detect a subtle, gulp-like “cluck” sound just preceding the main phrase.
Context and Timing of Vocalization
The vocal activity of the male Whippoorwill is almost entirely restricted to the hours between sunset and sunrise, reflecting the bird’s nocturnal lifestyle. The most concentrated periods of singing occur during the crepuscular hours, immediately following dusk and just before the onset of dawn. This timing relates to the bird’s foraging activity, as it is an aerial insectivore that catches flying insects mid-air during periods of low light.
Singing intensity is significantly influenced by the lunar cycle. Whippoorwills sing most actively and frequently during periods of brighter moonlight, particularly near the full moon. This heightened activity is believed to be directly linked to increased foraging success, as the additional light improves visibility for catching insects.
The male bird’s persistent vocalization serves a dual purpose: territorial defense, warning other males away from established boundaries, and attracting a mate. This distinctive call is only heard during the breeding season, which spans from late spring through the summer months. The birds remain largely silent during migration or while on their wintering grounds.
Distinguishing the Call from Similar Night Sounds
The Eastern Whippoorwill’s call is sometimes confused with the vocalizations of its close relative, the Chuck-will’s-widow (Antrostomus carolinensis), especially where their geographic ranges overlap. The primary distinction is the number of syllables: the Whippoorwill has a clear three-syllable call, while the Chuck-will’s-widow delivers a four-syllable phrase that sounds like “Chuck-will’s-widow.” Additionally, the Chuck-will’s-widow’s call is lower in pitch and slower in tempo, lacking the Whippoorwill’s rapid, insistent rhythm.
The Whippoorwill’s repetitive chant stands out against the nocturnal soundscape dominated by other creatures. Unlike the sustained trills or buzzing of insects, the Whippoorwill’s song is a consistently structured, rhythmic phrase. It also contrasts sharply with the deep hooting or screeches of various owl species, which are less repetitive and more variable in their cadence. Listeners can use the consistent three-syllable rhythm and the speed of the call to differentiate it from the complex chorus of night sounds.