Birds
Common Nighthawk
Chordeiles minor · also called common nighthawks
At dusk, a common nighthawk pulls sharply out of a steep dive, and a deep, booming sound rolls across the open field below, produced entirely by air rushing through the bird’s wing feathers rather than by any call from its throat.
Overview
The common nighthawk, Chordeiles minor, is a long-winged, nocturnal bird native to open grassland, forest clearings, and urban areas with flat gravel rooftops across a broad range of North America, wintering in South America. Its remarkable wing-produced courtship boom, habit of nesting on bare ground or gravel rooftops, and long-distance migration make it one of the more acoustically and behaviourally distinctive aerial insectivores found across the continent.
A sound made by wings, not a voice
The common nighthawk’s signature booming display sound comes entirely from air rushing through its wing feathers during a steep dive, a purely mechanical sound with no vocal cords involved at all.
Status
Least Concern, though declining significantly in parts of its range due to lost ground-nesting habitat, changing rooftop materials, and declining flying insect abundance.
Common Nighthawk: common questions
How does the common nighthawk make its booming sound?
A male of this species produces this deep, booming sound not with his voice but with his wings, caused by air rushing rapidly through the primary feathers as he pulls sharply out of a steep courtship display dive, a mechanical sound rather than a vocalisation, similar in concept to how some other birds use modified feathers to produce sound.
Why do common nighthawks nest on gravel rooftops?
This species lays its eggs directly on bare ground or gravel rather than building any nest structure, and flat gravel rooftops in urban areas closely resemble the open, sparsely vegetated ground the species naturally prefers, making them an attractive substitute nesting habitat, though modern roofing materials that lack loose gravel have reduced this option in many cities.
Why has the common nighthawk declined?
This species has declined significantly in parts of its range due to the loss of open ground nesting habitat and the replacement of flat gravel rooftops with roofing materials unsuitable for nesting, combined with a broader decline in the flying insect populations the species depends on for food.
Is the common nighthawk an owl?
No, despite its nocturnal habits and the word "hawk" in its name, this species is not related to owls or true hawks at all, instead belonging to the nightjar family, a group of birds specialised for catching flying insects at dusk and night using a wide mouth rather than talons.