Common Nighthawks nest in both rural and urban habitats including coastal sand dunes and beaches, logged forest, recently burned forest, woodland clearings, prairies, plains, sagebrush, grasslands, open forests, and rock outcrops. They also nest on flat gravel rooftops, though less often as gravel roofs are being replaced by smooth, rubberized roofs that provide an unsuitable surface. During migration, Common Nighthawks stop in farmlands, river valleys, marshes, coastal dunes, and open woodlands. Their South American wintering habitat is not well known.Back to top
Common Nighthawks eat flying insects almost exclusively. The Common Nighthawk hunts on the wing at dawn and dusk, opening its tiny beak to reveal a cavernous mouth well suited for snapping up flying insects. It often takes advantage of clouds of insects attracted to streetlamps, stadium lights, and other bright lights. Nighthawks eat queen ants, wasps, beetles, caddisflies, moths, bugs, mayflies, flies, crickets, grasshoppers, and other insects. They may also eat a small amount of vegetation. Though they forage in low light, they seem to locate prey by sight, possibly with the help of a structure in their eyes that reflects light back to the retina to improve their night vision. They occasionally forage during the day in stormy weather, but seem to never forage at night. Common Nighthawks may forage near the ground or water, or more than 500 feet into the sky.Back to top
The female probably selects the nest site, usually on unsheltered ground, gravel beaches, rocky outcrops, and open forest floors. Nests are typically out in the open, but may also be near logs, boulders, grass clumps, shrubs, or debris. In cities, Common Nighthawks nest on flat gravel roofs.
Common Nighthawks lay eggs directly on the ground, which may consist of gravel, sand, bare rock, wood chips, leaves, needles, slag, tar paper, cinders, or living vegetation, such as moss, dandelion rosettes, and lichens.
|Clutch Size:||2 eggs|
|Number of Broods:||1-2 broods|
|Egg Length:||1.2 in (3 cm)|
|Egg Width:||0.8 in (2.1 cm)|
|Incubation Period:||16-20 days|
|Nestling Period:||17-18 days|
|Egg Description:||Creamy white to pale olive gray, heavily speckled with gray, brown, and black.|
|Condition at Hatching:||Active and sparsely covered with down (dark gray above and creamy below), with eyes half or fully open.|
Common Nighthawks are most active from half an hour before sunset until an hour after sunset, and again starting an hour before sunrise (ending about 15 minutes after the sun comes up). They fly with looping, batlike bouts of continuous flapping and sporadic glides. Common Nighthawks are usually solitary, but they form large flocks during migration and males sometimes roost together. Large migrating flocks are most conspicuous in early evening, particularly as the birds gather above billboards and other bright lights to feed on insects. During the breeding season they are generally very territorial but in some areas may have overlapping territories. Males court females by diving through the air, making a booming sound as air rushes over their wings. The male eventually lands on the ground before the female, spreading and waggling his tail, and puffing out his throat to display his white throat patch, while croaking at her. Females incubate the eggs and young, leaving them unattended in the evening to feed. Both males and females feed regurgitated insects to their chicks. Parents perform diversion displays to draw intruders away from the nest. Common Nighthawks may be chased from feeding and breeding areas by smaller, more maneuverable bats and Lesser Nighthawks.Back to top
In the U.S., Common Nighthawk populations declined by almost 2% per year between 1966 and 2014, amounting to a cumulative decline of 61%, according to the North American Breeding Bird Survey. Canadian populations experienced declines of over 4% and recent data suggest the species’ numbers may have dropped more than half in Canada since the mid-1960s. Hard numbers are difficult to come by because the Common Nighthawk's cryptic colors and nearly nocturnal habits make them difficult to count during standardized surveys. Partners in Flight estimates the global breeding population at 16 million, with 88% breeding in the U.S., 5% in Canada, and 4% spending some part of the year in Mexico. The 2014 State of the Birds Report lists Common Nighthawk as a Common Bird in Steep Decline, and the species rates an 11 out of 20 on the Partners in Flight Continental Concern Score. Across North America, threats include reduction in mosquitoes and other aerial insects due to pesticides, and habitat loss including open woods in rural areas and flat gravel rooftops in urban ones. Nighthawks are also vulnerable to being hit by cars as they forage over roads or roost on roadways at night. People have had some success creating nesting habitat by placing gravel pads in the corners of rubberized roofs and by burning and clearing patches of forest to create open nesting sites.Back to top
Brigham, R. Mark, Janet Ng, Ray G. Poulin and S. D. Grindal. (2011). Common Nighthawk (Chordeiles minor), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.
Lutmerding, J. A. and A. S. Love. Longevity records of North American birds. Version 2015.2. Patuxent Wildlife Research Center, Bird Banding Laboratory 2015.
North American Bird Conservation Initiative. (2014). The State of the Birds 2014 Report. US Department of Interior, Washington, DC, USA.
Partners in Flight (2017). Avian Conservation Assessment Database. 2017.
Sauer, J. R., J. E. Hines, J. E. Fallon, K. L. Pardieck, Jr. Ziolkowski, D. J. and W. A. Link. The North American Breeding Bird Survey, results and analysis 1966-2013 (Version 1.30.15). USGS Patuxtent Wildlife Research Center (2014b). Available from http://www.mbr-pwrc.usgs.gov/bbs/.
Sibley, D. A. (2014). The Sibley Guide to Birds, second edition. Alfred A. Knopf, New York, USA.