Common Nighthawk (Chordeiles minor)

Common Nighthawk

[order] CAPRIMULGIFORMES | [family] Caprimulgidae | [latin] Chordeiles minor | [UK] Common Nighthawk | [FR] Engoulevent d’Amerique | [DE] Nachtfalke | [ES] Anapero (Arg, Uy), Anapero Migratorio/Yanqui (Bo), Anapero zumbon (Cr), Pucuyo Comun (HN) | [NL] Amerikaanse Nachtzwaluw

Subspecies

Genus Species subspecies Breeding Range Breeding Range 2 Non Breeding Range
Chordeiles minor NA, MA widespread SA
Chordeiles minor aserriensis se Texas (sc USA), ne Mexico
Chordeiles minor chapmani se USA
Chordeiles minor henryi sw USA, nc Mexico
Chordeiles minor hesperis sw Canada, w USA
Chordeiles minor howelli wc USA
Chordeiles minor minor c and s Canada, c and e USA
Chordeiles minor neotropicalis e and s Mexico
Chordeiles minor panamensis Belize and Honduras to Panama
Chordeiles minor sennetti sc Canada, c and nc USA

Physical charateristics

Common nighthawks are medium-sized birds. They are 22 to 24 cm long and weigh 65 to 98 g. Like other members of the Caprimulgidae, they have large mouths and eyes, and are cryptically colored. They have a notched tail and long, slender, pointed wings with white patches on the primaries. Males have a white tail band near the tip of the tail and a white throat patch. Females do not have a tail band and are more buff-colored on the throat. Both sexes have bold barring on the chest and belly, though light parts tend to be whiter on males and more buff-colored on females.

wingspan min.: cm wingspan max.: cm
size min.: 22 cm size max.: 24 cm
incubation min.: 18 days incubation max.: 20 days
fledging min.: 16 days fledging max.: 20 days
broods: 1   eggs min.: 2  
      eggs max.: 3  

Range

North America, Middle America : widespread

Habitat

Common nighthawks breeding habitats include coastal dunes and beaches, woodland clearings, grasslands, savannas, sagebrush plains, and open forests. They will also use habitat altered by human activity including logged or burned areas of forests, farm fields, and cities.

Common nighthawks choose nest sites on the ground in open areas with some cover from grasses, shrubs, logs, or boulders. They do not build nests. Instead, eggs are laid on a variety of substrates including sand, gravel, leaves, and bare rock. In areas of human habitation, common nighthawks often nest on flat, gravel roofs.

Reproduction

There is little information available about the mating system of common nighthawks. Males court females by displaying on the ground and in flight. They begin by flying 5 to 30 meters into the air and then diving steeply toward the ground, pulling up sharply about 2 meters above the ground. This display is accompanied by a ?booming? noise made by the air rushing through the primary feathers of the male. Males then land near the female, spreading and shaking their tail from side to side, displaying their white throat patch, and making a croaking noise.
Females typically lay 2 eggs, 1 to 2 days apart. The eggs are pale, splotched with gray, brown, and black. The female incubates the eggs, leaving the nest in early evening to feed. Incubation periods vary throughout the breeding range between 18-20 days. After the young hatch, the female continues to leave the nest site to forage in the evening. She feeds regurgitated insects to the young before sunrise in the morning and after sunset in the evening. Nestlings are semiprecocial and able to move in response to the female’s calls within a day of hatching. The young can move to shade or sun to regulate their body temperature. After 16 days, young can hop. At 18 days they make their first flight, and can fly well at about 25-30 days old. By the time they are 30 days old, chicks have left the nest for good. Full development is achieved at 45-50 days, after which young may join migrating flocks. In southern parts of the breeding range, pairs may have a second brood. In this case, the male takes over feeding the young of the first clutch while the female incubates the second clutch. He will also feed the female. The female of a breeding pair incubates the eggs and broods the young chicks. Though the young are able to move themselves only one day after hatching, the female may move them around to take advantage of nearby shade. The parents feed the chicks regurgitated insects until they are able to feed themselves at age 25 days or so. The male defends the nest site by wing-beating and hissing at intruders. The female may also defend the nest site by feigning injury or hissing at an intruder.

Feeding habits

Common nighthawks are crepuscular. They are most active at dawn and dusk, and rarely feed at night. They have been reported to occasionally feed during the day in low light conditions (stormy weather or fog, for example) They use their large mouths to ?hawk? insects in the air. Their large eyes help them find and distinguish among prey items in the dark. Like owls, common nighthawks have a tapetum (a mirror-like structure at the back of each eye that reflects light to the retina) that increases their ability to see in the dark. They fly with erratic, bat-like movements, taking as many as 50 different insect prey species. Studies indicate that the majority of the diet is made up of queen ants (Hymenoptera), beetles (Coleoptera), and true bugs (Homoptera). It also includes moths (Lepidoptera), mayflies (Ephemeroptera), caddisflies (Trichoptera), flies (Diptera), wasps (Hymenoptera), crickets and grasshoppers (Orthoptera) and other insects. In the urban parts of their range, common nighthawks are often seen flying around streetlights or bright yard lights, catching insects that are attracted to the light. Common Nighthawks drink while in flight by skimming the surface of lakes, streams, or water troughs with their bills.

Conservation

This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Common Nighthawks (Chordeiles minor) breed throughout much of North America and parts of Central America. Their winter distribution is less well known, but they are believed to range throughout middle South America in the lowlands east of the Andes.
Common Nighthawk status Least Concern

Migration

Highly migratory, breeding throughout North & Central America and wintering in South America, possibly as far S as N Patagonia. Migrates in loose flocks, large numbers often passing along favoured routes. Nominate race leaves breeding grounds late Jul to early Oct (mainly mid-Aug to early Sept), generally moving S through Central America, although some E populations may use transoceanic routes, as regular and occasionally very common autumn migrant on Bermuda. Winters in South America E of Andes, as far S as N Argentina. In spring, returning birds arrive on breeding grounds late Apr to late May (mainly middle to late May). After breeding season, race sennetti moves S through Colorado, Texas and Oklahoma, then possibly through E side of Central America. Race hesperis moves S through SW USA and Central America, although occasionally recorded E of normal routes. Race henyri moves SE through Central America, and possibly across Gulf of Mexico. Race howelli moves S through CS USA, Mexico and Nicaragua. Race chapmani possibly moves SE and winters from C Brazil to N Argentina. Race neotropicalis leaves breeding grounds in Aug and probably Sept. In spring, returning birds may begin arriving in Jan, though most not until Mar-May. Race aserriensis moves SE through Central America. Movements of race panamensis poorly documented. Vagrants have occurred in autumn in Iceland, Faeroes, Britain (mid-Sept to late Oct), at sea near Azores, and on Tristan da Cunha (late Nov).

Distribution map

Common Nighthawk distribution range map

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