Animal Diversity Web

Ge­o­graphic Range

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. (; Poulin, et al., 1996)

• Biogeographic Regions
• nearctic
  • native
• neotropical
  • native

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.

Lit­tle is known about the mi­gra­tion routes or win­ter habi­tat of com­mon nighthawks. They have been seen mi­grat­ing across wet­lands, farm­land, river val­leys, open wood­lands, and coastal dunes. They are pre­sumed to pre­fer open coun­try in their win­ter­ing sites and have been seen fly­ing over cities and towns. (; Poulin, et al., 1996; Stiles and Skutch, 1989)

• Habitat Regions
• temperate
• tropical
• terrestrial

• Terrestrial Biomes
• desert or dune
• savanna or grassland
• forest
• rainforest
• scrub forest

• Other Habitat Features
• urban
• suburban
• agricultural

• Range elevation

  sea level (low) m

  (low) ft

Phys­i­cal De­scrip­tion

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.

Nine sub­species of com­mon nighthawks have been de­scribed. These are dif­fer­en­ti­ated by light and dark color vari­a­tions in the plumage. Com­mon nighthawks are often con­fused with two very sim­i­lar species of nighthawks: Lesser nighthawks (Chordeiles acu­tipen­nis) and An­til­lean nighthawks (Chordeiles gund­lachii). Lesser nighthawks are slightly smaller than Com­mon Nighthawks, with buffy un­der­tail-coverts in­stead of white, and with the white wing-patch of the pri­maries slightly closer to the wing tip. They also for­age closer to the ground than do com­mon nighthawks. An­til­lean nighthawks are vir­tu­ally in­dis­tin­guish­able from com­mon nighthawks in the field but by call, a nasal kil­likidick with the same tone as com­mon nighthawks’ peent. In the hand, An­til­lean nighthawks’ wing mea­sure­ments are slightly shorter than com­mon nighthawks’. (Ehrlich, 1988; ; Poulin, et al., 1996)

• Other Physical Features
• endothermic
• bilateral symmetry
• polymorphic

• Sexual Dimorphism
• sexes colored or patterned differently

• Range mass

  65 to 98 g

  2.29 to 3.45 oz

• Range length

  22 to 24 cm

  8.66 to 9.45 in

• Average basal metabolic rate

  0.4421 W

  AnAge

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.

• Mating System
• monogamous

Com­mon nighthawk breed­ing phe­nol­ogy varies through­out their range, with more southerly pop­u­la­tions pro­duc­ing young as early as May and northerly pop­u­la­tions as late as Au­gust. Lit­tle is known about pair for­ma­tion or breed­ing ac­tiv­ity. Fe­male com­mon nighthawks have been shown to ar­rive first at their breed­ing grounds and se­lect the nest site. Banded in­di­vid­u­als have re­turned to the same nest sites over mul­ti­ple years. The age at first breed­ing is un­known for this species. Com­mon nighthawks are as­sumed to breed once per year.

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. (; Poulin, et al., 1996)

• Key Reproductive Features
• iteroparous
• seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• oviparous

• Breeding season

  spring and summer

• Range eggs per season

  1 to 2

• Average eggs per season

  2

• Average eggs per season

  2

  AnAge

• Average time to hatching

  18-20 days

• Average time to hatching

  19 days

  AnAge

• Average fledging age

  18 days

• Average time to independence

  30 days

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. (; Poulin, et al., 1996)

• Parental Investment
• precocial
• pre-fertilization
  • provisioning
  • protecting
    • male
    • female
• pre-hatching/birth
  • protecting
    • male
    • female
• pre-weaning/fledging
  • provisioning
    • male
    • female
  • protecting
    • male
    • female

Lifes­pan/Longevity

Com­mon nighthawks are ex­pected to live at least 4 to 5 years. The old­est known wild com­mon nighthawk was 9 years old. (; Poulin, et al., 1996)

• Range lifespan
  Status: wild

  9 (high) years

• Typical lifespan
  Status: wild

  4 to 5 years

• Average lifespan
  Status: wild

  4 to 5 years

Be­hav­ior

Com­mon nighthawks are some of the last mi­gra­tory birds to ar­rive at spring breed­ing grounds and some of the first to leave in fall. This is at­trib­uted to the fact that warm tem­per­a­tures are req­ui­site for fly­ing in­sect ac­tiv­ity in early evening and morn­ing. Also, while some caprimulgids go into tor­por to con­serve en­ergy on cold nights, com­mon nighthawks are not known to do so, thus mak­ing them more sen­si­tive to colder tem­per­a­tures.

Com­mon nighthawks mi­grate some 4,000 to 11,000 km (2,500 to 6,800 miles) – one of the longest mi­gra­tions of any bird in the Amer­i­cas. They mi­grate in flocks, es­pe­cially in the fall, most pass­ing through Mid­dle Amer­ica, but some cross­ing the Gulf of Mex­ico and Caribbean to Florida. They may be seen rid­ing ther­mals at this time, much like mi­grat­ing hawks.

Com­mon nighthawks are highly ter­ri­to­r­ial, soli­tary nesters. Males will de­fend their ter­ri­tory by div­ing at in­trud­ers. The ter­ri­tory size varies be­tween habi­tat types, but ap­pears to range be­tween 41,000 and 280,000 square me­ters.

Com­mon nighthawks are cre­pus­cu­lar. When not at the nest, Com­mon nighthawks will roost, sleep, or sun­bathe on fence posts, tree branches, the ground, or flat rooftops.

Bats and lesser nighthawks have been shown to dis­place com­mon nighthawks from feed­ing sites by chas­ing them away. Lesser nighthawk ag­gres­sion may ex­clude com­mon nighthawks from mu­tu­ally suit­able habi­tats. (El­ph­ick, 1995; ; Poulin, et al., 1996)

• Key Behaviors
• flies
• crepuscular
• motile
• migratory
• solitary
• territorial

• Range territory size

  41000 to 28000 m^2

Com­mu­ni­ca­tion and Per­cep­tion

Com­mon nighthawks use calls and dis­plays to com­mu­ni­cate with one an­other. The vo­cal­iza­tions of com­mon nighthawks are very sim­ple, and have few vari­a­tions. They also use non-vo­cal sounds, such as the boom­ing sound made by the pri­mary feath­ers of males dur­ing a courtship dis­play to com­mu­ni­cate. An ex­am­ple of the phys­i­cal dis­plays used by com­mon nighthawks is the div­ing dis­play given by males to prospec­tive mates. (; Poulin, et al., 1996)

• Communication Channels
• visual
• acoustic

• Perception Channels
• visual
• tactile
• acoustic
• chemical

Food 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. (Brigham and Bar­clay, 1995; Brigham, 1990; Nicol and Arnott, 1974; ; Poulin, et al., 1996; Ter­res, 1980)

• Primary Diet
• carnivore
  • insectivore

• Animal Foods
• insects

Pre­da­tion

Crows and ravens, owls, Amer­i­can kestrels, skunks, snakes, house­cats and canids such as coy­otes, foxes, and do­mes­tic dogs are preda­tors of com­mon nighthawks.

Fe­males and young rely on their cryp­tic brown col­oration to avoid de­tec­tion of the nest site by preda­tors. Males are not known to guard the nest but will de­fend it by div­ing over it and boom­ing with their wings or beat­ing the wings and hiss­ing. Fe­males may feign in­jury to dis­tract preda­tors from the nest. Chicks also spread their wings and hiss at in­trud­ers when threat­ened. (; Poulin, et al., 1996)

• Anti-predator Adaptations
• cryptic

• Known Predators

  • crows and ravens (Corvus)
  • owls (Strigiformes)
  • American kestrels (Falco sparverius)
  • skunks (Mephitinae)
  • snakes (Serpentes)
  • coyotes (Canis latrans)
  • foxes (Vulpes)
  • domestic dogs (Canis lupus familiaris)
  • domestic cats (Felis silvestris)

Ecosys­tem Roles

Com­mon nighthawks help to con­trol pop­u­la­tions of the in­sects that they prey on. They also com­pete with bats and lesser nighthawks Chordeiles acu­tipen­nis for food. (; Poulin, et al., 1996)

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Since com­mon nighthawks are in­sect eaters that fre­quent farm fields and cities, it is likely that they help con­trol pest in­sect species.

• Positive Impacts
• controls pest population

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

Com­mon nighthawks have no known neg­a­tive im­pact on hu­mans.

Con­ser­va­tion Sta­tus

Pop­u­la­tions of com­mon nighthawks are de­clin­ing. This de­crease may be at­trib­uted to a va­ri­ety of human ac­tiv­i­ties. In­dis­crim­i­nate pes­ti­cide use in cities and farm­lands af­fects pop­u­la­tions lo­cally. In urban areas, re­place­ment of gravel roofs with rub­ber roofs has re­duced nest­ing sites for these pop­u­la­tions. In­creased pre­da­tion is also a fac­tor in gen­eral pop­u­la­tion de­cline. Urban nesters are es­pe­cially vul­ner­a­ble to pre­da­tion by house­cats. Com­mon nighthawks are also killed by ve­hi­cles when roost­ing or feed­ing along road­ways. (Poulin, et al., 1996)

• IUCN Red List

  Least Concern
  More information

• IUCN Red List

  Least Concern
  More information

• US Migratory Bird Act

  Protected

• US Federal List

  No special status

• CITES

  No special status

• State of Michigan List

  No special status

Other Com­ments

Per­sonal anec­dote:

Com­mon Nighthawks are known for their loud, nasal “peent” calls made by both sexes, as well as the males’ amaz­ing, boom­ing courtship dives. My hus­band and I were equally freaked-out and cap­ti­vated by their mys­te­ri­ous sounds one sum­mer night in east­ern Ari­zona. We were dri­ving home from Col­orado, and the sun had long-since gone down. Eye­lids heavy, we pulled off onto na­tional for­est land just east of Show Low to camp for the night. We laid our tarp and sleep­ing bags on rough vol­canic grav­els in a sparse ju­niper wood­land. There was no moon. Just as we had fallen asleep, we were awaken by a loud “peent­ing” noise, fol­lowed by a boom­ing, zip­ping “woosh.” It passed right over our heads. A few sec­onds later, the peent came again from a com­pletely dif­fer­ent cor­ner of the sky, fol­lowed by an­other close woosh above our heads. Our first thought was that bored teenagers from Show Low had some­how found our camp­site and were mess­ing with our minds. What WAS that sound?!? Strangely muf­fled gun­shots? UFO’s land­ing? A huge bug-zap­per? It just didn’t sound nat­ural. How could some­thing be in one spot, then abruptly be 200 me­ters away, mak­ing such a mech­a­nized sound? Then, the sound ceased, leav­ing us to won­der its ori­gins. We drifted off to sleep, only to be awoken a while be­fore dawn.

Peent! Woosh! Si­lence. Peent… again from a spot im­pos­si­bly dis­tant from the first call…and woosh above our heads. Dis­be­lief gave way to rea­son as we hun­kered in our bags, com­mis­er­at­ing: “It’s got to be a bird.” “Maybe some kind of night­jar?” Sure enough, as the sun grad­u­ally light­ened the east­ern sky, we began to make out an avian shape. It would flap up on slen­der, pointed wings, hover, give out a loud “peent”, and dive steeply. The me­chan­i­cal woosh and zip­ping noise came with the dive and ceased with the bird’s abrupt re­turn sky­ward. It would peent again a cou­ple hun­dred me­ters from where it began its last dive, then plunge down­ward. Boom-woosh! As the sky light­ened, we saw the flash of white wing-patches on a sec­ond bird – per­haps a fe­male? Then they moved off and were gone. We con­sulted our bird books later and de­cided they must have been com­mon nighthawks. Could they have been court­ing? Were we dis­turb­ing a nest site? We’ll never know. Though no records of night­time div­ing dis­plays exist for this species, we def­i­nitely wit­nessed them late into the night and well be­fore dawn. An un­for­get­table ex­pe­ri­ence!

Con­trib­u­tors

Kari Kirschbaum (ed­i­tor), An­i­mal Di­ver­sity Web.

Robin Kropp (au­thor), Uni­ver­sity of Ari­zona, Jorge Schon­dube (ed­i­tor), Uni­ver­sity of Ari­zona.

Ref­er­ences

Brigham, R. 1990. Prey se­lec­tion by big brown bats (Eptesi­cus fus­cus) and Com­mon Nighthawks (Chordeiles minor). Amer­i­can Mid­land Nat­u­ral­ist, 124: 73-80.

Brigham, R., R. Bar­clay. 1995. Prey se­lec­tion by Com­mon Nighthawks: does vi­sion im­pose a con­straint?. Eco­science, 2(3): 276-279.

Ehrlich, P. 1988. A Birder’s Hand­book: a field guide to the nat­ural his­tory of North Amer­i­can birds. New York: Simon and Schus­ter.

El­ph­ick, J. 1995. Atlas of Bird Mi­gra­tion. Lon­don: Harper-Collins Pub­lish­ers, Ltd.

Nicol, J., H. Arnott. 1974. Tapeta lu­cidum in the eyes of goat­suck­ers (Caprimulgi­dae). Pro­ceed­ings of the Royal Acad­emy of Lon­don, 187: 349-352.

Poulin, R., S. Grindal, R. Brigham. 1996. Com­mon Nighthawk (Chordeiles minor). A Poole, F Gill, eds. The Birds of North Amer­ica, Vol. 213. Philadel­phia, PA and Wash­ing­ton DC: The Acad­emy of Nat­ural Sci­en­tists and The Amer­i­can Or­nithol­o­gists Union.

Stiles, F., A. Skutch. 1989. A Guide to the Birds of Costa Rica. Ithaca: Cor­nell Uni­ver­sity Press.

Ter­res, J. 1980. The Audubon so­ci­ety en­cy­clo­pe­dia of North Amer­i­can birds. New York: Al­fred A. Knopf.