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.
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!
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.
Communication Channels: visual ; acoustic
Perception Channels: visual ; tactile ; acoustic ; chemical
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.
US Migratory Bird Act: protected
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
IUCN Red List of Threatened Species: least concern
Common nighthawks have no known negative impact on humans.
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
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.
Animal Foods: insects
Primary Diet: carnivore (Insectivore )
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.
Biogeographic Regions: nearctic (Native ); neotropical (Native )
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.
Range elevation: sea level (low) m.
Habitat Regions: temperate ; tropical ; terrestrial
Terrestrial Biomes: desert or dune ; savanna or grassland ; forest ; rainforest ; scrub forest
Other Habitat Features: urban ; suburban ; agricultural
Common nighthawks are expected to live at least 4 to 5 years. The oldest known wild common nighthawk was 9 years old.
Range lifespan
Status: wild: 9 (high) years.
Typical lifespan
Status: wild: 4 to 5 years.
Average lifespan
Status: wild: 4 to 5 years.
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’.
Range mass: 65 to 98 g.
Range length: 22 to 24 cm.
Other Physical Features: endothermic ; bilateral symmetry ; polymorphic
Sexual Dimorphism: sexes colored or patterned differently
Average basal metabolic rate: 0.4421 W.
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.
Known Predators:
Anti-predator Adaptations: cryptic
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.
Breeding season: spring and summer
Range eggs per season: 1 to 2.
Average eggs per season: 2.
Average time to hatching: 18-20 days.
Average fledging age: 18 days.
Average time to independence: 30 days.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous
Average time to hatching: 19 days.
Average eggs per season: 2.
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.
Parental Investment: precocial ; pre-fertilization (Provisioning, Protecting: Male, Female); pre-hatching/birth (Protecting: Male, Female); pre-weaning/fledging (Provisioning: Male, Female, Protecting: Male, Female)
Son nocturnos.
Distribucion General: Se reproduce desde el norte de Canadá hasta el este de Panamá. Invierna por todo América del Sur hasta el norte de Argentina.
Chordeiles minor, tamién conocíu como añapero yanqui[1] o añapero boreal, ye un ave Caprimulxiforme de la familia Caprimulgidae mesma d'América.
El nome científicu d'esta especie, minor ("menor"), puede causar tracamundiu. Orixinalmente esta especie poner nel xéneru Caprimulgus, y ye de fechu más pequeña que dalgunos otros miembros d'esi xéneru, como Caprimulgus vociferus. Sicasí, cuando se movió al xéneru Chordeiles, resultó ser más grande qu'el atajacaminos menor (Chordeiles acutipennis).
Los adultos son escuros cola castañal, patrones grises y blancos nel envés y pechu; les ales llargues son negres y amuesen una barra blanca nel vuelu. La cola ye escura con una raya cruciada blanca; la parte cimera de les ales escures con raya blanca. El machu adultu adultu tien el gargüelu blancu; la fema tien un gargüelu castañu llixeru.
Enviernen en América del Sur; migren en bandaes. Ye raru velo n'Europa occidental. El so hábitat de cría ye América del Norte. De normal añeren nel suelu desnudu, dacuando en toconos o terraces de sable gruesu. Ponen dos güevos direutamente na tierra, nun hai nial. La incubación la realizada la fema y dura aproximao 20 díes. El mozu vuela a los 20 díes d'edá. Puede haber una segunda cría na parte del sur de los Estaos Xuníos.
Prinden inseutos al vuelu, buscando alimentu principalmente cerca del alba y tapecer, dacuando pela nueche con lluna llena o cerca del llume caleyero. La llamada de normal ye curtia. El machu realiza un esplegue etéreo mientres el cortexu, mientres emite un soníu.
Bird call of the Common Nighthawk (Chordeiles minor)Chordeiles minor volando.
Esta páxina forma parte del wikiproyeutu Aves, un esfuerciu collaborativu col fin d'ameyorar y organizar tolos conteníos rellacionaos con esti tema. Visita la páxina d'alderique del proyeutu pa collaborar y facer entrugues o suxerencies. Chordeiles minor, tamién conocíu como añapero yanqui o añapero boreal, ye un ave Caprimulxiforme de la familia Caprimulgidae mesma d'América.
El nome científicu d'esta especie, minor ("menor"), puede causar tracamundiu. Orixinalmente esta especie poner nel xéneru Caprimulgus, y ye de fechu más pequeña que dalgunos otros miembros d'esi xéneru, como Caprimulgus vociferus. Sicasí, cuando se movió al xéneru Chordeiles, resultó ser más grande qu'el atajacaminos menor (Chordeiles acutipennis).
An adren-Amerika (liester : adrened-Amerika)[1] a zo ur spesad evned, Chordeiles minor an anv skiantel anezhañ.
Anvet e voe Caprimulgus minor da gentañ-penn (e 1771) gant an naturour alaman Johann Reinhold Forster (1729-1798).
Chordeiles minor,Bevañ a ra ar spesad diwar amprevaned.
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Tiriad Chordeiles minor : Tachenn neizhañ, Tachenn c'hoañviñ. Ar spesad a gaver an nav isspesad[2] anezhañ en Amerika :
An adren-Amerika (liester : adrened-Amerika) a zo ur spesad evned, Chordeiles minor an anv skiantel anezhañ.
Anvet e voe Caprimulgus minor da gentañ-penn (e 1771) gant an naturour alaman Johann Reinhold Forster (1729-1798).
L'enganyapastors americà[1] (Chordeiles minor) és un ocell de la família dels caprimúlgids (Caprimulgidae) que habita zones praderies, sabanes, conreus i ciutats, criant des del nord-oest i centre de Canadà, cap al sud fins a l'Amèrica Central. En hivern habita a les Antilles i Amèrica del Sud.
L'enganyapastors americà (Chordeiles minor) és un ocell de la família dels caprimúlgids (Caprimulgidae) que habita zones praderies, sabanes, conreus i ciutats, criant des del nord-oest i centre de Canadà, cap al sud fins a l'Amèrica Central. En hivern habita a les Antilles i Amèrica del Sud.
Die Falkennachtschwalbe (Chordeiles minor), auch Nachtfalke genannt, ist einer der bekanntesten amerikanischen Sommervögel. Sie ist berühmt durch ihre Sturz- und Zickzackflüge.
Falkennachtschwalben sind etwa 23 Zentimeter lang und haben eine Flügelspannweite von 59 bis 68 cm, während ihr Gewicht ungefähr 65 Gramm beträgt. Charakteristisch sind für sie, neben dem unregelmäßigen Zickzackflug, die schmalen und spitzen Flügel, welche eine weiße Binde tragen. Das Gefieder ist dunkelbraun oder grau mit brauner Musterung. Beim Männchen ist die Kehle weiß, beim Weibchen gelblichbraun. Das Gefieder der Jungvögel ist noch blasser, die Kehle ist weniger auffällig gefärbt. Männchen haben außerdem noch eine weiße Schwanzbinde. Der Schnabel sieht im geschlossenen Zustand außergewöhnlich klein aus, kann aber bei der Beutejagd weit geöffnet werden.
Während der Brutzeit leben Falkennachtschwalben als Paar, und während des Zuges im Trupp. Oft sieht man mehrere Paare in unmittelbarer Nachbarschaft zusammen leben. Obwohl ihr Name vermuten lässt, dass sie nachtaktiv sind, sind sie keine ausgesprochenen Nachtvögel. Nur wenn die Jungen zu wenig Futter bekommen haben, jagen sie auch nachts. Normalerweise gehen sie am frühen Morgen und Abend auf Beutezug. Man trifft sie oft in Niederungen, vor allem auf offenen Graslandschaften und Nadelwäldern. Ihre Lebenserwartung beträgt bis zu 6 Jahren.
Ihre Nahrung besteht vor allem aus Fluginsekten, wie geflügelten Ameisen, Käfern, Faltern und Heuschrecken. Bei den Bauern sind sie sehr beliebt, da sie viele Schädlinge vertilgen. Sie jagen gerne über offenem Gelände, wie Seen, Flüssen und Wiesen. Sie sind sehr wendige Jäger und erhaschen oft im Sturzflug Insekten. Dabei verursachen die angelegten Flügel ein Geräusch, das klingt, also ob man mit dem Mund an die Öffnung einer leeren Flasche bläst.
Die Brutzeit der Falkennachtschwalben dauert von Mitte Mai bis Mitte Juli. Nach der Paarung legt das Weibchen 2 gräuliche weiße, kräftig lila und braun gescheckte Eier, welche nicht in ein Nest, sondern auf den blanken Felsen oder in eine kleine Bodenmulde gelegt werden. Ein Nest würde auf dem trockenen, felsigen Untergrund eher auffallen. Sie nisten nie im Schatten, da die Eier durch ihre Färbung an feuchten Stellen nicht so gut getarnt wären. Manchmal legen sie ihre Eier aber auch in Holzdach-Nischen der Städte. Wird das Gelege zerstört, folgt ein Nachgelege. Das Männchen bewacht den Nestplatz mit Patrouillenflügen und verteidigt das Gelege oft unter Einsatz seines Lebens. Nach einer Brutdauer von 14 bis 16 Tagen schlüpfen die Jungvögel aus und bleiben noch ungefähr 20 Tage im Nest. Ein Jahr später werden sie geschlechtsreif.
Ihre Brutplätze liegen in Nord- und Mittelamerika, von dem äußersten Südost-Zipfel Alaskas bis südlich nach Panama. Sie überwintern in Südamerika von Kolumbien bis nach Argentinien.
Bisher sind neun Unterarten bekannt:[1]
Die Falkennachtschwalbe (Chordeiles minor), auch Nachtfalke genannt, ist einer der bekanntesten amerikanischen Sommervögel. Sie ist berühmt durch ihre Sturz- und Zickzackflüge.
The common nighthawk or bullbat (Chordeiles minor) is a medium-sized [3][4] crepuscular or nocturnal bird[3][5] of the Americas within the nightjar family, whose presence and identity are best revealed by its vocalization. Typically dark[3] (gray, black and brown),[5] displaying cryptic colouration and intricate patterns, this bird is difficult to spot with the naked eye during the day. This bird is most conspicuous when in its buoyant and erratic flight. The most remarkable feature of this aerial insectivore is its small beak that belies the massiveness of its mouth. Some claim appearance similarities to owls. With its horizontal stance[3] and short legs, the common nighthawk does not travel frequently on the ground, instead preferring to perch horizontally, parallel to branches, on posts, on the ground or on a roof.[5] The males of this species may roost together but the bird is primarily solitary. The common nighthawk shows variability in territory size.[4]
This caprimulgid has a large, flattened head with large eyes; facially it lacks rictal bristles. The common nighthawk has long slender wings that at rest extend beyond a notched tail. There is noticeable barring on the sides and abdomen,[4] also white wing-patches.[3]
The common nighthawk measures 22 to 25 cm (8.7 to 9.8 in) long,[4] displays a wing span of 51 to 61 cm (20 to 24 in)[6] weighs 55 to 98 g (1.9 to 3.5 oz),[4][6] and has a life span of 4 to 5 years.[4]
The genus name Chordeiles is from Ancient Greek khoreia, a dance with music, and deile, "evening". The specific minor is Latin for "smaller".[7]
The term "nighthawk", first recorded in the King James Version of 1611, was originally a local name in England for the European nightjar. Its use in the Americas to refers to members of the genus Chordeiles and related genera was first recorded in 1778.[8]
The common nighthawk is sometimes called a "bull-bat", due to its perceived "bat-like" flight, and the "bull-like" boom made by its wings as it pulls from a dive.[6]
They, in addition to other nightjars, are also sometimes called "bugeaters", for their insectivore diet. The common nighthawk is likely the reason that Nebraska's state nickname was once the "Bugeater State", and its people were known as "bugeaters".[9][10][11] The Nebraska Cornhuskers college athletic teams were also briefly known the Bugeaters, before adopting their current name, which was also adopted by the state as a whole. A semi-professional soccer team in Nebraska now uses the Bugeaters moniker.
Within the family Caprimulgidae, the subfamily Chordeilinae (nighthawks) are limited to the New World and are distinguished from the subfamily Caprimulginae, by the lack of rictal bristles.
The American Ornithologists' Union treated the smaller Antillean nighthawk as conspecific with the common nighthawk until 1982.[4]
Up until the early 19th century, the common nighthawk and the whip-poor-will were thought to be one species. The latter's call was explained as the nocturnal expression of the common nighthawk. Alexander Wilson, "The Father of American Ornithology", correctly made the differentiation between the two species.
There are 9 currently recognized subspecies:[12]
This species is recorded as widespread during the Late Pleistocene, from Virginia to California and from Wyoming to Texas.[4]
In the late 19th and early 20th centuries, because their name contained the word "hawk", they had habits of diurnal insect hunting, and they travelled in migrating flocks, they were hunted for sport and nourishment and because they were seen as predators.[6]
The common nighthawk is distinguished from other caprimulguids by its forked tail (includes a white bar in males); its long, unbarred, pointed wings with distinctive white patches; its lack of rictal bristles, and the key identifier – their unmistakable calls.[13] These birds range from 21 to 25 cm (8.3 to 9.8 in) in total length and from 51 to 61 cm (20 to 24 in) in wingspan.[14] Body mass can vary from 55 to 98 g (1.9 to 3.5 oz). Among standard measurements, the wing chord is 17.2 to 21.3 cm (6.8 to 8.4 in), the tail is 13 to 15.1 cm (5.1 to 5.9 in), the bill is 0.5 to 0.8 cm (0.20 to 0.31 in) and the tarsus is 1.2 to 1.6 cm (0.47 to 0.63 in).
The common nighthawk resembles both the Antillean nighthawk and the lesser nighthawk and occurs at least seasonally in the entire North American range of both of these species. The lesser nighthawk is a smaller bird and displays more buffy on the undertail coverts, where the common nighthawk shows white. Common nighthawks and Antillean nighthawks exhibit entirely dark on the basal portion of the primary feathers, whereas lesser nighthawks have bands of buffy spots. Common and Antillean nighthawks have a longer outermost primary conveying a pointier wing tip than the lesser nighthawk. The common nighthawk forages higher above ground than the lesser nighthawk and has a different call. The only reliable way to distinguish Antillean nighthawk without disturbance is also by the differences in their calls. Visually, they may only be distinguished as different from the common nighthawk once in the hand. Subtle differences are reported to be a challenge in field identification.[4]
The common nighthawk may be found in forests, desert, savannahs, beach and desert scrub, cities,[3] and prairies,[4] at elevations of sea level or below to 3,000 m (9,800 ft).[3] They are one of a handful of birds that are known to inhabit recently burned forests, and then dwindle in numbers as successional growth occurs over the succeeding years or decades. The common nighthawk is drawn into urban built-up areas by insects.[5]
The common nighthawk is the only nighthawk occurring over the majority of northern North America.
Food availability is likely a key factor in determining which and when areas are suitable for habitation. The common nighthawk is not well adapted to survive in poor conditions, specifically low food availability. Therefore, a constant food supply consistent with warmer temperatures is a driving force for migration and ultimately survival.
It is thought that the bird is not able to enter torpor,[4] although recent evidence suggests it does.[13]
During migration, common nighthawks may travel 2,500 to 6,800 kilometres (1,600 to 4,200 mi). They migrate by day or night in loose flocks; frequently numbering in the thousands,[6] no visible leader has been observed. The enormous distance travelled between breeding grounds and wintering range is one of the North America's longer migrations. The northbound journey commences at the end of February and the birds reach destinations as late as mid-June. The southbound migration commences mid-July and reaches a close in early October.[4]
While migrating, these birds have been reported travelling through middle America, Florida, the West Indies,[6] Cuba, the Caribbean and Bermuda,[4] finally completing their journey in the wintering grounds of South America,[6][13] primarily Argentina.[13]
As aerial insectivores, the migrants will feed en route,[6] congregating to hunt in marshes, rivers and on lakeshores. In Manitoba and Ontario, Canada, it is reported that during migration the nighthawks are seen most commonly in the late afternoon, into the evening,[4][5] with a burst of sunset feeding activities.[5]
Additionally, it has been noted that during migration the birds may fly closer to the ground than normal; possibly foraging for insects. There is speculation that feeding also occurs at higher altitudes.
The common nighthawk winters in southern South America, but distribution in this range is poorly known due to difficulties in distinguishing the bird from the lesser nighthawk and in differentiating between migrants and overwintering birds. In some South and Central American countries, a lack of study has led to restricted and incomplete records of the bird. Records do support wintering in Ecuador, Peru, Bolivia, Brazil, Paraguay, Uruguay and Argentina.[4]
In the common nighthawk, all bodily plumage and rectrices are replaced in the post-juvenile moult. This moult commences in September at the breeding grounds; the majority of the body plumage is replaced but wing-coverts and rectrices are not completed until January–February, once the bird arrives at the wintering grounds. There is no other moult prior to the annual moult of the adult. Common nighthawk adults have a complete moult that occurs mostly or completely on wintering grounds and is not completed until January or February.[13]
There are no differences between the calls and song of the common nighthawk. The most conspicuous vocalization is a nasal peent or beernt during even flight. Peak vocalizations are reported 30 to 45 minutes after sunset.
A croaking auk auk auk is vocalized by males while in the presence of a female during courtship. Another courtship sound, thought to be made solely by the males, is the boom, created by air rushing through the primaries after a quick downward flex of the wings during a daytime dive.
In defense of their nests, the females make a rasping sound, and males clap their wings together.[15] Strongly territorial males will perform dives against fledglings, females, and intruders such as humans or raccoons.[4]
Frequent flyers, the long-winged common nighthawk hunts on the wing[13] for extended periods at high altitudes or in open areas.[5] Crepuscular, flying insects are its preferred food source. The hunt ends as dusk becomes night, and resumes when night becomes dawn.[13] Nighttime feeding (in complete darkness) is rare,[4] even on evenings with a full moon.[13] The bird displays opportunistic feeding tendencies, although it may be able to fine-tune its meal choice in the moments before capture.
Vision is presumed to be the main detection sense; no evidence exists to support the use of echolocation. The birds have been observed to converge on artificial light sources in an effort to forage for insects enticed by the light.[4] The average flight speed of common nighthawks is 23.4 km/h (14.5 mph).[16]
The common nighthawk was observed to drink on its winter range by flying extremely low over the surface of the water.[17]
No evidence suggests this bird casts pellets.
The common nighthawk is recognized to discharge feces around nest and roosting positions. The bird will sporadically defecate in flight. The defecation is pungent.[4]
The common nighthawk breeds during the period of mid-March to early October.[6] It most commonly has only one brood per season, however sometimes a second brood is produced. The bird is assumed to breed every year. Reuse of nests by females in subsequent years has been reported.[4] A monogamous habit has also recently been confirmed.[13]
Courting and mate selection occur partially in flight. The male dives and booms (see Vocalization) in an effort to garner female attention;[4][5] the female may be in flight herself or stationary on the ground.
Copulation occurs when the pair settles on the ground together; the male with his rocking body, widespread tail wagging and bulging throat expresses guttural croaking sounds. This display by the male is performed repeatedly until copulation.[4]
The preferred breeding/nesting habitat is in forested regions with expansive rocky outcrops, in clearings, in burned areas[5] or in small patches of sandy gravel.[4] The eggs are not laid in a nest, but on bare rock, gravel,[5] or sometimes a living substrate such as lichen.[4] Least popular are breeding sites in agricultural settings.[18] As displayed in the latter portion of the 20th century, urban breeding is in decline.[5] If urban breeding sites do occur, they are observed on flat gravel rooftops.
It is a solitary nester, putting great distances between itself and other pairs of the same species, but a nest would more commonly occur in closer proximity to other species of birds.
Females choose the nest site and are the primary incubators of the eggs; males will incubate occasionally. Incubation time varies but is approximately 18 days. The female will leave the nest unattended during the evening in order to feed. The male will roost in a neighbouring tree (the spot he chooses changes daily); he guards the nest by diving, hissing, wing-beating or booming at the sites. In the face of predation, common nighthawks do not abandon the nest easily; instead they likely rely on their cryptic colouration to camouflage themselves. If a departure does occur, the females have been noted to fly away, hissing at the intruder[4] or performing a disturbance display.[13]
The eggs are elliptical, strong, and variably coloured with heavy speckling. The common nighthawk lays two 6–7 g (0.21–0.25 oz) eggs per clutch; the eggs are laid over a period of 1 to 2 days. The female alone displays a brood patch.
The chicks may be heard peeping in the hours before they hatch. Once the chicks have broken out of the shells, the removal of the debris is necessary in order to avoid predators. The mother may carry the eggshells to another location or consume a portion of them. Once hatched, the nestlings are active and have their eyes fully or half open; additionally they display a sparing cover of soft down feathers. The chicks are semi-precocial. By day 2, the hatchlings' bodily mass will double and they will be able to self-propel towards their mother's call. The young will hiss at an intruder.
The young are fed by regurgitation before sunrise and after sunset. The male parent assists in feeding fledglings and will also feed the female during nesting. No records exist to support a parent's ability to physically carry a chick.
On their 18th day, the young will make their first flight; by days 25–30, they are flying proficiently. The young are last seen with their parents on day 30. Complete development is shown between their 45–50th day. At day 52, the juvenile will join the flock, potentially migrating. Juvenile birds, in both sexes, are lighter in colour and have a smaller white wing-patch than adult common nighthawks.[4]
Like other members of the caprimulgid clan, the nighthawk's ground nesting habits endanger eggs and nestlings to predation by ground carnivores, such as skunks, raccoons and opossums.[19] Confirmed predation on adults is restricted to domestic cats, golden eagles, and great horned owls.[20] Peregrine falcons have also been confirmed to attack nighthawks as prey, although the one recorded predation attempt was unsuccessful.[21] Other suspected predators are likely to attack them, such as dogs, coyotes, foxes, hawks, American kestrels,[22] owls, crows and ravens, and snakes.[23]
There has been a general decline in the number of common nighthawks in North America, but some population increases also have occurred[4] in other geographical locations.[13] The bird's large range makes individual risk thresholds in specific regions difficult to establish.[1] In Ontario, the common nighthawk is rated as a species of special concern.[24]
The Common nighthawk's trait of being a ground-nesting bird makes it particularly susceptible to predators, some of which include domestic cats, ravens, snakes, dogs, coyotes, falcons and owls.
Lack of flat roofs, pesticides,[4] increased predation and loss of habitat[13] are noted factors of their decline. Further unstudied potential causes of decline include climate change, disease, road kills, man-made towers (posing aerial hazards), and parasites.[4]
The absence of flat roofs (made with gravel) in urban settings is an important cause of decline. In an effort to provide managed breeding areas, gravel pads have been added in the corners of rubberized roofs; this proves acceptable, as nesting has been observed.[13]
The common nighthawk or bullbat (Chordeiles minor) is a medium-sized crepuscular or nocturnal bird of the Americas within the nightjar family, whose presence and identity are best revealed by its vocalization. Typically dark (gray, black and brown), displaying cryptic colouration and intricate patterns, this bird is difficult to spot with the naked eye during the day. This bird is most conspicuous when in its buoyant and erratic flight. The most remarkable feature of this aerial insectivore is its small beak that belies the massiveness of its mouth. Some claim appearance similarities to owls. With its horizontal stance and short legs, the common nighthawk does not travel frequently on the ground, instead preferring to perch horizontally, parallel to branches, on posts, on the ground or on a roof. The males of this species may roost together but the bird is primarily solitary. The common nighthawk shows variability in territory size.
This caprimulgid has a large, flattened head with large eyes; facially it lacks rictal bristles. The common nighthawk has long slender wings that at rest extend beyond a notched tail. There is noticeable barring on the sides and abdomen, also white wing-patches.
The common nighthawk measures 22 to 25 cm (8.7 to 9.8 in) long, displays a wing span of 51 to 61 cm (20 to 24 in) weighs 55 to 98 g (1.9 to 3.5 oz), and has a life span of 4 to 5 years.
La Amerika kaprimulgo aŭ Komuna noktofalko, Chordeiles minor, estas unu el la plej konataj specioj de la birdoj de la familio de kaprimulgedoj en ties genro Chordeiles propra de Ameriko. Vere Amerikaj kaprimulgoj povus esti nomo por ĉiuj membroj de la genro Chordeiles aŭ eĉ de la tuta subfamilio Chordeilinae, sed ĉar tiuj ricevas ankaŭ la nomon de noktofalkoj, povas resti Amerika kaprimulgo por tiu ĉi specio.
La Amerika kaprimulgo estas tre malhela birdo, inter grizbruna kaj nigreca, kun kelkaj blankaj markoj. Plenkreskuloj havas malhelbrunajn, grizajn kaj blankajn markobildojn en supraj partoj kaj brusto; la longaj flugiloj estas nigraj kaj montras blankan kurban strion antaŭ la flugilpintoj dumfluge. La vosto estas malhele nigreca kun blanka strio; la subaj partoj estas helaj kun nigra striado. Maskla plenkreskulo havas blankan gorĝon; la ino havas helbrunan gorĝon.
La reprodukta vivejo estas malferma kamparo tra Nordameriko el suda Kanado tra Usono (escepte Kalifornion) ĝis Centrameriko. Ili kutime nestumas sur nuda grundo, foje en altetaj lokigoj inkludante arbostumpojn aŭ ŝtonetamasojn. Ili ĉefe preferas bruligitajn areojn en arbaroj. La du ovoj estas demetitaj rekte sur nuda grundo —ne estas vera nesto. Kovado estas farita ĉefe de la ino kaj dum 20 tagoj. Idoj elnestiĝas post 20 tagoj. Povas okazi dua ovodemetado en suda parto de Usono.
Tiuj nearktisaj birdoj vintras en Sudameriko el norda Kolombio al suda Brazilo kaj norda Ĉilio. Ili migras en aroj. Tiu ĉi specio estas tre rara vaganto al okcidenta Eŭropo, ekzemple al Britio, Islando aŭ Azoroj.
Ili kaptas flugantajn insektojn dumfluge, ĉefe mateniĝe aŭ krepuske, foje dumnokte profitante la lunlumon aŭ tiun de la stratoj.
La voĉo estas mallonga piit kutime aŭdata de supre. La masklo realigas enaeran ceremonion dum pariĝado, produktante resonadon fine de falflugo. La sono estas produktita de la aero resonanta tra la flugilpintoj.
La scienca nomo por tiu specio, minor, alportas ian konfuzigon. Originale tiu ĉi specio estis lokita en la genro Caprimulgus, kaj vere tiam ĝi estis pli malgranda ol kelkaj aliaj membroj de tiu ĉi genro, kiel la Almozulo, Caprimulgus vociferus. Tamen, kiam la Komuna noktofalko translokiĝis al la genro Chordeiles, ĝi estis en la mala situacio dum estas nomata minor (malgranda), eĉ kvankam ĝi estas pli granda ol la Eta noktofalko, Chordeiles acutipennis.
La Amerika kaprimulgo aŭ Komuna noktofalko, Chordeiles minor, estas unu el la plej konataj specioj de la birdoj de la familio de kaprimulgedoj en ties genro Chordeiles propra de Ameriko. Vere Amerikaj kaprimulgoj povus esti nomo por ĉiuj membroj de la genro Chordeiles aŭ eĉ de la tuta subfamilio Chordeilinae, sed ĉar tiuj ricevas ankaŭ la nomon de noktofalkoj, povas resti Amerika kaprimulgo por tiu ĉi specio.
El atajacaminos común (Chordeiles minor), también conocido como añapero yanqui[2] o añapero boreal, es un ave Caprimulgiforme de la familia Caprimulgidae propia de América.
El nombre científico de esta especie, minor ("menor"), puede causar confusión. Originalmente esta especie se puso en el género Caprimulgus, y es de hecho más pequeña que algunos otros miembros de ese género, como Caprimulgus vociferus. Sin embargo, cuando se movió al género Chordeiles, resultó ser más grande que el atajacaminos menor (Chordeiles acutipennis).
Los adultos son oscuros con el castaño, patrones grises y blancos en el dorso y pecho; las alas largas son negras y muestran una barra blanca en el vuelo. La cola es oscura con una raya cruzada blanca; la parte superior de las alas oscuras con raya blanca. El macho adulto tiene la garganta blanca; la hembra tiene una garganta castaño claro.
Invernan en América del Sur; migran en bandadas. Es raro verlo en Europa occidental. Su hábitat de cría es América del Norte. Normalmente anidan en el suelo desnudo, a veces en tocones o terrazas de arena gruesa. Ponen dos huevos directamente en la tierra, no hay nido. La incubación la realizada la hembra y dura aproximadamente 20 días. El joven vuela a los 20 días de edad. Puede haber una segunda cría en la parte del sur de los Estados Unidos.
Capturan insectos al vuelo, buscando alimento principalmente cerca del alba y crepúsculo, a veces por la noche con luna llena o cerca de la iluminación callejera. La llamada normalmente es corta. El macho realiza un despliegue etéreo durante el cortejo, mientras emite un sonido.
Chordeiles minor volando.
El atajacaminos común (Chordeiles minor), también conocido como añapero yanqui o añapero boreal, es un ave Caprimulgiforme de la familia Caprimulgidae propia de América.
El nombre científico de esta especie, minor ("menor"), puede causar confusión. Originalmente esta especie se puso en el género Caprimulgus, y es de hecho más pequeña que algunos otros miembros de ese género, como Caprimulgus vociferus. Sin embargo, cuando se movió al género Chordeiles, resultó ser más grande que el atajacaminos menor (Chordeiles acutipennis).
Amerikar zata (Chordeiles minor) Chordeiles generoko animalia da. Hegaztien barruko Caprimulgidae familian sailkatua dago.
Amerikar zata (Chordeiles minor) Chordeiles generoko animalia da. Hegaztien barruko Caprimulgidae familian sailkatua dago.
Isohaukkakehrääjä (Chordeiles minor) on amerikkalainen kehrääjälintu.
Isohaukkakehrääjä on 23-25,5 cm pitkä ja sen siipiväli on 54-60 cm. Sen höyhenpuku on väriltään tummanruskeankirjava. Sillä on terävät siiet ja keskipitkä pytstö, jonka kärjessä on matala lovi. Siipien käsisulat ovat kuviottoman mustat ja niiden keskellä on leveä valkoinen poikkijuova, joka on naaraalla epäselvempi kuin koiraalla.[2]
Isohaukkakehrääjiä pesii Pohjois- ja Keski-Amerikassa. Laji talvehtii Etelä-Amerikan pohjois- ja keskiosissa.[1] Euroopassa laji on hyvin harvinainen harhailija, jota tavataan syys-lokakuussa lähinnä Isossa-Britanniassa.[2]
Isohaukkakehrääjä (Chordeiles minor) on amerikkalainen kehrääjälintu.
Chordeiles minor
L’Engoulevent d'Amérique (Chordeiles minor) est une espèce d'oiseau qui se trouve de l'extrême sud du Canada à l'Amérique du Sud (à l'exception du sud du continent). L'espèce était autrefois connu sous le nom de Chordeiles virginianus.
Les engoulevents adultes sont sombres avec des motifs châtain, gris et blanc sur le dos et la poitrine; les longues ailes sont noires et montrent une barre blanche dans le vol. La queue est sombre avec une traînée de croix blanche; la partie supérieure des ailes sombres avec une bande blanche. Le mâle adulte a la gorge blanche. la femelle a la gorge brun clair.
Les engoulevents hivernent en Amérique du Sud. Ils migrent en groupes. Leur habitat de reproduction est l'Amérique du Nord et l'Amérique Centrale. Ils nichent généralement sur le sol nu, parfois sur des souches ou des terrasses de sable grossier. Ils pondent deux œufs directement sur le sol, il n'y a pas de nid. L'incubation est faite par la femelle et dure environ 20 jours. Le jeune vole à l'âge de 20 jours.
Ils attrapent des insectes à la volée, cherchant de la nourriture principalement à l'aube et au crépuscule, parfois la nuit avec la pleine lune ou près d'un éclairage public. L'engoulevent boit en vol en écumant la surface de l’eau avec la mandibule inférieure, le bec grand ouvert.
Au début de la saison de reproduction, l’engoulevent d’Amérique mâle effectue des parades nuptiales pour attirer une femelle, en l'accompagnant de cris.
On peut trouver l'engoulevent d'Amérique dans les forêts, les déserts, les savanes, les garrigues de plage et de désert, les villes, les prairies, à une altitude égale ou inférieure à 3 000 m. L'engoulevent d'Amérique est attiré dans les zones urbaines par la présence d'insectes.
D'après la classification de référence (version 12.1, 2022) du Congrès ornithologique international, cette espèce est constituée des neuf sous-espèces suivantes (ordre phylogénique) :
Chordeiles minor
L’Engoulevent d'Amérique (Chordeiles minor) est une espèce d'oiseau qui se trouve de l'extrême sud du Canada à l'Amérique du Sud (à l'exception du sud du continent). L'espèce était autrefois connu sous le nom de Chordeiles virginianus.
De Amerikaanse nachtzwaluw (Chordeiles minor) is een vogel uit de familie van de nachtzwaluwen (Caprimulgidae) die voorkomt in de Nieuwe Wereld.
Ze zijn 22 tot 24 cm lang en wegen 45 tot 100 gram.
Deze vogels zijn insecteneters die jagen op vliegende insecten in zowel de avond- als de morgenschemering. De vogel staakt de jacht in de nacht en oriënteert zich waarschijnlijk niet met behulp van echolocatie maar op zicht.
Deze vogels kiezen nestplaatsen op de grond in open gebieden met enige dekking van grassen, struiken, stammen of keien. Ze bouwen geen nesten. In plaats daarvan worden eieren gelegd op een verscheidenheid van substraten zoals zand, grind, bladeren en kale rots. In gebieden van menselijke bewoning nestelen ze vaak op platte grinddaken.
Deze soort komt voor in een groot deel van Noord-Amerika en delen van Midden-Amerika. Over de overwinteringsgebieden is minder bekend, maar aangenomen wordt dat ze overwinteren in heel midden Zuid-Amerika in het laagland ten oosten van de Andes. Broedplaatsen zijn kustduinen en stranden, open bosplekken, graslanden, savannen, open vlaktes en bossen. Zij zullen ook gebruikmaken van leefgebieden, veranderd door menselijke activiteit.
De soort telt 9 ondersoorten:
De Amerikaanse nachtzwaluw heeft een enorm groot verspreidingsgebied en daardoor alleen al is de kans op de status kwetsbaar (voor uitsterven) uiterst gering. De grootte van de populatie is niet gekwantificeerd, maar neemt in aantallen af. Echter, het tempo ligt onder de 30% in tien jaar (minder dan 3,5% per jaar). Om deze redenen staat deze nachtzwaluw als niet bedreigd op de Rode Lijst van de IUCN.[1]
Bronnen, noten en/of referentiesDe Amerikaanse nachtzwaluw (Chordeiles minor) is een vogel uit de familie van de nachtzwaluwen (Caprimulgidae) die voorkomt in de Nieuwe Wereld.
Multimedia w Wikimedia Commons Lelczyk mały (Chordeiles minor) − ptak z rodziny lelkowatych (Caprimulgidae). Żeruje wieczorem oraz w nocy; obecność zdradza głosem. Podczas dnia odpoczywa, siedząc wzdłuż konarów drzew, na słupach ogrodzeniowych i dachach.
Wygląd - długie, ostro zakończone skrzydła, białe lusterko na lotkach I rzędu. Wierzch ciała w plamki, spód w prążki; na gardle widoczna biała półobroża, przed końcem ogona biała, kontrastowa przepaska. Samce szaro-czarne, samice brązowawe, z płową półobrożą i lusterkiem, nie mają białej przepaski na ogonie. Młode mogą być bez półobroży.
Rozmiary - 22 - 26 cm
Zasięg, środowisko - tereny otwarte i luźne zadrzewienia w całej Ameryce Północnej, poza skrajnie północnymi obszarami. Zimuje w północnej i środkowej Ameryce Południowej.
Podobne gatunki - lelczyk antylski, lelczyk ostroskrzydły
Lelczyk mały (Chordeiles minor) − ptak z rodziny lelkowatych (Caprimulgidae). Żeruje wieczorem oraz w nocy; obecność zdradza głosem. Podczas dnia odpoczywa, siedząc wzdłuż konarów drzew, na słupach ogrodzeniowych i dachach.
Wygląd - długie, ostro zakończone skrzydła, białe lusterko na lotkach I rzędu. Wierzch ciała w plamki, spód w prążki; na gardle widoczna biała półobroża, przed końcem ogona biała, kontrastowa przepaska. Samce szaro-czarne, samice brązowawe, z płową półobrożą i lusterkiem, nie mają białej przepaski na ogonie. Młode mogą być bez półobroży.
Rozmiary - 22 - 26 cm
Zasięg, środowisko - tereny otwarte i luźne zadrzewienia w całej Ameryce Północnej, poza skrajnie północnymi obszarami. Zimuje w północnej i środkowej Ameryce Południowej.
Podobne gatunki - lelczyk antylski, lelczyk ostroskrzydły
O bacurau-norte-americano (Chordeiles minor) é uma espécie migratória de bacurau que mede cerca de 23 cm de comprimento e recebe seu nome popular pelo fato de migra da América do Norte até a Argentina. Tais aves possuem garganta e asas barradas de branco, e uma larga faixa dessa cor entre a base e a extremidade das asas. Também são conhecidas pelo nome de bacurau-de-bando.
Normalmente escuro (cinza, preto e marrom),[1][2] exibindo coloração críptica e padrões intrincados, este pássaro é difícil de detectar a olho nu durante o dia. Outrora aéreo, com seu vôo flutuante mas errático, esse pássaro é o mais conspícuo. A característica mais notável deste insetívoro aéreo é seu pequeno bico, que desmente a maciça de sua boca. Alguns afirmam ter semelhanças de aparência com as corujas . Com sua postura horizontal e pernas curtas, o gavião-noturno comum não viaja com frequência no solo, preferindo empoleirar-se na horizontal, paralelo aos galhos, em postes, no solo ou no telhado.[2] Os machos desta espécie podem empoleirar-se juntos, mas a ave é principalmente solitária. O Nighthawk comum mostra variabilidade no tamanho do território.[3]
Este caprimulgídeo tem uma cabeça grande e achatada com olhos grandes; no bico, faltam cerdas rictais. O bacurau-norte-americano tem asas longas e delgadas que em repouso se estendem além de uma cauda talhada. Há barreiras visíveis nas laterais e no abdômen,[3] também manchas brancas nas asas.[1]
O bacurau-norte-americano mede 22 a 25 centímetros de comprimento,[3] exibe uma envergadura de 51 a 61 centímetros, pesa de 55 a 98 gramas e tem um tempo de vida médio de 4 a 5 anos.[3]
O nome do gênero Chordeiles vem do grego antigo khoreia, uma dança com música, e deile, "noite". O epíteto específico minor é o latim para "menor".[4]
O termo "nighthawk", usado para animais desse tipo em inglês, foi registrado pela primeira vez na Bíblia de King James de 1611, e era originalmente um nome local na Inglaterra para o noitibó-da-europa. Seu uso nas Américas para se referir a membros do gênero Chordeiles e gêneros relacionados foi registrado pela primeira vez em 1778.[5]
O bacurau-norte-americano é às vezes chamado de "morcego-touro", devido ao seu voo percebido como "semelhante ao de um morcego" e ao barulho "semelhante ao de um touro" feito por suas asas ao sair de um mergulho.[6]
Eles, além de outros bacuraus, também são chamados de "bugeaters" (comedores de inseto em inglês) por sua dieta insetívora. O bacurau-norte-americano é provavelmente a razão do apelido do estado de Nebraska ter sido outrora o "Estado Bugeater", e seu povo ser conhecido como "bugeaters".[7][8][9]
Dentro da família Caprimulgidae, a subfamília Chordeilinae (bacuraus) está limitada ao Novo Mundo e se diferencia da subfamília Caprimulginae, pela falta de cerdas rictais.
A União dos Ornitólogos Americanos tratou o pequeno bacurau das Antilhas como conspecífico com o bacurau-norte-americano até 1982.[3]
São 9 subespécies atualmente reconhecidas:[10]
Esta espécie é registrada como disseminada durante o Pleistoceno Superior, da Virgínia à Califórnia e de Wyoming ao Texas.[6]
No final do século XIX e início do século XX, os bacuraus-norte-americanos tinham hábitos de caça diurna de insetos, e viajavam em bandos migratórios, eram caçados por esporte e alimentação e por serem vistos como predadores.
O bacurau-norte-americano distingue-se de outros caprimulgídeos por sua cauda bifurcada (inclui uma barra branca nos machos); suas asas pontiagudas longas, sem barras, com manchas brancas distintas; sua falta de cerdas rictais e o identificador chave - seu canto inconfundível.[11]Essas aves variam de 21 a 25 cm em comprimento total e de 51 a 61 cm na envergadura de asa.[12] A massa corporal pode variar de 55 a 98 g. Entre as medidas padrão, a corda máxima da asa é de 17.2 a 21.3 cm, a cauda é de 13 a 15 cm, o bico é de 0.5 a 0.8 centímetros e o tarso é de 1,2 a 1,6 cm.
O bacurau-norte-americano assemelha-se ao bacurau das antilhas e ao bacurau-de-asa-fina e ocorre, pelo menos sazonalmente, em toda a distribuição norte-americana de ambas as espécies. O bacurau-de-asa-fina é um pássaro menor e exibe uma cor de couro nos abrigos infracaudais, onde o bacurau-norte-americano é branco. Os bacuraus-norte-americanos e os bacuraus das Antilhas são totalmente escuro na porção basal das penas primárias, enquanto bacuraus-de-asa-fina têm bandas de manchas cor de couro. Os bacuraus norte-americanos e das Antilhas têm uma primária externa, uma ponta de asa mais pontiaguda do que o bacurau-de-asa-fina. O bacurau-norte-americano comum forrageia mais acima do solo do que o bacurau-de-asa-fina e tem um canto diferente. A única maneira confiável de distinguir o bacurau das Antilhas sem perturbação é também pelas diferenças em seus cantos. Visualmente, eles só podem ser distinguidos como diferentes do bacurau-norte-americano uma vez na mão do pesquisador. Diferenças sutis são relatadas como um desafio na identificação de campo.[3]
O bacurau-norte-americano pode ser encontrado em florestas, desertos, savanas, praias e matagais desérticos, cidades,[1] e pradarias,[3] em elevações do nível do mar ou abaixo de 3,000 m (9,800 ft) . Eles fazem parte de um punhado de pássaros que habitam florestas recentemente queimadas e, em seguida, diminuem em número à medida que o crescimento sucessional ocorre nos anos ou décadas seguintes. O bacurau-norte-americano é arrastado para áreas urbanas construídas por insetos.[2]
Acredita-se que o pássaro não seja capaz de entrar em torpor, embora outras evidências sugiram que sim.
Durante a migração, os bacuraus-norte-amercanos podem viajar 2500 a 6800 quilômetros. Eles migram de dia ou de noite em bandos soltos; frequentemente na casa dos milhares, nenhum líder visível sendo observado. A enorme distância percorrida entre os criadouros e a área de inverno é uma das migrações mais longas da América do Norte. A jornada para o norte começa no final de fevereiro e as aves chegam ao destino em meados de junho. A migração para o sul começa em meados de julho e chega ao fim no início de outubro.[3]
Durante a migração, essas aves foram relatadas viajando através da América Central, Flórida, Índias Ocidentais,[6] Cuba, Caribe e Bermuda, finalmente completando sua jornada nas terras de inverno da América do Sul, principalmente Argentina.[11]
Como insetívoros aéreos, os migrantes se alimentam durante o trajeto, reunindo para caçar em pântanos, rios e margens de lagos. Em Manitoba e Ontário, Canadá, é relatado que durante a migração os bacuraus-norte-americanos são vistos mais comumente no final da tarde, à noite, se alimentando principalmente ao pôr-do-sol.[2]
O bacurau-norte-americano passa o inverno no sul da América do Sul, mas a distribuição nesta faixa é pouco conhecida devido às dificuldades em distinguir o pássaro do bacurau-de-asa-fina. Em alguns países da América do Sul e Central, a falta de estudos levou a registros restritos e incompletos da ave. Os registros mostram que a ave pode passar invernos no Equador, Peru, Bolívia, Brasil, Paraguai, Uruguai e Argentina.[3]
No bacurau-norte-americano todas as plumas corporais e rectrizes são substituídas na muda pós-juvenil. Esta muda começa em setembro no criadouro; a maior parte da plumagem do corpo é substituída, mas as coberturas das asas e rectrizes não são concluídos até janeiro-fevereiro, uma vez que a ave chega ao local de inverno. Não há nenhuma outra muda antes da muda anual do adulto. Os bacuraus-norte-americanos têm uma muda completa que ocorre principalmente ou completamente nas áreas de inverno e não é concluída até janeiro ou fevereiro.[11]
Em defesa de seus ninhos, as fêmeas fazem um som áspero e os machos batem as asas juntos.[13] Machos fortemente territoriais realizam mergulhos contra fêmeas e intrusos como humanos ou guaxinins.[3]
Voadores frequentes, o bacurau-norte-americano caça voando por longos períodos em grandes altitudes ou em áreas abertas. Insetos voadores crepusculares são sua fonte preferida de alimento. A caça termina quando o crepúsculo se transforma em noite e recomeça quando a noite chega ao amanhecer.[11] A alimentação noturna (na escuridão total) é rara, mesmo em noites de lua cheia. A ave apresenta tendências oportunistas de alimentação, embora possa ajustar sua escolha de refeição momentos antes da captura.
Presume-se que a visão seja o principal sentido de detecção; nenhuma evidência existe para apoiar o uso de ecolocalização. Observou-se que as aves convergem em fontes de luz artificial em um esforço para procurar por insetos atraídos pela luz.[3] A velocidade média de vôo de bacuraus-norte-americanos é 23.4 km/h (14.5 mph) .[14]
Observou-se que o bacurau-norte-americano bebe água em sua faixa de inverno voando extremamente baixo sobre a superfície da água. [15]
O bacurau norte-americano é conhecido por liberar fezes em torno dos ninhos e posições de empoleiramento. O pássaro defeca esporadicamente durante o vôo. A defecação é pungente.[3]
O bacurau norte-americano se reproduz durante o período de meados de março ao início de outubro.[6] É mais comum ter apenas uma ninhada por temporada, porém às vezes uma segunda ninhada é produzida. Presume-se que a ave reproduza todos os anos. Foi relatada a reutilização de ninhos por fêmeas nos anos subsequentes.[3] Um hábito monogâmico também foi recentemente confirmado.[11]
O cortejo e a seleção de parceiros ocorrem parcialmente durante o vôo. O macho mergulha e faz um som explosivo em um esforço para atrair a atenção feminina;[3][2] a fêmea pode estar voando sozinha ou parada no solo.
A cópula ocorre quando o par se estabelece no chão junto; o macho com seu corpo balançando, cauda espalhada abanando e garganta protuberante expressa sons guturais de coaxar. Essa exibição pelo macho é realizada repetidamente até a cópula.[3]
Os habitats de reprodução/nidificação preferido são as regiões de floresta com afloramentos rochosos, em clareiras, em áreas queimadas[2] ou em pequenas manchas de cascalho arenoso.[3] Os ovos não são colocados em um ninho, mas em rocha nua, cascalho[2] ou às vezes em um substrato vivo como o líquen. Menos populares são os criadouros em ambientes agrícolas.[16] Conforme exibido na última parte do 2 0ºséculo, reproduçãoão urbana está em declínio.[2] Se ocorrerem criadouros urbanos, eles são observados em telhados planos de cascalho.
Como outros membros do clã caprimulgida, os hábitos de nidificação terrestre do bacurau-norte-americano colocam seus ovos e filhotes em risco de predação por carnívoros terrestres, como guaxinins e gambás.[17] A predação confirmada em adultos é restrita a gatos domésticos, águias-reais e corujões-orelhudos .[18] Os falcões-peregrinos também foram vistos atacando bacuraus como presas, embora a tentativa de predação registrada não tenha sido bem-sucedida.[19] Outros predadores suspeitos são susceptíveis de atacá-los, como cães, coiotes, raposas, falcões, falcões americanos,[20] corujas, corvos e corvos e cobras.[21]
Houve um declínio geral no número de bacuraus-norte-americanosna América do Norte, mas alguns aumentos populacionais também ocorreram em outras localizações geográficas. A grande variedade da ave torna os limites de risco individuais em regiões específicas difíceis de estabelecer.[22] Em Ontário, o gavião-noturno comum é classificado como uma espécie de preocupação especial.[23]
A falta de telhados planos, pesticidas,[3] aumento da predação e perda de habitat[11] são fatores que contribuem de seu declínio. Outras causas potenciais não estudadas de declínio incluem mudanças climáticas, doenças, atropelamentos, torres feitas pelo homem (apresentando riscos aéreos) e parasitas.[3]
A ausência de telhados planos (feitos com cascalho) em ambientes urbanos é uma causa importante de declínio. Em um esforço para fornecer áreas de reprodução, blocos de cascalho foram adicionados nos cantos dos telhados emborrachados; e ninhos já foram observados nessas estruturas.[11]
O bacurau-norte-americano (Chordeiles minor) é uma espécie migratória de bacurau que mede cerca de 23 cm de comprimento e recebe seu nome popular pelo fato de migra da América do Norte até a Argentina. Tais aves possuem garganta e asas barradas de branco, e uma larga faixa dessa cor entre a base e a extremidade das asas. Também são conhecidas pelo nome de bacurau-de-bando.
Normalmente escuro (cinza, preto e marrom), exibindo coloração críptica e padrões intrincados, este pássaro é difícil de detectar a olho nu durante o dia. Outrora aéreo, com seu vôo flutuante mas errático, esse pássaro é o mais conspícuo. A característica mais notável deste insetívoro aéreo é seu pequeno bico, que desmente a maciça de sua boca. Alguns afirmam ter semelhanças de aparência com as corujas . Com sua postura horizontal e pernas curtas, o gavião-noturno comum não viaja com frequência no solo, preferindo empoleirar-se na horizontal, paralelo aos galhos, em postes, no solo ou no telhado. Os machos desta espécie podem empoleirar-se juntos, mas a ave é principalmente solitária. O Nighthawk comum mostra variabilidade no tamanho do território.
Este caprimulgídeo tem uma cabeça grande e achatada com olhos grandes; no bico, faltam cerdas rictais. O bacurau-norte-americano tem asas longas e delgadas que em repouso se estendem além de uma cauda talhada. Há barreiras visíveis nas laterais e no abdômen, também manchas brancas nas asas.
O bacurau-norte-americano mede 22 a 25 centímetros de comprimento, exibe uma envergadura de 51 a 61 centímetros, pesa de 55 a 98 gramas e tem um tempo de vida médio de 4 a 5 anos.
Större falknattskärra[2] (Chordeiles minor) är en nord- och centralamerikansk fågel i familjen nattskärror inom ordningen skärrfåglar.[3]
Falknattskärror är liksom övriga nattskärror kryptiskt tecknade i brunt, grått, vitt och svart men har karakteristiskt lång kluven stjärt och glider i snedställda vingar med knickad knoge. Större falknattskärra är mellan 23-25,5 centimeter i längd[4] och har svarta obandade handpennor med ett vitt tvärband halvvägs mellan knogen och spetsen,[4] längre in än den i övrigt lika sydligare och västligare mindre falknattskärran.[5] Hanen har även en tydlig vit strupfläck som hos honan är mindre och beigefärgad.[4]
Från hanen hörs ett raspande, nasalt och elektriskt "beeezrh". Honan är mestadels tyst, men kan avge låga kluckande läten.[5]
Större falknattskärra delas in i åtta underarter med följande utbredning:[3]
Arten är en sällsynt gäst i Europa med fynd i Storbritannien, Irland och Azorerna.[6]
Större falknattskärra är vanlig kring fält, dammar, skogsgläntor och andra öppna områden, till och med över byar och städer. Den är mestadels nattaktiv, men ses till skillnad från de flesta nattskärror även dagtid flyga rätt högt upp på jakt efter insekter. Fågeln ses mestadels enstaka, men kan också forma lösa grupper.[5]
Arten har ett stort utbredningsområde och en stor population, men tros minska i antal, dock inte tillräckligt kraftigt för att den ska betraktas som hotad.[1] IUCN kategoriserar därför arten som livskraftig (LC).[1] Världspopulationen uppskattas till 16 miljoner häckande individer.[7]
Wikimedia Commons har media som rör större falknattskärra.
Wikispecies har information om Chordeiles minor.
Större falknattskärra (Chordeiles minor) är en nord- och centralamerikansk fågel i familjen nattskärror inom ordningen skärrfåglar.
Chordeiles minor là một loài chim trong họ Caprimulgidae.[3] Loài chim này có thể được tìm thấy trong rừng, sa mạc, thảo nguyên, bãi biển và sa mạc chà, thành phố, và thảo nguyên, ở độ cao của mực nước biển hoặc dưới 3.000 m (9.800 ft). Thân dài 22–25 cm, sải cánh dài 51–61 cm, cân nặng 55-98 g, và có một tuổi thọ 4-5 năm.
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Chordeiles minor là một loài chim trong họ Caprimulgidae. Loài chim này có thể được tìm thấy trong rừng, sa mạc, thảo nguyên, bãi biển và sa mạc chà, thành phố, và thảo nguyên, ở độ cao của mực nước biển hoặc dưới 3.000 m (9.800 ft). Thân dài 22–25 cm, sải cánh dài 51–61 cm, cân nặng 55-98 g, và có một tuổi thọ 4-5 năm.
保全状況評価 LEAST CONCERN
分類 界 : 動物界 Animalia 門 : 脊索動物門 Chordata 亜門 : 脊椎動物亜門 Vertebrata 綱 : 鳥綱 Aves 目 : ヨタカ目 Caprimulgiformes 科 : ヨタカ科 Caprimulgidae 属 : Chordeiles 種 : アメリカヨタカ C. minor 学名 Chordeiles minorアメリカヨタカ（亜米利加夜鷹、学名：Chordeiles minor）は、鳥類の一種。
この項目は、鳥類に関連した書きかけの項目です。この項目を加筆・訂正などしてくださる協力者を求めています（ポータル鳥類 - PJ鳥類）。 
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