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Nighthawk | |
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Common nighthawk, Chordeiles minor | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Clade: | Strisores |
Order: | Caprimulgiformes |
Family: | Caprimulgidae |
Subfamily: | Chordeilinae |
Genera | |
Nighthawks are nocturnal birds of the subfamily Chordeilinae, within the nightjar family, Caprimulgidae, which is a grouping of 92 species of medium sized birds with long wings and short bills specialized for eating insects. [1] The nighthawk's subfamily consists of four genera: Chordeiles ; Swainson, 1832, Lurocalis; Cassin, 1851, Podager; Wagler, 1832, and Nyctiprogne; Bonaparte, 1857, which are all native to the western hemisphere. [2]
Species in the family Caprimulgidae exhibit similarities in plumage appearance, a fact that some attribute to convergent evolution, which occurs when species that do not share an evolutionary history develop similar adaptations, while others attribute it to parallelism which is the process by which similar adaptations arise in members of closely related species or populations. [3] Because of this, taxonomists in the past experienced difficulty in categorizing members of this group, however new advancements in molecular phylogeny have allowed for more conclusive classification. [3] Thanks to these techniques, it is now understood that there are nine genera in the family, not 16 as previously accepted, and that there are two main subfamilies: Caprimulginae (nightjars) and Chordeilinae which is the subfamily that nighthawks belong to. [3] Because of this taxonomic complexity, a lot of information regarding nightjars is conflated with information regarding nighthawks. Nighthawks are similar in most respects to the nightjars, but have shorter bills and plumage that is less soft. Nighthawks are less strictly nocturnal than many nightjars and may be seen hunting when there is still light in the sky. [3]
The subfamily Chordeilinae contains four genera and ten species. [4] Under the genus Chordeiles exists the greatest number of diversity in species in the subfamily with the lesser nighthawk (Chordeiles acutipennis), the Antillean nighthawk (Chordeiles gundlachii), the common nighthawk (Chordeiles minor), the nacunda nighthawk (Chordeiles nacunda), the least nighthawk (Chordeiles pusillus), and the sand-colored nighthawk (Chordeiles rupestris) comprising the category. [4] The genus Lurocalis contains the chestnut-banded nighthawk (Lurocalis nattereri), the Rufous-bellied nighthawk (Lurocalis rufiventris), and the short-tailed nighthawk (Lurocalis semitorquatus). [4] There is only one species in the monotypic genus Nyctiprogne which is the band-tailed nighthawk (Nyctiprogne leucopyga), a small bird differentiated from other nighthawks by it's long tail and dark appearance. [4] [5]
Image | Genus | Living species |
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Nyctiprogne Bonaparte, 1857 |
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Lurocalis Cassin, 1851 |
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Chordeiles Swainson, 1832 |
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While limited information is known regarding the discovery of nighthawks, it is believed that the term "nighthawk", first recorded in the King James Bible of 1611, was originally a local name in England for the European nightjar. [6] Its use in the Americas to refer to members of the genus Chordeiles and related genera was first recorded in 1778 when John Cassin, a renowned ornithologist responsible for the establishment of the Delaware County Institute of Science, established the classification. [6] [7] Fossil records indicate that specimens later identified to be the common nighthawks (Chordeiles minor) excavated in the Southwestern US could be traced back as far as 400,000 years (during the Pleistocene era) meaning that the subfamily has been an entrenched component of new world ecology for a significant duration of time. [8]
Nighthawks are medium-sized birds averaging 9 inches (22–24 cm) from bill to tail with a wingspan of about 21-22 inches (53–57 cm), short legs, and very short, wide bills that are moderately hooked at the tip. [9] The least nighthawk (Chordeiles pusillus), at 6.3 inches (15–19 cm) and 23 grams (0.81 oz), is the smallest of all Caprimulgiformes, while the Nacunda nighthawk (Chordeiles nacunda) is one of the largest nightjars in the world measuring at 11-13 inches (28–33 cm). [10] [11] Nighthawks have small feet, of little use for walking, and long pointed wings. Their soft plumage is cryptically coloured to resemble bark or leaves, aiding in protection from their primary predators; foxes and racoons. [12] To promote concealment during the day, some species perch facing lengthwise along a branch, rather than across it as birds usually do.
Nighthawks are generally solitary but form flocks for the purpose of migration and for elaborate mating displays. [13] These displays begin with the males diving from high in the air to produce the booming noises also associated with defense. [14] This process is followed by tail-shaking, the exposing of a white patch located on the throat of the male, and vocalizations similar to croaks. [14] Although it is unclear whether nighthawks mate for life, they are monogamous for the duration of mating season in which they develop a barren nest on the ground or another flat surface, such as an urban roof, where the female lays two patterned eggs directly onto bare ground. [15] These eggs incubate for 18 to 20 days between May and August and they emerge semi-precocial, meaning they have their eyes open and a layer of down. [14] Males will defend the nesting area, demonstrating indiscriminate aggression with displays involving diving and the production of a booming noise using their wings which deters predators and others of the same species. [15] This unselective hostility can result in a decline in the average proportion of breeding individuals in a population in densely occupied territories, even below that of the carrying capacity established by available resources. [15] This means that prey availability is not commonly cited as a concern for the conservation of nighthawks, but rather that habitat loss can be damaging to population stability. [15] Nighthawks are mostly active in the late evening and early morning or at night and feed on moths and other large flying insects by holding their beak open in flight. [16] There exists a mistaken belief that members of the Caprimulgidae family suck milk from goats (the Latin for goatsucker is Caprimulgus), however this claim is as of yet unsubstantiated. [16] Heard most often at dusk, nighthawks have been known to perform a loud, nasal call which has been described as sounding like the noise "pee-yah". [17]
Nighthawks are visually reliant predators that feed on flying insects such as beetles (Coleoptera), sawflies, bees, ants, and wasps (Hymenoptera), flies (Diptera), caddisflies (Trichoptera), butterflies, and moths (Lepidoptera) by opening their wide mouths to allow for the entrance of the insects as they are traveling. [16] Areas of high precipitation, cool temperature, or high elevation are therefore unfavorable to nighthawks because flying insects are less mobile in such conditions. [16] Nighthawks are most often observed hunting during crepuscular periods, or during twilight, which necessitates good eyesight with insects shorter than 5mm eliciting no reaction from experimental nighthawks. [16] This consideration could pose a long-term risk to nighthawk population stability as climate change is increasing vulnerability in larger insects due to extreme weather events and higher temperatures, thus restricting prey availability for nighthawks which cannot see the, in some circumstances, 20% smaller prey organisms. [18]
During the day, nighthawks roost in forested areas which provide them with cover from both predators and temperature fluctuations, although they may also occasionally be observed in grasslands and early successional habitats rich in foraging opportunities. [19] Nighthawks breed in more open habitats like beaches or clearings to allow for the males to perform their mating rituals. [14]
In October 2018, the University of Alberta published research on the common nighthawk revealing that it travels 20,000 km (12,000 mi) every year during migration between the rainforests and savannas of Brazil and its breeding grounds in northern Alberta. [20] Further research has determined that, in addition to this annual migration between general regions, nighthawks demonstrate a high breeding site fidelity, thus meaning they are especially susceptible to destabilization as a result of natural disasters such as forest fires, floods or droughts, as well as anthropogenic interventions such as development. [19] Nighthawks have been observed migrating at all hours of the day in flocks of, at times, hundreds of birds which winter in both rural and urban regions of South America. [13] Nighthawk migration is considered one of the longest routes traveled for any North American bird. [13]
Nightjars are medium-sized nocturnal or crepuscular birds in the family Caprimulgidae and order Caprimulgiformes, characterised by long wings, short legs, and very short bills. They are sometimes called bugeaters, their primary source of food being insects. Some New World species are called nighthawks. The English word nightjar originally referred to the European nightjar.
The European nightjar, common goatsucker, Eurasian nightjar or just nightjar, is a crepuscular and nocturnal bird in the nightjar family that breeds across most of Europe and the Palearctic to Mongolia and Northwestern China. The Latin generic name refers to the old myth that the nocturnal nightjar suckled from goats, causing them to cease to give milk. The six subspecies differ clinally, the birds becoming smaller and paler towards the east of the range. All populations are migratory, wintering in sub-Saharan Africa. Their densely patterned grey and brown plumage makes individuals difficult to see in the daytime when they rest on the ground or perch motionless along a branch, although the male shows white patches in the wings and tail as he flies at night.
The common nighthawk or bullbat is a medium-sized crepuscular or nocturnal bird of the Americas within the nightjar (Caprimulgidae) family, whose presence and identity are best revealed by its vocalization. Typically dark, 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.
The common poorwill is a nocturnal bird of the family Caprimulgidae, the nightjars. It is found from British Columbia and southeastern Alberta, through the western United States to northern Mexico. The bird's habitat is dry, open areas with grasses or shrubs, and even stony desert slopes with very little vegetation.
The lesser nighthawk is a nightjar found throughout a large part of the Americas. This bird looks similar to the common nighthawk but is slightly smaller, has a slightly less deeply forked tail, and is more buffy in coloration. Their distinctive mouths are very well adapted for capturing insects mid-flight.
The Antillean nighthawk is a nightjar native to the Caribbean, The Bahamas, and Florida Keys.
The eared nightjars are a small group of nocturnal birds in the nightjar family, although the taxonomy is uncertain. There are seven species, mainly found in forest and scrub from China to Australia. Five species are placed in the genus Eurostopodus, the other two species in Lyncornis. They are long winged birds with plumage patterned with grey and brown to camouflage them when resting on the ground. They feed on insects caught in flight. A single white egg is laid directly on the ground and incubated by both adults. The chicks can walk soon after hatching.
The Caprimulginae or typical nightjars are a nocturnal bird subfamily within the nightjar family, Caprimulgidae. They are medium-size with long wings, short legs, and very short bills. They usually nest on the ground. They feed on flying insects.
The Long-tailed Nightjar is one of 98 species of nightjar in the family Caprimulgidae, the "true nightjars". It is a nocturnal, insectivorous bird characterized by its distinctive long tail. It is found throughout mainland Africa in open areas, arid semi-deserts, and savannas, with common sightings alongside roadways.
The large-tailed nightjar is a species of nightjar known for its distinctive long, broad tail and cryptic plumage that allows it to blend into its surroundings. Found along the southern Himalayan foothills, eastern South Asia, Southeast Asia and northern Australia, its natural habitats are subtropical or tropical moist lowland forest, subtropical or tropical mangrove forest, and subtropical or tropical moist montane forest.
The fiery-necked nightjar is a species of nightjar in the family Caprimulgidae, which is found mostly in Africa south of the equator, though it has been spotted in a few countries north of the equator. It is most often found in woodland savannas or other deciduous woodlands. It is usually distinguished by its tawny coloured collar which gives the species its common name. It has a distinctive call that many have rendered as 'good-lord-deliver-us'. The fiery-necked nightjar is an insectivorous species that mostly eats butterflies, moths and other insects. The fiery-necked nightjar breeds after the dry season and typically produce two clutches with two eggs per clutch.
The rufous-cheeked nightjar is a species of nightjar in the family Caprimulgidae. It is an intra-African migrant that breeds in the south of its range. It spends the non-breeding season in eastern Nigeria, Cameroon, southern Chad and Sudan, the Republic of the Congo, the D.R.C. and western Central African Republic. Throughout the year it can be found in Southern Africa. It is a nocturnal species that feeds on flying insects, mainly hunting at dusk and the early night. They can hunt at night thanks to their large eyes that are adept at seeing in the dark. They cannot see in complete darkness and most likely cannot see colours either. The rufous-cheeked nightjar forms monogamous pairs and the egg laying period is from September to November. It looks very similar to other African nightjars and they are frequently misidentified during research and studies.
The least nighthawk is a species of nightjar in the family Caprimulgidae. It is found in Argentina, Bolivia, Brazil, Colombia, Guyana, Suriname, and Venezuela.
The spotted nightjar or spotted eared-nightjar is a species of nightjar in the family Caprimulgidae. It inhabits much of mainland Australia and has also been found in several Indonesian islands. Its natural habitats are open forests and woodlands, scrub, spinifex and tussock grassland, savannah woodland and mangroves.
The Malaysian eared nightjar or Malay eared nightjar is a species of nightjar in the family Caprimulgidae. They were previously known as Eurostopodus temminckii prior to their taxonomic revision. They are also known as Taptibau Kecil in Bahasa melayu or Tukang Tabtibau amongst Malaysian indigenous communities. They are dispersed throughout Southeast Asia, primarily occurring in Malaysia, Sumatra, Borneo, Thailand, Indonesia and Singapore. They are nocturnal insectivorous birds characterised by cryptic colouration of brown and white patterns, to aid them in camouflaging into their environment. Due to their nocturnal nature and feeding habits, they prefer subtropical, tropical and moist lowland forests, and have been recorded from sea-level to 1065 meters. They are easily distinguished by their 'ear-tufts,' giving them an "eared" appearance which led to their name.
The rufous-bellied nighthawk, sometimes also Taczanowski's nighthawk, is a species of nightjar in the family Caprimulgidae. It is found in Bolivia, Colombia, Ecuador, Peru, and Venezuela.
Lurocalis is a genus of nightjar in the family Caprimulgidae. The species are found in Central and South America.
The short-tailed nighthawk is a species of nightjar in the family Caprimulgidae. It is found in Mexico, in every Central American country except El Salvador, in Trinidad and Tobago, and in every mainland South American country except Chile and Uruguay.
The band-tailed nighthawk is a species of nightjar in the family Caprimulgidae. It is widely spread throughout northern and central South America. There are currently 5 subspecies. They are most vocal during the night time, indicating that they are nocturnal birds. They have an insectivorous diet, and feed on flying insects. Band-tailed nighthawks have an interesting reproductive strategy. Instead of building traditional nests, they lay their eggs directly on the ground, typically in concealed locations within their forested habitats. This adaptation may help reduce the chances of nest predation.
The nacunda nighthawk is a species of nightjar in the family Caprimulgidae. It is found in Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, French Guiana, Guyana, Paraguay, Peru, Suriname, Trinidad and Tobago, Uruguay, and Venezuela. Its natural habitats are dry savanna, subtropical or tropical seasonally wet or flooded lowland grassland, and heavily degraded former forest.