Savanna nightjar | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Clade: | Strisores |
Order: | Caprimulgiformes |
Family: | Caprimulgidae |
Genus: | Caprimulgus |
Species: | C. affinis |
Binomial name | |
Caprimulgus affinis Horsfield, 1821 | |
Distribution map of savanna nightjar by subspecies. |
The savanna nightjar (Caprimulgus affinis), also known as allied nightjar or Franklin's nightjar, is a species of nightjar found in South and Southeast Asia. The IUCN Red List has assessed the species to be of least concern because it has a large range and its population trend is stable. [1] As other nightjars, this nocturnal bird is characterised by its large eyes, gaping mouth and excellent camouflage. It can be distinguished from similar southasian nightjar species, like the chirruping nightjar, by its unique vocalisations.
The savanna nightjar belongs to the diverse family Caprimulgidae along with 89 other species, 39 of which share the genus Caprimulgus. Currently eight subspecies are recognized: C. a. monticolus, C. a. amoyensis, C. a. stictomus, C. a. affinis, C. a. kasuidori, C. a. timorensis, C. a. Propinquus and C. a. griseatus. A recent study on variation in vocalisations found significant differences between the northern (C. a. monticolus, C. a. amoyensis, C. a. stictomus), southern (C. a. affinis, C. a. kasuidori, C. a. timorensis and C. a. propinquus) and Philippine (C. a. griseatus) subspecies, suggesting they may represent three separate species. [2] This proposal comes over 100 years after ornithologist Richard Bowdler Sharpe described C. monticolus, C. affinis and C. griseatus as separate species, with each species corresponding to one of the previously mentioned geographic regions. [3] Despite Sharpes early work, taxonomic authorities throughout the twentieth century regarded them as a single species, which has now become the universally accepted standard. The newly discovered vocal variation is based on the fact that non-passerines, like nightjars, do not exhibit vocal learning, meaning that differences likely reflect genetic divergence. These groups are also geographically separated, and have differences in size and plumage. Molecular and genetic research is necessary to reveal more about how these species are truly related. [2]
The savanna nightjar has a widespread range stretching from northern Pakistan to Indonesia, with different subspecies occupying different parts of the range. [2] Populations are widely distributed in south China, Pakistan, India, Indonesia and Taiwan, [4] where they occupy low-land open grasslands, sugar cane plantations, wheat fields, or rocky soils around rivers and streams. [5] With the increase of urban development across southern Asia, the roofs of tall buildings have proven to be an ideal nesting site for savanna nightjars, a phenomenon observed in Indonesia [6] and Taiwan. [5] The migration of savanna nightjars is poorly understood, as different subspecies vary from nonmigratory to locally migratory. C. a. Monticolus migrates through the Punjab plains to northeastern Pakistan for summer breeding. [7]
The savanna nightjar measures 20-26cm in length, has a body weight of 54-110g, and a wingspan of 64cm, [5] with size varying by subspecies, ranging from small to medium-large. Like other nightjars, they have long pointed wings and small legs and feet, indicating their reliance on flight over walking. The bill is wide, revealing a large gape when opened, and is surrounded by facial feathers, called rictal bristles. Their vermiculated grey-brown plumage, characteristic of all nightjars, makes them difficult to tell apart from other species based on sight alone. [8] However, males and females do exhibit sexual dimorphism and can be distinguished based on the presence of white throat patches. Male savanna nightjars have distinct white patches on their throat, tail and wings. In comparison, females have subtle throat patches, a red tint to their feathers and a lack of white patches on the tail. Immature and juvenile savanna nightjars resemble adult females, they lack white patches and have mottled colouration. [6]
Breeding season of the savanna nightjar varies among subspecies, occurring from March-August in the western range and March-January in the eastern range. [8] Typical of most nightjar species, the savanna nightjar nests in open and exposed places. Nests are not constructed, [4] instead eggs are laid on the ground in low-elevation rocky soils or open spaces. [5] 1-2 pale pink, blotched eggs are laid, which camouflage into the stones surrounding them. The eggs are incubated by the female, while the male parent guards the nest. Incubation time is unknown. Being precocial, savanna nightjar chicks are active and mobile 4 days after hatching. Parents defend their eggs and young by feigning injury, [4] a behaviour which provides an advantage to birds nesting in open areas, where they are more vulnerable to predators than cavity nesters. [9] To divert the attention of predators, savanna nightjar parents will act injured or crippled, luring the predators away from the nest at the risk of their own survival. [4] As with adult savanna nightjars, the chicks exhibit excellent camouflage to provide them added protection. [10]
Savanna nightjars begin vocalisation during early dusk and can be heard throughout the night until dawn, becoming especially vocal during breeding. [7] The characteristic “chwip” call [8] is used for both marking territory and attracting females during breeding season. Females vocalise less, emitting soft squeaks during brooding. [6] Savanna nightjars vocalise while in flight or perched on the ground, in low vegetation and urban structures like rooftops or poles. [7] Analysis of vocalisations across the subspecies revealed significant differences in frequencies and length of calls. The Philippine group has a raspier call than the northern and southern subspecies. The northern group has longer calls with higher variation in frequency than the southern group. [2]
The savanna nightjar is a nocturnal, insectivorous bird, most active in feeding from dusk to dawn. Hunting by sight, their large eyes and massive gape allows them to capture insects in flight and near-darkness, [11] a technique called sallying. During a sally, the bird spots an insect, spreads its wings, dives at it, and captures the prey in its beak before either landing on a nearby branch or returning to its perch. [12] Moths compose 80-85% of savanna nightjar food composition, but they also feed on beetles, ants, grasshoppers, crickets, wasps and bees. [10] Their rictal bristles serve two potential purposes: serving as a “scoop” in prey capture, and protecting the eyes from impact with hard-bodied insects or stinging or biting prey. [11]
A population of savanna nightjars have slowly expanded their range away from their natural habitats into the urban areas of Taiwan. Heard at night especially during the breeding season, the savanna nightjars booming call can reach up to 90 decibels and has become a nuisance to residents. In an attempt to remedy the sleep disruption and nightmares the calls have caused, citizens have resorted to firecrackers and flashlights in an attempt to drive away the birds. Urbanised savanna nightjars prefer to nest on flat roofs, most likely due to lack of predators. As their native habitats continue to be altered by dams, flooding and dredging, this population of savanna nightjars is expected to continue expanding to all major cities in Taiwan. [5]
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 standard-winged nightjar is a nocturnal bird in the nightjar family. Previously placed with the pennant-winged nightjar in their own genus, Macrodipteryx, it is native to Africa and displays extreme sexual dimorphism during the breeding season, wherein males will grow broad ornamental flight feathers longer than their body.
The Indian nightjar is a small nightjar which is a resident breeder in open lands across South Asia and Southeast Asia. Like most nightjars it is crepuscular and is best detected from its characteristic calls at dawn and dusk that have been likened to a stone skipping on a frozen lake - a series of clicks that become shorter and more rapid. They are sometimes spotted on roads when their eyes gleam red in the spotlight of a vehicle. There is considerable plumage variation across its range and can be hard to differentiate from other nightjars in the region especially in the field.
Jerdon's nightjar is a medium-sized nightjar species native to southern India and Sri Lanka. Formerly considered as a subspecies of the long-tailed nightjar, it is best recognized by its distinctive call which sounds like a wooden plank being beaten periodically with each note ending in a quaver. The common name commemorates Thomas C. Jerdon who described the species.
Prigogine's nightjar or the Itombwe nightjar, is a bird species of tropical central Africa. It is known from only one specimen taken at Malenge in the Itombwe Mountains in Zaire in August 1955.
The Puerto Rican nightjar, Puerto Rican whip-poor-will or guabairo is a bird in the nightjar family found in the coastal dry scrub forests in localized areas of southwestern Puerto Rico. It was described in 1916 from bones found in a cave in north central Puerto Rico and a single skin specimen from 1888, and was considered extinct until observed in the wild in 1961. The current population is estimated as 1,400-2,000 mature birds. The species is currently classified as Endangered due to pressures from habitat loss.
Caprimulgus is a large and very widespread genus of nightjars, medium-sized nocturnal birds with long pointed wings, short legs and short bills. Caprimulgus is derived from the Latin capra, "nanny goat", and mulgere, "to milk", referring to an old myth that nightjars suck milk from goats. The common name "nightjar", first recorded in 1630, refers to the nocturnal habits of the bird, the second part of the name deriving from the distinctive churring song.
The jungle nightjar is a species of nightjar found in the Indian Subcontinent. It is found mainly on the edge of forests where it is seen or heard at dusk. The taxonomy of this and related nightjars is complex and a range of treatments have been followed that cover this and several other nightjars in the Asian region. It was formerly called the grey nightjar or Indian jungle nightjar and sometimes included the East Asian grey nightjar as a subspecies.
The Sykes's nightjar, Sykes' nightjar, Sind nightjar or Sindh nightjar is a nightjar species found in northwestern South Asia. They are insectivorous nocturnal birds known for their sandy plumage used for camouflage and their excellent flight abilities, allowing them to catch their prey mid-air. This species has a large range with stable population size and therefore has been listed as “Least Concern” with no prediction of substantial human influence on their habitats in the near future.
The Satanic nightjar, also Heinrich's nightjar, satanic eared-nightjar, Sulawesi eared-nightjar or diabolical nightjar is a mid-sized, spotted, dark brown nightjar endemic to the Indonesian island of Sulawesi. The species was discovered in 1931 by Gerd Heinrich, a German natural historian who collected a single female holotype from Mount Klabat on the Minahasa peninsula of Northern Sulawesi.
The great potoo or grand potoo is the largest potoo species and is widely distributed in Central and South America.
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 band-winged nightjar or greater band-winged nightjar is a species of nightjar in the family Caprimulgidae. It is widespread in South America, where it is found in the Andes, Venezuelan Coastal Range, Santa Marta Mountains, Tepuis, most of Chile, Argentina, Paraguay, Uruguay, and eastern Brazil. It occurs in a wide range of habitats, from the edge of humid montane forests to shrubby semi-deserts and urban rooftops.
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 little nightjar is a species of nightjar in the family Caprimulgidae. It is found in Argentina, Bolivia, Brazil, Paraguay, Peru, and Uruguay.
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 grey nightjar is a species of nightjar found in East Asia, breeding from southeastern Russia south through China, the Korean Peninsula and Japan to northern Indochina and westward along the Himalayas. It is largely migratory, wintering in Indochina south to Java in Indonesia, but is resident in warmer areas in the south of its breeding range. It is sometimes treated as a subspecies of the jungle nightjar, its South Asian relative. The grey nightjar breeds and forages in early successional habitats surrounded by forests; its populations have declined since the 1970s in Japan. Like all nightjars, it is crepuscular to nocturnal, feeding on flying insects, including moths, beetles, flying ants, grasshoppers, and others.
The chirruping nightjar or kayumanggi nightjar is a species of nightjar found in Philippines. Two subspecies are recognised: C. g. griseatus and C. g. mindanensis. It was once considered conspecific with the savanna nightjar, while it is significantly different in vocalization.
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