Eurasian Nightjar Caprimulgus europaeus Scientific name definitions

The Eurasian Nightjar is most familiar and best-known in its breeding grounds in Europe, where it inhabits a variety of open and edge habitats, mostly in the lowlands. Over much of the breeding range it is the only nightjar. It is typically difficult to find during the day but at dusk its prolonged churring song that seems to change pitch frequently, and its foraging flights, give it away. Like many of its congeners, its plumage is highly cryptic; males have white patches in primaries and tail lacking in the female. It lays its eggs directly on the ground and relies on its excellent camouflage for protection. The female incubates but may leave the young prefledging to start a second clutch, in which case the male likely takes over rearing of the first brood. It winters in subsaharan Africa, where silent birds can be difficult to identify with certainty from the many co-occurring nightjar species there. Recent mtDNA research strongly suggests that "Vaurie's Nightjar C. centralasicus" is an immature bird of C. europaeus unwini.

24·5–28 cm; male 51–101 g, female 67–95 g. Upperparts greyish-brown streaked blackish-brown with indistinct pale buff nuchal collar; lesser coverts brown, rest of wing-coverts greyish-brown spotted buffish, showing buff line across forewing and buff line along scapulars; broad buffish-white submoustachial stripe and white throat patch; underparts greyish-brown, barred brown and spotted buff, becoming buff barred brown on belly and flanks. Male has white spot on three (occasionally four) outermost primaries and white tips to two outermost tail feathers, while female lacks white markings. Iris dark brown, bill blackish, legs and feet brown or flesh-brown. Immature similar to adult female.

Caprimulgus europaeus is smaller and darker brown than C. ruficollis, with white spots on primaries closer to wingtip. It is larger than C. rufigena, with nuchal collar far less distinct. C. europaeus is paler and generally larger than C. fraenatus, which is more heavily spotted, and has broad buff or tawny-buff nuchal collar.

Sexually dimorphic, with females lacking the white wing and tail markings of the male. Immatures generally paler than adults.

Much of geographical variation is clinal. Six subspecies recognized, but a recent mtDNA analysis found no correspondence between genetic variability and described subspecies (1 Schweizer, M., C. Etzbauer, H. Shirihai, T. Töpfer, and G. M. Kirwan (2020). A molecular analysis of the mysterious Vaurie’s Nightjar Caprimulgus centralasicus yields fresh insight into its taxonomic status. Journal of Ornithology 161:635-650. Close ).

The status of Vaurie's Nightjar "C. centralasicus" has long been disputed, as it is known only from the type specimen, an immature female originally identified as C. aegyptius, and compared only with that species when described. One reassessment strongly supported the validity of "centralasicus", noting that the specimen is markedly smaller than any of plumipes even allowing for incomplete growth of wings (2 Leader, P.J. (2009). Is Vaurie’s Nightjar Caprimulgus centralasicus a valid species? BirdingASIA. 11: 47–50. Close ). However, in a more recent mtDNA analysis, the type specimen of "centralasicus" clusters within an eastern clade of C. europaeus, and thus the most likely explanation is that "centralasicus" is a synonym of C. e. plumipes, one of the eastern races of europaeus, despite its seemingly distinctive plumage and size (1 Schweizer, M., C. Etzbauer, H. Shirihai, T. Töpfer, and G. M. Kirwan (2020). A molecular analysis of the mysterious Vaurie’s Nightjar Caprimulgus centralasicus yields fresh insight into its taxonomic status. Journal of Ornithology 161:635-650. Close ). However, predefinitive plumages remain poorly known for C. e. plumipes and the only other plausible, but less likely, explanation for these findings would be if "centralasicus" represents a hybrid between a female C. europaeus plumipes and a male of some other species (1 Schweizer, M., C. Etzbauer, H. Shirihai, T. Töpfer, and G. M. Kirwan (2020). A molecular analysis of the mysterious Vaurie’s Nightjar Caprimulgus centralasicus yields fresh insight into its taxonomic status. Journal of Ornithology 161:635-650. Close , 3 Kirwan, G. M., and M. Schweizer (2020). Resolving the mystery of Vaurie's Nightjar and problems posed by single-specimen series. Dutch Birding 42:355–366. Close ).

Variation is generally clinal, birds becoming smaller and paler to east through range, with white wing spots of males becoming larger.

The single specimen on which the putative species Vaurie's Nightjar "C. centralasicus" is based is smaller (19 cm), and is a suspected immature female. Closest in size to C. nubicus and C. mahrattensis (2 Leader, P.J. (2009). Is Vaurie’s Nightjar Caprimulgus centralasicus a valid species? BirdingASIA. 11: 47–50. Close ). Upperparts sandy-buff, streaked and vermiculated brown, no nuchal collar; wing-coverts sandy-buff vermiculated brown and spotted pale buff, scapulars buff with dark central streaks; underparts pale buffish barred brown; underwing rufous-cinnamon with brown markings (2 Leader, P.J. (2009). Is Vaurie’s Nightjar Caprimulgus centralasicus a valid species? BirdingASIA. 11: 47–50. Close ) (lacks white markings); two outermost tail feathers narrowly tipped pale buffish white. Iris dark brown, bill dark horn, legs and feet fleshy-brown. Smaller than C. aegyptius (unknown in China) (2 Leader, P.J. (2009). Is Vaurie’s Nightjar Caprimulgus centralasicus a valid species? BirdingASIA. 11: 47–50. Close ), which is slightly greyer and more spotted, with unbarred darker upperwings becoming barred over distal half of feathers and white underwings, whereas the outer primaries of "centralasicus" are evenly barred mid-brown and pale buff, with those primaries visible when wing closed very pale and almost unmarked (2 Leader, P.J. (2009). Is Vaurie’s Nightjar Caprimulgus centralasicus a valid species? BirdingASIA. 11: 47–50. Close ). Furthermore, the uppertail is almost unmarked in "centralasicus" (aegyptius has thin black bars), the crown and scapulars have distinct black streaks (lacking in aegyptius), while other differences in "centralasicus" are presence of supercilium, buffy rather than pure white patches at base of throat, chestnut rather than greyish ear-coverts, and paler tips to greater wing-coverts (2 Leader, P.J. (2009). Is Vaurie’s Nightjar Caprimulgus centralasicus a valid species? BirdingASIA. 11: 47–50. Close ). Immature plumages unknown, although the only known specimen could perhaps be of an immature bird.

Considered to be closely related to C. fraenatus and C. rufigena. Sometimes reckoned to be replaced to the east by C. indicus, but in a recent mtDNA phylogeny, C. jotaka (to which the samples pertain, formerly considered conspecific with C. indicus) and C. europaeus showed a non-sister relationship (1 Schweizer, M., C. Etzbauer, H. Shirihai, T. Töpfer, and G. M. Kirwan (2020). A molecular analysis of the mysterious Vaurie’s Nightjar Caprimulgus centralasicus yields fresh insight into its taxonomic status. Journal of Ornithology 161:635-650. Close ). Rather, C. europaeus was sister to a clade comprising (among those species sampled) C. aegyptius, C. mahrattensis, C. eximius, and C. nubicus (1 Schweizer, M., C. Etzbauer, H. Shirihai, T. Töpfer, and G. M. Kirwan (2020). A molecular analysis of the mysterious Vaurie’s Nightjar Caprimulgus centralasicus yields fresh insight into its taxonomic status. Journal of Ornithology 161:635-650. Close ).

Although "C. centralasicus" is now considered a synonym of C. europaeus, it is not yet completely clear to which subspecies it should be referred. Presumably this would be C. e. plumipes, the breeding subspecies in the area in which the type specimen, now generally agreed to be a young juvenile, was collected.

Breeding range extends from the British Isles, Iberian Peninsula, and northwestern Africa through southern Fennoscandia, Turkey, and Afghanistan to Mongolia and southern Russia. Wintering range subsaharan Africa, mainly eastern Africa.

Breeds in a variety of dry, open country habitats, as well as openings and edges in forest, woodland, and plantations. Often forages over open farmland and wet habitats.

Mainly dry, open country: lowland heaths with scattered trees and bushes, commons and moorland, forest and woodland (especially glades, clearings and edges), recently felled woodland and young forestry plantations. Also chalk downland, industrial waste tips, wooded or scrub-­covered steppe, sparsely forested or stony hillsides, oak scrubland, dense coppices, shingle, sand dunes, semi-deserts and deserts. Tends not to breed in urban areas, mountains, steppes, treeless plains, dense forest interior, mature plantations, cultivation and tall grassland, but not infrequently forages over such areas as farmland, gardens, reedbeds and wet habitats (e.g. marshes). Recorded from sea-level to 2800 m on breeding grounds.

On wintering grounds in wooded country, dry coastal acacia steppe, forest clearings, open sandy country and highlands, up to 5000 m during winter.

Highly migratory. Nominate race leaves breeding grounds late Jul to Nov (mainly late Aug to Oct), W populations moving S on broad front across Europe, Mediterranean and N Africa, E populations moving SW on broad front through Middle East (mid-Aug to early Dec) and E Africa. Winters mainly in E & S Africa, although small numbers may winter in W Africa. In spring, returning birds move N or NE, Mar–Jun, generally returning to breeding grounds Apr–May. In recent study, light-geolocation tags (using timing of dawn and dusk to gauge longitude, and daylight length to gauge latitude) fitted to three individuals breeding in S England were used to determine non-breeding areas: all three found to be wintering in S & E of DR Congo (not previously considered part of species’ wintering range); migration route detected for one individual, which crossed C Sahara in autumn, but took spring return route to W of Sahara (4 Cresswell, B. and Edwards, D. (2013). Geolocators reveal wintering areas of European Nightjar (Caprimulgus europaeus). Bird Study. 60(1): 77-86. . Close ). Race meridionalis moves S on broad front across Mediterranean, N parts of Middle East and N Africa, and winters mainly in S and perhaps C Africa, though small numbers may winter in W Africa. Return movements probably at same time as nominate race. Race sarudnyi possibly winters mainly in E & SE Africa. In spring, moves NE through Arabian Peninsula, perhaps late Feb to May. Race unwini leaves breeding grounds possibly Aug–Sept and moves SE on broad front across Middle East; winters mainly in E & SE Africa, although small numbers occasionally overwinter in Israel, Pakistan and possibly NW India. Return route in spring apparently farther N. After breeding, race plumipes moves SW on broad front and winters mainly in SE Africa. Race dementievi probably also winters in E & SE Africa. Vagrants recorded in Iceland, Faeroes, Azores, Madeira, Canary Is and Seychelles.

Diet includes a wide variety of insects and occasionally other invertebrates. Forages mostly in flight, usually solitarily,

Foraging flight is agile and buoyant. Hunts over open country, in clearings, along woodland edges and borders, in woodland glades and rides, in gardens and orchards, over wetlands, in meadows and farmland, around grazing animals, and over stagnant ponds. Usually feeds solitarily , but loose feeding flocks sometimes occur. Also feeds on insects at artificial lights. May forage diurnally on overcast days. Also makes short flycatching sallies from ground or low perches, and hovers close to vegetation to take food from foliage. Occasionally hovers and swoops down after prey. Rarely feeds on ground, but does so by darting forward to take prey.

Diet includes moths, beetles, mantises, mayflies, dragonflies, Orthoptera, cockroaches, bugs, Hymenoptera, antlions, lacewings, caddisflies and flies. Occasionally takes butterflies and flightless glow-worms, and also feeds on spiders and mites, latter probably taken with other prey items. Grit and small stones are also ingested and vegetable matter is probably taken accidentally.

Drinks in flight.

Song of male is a distinctive, continuous churring that frequently changes to a lower pitch and back again. Sings from perches and occasionally from ground. Contact call of both sexes, usually given in flight, is a short co-ic; bubbling trills are given by male during interactions with female. A wide variety of calls given by both sexes have been represented as chunk, chink, chik, dak, chuk, chek, chek-ek, chuk or clucking notes. At nest-site adult grunts or gives gruff wuk, wuk, wuk or muffled oak, oak notes; female also gives loud quacks. All birds make guttural hissing sounds during threat/defence displays. Chick utters a variety of chirps and cheeps.

Breeds late May to Aug, occasionally Apr–Jul in some regions; breeding often ­influenced by lunar phase. Single-brooded or double-brooded. Generally monogamous; territorial. Nest-site in open, beneath tree, bush or shrub, within upturned tree roots or among vegetation, occasionally inside mature plantation; sometimes used for several successive years; no nest, eggs laid on ground, on leaf litter, pine needles or bare soil. Clutch usually 1–2 eggs , elliptical, smooth and fairly glossy, whitish, greyish-white or cream, spotted and blotched yellow-brown, dark brown and grey or densely scrawled brown and grey, rarely unmarked, laid at intervals of 36–48 hours; incubation begins with first egg, mainly by female, period 17–21 days, eggs hatching asynchronously; chick semi-precocial, covered in dark brown and creamy-buff down, brooded by female for 10–16 days, then by male if female lays second clutch; female threatened at nest-site performs injury-feigning distraction display on ground, from exposed perch or in flight; young fledge at 16–17 days and become independent at c. 32 days. If two broods, female leaves first brood when chicks 10–16 days old; male then generally tends first brood and helps with second.

Breeds late May to Aug, occasionally Apr–Jul in some regions; breeding often ­influenced by lunar phase. Single-brooded or double-brooded.

Nest-site in open, beneath tree, bush or shrub, within upturned tree roots or among vegetation, occasionally inside mature plantation; sometimes used for several successive years.

No nest; eggs are laid on ground, on leaf litter, pine needles or bare soil.

Clutch usually 1–2 eggs , elliptical, smooth and fairly glossy, whitish, greyish-white or cream, spotted and blotched yellow-brown, dark brown and grey or densely scrawled brown and grey, rarely unmarked, laid at intervals of 36–48 hours.

Incubation begins with first egg, mainly by female, Incubation period 17–21 days,

Eggs hatch asynchronously.

Chicks semi-precocial, covered in dark brown and creamy-buff down, brooded by female for 10–16 days; young fledge at 16–17 days and become independent at c. 32 days.

Chicks brooded by female for 10–16 days, then by male if female lays second clutch; female threatened at nest-site performs injury-feigning distraction display on ground, from exposed perch or in flight. If two broods, female leaves first brood when chicks 10–16 days old; male then generally tends first brood and helps with second.

Not globally threatened. Locally common to very common in suitable habitat throughout breeding range, though decreasing in numbers and/or range in many regions, especially in NW Europe. Total European breeding population estimated at 290,000–830,000 pairs, most in Russia (up to 500,000 pairs), Spain (up to 112,000 pairs) and Belarus (up to 60,000 pairs). Throughout range, breeding densities vary from 0·1 pair per km² to 19·4 pairs per km²; territory size variable, 1·5–31·9 ha. In Europe, major declines noted in late 19th century and these have continued through current century, most notably since 1970’s, in Britain and Ireland, France, Belgium, Luxembourg, Netherlands, Denmark, Sweden, Finland, Czech Republic, Austria, Switzerland, Spain, Italy, Albania, Romania, Croatia, Bulgaria, Ukraine and Moldova; contraction of range also recorded in Andorra, Portugal and possibly Denmark; numbers also declining in Norway, Germany, Estonia, Latvia and Greece. Decreases probably due to reduction of insect availability resulting from pesticide use, increasing road traffic, disturbance at breeding sites, and loss or degradation of habitat, although in some countries, e.g. Britain, creation of habitat through commercial forestry has seen increase in numbers in recent years, though habitats not permanent and stability of higher population levels not guaranteed. Numerous predators, especially of eggs and chicks, include crows (Corvus), Magpies (Pica pica), Jays (Garrulus glandarius), owls (Strigidae), Sooty Falcon (Falco concolor), hedgehogs (Erinaceus europaeus), weasels (Mustela nivalis) and domestic dogs. In Pakistan, a widely distributed and common breeding bird and passage migrant, a few birds possibly overwintering occasionally. On African wintering grounds, often common in SW Mauritania, probably under-recorded in NW Senegal, decreased in Gambia since early 20th century, rare in Ghana, fairly common in E Nigeria and S Cameroon, but very few records from other W African countries. Not uncommon in much of SE African range from Kenya (passage migrant only) and Tanzania S to Natal, though fairly common locally in Mozambique; widely distributed, especially in SE low veld, but possibly not common in Zimbabwe; scarce in Zambia.