Spotted nightjar

Last updated

Spotted nightjar
Eurostopodus argus 2 - Christopher Watson.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Clade: Strisores
Order: Caprimulgiformes
Family: Caprimulgidae
Genus: Eurostopodus
Species:
E. argus
Binomial name
Eurostopodus argus
Hartert, 1892

The spotted nightjar or spotted eared-nightjar (Eurostopodus argus) 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. [2]

Contents

Spotted nightjars are larger and more colorful than other species of nightjar, and are known for their intricately flecked plumage patterns which allow them to camouflage well against the ground. Adult spotted nightjar have large white spots on four outer primary feathers, lacking the white tail markings of the more tropical large-tailed nightjar.

Spotted nightjars are nocturnal and insectivorous, and primarily roost and on the ground, rarely perching in trees. They tend to both eat and drink while in flight, skimming along the surface of water holes in order to do so.

Taxonomy

The spotted nightjar was first described by Ernst Hartert in 1892. [2] The order Caprimulgiformes includes four families; oilbirds, frogmouths, potoos, and the nightjars. The nightjars are split into two subfamilies, Chordelinae (American nighthawks) and Caprimulginae (typical nightjars). [3] Within the Caprimulginae, the genus Eurostopodus (the eared nightjars) consists of seven extant species, including Eurostopodus argus. [4]

Distribution

The spotted nightjar occurs across most of mainland Australia, although it is generally absent east and south of the Great Dividing Range along the eastern seaboard from central Queensland to southeast South Australia and does not occur in Tasmania. Individuals may be locally nomadic or sedentary in northern regions, while southern birds are partially sedentary or migratory, wintering in northern Australia from May to September. The species may also winter on Indonesian islands in the Banda Sea, possibly for some individuals as a result of overshooting, with vagrants recorded as far north as Irian Jaya. [2]

Habitat

The spotted nightjar occurs in a variety of habitats from deserts to mangroves, generally preferring warmer, drier country than areas with more humid, cooler climates. Habitat types include savannah woodland; low open sclerophyll forest; mallee; mulga and acacia scrubland as well as spinifex and tussock grasslands. The species has also been recorded in relatively harsh environments including gibber plains, semi deserts and deserts. [5] The species generally avoids dense grasslands and tall, closed forest. Winter habitats on Indonesian islands include savannahs, grasslands and the edges of rainforests. [2]

Description

One of the larger and more colourful of the nightjars, the intricate, heavily spotted and flecked patterns of the spotted nightjar enable it to blend perfectly where red, grew or brown soils are strewn with rocks, leaves, branches and twigs. [6] Similar in appearance to two other Australian nightjar species, the large-tailed nightjar (Caprimulgus macrurus) and white-throated nightjar (Eurostopodus mystacalis), an adult spotted nightjar in flight displays large white spots on four outer primary feathers, lacking the white tail markings of the more tropical large-tailed nightjar. Adult body length is 25–28 cm. [6] Adult males weigh 81-132 g while adult females are slightly smaller (74–123 g). Adult wingspan is 20.5-23.9 cm; tail length is 13.4-16.8 cm and bill length is 1.5-2.5 cm. [2] The spotted nightjar's bill is flesh-brown to blackish, occasionally paler nearer to the gape of the lower mandible. The iris is brown to very dark brown; legs and feet are brown with darker claws. [7]

Plumage

An adult spotted nightjar's head is speckled grey, with black central crown feathers and rufous to buff edges, while the sides of the head are blackish with tawny spots. The hind-neck is a rufous or buff collar often flecked with black marks. Upper parts are mid-grey with tawny or rufous and black streaks. Wing-coverts are speckled grey to blackish, often with pronounced buff to rufous spots. Four outermost primary wing-covert feathers feature white patches forming a distinctive speculum. The mid-throat has a pair of large oval white patches, while the upper throat is blackish with buff spots. The tawny lower throat and breast feature blackish-brown bars often flecked with grey, while underparts are tawny to ochre. [7] Although the species is generally considered monotypic, adult females may tend to be a slightly lighter and paler tawny colour around the back, under-parts and collar, while also having slightly less prominent white markings on the outer wing-coverts. [7] Juveniles have finely patterned upper parts and are redder overall than adults, with a single narrow black central stripe along the crown. The white outer wing-covert patterns are smaller and less pronounced, usually surrounded with ochre margins. The juvenile's breast is greyer and more finely mottled with dusky bars extending onto the belly. Downy young hatch with a uniform cover of short, reddish-brown down, shortly after which they moult into their juvenile plumage. [7]

Behaviour

A crepuscular/nocturnal species most active after dark and before dawn, spotted nightjars are usually observed roosting, walking or running along the ground and are rarely seen perching in trees. They are often found on roads at night and have been observed hawking insects with highly maneuverable flight around campfires, artificial lighting and flowering bushes. [2] When flushed, individuals may initially fly only a short distance before landing, but when facing more persistent threats may fly further away beyond sight. If threatened while brooding, the spotted nightjar may begin hissing, opening its bill widely and spreading its wings and tail in a defensive posture or distraction display. [6] The species typically roosts in partly shaded sites, often camouflaged amongst leaf litter or on stony ground. [2] They manage to endure high temperatures during the hottest periods by gular-fluttering (evaporative cooling) and by keeping their backs to the sun, while also maintaining relatively low metabolic rates. [8] While the species generally occurs singularly, flocks of up to 15 birds have been observed during migration. [2]

Voice

A typical breeding call of the spotted nightjar involves about 9-12 notes, ascending in frequency and pitch, then proceeded by a series of gobbling sounds. When on ground, approaching their nesting area, birds may emit frog-like croaking and low cooing noises. [5] Its melodic territorial song has a duration of 4–6 seconds, beginning 2-5 upwardly pitched notes, each becoming more rapid, followed by a quick succession of 8-15 high pitched double notes. [9]

Diet

Spotted nightjars hawk insects and feed on the wing, often hunting at relatively low levels within 20–30 m of the ground. The species has been observed drinking water on the wing by skimming over water holes. [9] They may also obtain preformed water from their insect prey. [8] Spotted nightjars are thought to be almost exclusively insectivorous. Prey species include bugs; beetles; moths; winged ants; grasshoppers; locusts; lacewings and mantids. [10]

Breeding

Breeding usually takes place between September and December, with northern populations breeding earlier than those in the south. [6] In central Australia, seasons are less clearly defined, such that breeding tends to occur after significant rain events. [5] Adults do not build a nest, instead a single pale yellow-green egg with purple-brown blotches is laid on the ground among leaf litter, twigs, grass and stones, usually making detection of sitting adults difficult. [6] Both parents are understood to contribute to incubating the egg over a period of around 30 days. Chicks are able to walk within a short period after hatching and are able to flutter over short distances around 20 days, becoming more or less independent after 30 days. In favourable conditions, brooding females may lay a second egg after their chick is around 22 days old. [2] A female has been recorded laying as many as five eggs, successfully rearing two broods during a single season. [5]

Status and Conservation

Previously considered moderately abundant across inland and northern areas, the spotted nightjar may be becoming more rare, particularly in southern parts of its range as a result of habitat loss associated with land clearing, reduced productivity and overgrazing of remnant native vegetation. [7] [11] Predation by feral cats and foxes is also likely to be significantly impacting abundance in some areas. [9] The species is now listed among Australia's 26 declining woodland birds. [11]

Related Research Articles

<span class="mw-page-title-main">Carola's parotia</span> Species of bird

Carola's parotia, also known as Queen Carola's six-wired bird-of-paradise or Queen Carola's parotia, is a species of bird-of-paradise.

<span class="mw-page-title-main">Satanic nightjar</span> Species of bird

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. In the following decades, there were a few unconfirmed reports of sightings and calls of the bird, but it did not officially resurface until 1996 when David Bishop and Jared Diamond positively identified it in Lore Lindu National Park by its sound. Making the visible rediscovery available for multiple people in the tour group including poet and writer Jan Zwaaneveld. This increased the bird's estimated range by 750 km (470 mi). It has since been observed and described in the literature multiple times.

<span class="mw-page-title-main">Grasshopper buzzard</span> Species of bird

The grasshopper buzzard is a species of bird of prey in the family Accipitridae which is found in a narrow zone of sub-Saharan Africa north of the equator.

<span class="mw-page-title-main">Rufous-naped lark</span> Species of bird

The rufous-naped lark or rufous-naped bush lark is a widespread and conspicuous species of lark in the lightly wooded grasslands, open savannas and farmlands of the Afrotropics. Males attract attention to themselves by a bold and often repeated wing-fluttering display from a prominent perch, which is accompanied by a melodious and far-carrying whistled phrase. This rudimentary display has been proposed as the precursor to the wing-clapping displays of other bush lark species. They have consistently rufous outer wings and a short erectile crest, but the remaining plumage hues and markings are individually and geographically variable. It has a straight lower, and longish, curved upper mandible.

<span class="mw-page-title-main">Anthony's nightjar</span> Species of bird

Anthony's nightjar, also known as the scrub nightjar, is a species of nightjar in the family Caprimulgidae. It is found in Ecuador and Peru.

<span class="mw-page-title-main">Yucatan nightjar</span> Species of bird

The Yucatan nightjar is a species of nightjar in the family Caprimulgidae. It is found in Belize, Guatemala, Mexico, and Honduras.

<span class="mw-page-title-main">White-tailed nightjar</span> Species of bird

The white-tailed nightjar is a species of nightjar in the family Caprimulgidae. It is found in the tropic regions of Central and South America.

<span class="mw-page-title-main">Band-winged nightjar</span> Species of bird

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.

<span class="mw-page-title-main">Tawny-collared nightjar</span> Species of bird

The tawny-collared nightjar is a species of nightjar in the family Caprimulgidae. It is endemic to Mexico.

<span class="mw-page-title-main">White-throated nightjar</span> Species of bird

The white-throated nightjar or white-throated eared-nightjar is a species of nightjar in the family Caprimulgidae. It is endemic to eastern Australia; it is a non-breeding winter visitor in Papua New Guinea. Its natural habitat is subtropical or tropical dry forests.

<span class="mw-page-title-main">Jamaican poorwill</span> Species of bird

The Jamaican poorwill, also known as the Jamaican pauraque or Jamaican least pauraque, is a species of nightjar in the family Caprimulgidae. It is endemic to Jamaica and has not been recorded since 1860.

<span class="mw-page-title-main">Madagascar sandgrouse</span> Species of bird

The Madagascar sandgrouse is a species of bird in the family Pteroclidae. It is endemic to Madagascar and is a ground-dwelling short-legged plump bird. The head of the male is brown with a black area surrounding the beak. It has a pinkish-buff coloured breast, a light brown mottled back, brown wings and paler underparts barred with dark brown. The female has a generally duller appearance being cryptically coloured brown with dark specks and bars.

<span class="mw-page-title-main">Scribble-tailed canastero</span> Species of bird

The scribble-tailed canastero is a species of bird in the Furnariinae subfamily of the ovenbird family Furnariidae. It is found in Argentina, Bolivia, and Peru.

<span class="mw-page-title-main">Cordilleran canastero</span> Species of bird

The cordilleran canastero is a species of bird in the Furnariinae subfamily of the ovenbird family Furnariidae. It is found in Argentina, Bolivia, Chile, and Peru.

<span class="mw-page-title-main">Streak-backed canastero</span> Species of bird

The streak-backed canastero is a species of bird in the Furnariinae subfamily of the ovenbird family Furnariidae. It is found in Argentina, Bolivia, Colombia, Ecuador, Peru, and Venezuela.

<span class="mw-page-title-main">Buff-winged cinclodes</span> Species of bird

The buff-winged cinclodes is a species of bird in the Furnariinae subfamily of the ovenbird family Furnariidae. It is found in Argentina, Brazil, Chile, Paraguay, Uruguay and as a vagrant on the Falkland Islands.

<span class="mw-page-title-main">Streak-backed tit-spinetail</span> Species of bird

The streak-backed tit-spinetail, or streaked tit-spinetail, is a species of bird in the Furnariinae subfamily of the ovenbird family Furnariidae. It is found in Chile and Peru.

<span class="mw-page-title-main">Dark-winged canastero</span> Species of bird

The dark-winged canastero, or Arequipa canastero, is a species of bird in the Furnariinae subfamily of the ovenbird family Furnariidae. It is found in Bolivia, Chile, and Peru.

References

  1. BirdLife International (2016). "Eurostopodus argus". IUCN Red List of Threatened Species . 2016: e.T22689656A93241881. doi: 10.2305/IUCN.UK.2016-3.RLTS.T22689656A93241881.en . Retrieved 12 November 2021.
  2. 1 2 3 4 5 6 7 8 9 Cleere, N. (2010). Nightjars: A Guide to Nightjars and related birds. A&C Black. ISBN   1-873403-48-8
  3. Christidis, L., & Boles, W. E. (2008). Systematics and taxonomy of Australian birds. Csiro Publishing.
  4. <Han, K.-L., M.B. Robbins, and M.J. Braun. (2010)A multi-gene estimate of phylogeny in the nightjars and nighthawks (Caprimulgidae)Molecular Phylogenetics and Evolution,volume 55, pp 443;453.
  5. 1 2 3 4 Hollands, D. (2008). Owls, frogmouths and nightjars of Australia. Bloomings Books Pty Ltd. ISBN   9781876473648.
  6. 1 2 3 4 5 Morcombe, M. (2003). Field guide to Australian birds. Steve Parish Publishing Pty Ltd. Archerfield, Queensland. ISBN   174021564-8
  7. 1 2 3 4 5 Schodde, R., & Mason, I. J. (1980). Nocturnal birds of Australia. Lansdowne Editions.
  8. 1 2 Dawson, W. R., & Fisher, C. D. (1969). Responses to temperature by the spotted nightjar (Eurostopodus guttatus). The Condor, 71(1), 49-53.
  9. 1 2 3 Holyoak, D. T. (2001). Nightjars and their allies: the Caprimulgiformes (Vol. 7). Oxford University Press. ISBN   0198549873
  10. Barker, R. D., & Vestjens, W. J. M. (1989). The Food of Australian Birds. 1. Non-passerines.CS1RO Division of Wildlife and Ecology & Parchment Press: Melbourne.
  11. 1 2 Watson, D. M. (2011). A productivity-based explanation for woodland bird declines: poorer soils yield less food. Emu, 111(1), 10-18.