Chotacabras Argos

Identificación

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. 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. 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. 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.<p>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. 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. 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.

Taxonomía

The spotted nightjar was first described by Ernst Hartert in 1892. 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). Within the Caprimulginae, the genus Eurostopodus (the eared nightjars) consists of seven extant species, including Eurostopodus argus.

Nombre científico

Eurostopodus argus

Autoridad

Hartert, EJO, 1892

Orden

Caprimulgiformes

Familia

Caprimúlgidos

Género

Eurostopodus

Distribución y hábitat

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. 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. The species generally avoids dense grasslands and tall, closed forest. Winter habitats on Indonesian islands include savannahs, grasslands and the edges of rainforests.

Área de cría

AU : Australia (except se, Tasmania)

Área no reproductiva

to s Moluccas

Migración

Migrantes completos

Comportamiento

Patrón migratorio: Migrantes completos.

Conservación

Tendencia poblacional: estable.

Tendencia poblacional

estable