The eared nightjars are a small group of nocturnal

birds Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...

in the

nightjar 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 goatsuckers, due to the ancient folk tal ...

family, although the taxonomy is uncertain. There are seven

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...

, mainly found in

forest A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' ...

and scrub from China to Australia. 5 species are placed in the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

, ''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.

Taxonomy

The order

Caprimulgiformes 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 goatsuckers, due to the ancient folk tal ...

contains several families of nocturnal insectivores, these are the frogmouths, the

potoo Potoos (family Nyctibiidae) are a group of birds related to the nightjars and frogmouths. They are sometimes called poor-me-ones, after their haunting calls. The family Nyctibiidae was formerly included with the nightjars in the order Caprim ...

s, the

oilbird The oilbird (''Steatornis caripensis''), locally known as the , is a bird species found in the northern areas of South America including the Caribbean island of Trinidad. It is the only species in the genus ''Steatornis'', the family Steatornith ...

and the

s. The latter family is normally split into two subfamilies, the American

nighthawk The nighthawk is a nocturnal bird of the subfamily Chordeilinae, within the nightjar family, Caprimulgidae, native to the western hemisphere. The term "nighthawk", first recorded in the King James Bible of 1611, was originally a local name in ...

s, Chordelinae, and the typical nightjars Caprimulginae.Cleere (1998) p. 15 The eared nightjars are sometimes considered a

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus Genus ( plural genera ) is a taxonomic rank used in the biological classifica ...

Eurostopodinae of the Caprimulgidae but some studies have them as a sister group, while others treat them as a clade within the caprimulgids; others consider that the genus ''Eurostopodus'' may not be monophyletic. The eared nightjars consist of seven extant species in two genera, ''Eurostopodus'' and ''Lyncornis'':

Description

The eared nightjars are large compared to many nightjars, but otherwise are similar in structure. They are long-winged and long-tailed, and are light for the wing area, making them powerful and agile in flight. An important difference from typical nightjars is the lack of bristles around the beak. They are nocturnal and have a reflective

tapetum lucidum The ''tapetum lucidum'' ( ; ; ) is a layer of tissue in the eye of many vertebrates and some other animals. Lying immediately behind the retina, it is a retroreflector. It reflects visible light back through the retina, increasing the light a ...

at the back of the eye. The beaks are small, but these birds have a very large gape for catching insects in flight. The feet and legs are small and weak, and the toes are partly webbed. The middle toe's claw has a comb-like pecten on its inner edge, which may be used for plumage care.Cleere (1998) p. 24 The plumage is cryptically patterned with browns and greys, to make these ground-nesting birds difficult to see when resting during the day. Some species have white patches in the wings, and the two in the genus Lyncornis (Great and Malaysian) have "ear tufts" at the rear of the crown.Cleere (1998) pp. 106–112 The songs of these birds are three or more repeated notes, sometimes with whistles or bubbling sounds, and are typically given at dawn or dusk.Cleere (1998) pp. 174–184

Distribution and habitat

The eared nightjars are found from China through Southeast Asia to Australia. Tropical populations are mostly sedentary, but the two Australian species (spotted and white-throated nightjars) are partial migrants. These are birds of open woodland or forest clearings and edges.

Behaviour

Breeding

No nest is built, the single white egg is laid directly on to the ground or leaf litter. The female incubates the egg during the day, relying mainly on the excellent

camouflage Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Examples include the leopard's spotted coat, the b ...

of the plumage to avoid predators. The male takes over incubation during the night, but roosts some distance away when the female is brooding.Cleere (1998) pp. 24–35 If necessary, the female will attempt to distract the intruder away from the eggs, or perform a defence display with spread wings, puffed throat and hissing sounds. The eggs hatch in three to four weeks, and the young can walk soon after hatching. The chicks are fed by both parents.

Feeding

All eared nightjars feed almost entirely on insects caught in flight, typically moths and beetles. They hunt at twilight and in the night, and eat their prey on the wing. The flight is buoyant and twisting,Cleere (1998) pp. 32–33 and may be interspersed with periods of resting on the ground, a road, or in a tree. These birds drink in flight, gliding low over the water and dipping the beak.

Citations

General and cited sources

* {{Cite book , last1=Cleere , first1=Nigel , last2=Nurney , first2=David , year=1998 , title=Nightjars: A Guide to the Nightjars, Frogmouths, Potoos, Oilbird and Owlet-nightjars of the World , publisher=Pica/Christopher Helm , isbn=1-873403-48-8 Caprimulgiformes