Ladder-tailed Nightjar (Hydropsalis climacocerca)

By /
Image of a Ladder-tailed Nightjar in its natural habitat
Birds Nightjar

Introduction

The Ladder-tailed Nightjar (Hydropsalis climacocerca) is a nocturnal member of the nightjar family, Caprimulgidae. It is distributed widely across the Amazon Basin and is particularly associated with riverine habitats, including sandy banks, gravel bars, river islands and the margins of oxbow lakes. Its cryptic plumage and ground-nesting habits are typical of nightjars, while the male’s long, patterned tail provides its most distinctive feature. (itis.gov)

Physical Description

The Ladder-tailed Nightjar is a medium-sized nightjar measuring approximately 23–26 cm in length, with males generally larger and more elaborately tailed than females. The plumage is predominantly grey-brown, with darker barring, buff-edged scapulars and pale spotting on the wing coverts. The barred breast and belly provide effective camouflage among sand, gravel, leaf litter and low riverbank vegetation.

Adult males have a strongly forked, W-shaped tail. The elongated outer tail feathers are marked with conspicuous pale or white areas, while the central feathers are grey, creating the ladder-like pattern for which the species is named. Females have a shorter, less contrasting tail that is mainly grey and dusky-barred. The male’s primary flight feathers also show prominent white bands, whereas the corresponding markings in females are narrower and more rufous. Juveniles resemble females but usually have warmer, tawny tones in the flight feathers. (peruaves.org)

Range and Habitat

The species occurs across much of the Amazon Basin, including parts of Brazil, Bolivia, Colombia, Ecuador, Peru and Venezuela, as well as Guyana, Suriname and French Guiana. Its distribution is centred on the Amazonian lowlands but extends into foothill regions. It is not known to be a long-distance migrant.

Although it may occur near forest edges and open clearings, the Ladder-tailed Nightjar is especially associated with riverine environments. Favoured sites include sandy and gravelly riverbanks, exposed river islands, vegetated margins of streams, pools, lakes and oxbow lagoons, and low shrubland beside water. Records from southeastern Peru also show that it can breed along Andean rivers at approximately 1,450 m elevation, demonstrating that its habitat use is not limited strictly to lowland rainforest. (en.wikipedia.org)

Behaviour and Diet

The Ladder-tailed Nightjar is primarily active at night, especially around dusk and dawn. It commonly rests by day on the ground or among low vegetation, where its mottled grey-brown plumage makes it difficult to detect. When flushed, it may fly only a short distance before settling again, although it also makes agile aerial flights while foraging.

Like other nightjars, it feeds mainly on flying insects captured in the air. Its broad gape and manoeuvrable flight are suited to catching moths, beetles and other nocturnal insects around riverbanks, clearings and open water. The species is generally encountered singly or in pairs rather than in large groups.

Breeding information remains incomplete, but the species is a ground nester. The female lays her eggs directly on sand, gravel, mud or bare soil, often near driftwood, rocks, low vegetation or other features that provide concealment. A clutch usually contains two eggs. In southeastern Peru, nests have been recorded on river islands and river edges, and the species does not construct a conventional nest. River islands may reduce access by some terrestrial predators, although flooding and nest predation remain important risks. (cebc.cnrs.fr)

Identification Tips

Look for the following combination of features:

  • A grey-brown, heavily camouflaged nightjar associated with rivers, sandbars and gravelly banks.
  • A barred breast and belly, with buff or whitish spotting on the wing coverts.
  • In males, a long, deeply forked tail with contrasting pale markings and a distinctive W-shaped outline in flight or when spread.
  • A generally low, short flight when flushed, followed by a return to the ground or low vegetation.
  • A close association with exposed river margins, islands and other open patches within forested landscapes.

The male’s tail is the most useful distinguishing feature. Females and juveniles are less conspicuous and may be confused with other brown nightjars when seen briefly. In riverine Amazonian habitats, careful attention to the bird’s tail shape, pale primary bands and preference for sandy or gravelly margins is more reliable than plumage colour alone. (peruaves.org)

Conservation Status

The Ladder-tailed Nightjar is currently classified as Least Concern. Its broad distribution across Amazonia and its occurrence in numerous riverine habitats mean that it is not presently considered globally threatened. A precise global population estimate and a confirmed population trend are not stated here because reliable, current figures are not readily available.

Local populations may be affected by the alteration of riverbanks, loss of natural sand and gravel bars, flooding changes, vegetation clearance and disturbance of river islands during the breeding season. Protecting intact river corridors, maintaining natural river processes and avoiding unnecessary disturbance at active nesting sites are appropriate conservation measures. (peruaves.org)

Frequently Asked Questions

Where does the Ladder-tailed Nightjar live?

It occurs across much of the Amazon Basin, including Brazil, Bolivia, Colombia, Ecuador, Peru, Venezuela, Guyana, Suriname and French Guiana. It is most closely associated with rivers, streams, sandy banks, gravel bars and river islands.

Why is it called the Ladder-tailed Nightjar?

The name refers to the male’s elongated, patterned tail. The pale markings and arrangement of the tail feathers can suggest the rungs of a ladder, particularly when the tail is spread or seen in flight.

What does the Ladder-tailed Nightjar eat?

It feeds mainly on flying insects captured during nocturnal or crepuscular aerial foraging. Moths, beetles and other night-flying insects are typical prey for nightjars, although detailed dietary studies of this species are limited.

Does the Ladder-tailed Nightjar build a nest?

No. It lays its eggs directly on bare ground, usually on sand, gravel, mud or another sparsely covered surface near a river or stream. The usual clutch contains two eggs.

Are male and female Ladder-tailed Nightjars different?

Yes. Males are usually larger and have a longer, more conspicuously patterned tail, together with stronger white markings on the primary feathers. Females have a shorter, greyer and more subdued tail.

Is the Ladder-tailed Nightjar endangered?

No. It is currently assessed as Least Concern. Nevertheless, local nesting sites can be vulnerable to riverbank development, habitat alteration, disturbance and changes to natural flooding and sediment processes.

References

Views: 524

Related posts

Scroll to Top