Nacunda Nighthawk (Chordeiles nacunda)

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Image of a Nacunda Nighthawk in its natural habitat
Birds Nighthawk

Introduction

The Nacunda Nighthawk, Chordeiles nacunda, is a large South American member of the nightjar family, Caprimulgidae. It is an aerial insectivore of open country, including grasslands, savannas, pastures, sandy areas and some urban or agricultural landscapes. Although mainly active at dusk and during the night, it is often seen flying in daylight, sometimes in sizeable flocks. The species was formerly placed in the separate genus Podager, but molecular studies led to its transfer to Chordeiles.

Physical Description

The Nacunda Nighthawk is approximately 28–33 centimetres long. Published measurements from Argentina give average body masses of about 187 grams for males and 170 grams for females, although size varies geographically.

It has a large head, broad rounded wings and a relatively short tail. The upperparts are sandy brown or grey-brown, marked with darker spots and streaks that provide camouflage when the bird is resting on the ground. The throat and underparts are whitish, and the wings show conspicuous white bands bordered by darker feathers. The white underwing and belly markings are particularly noticeable in flight.

Sexes differ in plumage. Adult males generally have a more extensive white throat and white tips to the outer tail feathers. Females usually have a narrower or buff-toned throat marking and lack the prominent white tail tips. Juvenile plumage is less well documented than that of adults but is expected to be more subdued and cryptically marked.

Range and Habitat

The Nacunda Nighthawk is distributed widely across South America, mainly east of the Andes. Its range includes Argentina, Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Paraguay, Peru, Suriname, Trinidad and Tobago, Uruguay and Venezuela. Two geographical forms are generally recognised in major taxonomic treatments: the southern and central South American C. n. nacunda, and the northern form C. n. coryi.

The species favours open habitats, including natural grasslands, savannas, seasonally wet or flooded lowlands, pastures, palm savannas, sandy river margins and open areas near forest edges. It may also use roadsides, parks, airports, cultivated landscapes and other modified habitats where suitable open ground and abundant flying insects remain available.

Movements are complex. Populations in the southern part of the range are migratory or seasonally mobile, with some birds moving northwards during the austral winter. The extent and timing of movement vary between regions and are not fully understood.

Behaviour and Diet

Nacunda Nighthawks feed by catching insects in the air. They use a wide, deeply opened mouth to take flying prey during looping, gliding and rapidly manoeuvring flights. Moths, beetles and other aerial insects form important parts of the diet. Birds may gather in loose or large flocks where food is plentiful, and they can take advantage of insects concentrated around artificial lights.

Although most active at dusk and at night, this species is more frequently active by day than many other South American nightjars. During daylight it commonly rests on bare ground, short grass, sand, rocks or other open surfaces, relying on its mottled plumage for concealment. When disturbed, it may flush suddenly and circle high overhead before settling again.

Breeding behaviour and timing vary across the range. In Argentina, breeding has been recorded mainly from October to February. Courtship may include aerial displays and vocalisations. The species does not build a conventional nest. Instead, the female lays one or two eggs directly on bare ground or in a sparsely vegetated site, often among short grass, sand or other open substrate. An incubation period of about 18 days has been recorded in Argentina, with the female responsible for incubation and protection of the young in the study population.

Identification Tips

Look for the following combination of features:

  • A large, broad-winged nighthawk with a relatively short tail.
  • Sandy or grey-brown upperparts with dark spotting and streaking.
  • A pale throat, whitish belly and conspicuous white underwing in flight.
  • Bold white wing bands bordered by darker feathers.
  • White tail tips in adult males.
  • Frequent daytime activity over grasslands, savannas, river margins and other open habitats.

The large size, rounded wing shape, pale underparts and extensive white wing pattern usually separate the Nacunda Nighthawk from smaller Chordeiles species. The Sand-coloured Nighthawk is a genuine potential comparison in parts of Amazonia, but it is smaller and generally shows a different, less extensive wing pattern. Location is also important when distinguishing the species from other nighthawks and nightjars.

Conservation Status

The Nacunda Nighthawk is classified as Least Concern on the IUCN Red List. It has a broad distribution and uses a range of natural and modified open habitats. A precise global population estimate is not available, and the species’ movements and population structure remain incompletely documented.

Local populations may be affected by the loss or alteration of open habitats, intensive agricultural development, urban expansion, disturbance of ground-nesting sites and changes in insect abundance. These pressures do not currently justify a higher global threat category, but maintaining suitable grasslands, savannas, wetlands and sparsely vegetated breeding areas is important. Further research on migration, breeding success, population trends and habitat use would improve conservation planning.

Frequently Asked Questions

Where can the Nacunda Nighthawk be found?

It occurs widely across South America, mainly east of the Andes, from Colombia, Venezuela and the Guianas southwards through Brazil, Bolivia, Paraguay, Peru, Uruguay and Argentina. Trinidad and Tobago is also included in its range.

Is the Nacunda Nighthawk nocturnal?

It is mainly crepuscular and nocturnal, but it is unusually likely to be seen flying during the day. Daytime activity is especially associated with open habitats, disturbance and movements between roosting or feeding areas.

What does the Nacunda Nighthawk eat?

It is an aerial insectivore. Its prey includes flying insects such as moths, beetles and other insects captured during agile flight. Birds may feed around artificial lights where insects congregate.

Does the Nacunda Nighthawk build a nest?

No. The female lays one or two eggs directly on bare ground or in a sparsely vegetated site. There is no substantial nest structure.

How can the Nacunda Nighthawk be identified in flight?

The most useful features are its large size, broad rounded wings, pale underparts, white underwing and bold white wing bands. Adult males may also show white tips to the outer tail feathers.

Is the Nacunda Nighthawk migratory?

Some populations are migratory or seasonally mobile, particularly in the southern part of the range. However, movements are complex and differ between regions, so the species should not be treated as uniformly migratory throughout South America.

References

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