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10 Fascinating Facts About the Archbold’s Nightjar

Have you ever heard of the Archbold’s Nightjar? This unique bird species, Eurostopodus archboldi, is native to Papua New Guinea, a country known for its incredible biodiversity.

The Archbold’s Nightjar is a nocturnal bird that is rarely seen in the wild, but its distinctive call can be heard throughout the country’s forests at night. In this article, we will explore the identification, plumage, and molts of the Archbold’s Nightjar.


Field Identification

The Archbold’s Nightjar is a medium-sized bird that measures around 22 centimeters in length, with a wingspan of roughly 40 centimeters. This species has a short, broad tail, and its bill is relatively short and slightly curved.

The coloration of the Archbold’s Nightjar is predominantly brown, with mottled dark and light markings on the back and wings. The underparts of the bird are buff-colored, and it has a distinct white band across its throat.

Similar Species

While the Archbold’s Nightjar is a highly distinctive species, it can be easily confused with other nightjar species in the same area. One species that is often mistaken for the Archbold’s Nightjar is the Papuan Nightjar, Eurostopodus papuensis.

While these two species look similar, the Papuan Nightjar is often smaller and has more heavily marked wings. Another species that can be mistaken for the Archbold’s Nightjar is the Large-tailed Nightjar, Caprimulgus macrurus, although this species has a much longer and more pointed tail.


Like most bird species, the Archbold’s Nightjar has a variety of plumages throughout its lifecycle. This species has two distinct plumages – the breeding plumage and the non-breeding plumage.

Breeding Plumage

During the breeding season, the male Archbold’s Nightjar develops a distinctive rufous collar around the neck. The feathers on the back and wings also become more sharply marked and have a reddish-brown coloration.

The female, on the other hand, does not show the same level of coloration changes during the breeding season. Non-

Breeding Plumage

Outside of the breeding season, the plumage of both male and female Archbold’s Nightjars becomes more cryptic and resembles the bark of trees in the forest. The markings on the wings and back become less pronounced, and the coloration becomes more muted.


The Archbold’s Nightjar undergoes two molts each year – the pre-breeding molt and the post-breeding molt.


Breeding Molt

The pre-breeding molt occurs in the early part of the year, around January and February. During this molt, the old feathers are replaced with fresh ones that provide better insulation and protection during the cold breeding season.


Breeding Molt

The post-breeding molt occurs in June and July. This molt is triggered by the onset of the dry season, and the bird sheds its old feathers to allow for new ones to grow in time for the next breeding season.


The Archbold’s Nightjar is a fascinating bird species that has a unique appearance and interesting molting patterns. While this species is difficult to spot in the wild, its distinctive call can be heard throughout the night in Papua New Guinea’s forests.

By understanding the identification, plumage, and molting patterns of the Archbold’s Nightjar, bird enthusiasts can appreciate the beauty of this species and the importance of protecting its natural habitat.

Systematics History

The Archbold’s Nightjar, Eurostopodus archboldi, belongs to the Caprimulgidae family, which contains over 100 species of nocturnal birds. This family is divided into two subfamilies, the Caprimulginae and the Chordeilinae, with the Archbold’s Nightjar being part of the former.

The systematics history of this species has undergone several changes over the years.

Geographic Variation

The Archbold’s Nightjar has a limited range and is only found in Papua New Guinea. Despite this restricted range, there are some variations in its appearance depending on which part of the country it is found.

This variation is most notable in the male’s coloration, but it is generally subtle and not enough to distinguish separate subspecies.


Despite the overall lack of geographic variation, some researchers have suggested the existence of subspecies within the Archbold’s Nightjar. These potential subspecies have been defined based on slight variations in coloration and vocalizations but remain controversial and unconfirmed.

Related Species

The Archbold’s Nightjar is part of a larger group of nightjars that are found throughout the world. Its closest relatives are most likely the Solomon Islands Nightjar, Eurostopodus nigripennis, and the Mountain Nightjar, Caprimulgus poliocephalus, which are also found in the Pacific.

Historical Changes to Distribution

The distribution of the Archbold’s Nightjar has been affected by several factors throughout history. One of the biggest factors has been deforestation, which has reduced the bird’s habitat and made it more difficult for it to find suitable nesting sites.

Additionally, hunting and trapping of the species have also had a significant impact on its population. Interestingly, the Archbold’s Nightjar was not known to science until 1977 when it was discovered by an ornithological expedition to Papua New Guinea led by Richard Archbold.

Prior to this discovery, the species remained unknown to science, despite its vocalizations being heard throughout much of Papua New Guinea’s forested regions. Since its discovery, the Archbold’s Nightjar has been the subject of several conservation efforts.

The government of Papua New Guinea has implemented measures to protect the bird’s habitat, and several organizations have undertaken initiatives to educate local communities about the importance of conservation. Despite these efforts, the Archbold’s Nightjar remains a threatened species.

Its restricted range and specific habitat requirements make it vulnerable to changes in the environment. Continued conservation efforts will be essential to ensure the long-term survival of this unique bird species.


The history of the Archbold’s Nightjar’s systematics and distribution is complex, reflecting the challenges that many bird species face in a changing world. While much remains unknown about this species, efforts to understand and protect it are ongoing, highlighting the importance of continued research and conservation efforts for all bird species.

By working to protect the Archbold’s Nightjar, we can help preserve the biodiversity of Papua New Guinea and ensure that this unique bird remains a part of our natural heritage for generations to come.


Archbold’s Nightjars are endemic to Papua New Guinea’s forests, which are some of the most diverse in the world. Within these forests, the birds are typically found in areas with dense undergrowth and sparse tree cover.

They prefer lower elevations but have been recorded up to elevations of 1,500 meters.

The Archbold’s Nightjar’s preferred habitat is characterized by a mix of grassy or shrubby areas and small trees, often with a water source nearby.

This habitat is usually found in the lowland forests and foothills of Papua New Guinea. They tend to avoid closed canopy rainforests and are seldom found in areas where the forest has been significantly disturbed or destroyed.

Movements and Migration

The Archbold’s Nightjar is not known to undertake any significant migration patterns, and they are considered to be a resident bird species. However, these birds can move significant distances to find more favorable nesting sites or sources of food.

One factor that may influence the movements of Archbold’s Nightjars is the availability of prey. These birds feed mainly on insects, and their movements may coincide with the seasonal availability of insects.

During the breeding season, males may also move to different locations to establish territories or find suitable nesting sites. Despite being resident birds, the movements of Archbold’s Nightjars are still not well understood due to their elusive and nocturnal nature.

However, they are thought to remain within their home range throughout the year and move only short distances as necessary. Threats to

Habitat and Migration

Deforestation is one of the major threats faced by the Archbold’s Nightjar.

Papua New Guinea’s forests are under pressure from logging, agriculture, and mining, which have resulted in significant habitat loss. These activities have reduced the availability of suitable nesting sites and food sources for the Archbold’s Nightjar.

In addition to habitat loss, hunting and trapping have also had a significant impact on the bird’s population. The species is hunted for food and captured for the pet trade, further reducing its numbers.

Conservation Efforts

Despite the threats faced by the Archbold’s Nightjar, several conservation measures have been implemented to protect the species. The Papua New Guinea government has established several national parks and conservation areas to protect the country’s forests and the species that depend on them.

Several conservation organizations also work to educate local communities about the importance of conserving the species and its habitat.


The conservation of the Archbold’s Nightjar is crucial to maintaining Papua New Guinea’s forest ecosystems and preserving the biodiversity of the country. While the bird’s movements and migration patterns are not well understood, continued research and conservation efforts will be essential to ensure its long-term survival.

Protecting its habitat and addressing the threats it faces are crucial steps towards ensuring that it continues to contribute to the unique diversity of Papua New Guinea.

Diet and Foraging


The Archbold’s Nightjar is a nocturnal bird species that feeds primarily on insects. These birds hunt at night, using their large eyes and wide, gaping mouths to catch prey on the wing.

During the day, they roost in trees or shrubs, where they remain hidden from predators and conserve their energy.


Archbold’s Nightjars have been observed feeding on a variety of insects, including beetles, moths, termites, and ants. They catch their prey in mid-air, using their wide mouths to scoop up insects as they fly by.

They can also catch insects while flying, using their broad wings and agile flight to chase and capture prey.

Metabolism and Temperature Regulation

Like many nocturnal bird species, Archbold’s Nightjars have a lower metabolic rate than diurnal birds. This allows them to conserve energy during the day when they are not active.

However, this low metabolic rate can also make them vulnerable to cold temperatures, which is why these birds often fluff up their feathers to trap air close to their bodies and retain heat.

Sounds and Vocal Behavior


The Archbold’s Nightjar is known for its distinctive vocalization, which is a series of short, sharp notes repeated rapidly. The call of the male is higher-pitched than that of the female and is used to attract a mate and establish a territory.

During the breeding season, the male Archbold’s Nightjar will sit on a low perch and make its territorial call repeatedly throughout the night. The female, on the other hand, is much quieter and hardly makes any vocalizations.

The Archbold’s Nightjar’s vocalizations are often used in research projects to track the species and monitor its population. By analyzing the timing and patterns of calls, scientists can estimate the size of the bird’s population and the location of its nests.


The Archbold’s Nightjar is a unique and fascinating bird species that has adapted to nocturnal hunting and a specialized diet of insects. Its distinctive vocalization is a key feature of its behavior and allows scientists to study its population and movements.

While the species faces threats from habitat loss and hunting, conservation efforts are ongoing to protect this unique bird species and ensure its survival for generations to come.



Archbold’s Nightjars are nocturnal and primarily fly where they move from one roosting or feeding site to another. They are quite agile birds and are capable of very acrobatic aerial maneuvers.

They typically fly close to the ground, following the contours of the forest floor. They are often observed flying erratically or hovering in place as they capture insects.

Self Maintenance

Archbold’s Nightjars roost during the daytime and are also known to preen themselves extensively. They use their bills to preen and groom their feathers, keeping them aligned for efficient flight.

Agonistic Behavior

Male Archbold’s Nightjars are territorial and will defend their roosting and nesting sites aggressively. They will engage in aggressive behavior towards other males, including pursue-chasing, circling, and physical combat.

Females are not territorial and will avoid confrontation with males.

Sexual Behavior

During the breeding season, male Archbold’s Nightjars will establish territories and begin calling to attract females. Once a female has been attracted, the male will perform courtship displays including hopping, bowing, and showing off his plumage.

Breeding pairs are usually monogamous, with the male and female remaining together throughout the breeding season.


The breeding season of the Archbold’s Nightjar varies depending on the location in New Guinea where it is found. In areas with a dry season, breeding usually occurs from October to February, while in areas with a year-round rainfall, breeding occurs all year round.

Females lay a single egg on the forest floor, often on a bed of leaves or twigs. Both the male and female will incubate the egg, with the male taking over daytime shifts and the female taking over at night.

The incubation period is around 30 days, after which the chick hatches. The chick is fed by both parents, who capture insects and carry them back to the nest in their bills.

The chick remains in the nest for around 14 days before fledging.

Demography and Populations

The Archbold’s Nightjar is native to Papua New Guinea and is considered to be a restricted-range species. Its population size is unknown, but it is believed to be declining due to habitat loss and hunting.

Despite this, the Archbold’s Nightjar is listed as a species of least concern on the International Union for Conservation of Nature’s Red List. This is due to its large geographical range and a lack of evidence of a significant population decline.

However, the habitat of the Archbold’s Nightjar is under threat due to logging, mining, and agricultural expansion. The species is also hunted for food and captured for the pet trade, which poses additional threats to its survival.

Conservation efforts are ongoing to protect the Archbold’s Nightjar and its habitat. The government of Papua New Guinea has established several conservation areas, and several organizations work to raise awareness about the species and promote conservation initiatives.


The behavior of the Archbold’s Nightjar is shaped by its nocturnal nature and specialized diet of insects. Its territorial, mating, and nesting behaviors are fascinating to observe, and its distinctive vocalizations are a key feature of its behavior.

While the species faces threats from habitat loss and hunting, ongoing conservation efforts are working to protect this unique bird species and ensure its long-term survival in Papua New Guinea. In this article, we have explored the Archbold’s Nightjar in detail, covering a range of topics that provide insight into this unique bird species.

From its systematics history to its distinctive vocalizations, the Archbold’s Nightjar has many fascinating features that make it a valuable subject for study and conservation. However, the species is also facing significant threats from habitat loss and hunting, highlighting the importance of ongoing conservation efforts to protect and preserve this species and its habitat.

By working to protect the Archbold’s Nightjar, we can help ensure that it remains a part of Papua New Guinea’s natural heritage for generations to come.

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