Archbold's Nightjar

The body length of adults is around 26–30 centimetres (10–12 in). The adult wingspan is 19.6–21.9 centimetres (7.7–8.6 in), and the tail length 13.4–15.7 centimetres (5.3–6.2 in); the bill length is 1.35–1.61 centimetres (0.53–0.63 in). Archbold's nightjar's small, hooked beak is black, its irises are dark brown, and its legs and feet are dark grey or brown with black claws.

Plumage. The top of the head is dark brown and streaked buff-rufous along the edges of the feathers. Sides of the crown are grey-brown with thin black streaks. The lore and ear coverts are black-dark brown and lightly spotted buff. The throat is dark brown, vividly covered in buff-rufous coloured spots, with a distinct white patch on both sides of the lower throat. The mantle and back are black-dark brown with vivid buff-rufous coloured spots and grey streaks. This blackish-brown colour transitions into a slightly paler, greyish colour on the rump and the uppertail coverts. The breast is dark brown with bold, short buff-rufous streaks, and feathers become increasingly spotted buff-white as we reach the belly down to the undertail coverts. At rest, the dark brown tail is held into a rigid "tent" shape. The innermost tail feathers are faintly barred grey-white, whereas the outer tail feathers have a distinct pale grey-white bar and a broad buff-tawny bar on the edges of the feathers. …

Archbold's nightjar is a species endemic to New Guinea, dwelling in the highlands of the Central Cordillera mountain ranges. It has a patchy distribution, restricted to montane forests situated near clearings and open heathy regions. In fact, Archbold's nightjar is the sole high-mountain nightjar species of New Guinea, found in elevations of 1,800 metres (5,900 ft) up to 3,260 metres (10,700 ft). Records indicate that this species is sedentary , exhibiting limited seasonal movement.

This secretive bird is nocturnal and crepuscular, emerging at night and exhibiting peak activity at dusk when it forages. During the day, individuals typically roost on the ground, on logs, or on branches. These roosting sites are generally found in small forest clearings. E. archboldi may occur solitarily, in pairs, or even in small groups. In fact, in some instances, 2-3 individuals may roost together, resting alongside one another across adjacent branches.

Flight. Archbold's nightjar has an undulating, fluttery flight pattern consisting of rapid wing strokes interspersed with long sweeping glides. In flight, the wings appear elongated with blunt-ended, "fingered" wing tips, an adaptation consistent with their skillful gliding maneuverability. Like other nightjar species, Archbold's nightjar holds its wings upward in a "V" shape as it glides.

Diet. Like other members of the Caprimulgidae family, Archbold's nightjar is exclusively an insectivore. At dusk, individuals have been reported to feed by sallying, catching insects in flight before promptly returning to perch on a nearby branch or log. Stomach content analysis of captured specimens has documented that E. archboldi prefers feeding on larger insect species. Commonly consumed insects include beetles, moths, and cicadas. E. …

The genus name Eurostopodus is derived from the Ancient Greek words eurōstos, meaning "strong" or "stout" and pous (genitive podos) meaning "foot", while the species name archboldi honours the American explorer, Richard Archbold, who conducted a series of expeditions in New Guinea which led to the discovery of the great biodiversity of this region. During his first expedition in southeast New Guinea, known as the First Archbold Expedition (1933-1934), Archbold collected a total of 3,200 bird specimens, including E. archboldi.