Little Nightjar

Belonging to the family Caprimulgidae, this small nocturnal bird is characterized by its compact size of approximately 19 to 21 centimeters in length and a body mass ranging between 30 and 45 grams. It exhibits highly cryptic plumage, predominantly patterned in shades of grayish-brown intricately vermiculated with black, buff, and rufous streaks. A distinctive pale buff or rufous-chestnut collar is visible on its hindneck, accompanied by a white throat patch which, in males, is sharply divided into two lateral white patches, whereas in females, it is smaller and tinged with buff. Males display small white spots on their primary flight feathers and prominent white tips on the outer tail feathers, features that are either greatly reduced or entirely absent in females. Its bill is short but features an extremely wide gape lined with stiff rictal bristles that assist in capturing aerial prey.

Geographical distribution: It is widely distributed across central and southern South America, ranging from eastern Bolivia, central and southern Brazil (most notably within the Cerrado and Caatinga biomes), across most of Paraguay, northern and central Argentina (reaching as far south as Córdoba and Buenos Aires provinces), to western Uruguay. Occasional records and localized populations of Setopagis parvula have also been documented in extreme southeastern Peru. While the species is generally considered sedentary throughout most of its range, southern populations may perform localized seasonal movements during winter in response to declining temperatures and fluctuating food availability.

Habitat: It primarily frequents lowland terrestrial ecosystems, preferring deciduous and semi-deciduous forests, wooded savannas such as the Cerrado, dry scrubby woodlands of the Caatinga and Chaco regions, as well as forest edges, second-growth woodlands, and exotic plantations (such as eucalyptus groves). It actively avoids the dense, continuous evergreen rainforests of the Amazon basin, choosing instead more open or semi-open landscapes with a relatively clear understory where the forest floor is covered with abundant leaf litter for roosting.

Feeding: Its diet is strictly insectivorous. Foraging activities take place during twilight and nighttime hours, often utilizing moonlight to enhance visual detection of prey. It captures insects on the wing via agile, short-distance aerial sallies launched from the ground or low-lying perches, such as fallen branches and fence posts. Its primary prey items consist of beetles (Coleoptera), moths (Lepidoptera), true bugs (Hemiptera), winged termites, and various other flying insects that are active during the night or attracted to artificial light sources.

Behavior: It is a highly nocturnal and crepuscular species. During daylight hours, it remains completely motionless on the forest floor, relying entirely on its disruptive coloration to blend seamlessly with dry leaves and fallen twigs to avoid detection by predators; it will only flush silently at the very last moment when approached within a few inches. The male´s song is a rhythmic, rapid series of high-pitched whistling notes, delivered from low branches or directly from the ground to defend territories and attract mates during the breeding season.

Nesting: It does not construct a physical nest of any kind. The female deposits exactly two eggs directly onto the leaf litter of the forest floor, typically positioned under the protective shade of a shrub, fallen log, or dense vegetation to shield them from predators and harsh sunlight. The eggs are elliptical, creamy or pale pinkish-buff, adorned with brown and gray blotches. Both parents share incubation duties, which last approximately 19 to 21 days, ensuring continuous coverage. The chicks hatch with highly cryptic down and are semi-precocial, capable of shifting their position on the ground shortly after hatching if disturbed.

Conservation status: It is currently evaluated as Least Concern (LC) on the IUCN Red List of Threatened Species. Although it faces localized threats from habitat fragmentation, intensive livestock grazing, agricultural expansion, and seasonal wildfires, its overall population remains stable, and its extensive geographical range ensures that it is not currently facing any immediate threat of global extinction.