Appearance

Nightjars are nocturnal birds with plumage that is cryptically patterned, and that is dominated by shades of brown. They have long wings, short tarsi, very wide but short bills, and prominent rictal bristles. Little Nightjar is a small species of nightjar, although it is littler than any of several other species of nightjar, including other species of Setopagis. The plumage of Little Nightjar generally is grayish brown, with a broad but indistinct tawny collar across the nape. The throat is white on the male, but buffy on the female. The male also has a white band across the four outermost primaries, and white tips to the outer rectrices; the female lacks white on the wings and tail.

Spot-tailed Nightjar (Hydropsalis maculicaudus) is similar to Little Nightjar, but overall is buffier, less gray. Male Spot-tailed Nightjar lacks white in the wing, and has a buffy, not white, throat, as in male Little. Females of Spot-tailed and Little are more similar, but female Spot-tailed Nightjar has a blacker crown, a more prominent supercilium that contrasts with the duskier sides of the head, and more conspicuous spotting on the breast (Hilty 2003). Band-winged Nightjar (Systellura longirostris) is larger than Little Nightjar, with a longer tail; male Band-winged also has larger white tips to the outer rectrices, and female Band-winged has buff or whitish band across the outer primaries.

There is no geographic overlap with Todd's Nightjar (Setopagis heterura), of northern Colombia and Venezuela. The plumage of Todd's is similar to that of Little, but the white wing band of the male is much broader, and the underparts are slightly darker. The songs of these two species also differ. Little Nightjar also is allopatric with Scrub Nightjar (Nyctidromus anthonyi), which formerly was classified as a subspecies of Little. Scrub Nightjar has a very different tail pattern, with longitudinal white stripes on the outer rectrices (rather than white tips), and a very different song.

The following description is based on Cleere (1998):

Adult male: Forecrown, crown, and nape grayish brown, finely speckled with pale brown, and thinly streaked with blackish brown; the central feathers very broadly streaked with blackish brown. Broad but indistinct buff or tawny buff collar across the rear of the neck. Back, rump, and uppertail coverts grayish brown, speckled with pale brown and thinly streaked with blackish brown. Tail brown, indistinctly barred with buff or pale tawny. The outermost two rectrices (R5-R4) with a white spot, ca 10-15 mm wide, at tips, either across both webs or only on the inner webs; the next innermost two pairs (R3-R2) have a white spot at the tips of the inner webs; and the central pair (R1) grayish brown, speckled and barred with brown, but with no white tips. Scapulars blackish brown, broadly edged with buff or pale buff. Lesser wing coverts dark brown, indistinctly barred with buff. Greater wing coverts and some median coverts brown, spotted and barred with rufous. Primaries brown. The outermost primary (P10) has a large white spot, about midway out the length of the feather, on the inner web; the next three innermost primaries (P9-P7) have a large white spot that crosses both webs); and P6 either lacks white, has only a vestigial white spot, or has a small white spot that is speckled with brown around the edges. The secondaries are brown, barred with tawny on the outer webs, and with buff on the inner webs. Tertials are grayish brown, speckled with brown and broadly streaked with blackish brown. The lores and auriculars are rufous, speckled with dark brown. Whitish submoustachial streak. Chin buffy Throat with large triangular white patch; lower feathers tipped with blackish brown, with a buff subterminal band. Breast grayish brown, narrowly barred with brown, and spotted with pale buff. Belly, flanks, and underwing coverts buff, barred with brown. Undertail coverts buff or buff barred with brown.

Adult female: Similar to adult male, but lacks the white band across the outer wing; the primaries are brown, irregularly spotted with buff or pale tawny. Tail also usually lacks white, but rarely, some females have a very small white spot on the inner webs of the outermost rectrices (R5-R3).

Immature and juvenile: Similar to adult female, but the remiges are narrowly tipped with buff or buffy white.

Chick: Little information; described as "pinkish cream" (Marini et al. 2012).

Very little information. Specimens in fresh plumage noted from October and January (Cleere 1998). Primaries are molted descendantly, commencing with the innermost primary (P1) and advancing towards the outermost primary (P10) (Cleere 1998).

Iris: brown, reddish brown; eye ring very pale yellow

Bill: black

Tarsi and toes: pinkish brown or pinkish gray

Bare parts color data from Friedmann (1927) and Belton (1984).

Total length: 19-21 cm (Cleere 1998)

Linear measurements (from Cleere 1998; n = ?):

wing length: male, range 133-144 mm; female, range 128-141 mm

tail length: male, range 90-105 mm; female, range 85-105 mm

bill length: male, range 13-14.5 mm; female, range 12.5-13.3 mm

tarsus length: male, range 13.2-17.4 mm; female, range 16.3-17.2 mm

Mass: mean 37 g ± 5.9 g (sexes combined, range 25-46.5 g, n = 14; Dunning 2008)