Nightjars are long winged, short legged crepuscular or nocturnal birds with predominantly brown cryptic plumage, conspicuous rictal bristles, and short bills with a very wide gape. Band-winged is a medium sized nightjar. Its plumage varies geographically, from small pale subspecies to populations that are quite dark in general color. All subspecies, however, have some features in common, including a tawny or rufous collar across the hindneck, a narrow pale band across the outer primaries, and white tips to outer rectrices. Band-winged Nightjar is sexually dimorphic: the primary band is white in males buff in females, and males have much larger white spots on the rectrices.
Band-winged is the only nightjar that occurs in much of southern Argentina and Chile. There are few nightjars that occur at high elevations in the Andes; Band-winged can distinguished from sympatric species in these areas (such as Swallow-tailed Nightjar Uropsalis segmentata and Lyre-tailed Nightjar Uropsalis lyra) by the white or buff wing band.
Elsewhere in its range, especially at lower elevations, Band-winged Nighjar may overlap with several other species of nightjar. Common Pauraque (Nyctidromus albicollis) is larger and longer tailed, with chestnut auriculars, boldly spotted scapulars, and a different pattern of white in the tail. White-tailed Nightjar (Hydropsalis cayennensis) lacks the white tips to the outer rectrices, although the underside of its tail is mostly white in the male (rather than dark as in Band-winged). White-winged Nightjar (Eleothreptus candicans) has a very short tail, and lacks the rufous nuchal collar; the wings of female White-winged Nightjar are entirely dark (with no pale primary band), whereas the wings and tail of the male are extensively white. Little Nightjar (Setopagis parvula) is smaller and shorter tailed than Band-winged Nightjar; the male has smaller white tips to the outer rectrices, and female Little has entirely dark wings, with no buff wing band.
In the Pantepui highlands of southern Venezuela, both Roraiman Nightjar (Setopagis whitelyi) and Blackish Nightjar (Nyctipolus nigrescens) are quite similar to the dark local subspecies (roraimae) of Band-winged, but are typically slightly smaller and blacker. In addition, both Roraiman and Blackish nightjars lack the rufous nuchal collar. The tail of Roraiman Nightjar is more distinctly barred black and gray (the tail of Band-winged is more mottled), and the wing coverts of Roraiman are more distinctly spotted with white. Male Blackish Nightjar has a smaller white wing band and less white in the tail than male Band-winged. Blackish Nightjar occurs at lower elevations than Band-winged, so these species rarely if ever are syntopic.
Band-winged Nightjar also overlaps with Scrub Nightjar (Nyctidromus anthonyi). Scrub Nightjar is darker and more heavily mottled than sympatric Band-winged Nightjar, and Scrub Nightjar has a different tail pattern (white longitudinal stripes on the outer rectrices, rather than white tips).
The following description is based on Cleere (1998), and refers to nominate longirostris; see also Geographic Variation:
Adult male: Forecrown, crown, and nape grayish brown, speckled with brown; the central feathers are broadly streaked with blackish brown. The sides of the forecrown and crown often are white or grayish white. Broad tawny buff collar across the rear of the neck, barred or spotted with blackish brown. The back is dark grayish brown, speckled and spotted with blackish brown. The rump and uppertail coverts are grayish brown, speckled and barred with blackish brown. The tail is mostly brown. The outermost rectrices (R5-R3, occasionally R2) are broadly (ca 40-50 mm) tipped with white, with a white bar (ca 10 mm wide) across the upper half of the innerweb, above the white bar. R5-R3 also are barred buff or pale tawny along the outer webs, above the white tips. R2 is mottled grayish brown or buffy brown. The central pair (R1) is grayish brown, mottled and barred with brown. The lesser wing coverts are blackish brown, speckled with buff. The primary coverts are brown, with bold tawny spots and speckling. The alula and the adjacent marginal wing coverts are white. The remaining wing coverts are brown, speckled with grayish brown, and boldly spotted buff, with brown speckling. The primaries and secondaries are brown. The outermost primaries (P10-P7) with a broad (ca 15 mm) white band almost midway along the feather, the outer webs of which occasionally are narrowly edged with buff; the inner primaries (P6-P1) and the secondaries are boldly spotted and barred tawny with brown speckling. The tertials are grayish brown, mottled with brown. The lores and auriculars are blackish brown, barred or speckled with buff. The chin and upper throat are buff, barred with brown. There is a large white patch, often edged with buff, across the lower throat, lower feathers of which also are tipped or spotted with blackish brown. The breast is grayish brown, speckled and barred with buff. The belly, flanks and underwing coverts are buff, barred with brown.
Adult female: Similar to the adult male, but the throat is buff; the band across the outer primaries (P10-P7) is narrow and tawny buff, buff, or buffy white; and there is no white in the tail, or only an indistinct whitish spot towards the tip of the innerweb of the outermost rectrices (R5).
Immature and juvenile: Similar to the adult but plainer, with a narrow tawny band across the outermostP10-P7.
Chick: Covered in buff down except on their backs (Hoffmann et al. 2010).
Very little information. Of two specimens (roraimae) from Venezuela, one (February) showed no molt, and the second (April) exhibited body molt (Willard et al. 1991).
Iris: chestnut, dark brown
Tarsi and toes: black, dusky brown
Bare parts color data from Belton (1984) and Willard et al. (1991).
Total length: 20-27 cm (Jaramillo 2003), 21.5-23 cm (Ridgely and Greenfield 2001b), 22 cm (Hilty and Brown 1986, Hilty 2003)
longirostris, male (n = 3): wing length 162-163 mm; tail length 117-128 mm; bill length ca 16-19.4 mm; tarsus length 10.7-22 mm (Cleere 1998)
longirostris, female (n = 3): wing length 163-167 mm; tail length 117-122 mm; bill length 15-19.7 mm; tarsus length 18.2-21 mm (Cleere 1998)
ruficervix, male (n = ?): wing length 152-161 mm; tail length 103-112 mm (Cleere 1998)
ruficervix, female (n = ?): wing length 152-161 mm; tail length 103-112 mm (Cleere 1998)
roraimae, male (n = ?): wing length 167-177 mm; tail length 110-125 mm (Cleere 1998)
roraimae, female (n = ?): wing length 165-168 mm; tail length 110-124 mm (Cleere 1998)
atripunctata, male (n = ?): wing length 151-167 mm; tail length 112-119 mm (Cleere 1998)
atripunctata, female (n = ?): wing length 152-163 mm; tail length 112-122 mm (Cleere 1998)
decussata, male (n = ?): wing length 136-139 mm (Cleere 1998)
decussata, female (n = 1): wing length 142 mm (Cleere 1998)
bifasciata, male (n = 9): wing length, mean 162.8 mm (range 157-167 mm); tail length, mean 120.4 mm (range 100-127 mm) (Cleere 2006)
bifasciata, female (n = 4): wing length, mean 160.2 mm (range 158-164 mm); tail length, mean 111.2 mm (range 92-122 mm) (Cleere 2006)
mochaensis, male (n = 2): wing length, mean 174.5 mm (range 171-178 mm); tail length, mean 133 mm (range 130-136 mm) (Cleere 2006)
mochaensis, female (n = 1): wing length 171 mm; tail length 128 mm (Cleere 2006)
patagonica, male (n = ?): wing length 161-178 mm; tail length 130-148 mm (n = 2) (Cleere 1998)
patagonica, female (n = 1): wing length 162 (Cleere 1998)
pedrolimai, male (n = 2): wing length 140 mm, 141 mm; tail length 99 mm, 110 mm; bill length 12 mm, 12 mm; tarsus length 14 mm, 16 mm (Grantsau 2008)
pedrolimai, female (n = 2): wing length 135 mm, 140 mm; tail length 110 mm, 115 mm; bill length 12 mm, 13 mm; tarsus length 13 mm (n = 1) (Grantsau 2008)
longirostris: male, 63 g (n = 1; Grantsau 2008); female, 33 g, 52 g (n = 2; Grantsau 2008); sex undeterminted, 50 g (n = 1; Belton 1984)
roraimae: female, 54 g (n = 1; Willard et al. 1991); sex undetermined, 52 g (n = 1; Pérez-Emán et al. 2003)
ruficervix: male, mean 44.7 g ± 2.5 g (range 42.2-48.1 g, n = 4; Echeverry-Galvis et al. 2006); female, mean 44.7 g ± 5.1 g (range 39.6-51.4 g, n = 4; Echeverry-Galvis et al. 2006)
atripunctata: female, 36.4 g (n = 1; Weske 1972)
pedrolimai: male, 39 g, 40 g (n = 2; Grantsau 2008); female, 32 g, 38 g (n = 2; Grantsau 2008)