Like most nightjars, Ladder-tailed Nightjar is cryptically colored, with plumage that primarily is grayish brown. Also in common with other nightjars, this species has a short bill with a very broad gape, and short tarsi. Both sexes of Ladder-tailed Nightjar have a tawny collar across the nape. The tail has a distinctive shape: it is long, and has a W shape, as the longest rectrices are the central and outermost pairs, creating a deep notch on each side of the tail. The outer rectrices of the male also are broadly edged with white, and the male has a white band across the outer primaries. Females are browner and have less white on the wings, tail, and throat.
Male Ladder-tailed Nightjar, with the long, triple-pointed tail, is unlikely to be confused with any other species. Female Ladder-tailed Nightjar is somewhat less distinctive, but overlaps with few other similar species. Female of White-tailed Nightjar (Hydropsalis cayennensis) is less sandy above, has a distinct rufous collar, and a shorter tail that lacks the double-notched appearance (Hilty 2003). White-tailed Nightjar also inhabits very different habitats, including grassland and scrub, than Ladder-tailed Nightjar (Hilty and Brown 1986).
Scissor-tailed Nightjar (Hydropsalis torquata) has a conspicuous tawny collar on the hindneck, and lacks a white or buff band on the outer primaries. Male Scissor-tailed Nightjar also has an even longer tail that male Ladder-tailed Nightjar.
The following description is based on Cleere (1998), and refers to nominate climacocerca; see also Geographic Variation:
Adult male: Forecrown, crown, and nape grayish brown or grayish white, speckled with brown and streaked blackish brown; central feathers very broadly streaked with blackish brown. Indistinct collar across rear of neck tawny buff, barred with brown. Back and rump grayish brown, streaked and spotted with dark brown. Scapulars blackish brown, speckled with grayish brown and buff, broadly edged with tawny, buff, or pale on outer webs. Uppertail coverts pale grayish brown, barred with dark brown. Tail with a triple point: the outermost rectrix (R5) is the longest, with a pointed tip; R4 is 4-5 cm shorter; R3 and R2 blunt tipped and 2-2.5 cm shorter than R4; central pair (R1) is almost as long as R5. R5 is brown, broadly edged with white, the white extending diagonally across and along the distal half of the inner web; the rest of the feather is barred with whitish. R4-R2 are mostly whitish, broadly tipped with brown and buff. The central pair grayish brown, mottled and barred with brown. Lesser wing coverts brown, speckled with grayish brown and buffish. Primary coverts brown, spotted with white on the inner webs. Rest of wing coverts brown, speckled with grayish brown, buffish or cinnamon, boldly spotted with buff, grayish white, or whitish on the tips of the outer webs. Primaries brown; broad white band, almost midway along the length of the feather, from the outermost remige (P10) to P7, and a small white spot or band towards the tip of P6. Secondaries brown narrowly tipped pale buff or whitish, boldly spotted white on the inner webs. Tertials brown, mottled with grayish brown. Lores and auriculars buffish, speckled with brown. Chin and throat white. Breast buffish, often tinged with cinnamon or whitish, and narrowly barred with brown. Belly, flanks, and undertail coverts whitish.
Adult female: Similar to adult male, but throat buffy. Band on primaries narrower, and often buffy. Tail less strongly shaped. R4-R2 broadly edges white on the proximal half of the inner webs.
Juvenile and immature: Similar to adult female, but with tawnier markings on the primaries and secondaries.
Chick: Newly hatched nestlings have pale gray down, speckled with dark gray and brown (Maccormick and MacLeod 2004).
Very little information. Friedmann (1948) reported one male collected in February that was molting. Blake (1950) noted three males and one female collected in October from Guyana that had very worn rectrices, suggesting that the last molt was not recent.
Iris: dark brown
Tarsi and toes: brown
Bare parts color data from Cleere (1998).
Total length: male 25-26 cm (Ridgely and Greenfield 2001b), 28 cm (Hilty and Brown 1986), Hilty (2003); female 20.3 cm (Hilty 2003), 22.5-23.5 cm (Ridgely and Greenfield 2001b), 23 cm (Hilty and Brown 1986)
Linear measurements (from Cleere 1998):
male (n = ?)
wing length: range 153-173 mm
tail length: range 149-169 mm
bill length: range 10.7-14.5 mm
tarsus length: range 16.0-18.9 mm
female (n = ?)
wing length: range 152-156 mm
tail length: range 131-135 mm
bill length: range 13.6-15.3 mm
tarsus length: range 17.3-19.0 mm
male: mean 46 g (range 42-52 g, n = 5, Suriname; Haverschmidt and Mees 1994); mean 46.4 g (range 45-47 g, n = 5, Brazil; Bokermann 1978)
female: mean 49 g (range 45-52, n = 2, Suriname; Haverschmidt and Mees 1994); 53 g (n = 1, Brazil; Bokermann 1978)