Tschudi's Nightjar Systellura decussata Scientific name definitions

Tschudi's Nightjar is named after Johann Jakob von Tschudi, a Swiss explorer who visited Peru in the early 19th century, and who was the first European naturalist to notice this species. This bird just as easily could be called "Desert Nightar", however, as it is restricted to the very arid coast of Peru and northern Chile. Tschudi's Nightjar formerly was considered to be a subspecies of the very widespread Band-winged Nightjar (Systellura longirostris), but the song of Tschudi's now is known to be very different from that of Band-winged, and genetic analysis confirms that these two species are not closely related. This nightjar occurs in arid scrub and fields, as well as in urban areas, even in the city of Lima. It roosts on the ground during the day, singly or in pairs, and forages for insects at night. Otherwise very little is known about the biology of Tschudi's Nightjar.

20–21 cm; male 28·5–35 g, female 32 g. A comparatively small and above all pale member of the S. longirostris species complex, most similar overall to S. l. bifasciata or intermediate between the latter taxon and S. l. ruficervix. Generally greyish brown in overall coloration, with a broad tawny or sandy-cinnamon hindneck collar, small and very obscure white throat patch, narrow white band on four outermost primaries and another on alula and adjacent marginal wing-coverts, while tail shows broad white tips to feathers and white band across upper, inner webs to three or four outermost rectrices. Female differs in having buff-coloured throat patch, buff band on outermost primaries and generally lacks any white in tail. Juvenile generally very similar to respective adult.

Until recently considered conspecific with S. longirostris, but differs in strongly divergent voice (a loud series of “cueeo” notes vs a series of high, thin slurred whistles (1 Schulenberg, T. S., D. F. Stotz, D. F. Lane, J. P. O’Neill, and T. A. Parker (2007). Birds of Peru. Princeton University Press, Princeton, NJ, USA. Close ), rather abruptly modulated in the pattern up-down-up “iiiiui” (2 Xeno-canto (2005-2013). Band-winged Nightjar. Systellura longirostris. URL: http://www.xeno-canto.org/species/Systellura-longirostris (download Aug 2013). Close ) ) (3); smaller size, with shorter wing, effect size 5.84 (score 3); males with narrower outer rectrices distally (apparently a previously unreported character, but perhaps proportionate to smaller size) (ns); paler overall coloration including greyer, less obviously vermiculated (as well as less black-marked) crown (2); white bar in wing of male narrower, white distal tips of tail extending less far up tail (1). Genetic position is still not completely resolved, it being part of a four-way polytomy, within which this species apparently forms a clade apart (3 Sigurðsson, S., and J. Cracraft (2014). Deciphering the diversity and history of New World nightjars (Aves: Caprimulgidae) using molecular phylogenetics. Zoological Journal of the Linnean Society 170(3):506–545. Close ). Monotypic.

W Peru and extreme N Chile (Arica and Tarapacá S to Quillagua) (4 Cleere, N. (2006). A new subspecies of Band-winged Nightjar Caprimulgus longirostris from central Chile. Bull. Brit. Orn. Club. 126(1): 12–19. Close ).

The song  is a loud series of well-defined, but slightly buzzy “cueeo” notes, to some extent reminiscent of both Nyctidromus albicollis and N. anthonyi, but distinctly more monosyllabic. Gives a slightly squeaky-sounding “wick” in alarm  .

Almost nothing is known, but the season is speculated to be at least Nov–Jan, although a hatching has been observed in N Chile in the first-named month, so presumably longer. Eggs white, size 26·9–27·8 mm × 19·8–20·4 mm. No further information.

Not globally threatened (Least Concern). Global population size not quantified, but the species is generally considered to be not uncommon, and the population is suspected to be stable in the absence of evidence for any declines or substantial threats. The overall range is quite large, being estimated at 201,000 km².