Systematics

Three subspecies currently recognized (Dickinson and Remsen 2013):

griseifrons, described as Cypselus brunneitorques griseifrons Nelson 1900; type locality Santa Teresa, Nayarit, Mexico.

Distribution incompletely known; generally considered to occurs in western Mexico, from Sinaloa, Durango and Zacatecas south to Oaxaca (west of the Isthmus of Tehuantepec) (Friedmann et al. 1950, Binford 1989). A single specimen from Peru, collected in March, also has been attributed to griseifrons (Zimmer 1953), although there is little other indication that griseifrons is a long distance migrant, much less that it regularly occurs in Peru (or anywhere else in South America). Phillips (1962), however, suggested that the type of brunnitorques, supposedly collected in Colombia, was a wintering individual of griseifrons. Most authors follow Monroe (1968) in discounting Phillips's proposal.

Similar to brunnitorques, but paler: upperparts sooty rather than almost black, and underparts sooty grayish brown. Feathers of the forecrown, lores, and just above the eye fringed with pale gray (Chantler 2000).

brunnitorques, described as Chaetura brunnitorques Lafresnaye 1844; type locality Colombia.

Distribution incompletely known; reportedly occurs from southeastern Mexico south through Central America to the Andes, from Colombia south to Bolivia. Records from the Andes and coastal mountains of Venezuela also have been attributed to brunnitorques (e.g., Zimmer 1953), but Chantler (2000) includes Venezuela in the range of nominate rutila.

The validity of brunnitorques is highly doubtful. Earlier authors (e.g. Peters 1940, Zimmer 1953) mistakenly applied the name rutila o the taxon that Collins (1972) described as phelpsi (Tepui Swift). To date no clear diagnosis of distinctions between brunnitorques and rutila has been published. Collins (1972) considered them to be "so similar as to be doubtfully distinct even as subspecies". Chantler (2000) suggested that brunnitorques may average slightly longer winged, but it is not clear from this source whether such a slight difference is clinal (which would cast further doubt on the validity of brunnitorques), or whether there is an abrupt, if slight, change in wing length somewhere in the range of the species.

rutila, described as Hirundo rutila Vieillot 1817; type locality not indicated [= Trinidad; Collins 1972]

Distribution incompletely known; this name currently is applied to populations in Venezuela (Andes and coastal ranges) and on Trinidad.

See Detailed Description.

This species previously was classified in the genus Chaetura (e.g. Peters 1940) or in Cypseloides (e.g. Zimmer 1953). The current assignment to the genus Streptoprocne follows Marín and Stiles (1992), based on differences in reproductive biology between Streptoprocne and Cypseloides: the former have two-egg clutches and a faster nestling growth rate, while the latter have a clutch of one egg, and a slower nestling growth rate. Phylogenetic relationships within Streptoprocne have not been resolved; presumably Streptoprocne rutila is sister to Streptoprocne phelpsi (Tepui Swift). Sibley and Monroe (1990) considered rutila and phelpsi to form a superspecies.