Argentina, Bolivia, Brazil, Colombia, Costa Rica, Ecuador, Falkland Islands (Malvinas), French Guiana, Guyana, Honduras, Mexico, Nicaragua, Panama, Paraguay, Peru, South Georgia and the South Sandwich Islands, Suriname, Trinidad and Tobago, Uruguay (B), Venezuela.
Population
Estimated population is unknown (2010).
Southern Rough-winged Swallow (Stelgidopteryx ruficollis) [XC304764]
by Fernando Igor de Godoy from Alrededores Paso Centuri\u00f3n, Cerro Largo, Uruguay (song)
Southern Rough-winged Swallow (Stelgidopteryx ruficollis) [XC664254]
by Niels Krabbe from Taratara, Venezuela (?)
Subspecies
Formerly considered conspecific with Northern Rough-winged Swallow (Stelgidopteryx serripennis), and subspecies decolor has been regarded as intermediate between the two species, but they are separated altitudinally where ranges overlap in Costa Rica. Sometimes treated as monotypic, as subspecies intergrade, also depth of plumage colour varies clinally, becoming generally darker from north to southern and east. Birds from Surinam named as subspecies cacabata, but description believed to have been based on migrants of nominate subspecies.
The following 4 subspecies are recognised:
decolor Griscom, 1929 - Western Costa Rica and western Panama.
uropygialis (Lawrence, 1863) - Caribbean lowlands southern from eastern Honduras, Pacific lowlands of eastern Panama, western Colombia, Ecuador and north-western Peru.
aequalis Bangs, 1901 - Northern Colombia, western Venezuela and Trinidad.
ruficollis (Vieillot, 1817) - South-eastern Colombia, eastern Venezuela, the Guianas and Brazil south to eastern Peru, Bolivia, northern and north-eastern Argentina (south to Salta, Formosa, Entre Ríos and northern Buenos Aires) and Uruguay.
BirdLife International Species Factsheet