Cave Swallow - Taxonomy

Taxonomy

The Cave Swallow is a passerine belonging to the swallow and martin family, Hirundinidae. The genus Petrochelidon is a collection of cliff-nesting swallows and martins, though only the two South American subspecies prefer nesting on cliff-faces. The three North American subspecies prefer nesting in caves and sinkholes, as their common name suggests. Five subspecies of Petrochelidon fulva are currently recognized.

The three North American subspecies are P. f. fulva, P. f. pallida, and P. f. citata. All three will usually nest in natural caves and sinkholes, or in some areas they will nest in or underneath man-made structures (highway culverts, under bridges, etc.). All three have larger wing-spans than the remaining two South American subspecies. P. f. fulva occurs in the Greater Antilles and southern Florida. P. f. pallida (also known as P. f. pelodoma) is found farther west in the south-western United States and into north-eastern Mexico. H. f. citata has the southernmost range of the North American subspecies and is found on the Yucatán Peninsula of Mexico.

The remaining two South American subspecies of the Cave Swallow are sometimes regarded as distinct species separate from the species fulva; not only is their range geographically separate from the North American subspecies but they also choose distinctly different nesting sites. Rather than nesting in caves and sinkholes, P. f. aequatorialis and P. f. rufocollaris are nest in open areas, such as on cliff faces and the sides of buildings. P. f. aequatorialis is found in Ecuador, and it is speculated that it may extend its range into Peru. P. f. rufocollaris occurs in north-western Peru. These two subspecies have smaller wingspans than their North American counterparts

P. f. citata and P. f. pallida are generally accepted as distinct subspecies of P. fulva, however, cytochrome b and microsatellite data support an emerging consensus that P. f. rufocollaris should in fact be considered its own species within Petrochelidon.