distinctly different nesting sites. Rather than nesting in caves and sinkholes, P. f. aequatorialis and P. f. rufocollaris 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. Habitat During the breeding season, P. f. fulva, P. f. pallida, and P. f. citata, the North American subspecies of the cave swallow, will usually nest in a caves, sinkholes, and sometimes in man-made structures offering similar habitat, such as highway culverts. P. f. aequatorialis and P. f. rufocollaris, the South American subspecies, prefer to nest in open areas such as on cliff faces and the sides of buildings. All subspecies of the cave swallow forage for insects over open areas and water nearby their roosting sites. Their spring and fall migrations are poorly known; however, P. f. citata, P. f. aequatorialis and P. f. rufocollaris are considered resident species and winter in their breeding range. Distribution P. f. pallida is found farther west in the south-western United States and into north-eastern Mexico. P. f. citata has the southernmost range of the North American subspecies and is found on the Yucatán Peninsula of Mexico. 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. Breeding is known to occur in Mexico, south-eastern New Mexico, southern Florida, Greater Antilles and in areas of Texas. The South American populations, as well as most Mexican and Caribbean populations, are considered resident populations which breed and overwinter in the same geographic range. The New Mexico and other northern populations migrate south; however, it is not known where they migrate to or which migration routes they take. Cave swallows have been observed to overwinter in southern Texas since at least the 1980s. Behaviour Vocalizations Cave swallow chicks begin giving faint calls shortly after hatching. As the chicks develop their calls become louder and more aggressive. These calls allow the chicks