Cave Swallow

The cave swallow (Petrochelidon fulva) is a medium-sized, squarish-tailed swallow belonging to the same genus as the more familiar and widespread cliff swallow of North America. The cave swallow, also native to the Americas, nests and roosts primarily in caves and sinkholes. Cave swallows are found in Mexico and the Greater Antilles, with fall and winter vagrants reaching the east and Gulf Coasts of the U.S. Breeding colonies occur in south-eastern New Mexico, Texas, Florida, the Greater Antilles, portions of southern Mexico, and along the west coast of South America. Five subspecies are currently recognized according to Birds of North America, three occurring in North America and two in South America. == Description == The cave swallow measures 12 to 14 cm in length and weighs 19 g on average. The largest of the five subspecies, P. f. pallida, has an average wing length between 107.0 and 112.3 mm; the smallest subspecies, P. f. aequatorialis, has an average wing length between 93.0 and 93.5 mm. Differences between the sexes are minimal, both are similar in size and weight and are difficult to distinguish from their plumage. It has grey-blue upperparts and brown-tangerine forefront and throat. == Taxonomy == The cave…