Cave Swallow

The Cave Swallow (Petrochelidon fulva) is a medium-sized swallow with a distinctive squarish tail. Exhibiting grey-blue upperparts and a brown-tangerine forehead and throat, this bird is a member of the Hirundinidae family, which includes swallows and martins. The species displays minimal sexual dimorphism, making it challenging to distinguish males from females based on plumage alone.

Identification Tips

Adult Cave Swallows measure approximately 12 to 14 cm in length and weigh around 19 grams. The largest subspecies, P. f. pallida, boasts a wing length averaging between 107.0 and 112.3 mm, while the smallest, P. f. aequatorialis, has wings spanning between 93.0 and 93.5 mm on average.

Habitat

The North American subspecies of the Cave Swallow, namely P. f. fulva, P. f. pallida, and P. f. citata, typically nest in natural caves and sinkholes. They have also adapted to nesting in man-made structures such as highway culverts and under bridges. The South American subspecies, P. f. aequatorialis and P. f. rufocollaris, show a preference for nesting in open areas like cliff faces and building sides.

Distribution

The Cave Swallow is found across various regions, with P. f. pallida inhabiting the southwestern United States and northeastern Mexico, and P. f. citata located on the Yucatán Peninsula. The South American subspecies, P. f. aequatorialis and P. f. rufocollaris, are found in Ecuador and northwestern Peru, respectively. Breeding colonies are established in southeastern New Mexico, Texas, Florida, the Greater Antilles, and along the west coast of South America.

Behaviour

Cave Swallows are social birds that nest in colonies. They exhibit a range of vocalizations, from faint calls in chicks to complex songs in adults. These birds forage for insects in loose flocks over open areas and water, often in the early morning and late afternoon during the breeding season.

Song & Calls

The Cave Swallow's vocal repertoire includes a song, a "che" note, and three types of chattering. The song is a blend of squeaks and warbles, ending with double-toned notes. The "che" note is a high-pitched, nasal sound, while the chattering varies from short, clear notes to high-pitched series in response to predators.

Breeding

Breeding occurs from April to August, with North American subspecies showing a preference for caves and sinkholes, and South American subspecies opting for open spaces. Cave Swallows are open-cup nesters, constructing their nests from mud and bat guano. They may also modify and reuse old barn swallow nests.

Similar Species

Cave Swallows can be confused with other swallow species, but their squarish tail and nesting habits can help differentiate them.

Diet and Feeding

These swallows feed on a variety of flying insects, capturing them in flight over open areas. They drink on the wing by skimming the surface of water bodies.

Conservation status

The Cave Swallow is currently listed as Least Concern on the IUCN Red List, indicating a stable population without significant threats at this time.