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.
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.
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. P. 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.
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.
Both will forage for insects over open areas and water nearby their roosting sites. The spring and fall migration of cave swallows is poorly known; however, P. f. citata, P. f. aequatorialis and P. f. rufocollaris are considered resident species and winter in their breeding range.
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.
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 to communicate to the attending parent(s) their basic needs, such as hunger.
There is currently no data regarding differences in vocalizations between the subspecies of cave swallows, however, the following descriptions are based on observations of H. f. pallida. Adults utilize five main vocalizations: a song, "che" note, and three types of chattering described by Selander and Baker (1957).
Cave swallows are most often heard singing from March to August in Texas and New Mexico, corresponding more or less to their breeding season. In general, birds are vocal throughout the day when their nesting colony is active, however, they are usually loud and vocal at their nest site, becoming quieter as they move away from their nest.
Cave swallows feed on small to medium-sized flying insects throughout the day. They forage in loose flocks over open areas, on open vegetation, and against cliff-faces. During the nesting season, adult cave swallows preferentially forage in the early hours of the morning and in the late afternoon. They capture a wide variety of insects during the nesting season, included species from the families Acrididae, Lygaeidae, Reduviidae, and others. They drink while in flight by skimming the surface of pools and rivers.
A benefit to nesting in colonies could be the ability to share and procure information about food sources from neighbouring birds while raising chicks. While research has not been conducted on cave swallows themselves, some studies have been done on the closely related cliff and bank swallows. Cliff swallow nesting colonies have been suggested to serve as, "information centres", where swallows can gather and glean information from one another regarding how well they are foraging. Cliff swallows have been observed to follow, or be followed by, other birds within the nesting colony to food sources; birds that were unsuccessful foraging will return to the colony to find a fellow roost-mate that has been successful, whom they will follow to a food source. Bank swallows, however, do not appear to use small nesting colonies (26-52 nesting pairs is considered a small colony) as, "information centres", but the cliff swallow colonies previously mentioned were large colonies in which there are more potentially successful foragers for other birds to follow.
As previously mentioned, North American subspecies of cave swallows roost and nest primarily in caves and sinkholes while the South American subspecies prefer open spaces such as cliff-faces and the sides of buildings. Breeding occurs between April and August. North American subspecies are currently undergoing a human-facilitated range expansion due to the increased availability of alternative nesting sites. These include highway culverts and bridges. In Texas alone cave swallows have increased their breeding range 898% between 1957 and 1999, with populations increasing at a rate of about 10.8% each year.
Cave swallows are open-cup nesters, meaning they build a nest shaped like a cup with the top left open for them to fly in and out. The nests are made of mud and bat guano and can be reused for multiple breeding seasons. Old barn swallow nests are also utilized by cave swallows, which will modify them to suit their needs. Barn swallows and cave swallows are observed to co-exist at some nesting sites, making old barn swallow nests easily available to the cave swallow. Cave swallows are social and prefer to nest in variably sized colonies. They are even observed to occasionally share nest sites with other species of swallows, such as barn swallows. This occurs particularly often in north central Mexico and increasingly in the United States with the increased use of highway culverts as nesting sites. Some concerns have been raised about the potential for, and instances of, interbreeding between the two species and the viability of the hybrids.
While the use of human-made nesting sites has allowed the cave swallow to greatly increase its range across North America, it may come with its own risks. Culvert and bridge nesting sites have an increased risk of flooding the nest area, a more variable thermal regime during the breeding season, an increased instance of sharing the colony site with other species, an increased risk of nest predation, and fewer available nesting materials. Caves and sinkholes, however, are not at great risk of flooding, have a less variable thermal regime, lower instance of sharing the site with other species, lower risk of predation, and easily available nesting materials. All this being said, cave swallows nesting at the culvert site laid more eggs, had more eggs hatch, and had more nestlings survive than those nesting at Dunbar Cave in 1974, which could explain why the population is growing so rapidly while using a riskier nest site.
Cave swallow eggs are elliptical ovate in shape and typically white in colour with some variation of fine spotting of light to dark brown or even lilac and dull purple. Clutches of three to five eggs are typical and both sexes are thought to contribute to the incubation of the clutch. Only the female is observed to develop a brood patch.
Cave swallows are altricial when they hatch; they are blind and incapable of sustaining their own body heat. They remain in the nest until they are capable of flying, which is approximately 20 to 22 days after hatching. Both parents will feed the nestlings small insects throughout the day and will defend the nest if threatened by swooping and loudly calling at the threat.
The American cliff swallow (Petrochelidon pyrrhonota) is a member of the passerine bird family Hirundinidae, the swallows and martins. The scientific name is derived from Ancient Greek; Petrochelidon originates from the petros meaning "rock" and khelidon "swallow", pyrrhonota comes from purrhos meaning "flame-coloured" and -notos "-backed".American cliff swallows are extremely social song birds that can be found in large nesting colonies reaching over 2,000 nests. They are frequently seen flying overhead in large flocks during migration, gracefully foraging over fields for flying insects or perching tightly together on a wire preening under the sun.Cliff swallows build gourd-shaped nests made from mud with small entrance holes. They build their nests tightly together, on top of one another, under bridges or alongside mountain cliffs. Living in large populations, these aerial insectivores use extensive vocalizations to communicate warnings or food availability to the other individuals.Atticora
Atticora is a genus of bird in the swallow family Hirundinidae. These species are found in South America.
It contains the following two species:
White-banded swallow (Atticora fasciata)
Black-collared swallow (Atticora melanoleuca)Banded martin
The banded martin or banded sand martin (Riparia cincta) is a small passerine bird in the swallow family. It is an inhabitant of the African continent.Black-and-rufous swallow
The black-and-rufous swallow (Hirundo nigrorufa) is a species of bird in the family Hirundinidae.Forest swallow
The forest swallow (Petrochelidon fuliginosa) is a species of bird in the family Hirundinidae.
It is found in Cameroon, Republic of the Congo, Equatorial Guinea, Gabon, and Nigeria.Galápagos martin
The Galápagos martin (Progne modesta) is a species of bird in the Hirundinidae family, endemic to the Galápagos Islands.
Its natural habitats are subtropical or tropical dry shrubland, subtropical or tropical seasonally wet or flooded lowland grassland, pastureland, and heavily degraded former forest.Grey-rumped swallow
The grey-rumped swallow (Pseudhirundo griseopyga) is a species of bird in the monotypic genus, Pseudhirundo, in the family Hirundinidae.
It is found in Angola, Benin, Botswana, Burkina Faso, Burundi, Cameroon, Central African Republic, Republic of the Congo, Democratic Republic of the Congo, Ivory Coast, Equatorial Guinea, Ethiopia, Gabon, Gambia, Ghana, Guinea, Guinea-Bissau, Kenya, Liberia, Malawi, Mali, Mozambique, Namibia, Niger, Nigeria, Rwanda, Senegal, Sierra Leone, South Africa, Sudan, Swaziland, Tanzania, Uganda, Zambia, and Zimbabwe.Peruvian martin
The Peruvian martin (Progne murphyi) is a species of bird in the family Hirundinidae. It is found in Peru and far norther Chile.
Its natural habitats are subtropical or tropical moist lowland forest, subtropical or tropical moist montane forest, subtropical or tropical dry lowland grassland, subtropical or tropical high-altitude grassland, pastureland, and urban areas. It is threatened by habitat loss.Phinizy Swamp Nature Park
Phinizy Swamp Nature Park is a 1,100-acre (450 ha) nature park in Augusta, Georgia. The park contains wetlands and woodlands and has a campus for water research and environmental education, which includes a visitor center. It has many bald cypresses draped in Spanish moss and forests of loblolly and longleaf pine trees. Birds commonly found at Phinizy Swamp include: red-shouldered hawks, great blue herons, sora, wood ducks and bald eagles. Sometimes the park yields rarities for Georgia, including black-bellied whistling ducks, and a cave swallow, in 2004. Other wildlife commonly found in the park include frogs and toads; snakes, including water moccasin, pigmy rattlesnake, and copperhead; beavers and muskrat; turtles; and dragonflies. Fishing and hunting are not permitted within the park. Phinizy Swamp Nature Park is managed by Phinizy Center for Water Sciences.Preuss's cliff swallow
Preuss's cliff swallow (Petrochelidon preussi), also known as Preuss's swallow, is a species of bird in the family Hirundinidae.Progne
Progne is a genus of birds. The genus name refers to Procne (Πρόκνη), a mythological girl who was turned into a swallow to save her from her husband. She had killed their son to avenge the rape of her sister.Saw-wing
The saw-wings, Psalidoprocne, is a small genus of passerine birds in the swallow family. The common name of this group is derived from the rough outer edge of the outer primary feather on the wing, which is rough due to recurved barbs. The function of this is unknown. The birds are 11–17 cm long and black or black-and-white in colour. The genus has an African distribution and all species can be found foraging over forest and woodland.Sinaloa martin
The Sinaloa martin (Progne sinaloae) is a species of bird in the family Hirundinidae.
It breeds semicolonially in sheer cliff faces within pine-oak forests of the Sierra Madre Occidental of western Mexico. Presumed migrant records also come from Belize and Guatemala. It is assumed to winter in South America.Southern martin
The southern martin (Progne elegans) is a species of bird in the family Hirundinidae.
It is found in Argentina and southern Bolivia ; in winter it migrates to the western Amazon Basin.
Its natural habitats are subtropical or tropical moist lowland forest, subtropical or tropical moist montane forest, subtropical or tropical dry lowland grassland, subtropical or tropical high-altitude grassland, and urban areas.Stelgidopteryx
Stelgidopteryx (Baird, 1858) is a small genus of swallows. It contains two species:
Adults of both species are brown on top with lighter underparts and a slightly forked tail. They nest in cavities but do not excavate their holes or form colonies.
These birds forage in flight over water or fields, usually flying low. They eat insects.
"Rough-winged" refers to the serrated edge feathers on the wing of this genus; this feature would only be apparent in the hand.Streak-throated swallow
The streak-throated swallow or the Indian cliff swallow (Petrochelidon fluvicola) is a species of swallow found as Native (breeder, year-round resident or winter visitor) in South Asia in the countries of Afghanistan, Bangladesh, India, Nepal and Pakistan. It occurs as a Vagrant in the Maldives, Sri Lanka, and the Middle-east.Tumbes swallow
The Tumbes swallow (Tachycineta stolzmanni) is a species of bird in the family Hirundinidae.
It is found in northwestern Peru and far southwestern Ecuador.
Its natural habitats are dry savanna, coastal saline lagoons, and arable land.