Cave Swallow (Petrochelidon fulva)

The Cave Swallow is found in much of Texas and in southern New Mexico in the United States, and is also found in parts of Mexico, Cuba, and other locations in the Caribbean. In the United States, they are perhaps best known from the very large colony found in Carlsbad Caverns in New Mexico, a habitat they share with Mexican Free-tailed Bats. As a species they have likely benefited from a human presence. Highway underpasses and other bridges and man-made structure provide more suitable nesting locations than were naturally present before man came on the scene.

Habitat

The Cave Swallow inhabits open country near cliffs, canyons, sinkholes, caves, bridges, culverts, and other structures that provide sheltered nesting sites. In North America it is most common in southern Texas and parts of the Southwest, where it forages over grasslands, agricultural fields, wetlands, rivers, and other open habitats rich in flying insects.

Diet

The Cave Swallow feeds almost entirely on flying insects captured in the air. Its diet includes flies, beetles, winged ants, wasps, bees, true bugs, and other small aerial insects that it catches while flying over open landscapes, wetlands, rivers, and grasslands.

Behavior

The Cave Swallow is a highly aerial bird that spends much of the day in flight catching insects. It is social throughout the year, often foraging in flocks and nesting colonially in caves, sinkholes, under bridges, and on other sheltered structures. Like other swallows, it frequently glides and wheels over open country, wetlands, and rivers while feeding. During migration and post-breeding periods, large groups may gather at favored roosting sites.

Nesting

The nest of a Cave Swallow is an enclosed structure of mud and clay, lined with softer vegetative material or feathers. Nests were traditionally located in protected caves and crevices. The clutch consists of 3 to 5 eggs. Both parents help to incubate the eggs and feed the young upon hatching.

Song

The Cave Swallow gives a variety of soft, rapid twittering, chirping, and chattering calls that are often heard as birds circle around nesting colonies. Its vocalizations are generally higher-pitched and less harsh than those of the Cliff Swallow, consisting of buzzy twitters, short trills, and conversational chatter notes exchanged among flock members.

Migration

The Cave Swallow breeds primarily in southern Texas, parts of the southwestern United States, Mexico, and the Caribbean. Most North American birds migrate south after breeding, wintering mainly in Mexico, Central America, and portions of the Caribbean, although some populations along the Gulf Coast may remain year-round. During migration, Cave Swallows occasionally wander far beyond their normal range, producing rare records across much of the United States, including the Great Plains and Midwest.

Similar Species

The Cave Swallow is most likely to be confused with the Cliff Swallow because both are colonial swallows that nest on cliffs and human-made structures. Cave Swallows have a rich cinnamon-buff forehead, throat, and rump, giving them a noticeably warmer appearance. Cliff Swallows typically show a pale buff or whitish forehead, a dark throat patch, and a contrasting pale rump that lacks the extensive cinnamon coloration.

In flight, Cave Swallows often appear more uniformly warm-colored below, while Cliff Swallows show a stronger contrast between the pale forehead and darker face and throat. The tail of the Cave Swallow is also slightly less squared and often appears a bit more notched.

Conservation Status

The Cave Swallow is generally considered a species of low conservation concern, with populations stable or increasing in parts of North America. The species has benefited from the widespread availability of artificial nesting structures such as bridges, culverts, and highway overpasses, which supplement natural cave and sinkhole nesting sites. While local populations can be affected by severe weather, habitat changes, and declines in flying insect abundance, the overall outlook for the species remains favorable. The IUCN lists the Cave Swallow as a species of "Least Concern".

Cave Swallow