American Cliff Swallow

The Cliff Swallow, Petrochelidon pyrrhonota, is a small, agile bird with a body length averaging 13 cm (5.1 in). It possesses short legs, a small bill, and long, pointed wings suited for adept flight. Adults are adorned with dark brownish plumage on their back and wings, a distinctive white forehead, and rich red cheeks contrasted by a dark throat. Their underparts are primarily white, and they feature a buffy rump. In favorable lighting, their crowns and mantle exhibit an iridescent sheen.

Identification Tips

To identify the Cliff Swallow, look for its square-shaped tail, which sets it apart from the forked tail of the similar Barn Swallow. The white forehead and red cheeks are key features, along with the buffy rump. Juveniles share the adults' coloration but are paler and lack the iridescent quality. Their foreheads and throats are speckled white, a pattern that fades as they mature.

Habitat

Cliff Swallows historically nested along mountain cliffs, particularly along the western North American coast. Today, they have adapted to human-made structures and are often found nesting under bridges and on buildings, expanding their range across much of Canada and the United States.

Distribution

These birds breed across a wide swath of North America and migrate to wintering grounds in South America, including southern Brazil, Uruguay, and parts of Argentina. They are known for their long-distance, diurnal migration along coastlines.

Behaviour

Cliff Swallows are highly social and colonial, with nesting colonies that can exceed 2,000 nests. They exhibit a range of behaviors from cooperative mud-gathering for nest building to complex vocal communication. Their colonial life offers both benefits and risks, such as efficient information sharing and increased disease transmission.

Song & Calls

The Cliff Swallow has a sophisticated vocal repertoire with at least five distinct calls used for begging, alarm, recognition, and other social interactions. A unique "squeak" call is employed to signal the discovery of abundant food sources.

Breeding

These swallows are socially monogamous but may engage in polygamy. They exhibit brood parasitism, with females laying eggs in other nests and males mating with multiple females. Nesting success can be influenced by colony size, with younger pairs benefiting from larger colonies.

Similar Species

The Cliff Swallow can be confused with the Barn Swallow but can be distinguished by its square tail and different facial markings. The Cave Swallow is its closest relative in North America, with similar plumage but a dark cap and pale throat.

Diet and Feeding

Cliff Swallows forage on a variety of flying insects, often feeding high above the ground. They are diurnal hunters, returning to their nests at dusk, and their foraging is closely tied to their reproductive cycle.

Conservation status

The Cliff Swallow is currently listed as Least Concern by the IUCN, indicating a stable population without significant threats at this time.