Petrochelidon pyrrhonota
If the Cliff Swallow were to be renamed in the 20th century, it would probably be called the Bridge Swallow or the Building Swallow: there seems to be a colony of Cliff Swallows under just about every low-elevation bridge that spans a large river. Unlike Barn Swallows, however, which have all but abandoned natural structures, Cliff Swallows continue to build their all-mud nests on natural, rocky cliffs as well. The colonial nests are rarely built lower than 8 ft. (2.4 m) from the ground, unless they are over water, where they may be just 3 ft. (91 cm) above the surface. During years of high run off and prolonged rains, floods can wipe out entire nesting colonies of Cliff Swallows. The Cliff Swallow is the species that predictably returns each spring to the Capistrano mission in California. |
I.D.: Sexes similar: square tail; buffy rump; blue-gray head and wings; cream-colored forehead; rusty cheek, nape and throat; buffy breast; white belly; spotted undertail coverts. Size: L 51/2 in. (14 cm). Range: locally common migrant and breeder throughout the Rockies. Habitat: steep banks, cliffs, bridges and buildings near watercourses; forages over water, fields and marshes up to the lower subalpine. Nesting: colonial; under bridges, on cliffs and on buildings; pair builds a gourd-shaped mud nest with a small opening on the bottom; pair incubates 4-5 eggs for up to 16 days. Feeding: catches flying insects on the wing; occasionally eats berries; drinks on the wing. Voice: twittering chatter: churrr-churrr; also an alarm call: nyew. Similar Species: Barn Swallow: deeply forked tail; dark rump; rust-colored underparts. |
