Cliff Swallow
Petrochelidon pyrrhonota
(Hirundo pyrrhonota)
Description
5-6" (13-15 cm). Sparrow-sized. A
stocky, square-tailed swallow with pale buff rump. Upperparts dull
steel-blue; underparts buff-white; throat dark chestnut; forehead
white. Southwestern birds have chestnut foreheads. Cave Swallow of
Texas and Southwest is similar but smaller, with darker rump and
pale buff throat.
Voice
Constant squeaky chattering and
twittering.
Habitat
Open country near buildings or cliffs;
lakeshores and marshes on migration.
Nesting
4-6 white eggs in a gourd-shaped
structure of mud lined with feathers and placed on a sheltered cliff
face or under eaves. Nests in colonies.
Range
Breeds from Alaska, Ontario, and Nova
Scotia southward through most of United States except Southeast.
Winters in tropics.
Discussion
As its name implies, this swallow
originally nested on cliffs. The introduction of House Sparrows was
a disaster for these birds, since the sparrows usurp their nests and
often cause the swallows to abandon a colony. Long, cold, rainy
spells while the young are in the nest also cause widespread
mortality since the adults are unable to obtain enough insects. In
California they often return in early spring to ancestral colonial
breeding sites. If it turns chilly, however, they will abandon the
area until weather and feeding patterns are more favorable, and
return "on schedule" for their publicized arrival on March 19 at
Mission San Juan Capistrano.
