Swallow-like Birds
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.
