MICROPODIDJE: Swifts 



137 



Nest in hollow trees or chimneys, or inaccessible (usually) rock crevices, 

 clinging to vertical surfaces with their stout, curved claws. Eggs white, 

 three to five in number. 



Southern California Mi- 

 grant Apr.-May and Aug.- 

 Sept. Common, especially in 

 spring. 



Arizona Appears rare, as 

 authentic records are few. 

 Nests in hollow trees and rock 

 crevices, even in chimneys. 



Res. Common locally, 

 about high, vertical cliffs 

 wherein it nests in colonies. 

 Less numerous in winter, 

 when occurring in flocks 

 and confined chiefly to low- 

 lands. At this season speci 

 mens have been taken from 

 rock-cavities in a semi- 

 torpid condition. 



