184 SWIFTS. 



Y. SWIFTS. Cypseli. 



Compact birds with long primaries but the other portion 

 of the wing shortened ; bill, small with a wide gape; color, 

 dull sometimes relieved by white markings. 

 A. SPINE-TAILED SWIFTS. Cliaeturidae. 

 Tail feathers denuded at tip and produced into a spine, 

 Fig._234. fig. 234; nests of sticks fastened to- 



gether with a gluey secretion from 

 the mouth, placed in a hollow tree, 

 cave or other rock shelter orinchim- 

 Y, A, a, 1. neys; eggs, white, 4; young naked 



and helpless ; adults are incapable of alighting on other than 

 a vertical surface, hence are seldom seen at Fig. 235. 

 rest ; move with a swift, continuous flight by 

 alternately moving the wing tips with a 

 quivering motion and sailing. Food, insects. 

 a. Spine-tailed Swifts. Chaetura. 

 Characters as above. 

 1. CHIMNEY SWIFT, C. PELAGICA. 

 5.30; sooty-brown; wings, blackish, fig. 235. 

 Eastern N. A. north to Labrador; winters 

 south of the U. S. ; migrates in Oct. and late 

 April. Cries, a shrill chatter. Common. 

 Z. HUMMINGMBIRIDS. 



Troeliili. Y, A, a, 1. 1-4. 



Small birds with wings similar to Y but which differ in 

 having an awl-shaped bill, with a peculiar tongue ; portions 

 of plumage, frequently iridescent; nests in trees, bushes, etc. 

 made of fine material often covered with lichens; eggs, 2, 

 white; young naked and helpless; flight swift and darting; 

 wing-beats exceedingly rapid ; food, the sweet juices of flow- 

 ers, and small insects ; sexes usually different, often with very 

 differently formed tails. Found only in America. 



