SWIFTS 229 



wing. Their voice also marks them. They do not boom or give 

 the quaiik characteristic of other members of the family. ISlv. Bai- 

 ley describes their notes as a low rapid chuck, chuck, chuck, followed 

 by a soft i^arrr'rrr'r, which, when several birds are about, be- 

 comes almost incessant. 



In parts of southwestern Texas during the breeding season the 

 Texan is the only nighthawk, and Dr. ]\Iearns states that he has 

 never known henryi to infringe on the territory of texends in the 

 breeding season, henryi nesting in the pines and spruces of Transi- 

 tion and Boreal zones; texensi.s below the pines in Lower Sonoran 

 zone. In California, ]\Ir. Grinnell says, tc.rensis nests in dry parts 

 of river-l)eds and sandy places among sagebrush. 



FAMILY MICROPODIDiE : SWIFTS. 



KEY TO GENEKA. 



1. Tarsus and part of toes feathered Aeronautes. p. 2:52. 



1 . Tarsus and toes naked. 



2. Tail feathers tipped with spines . . ChcCtura. p. 230. '^^^ 



Fig. 2^. 



Tail feathers not tipped with .spines . Cypseloides. p. 220. 



GENUS CYPSELOIDES. 



422. Cypseloides niger borealis (Ketm.). Black Swift. 



Tail slightly forked : tarsus and toe.s naked, the hind toe poinHng back- 

 ward. Adults: dusky or blackish, 

 lighter on head and neck, the forehead 

 hoary, a velvety black area in front of 

 eye. Youny : .similar, but feathers _ ^ 



tipped with whitish. Lentft/i : ".OH- Pip •>or, 



T.rjO, wing- r)J)()-l.r>i), tail 2.:]o-;iO(). 



iJistrihution. — From the Rocky Mountain region west to the Pacific, 

 and from British ('olund)ia south to Lower California and Costa Kica. 



Ntst. — On cliffs or ahout buildings. One described by M. H. Gorm- 

 ley, on the conncc of a building, made (»f straws, chips, and luu-seliair, 

 lined witli green leaves and pajjcr. Eyys : .">. white 



Food. — Insects. 



The black swift has been found breeding on inaccessible clilTs in 

 various parts of the west, but littlr that is peculiar has been di.scov- 

 ered about its habits except that it is less noisy than most of the 

 swifts. A nest was accideidally discovered by ]Mr. Vrooman at 

 Santa Cruz when collecting cormorants' eggs on the clilTs. 



.Mr. Hatlibun says the swifts may Ite seen circling about above the 

 city of Seatth', rarely being seen, except when rain threatens, lower 

 than from :i()(»(> toTjOOO feet. 



