BIRDS OF YOSEMITE NATIONAL PARK 



103 



POOR -WILL (Phalaenoptihis nut- 

 talli): 7-8 in. Grayish-brown, marked 

 with black and silvery gray; darker be- 

 low; ichitc band on throat bordered 

 ivith black; white tips on outer tail 

 feathers; tail short, cut straight across; 

 no ivhite :ving-bars seen in flight as in 

 nighthawks; mouth large, bristled. For- 

 ages later and at a lower elevation than 

 the booming nighthawk. Song a plain- 

 tive whistle, poor-will, the second note 

 slurred, longer and lower than first. 



Frequents rocky, gravelly terrain or 

 bare soil, grown scatteringly to bushes 

 and trees. Frequents the Lower Sonoran 

 to the Transition life-zone, from San 

 Joaquin Valley to Yosemite Valley. 

 S.V. at lower elevations in Yosemite. 



VAUX'S SWIFT 



WHITE-THROATED 

 SWIFT 



GWIFTS AND HIIMMINGBIRDS: 

 Order Micropodifonnes 



SWIFTS: Family Micropodidae 



VAUX'S SWIFT (Chaetura vauxi): 

 4/2 in. Above dark brown, lighter on 

 rump and tail; throat and breast light 

 gray; rest of under parts sooty; tail 

 short, not forked. Flight strong, swift, 

 erratic, consisting of glides with wings 

 extended stiffly from body and distinct- 

 ly bowed downward, alternating with 

 rapid wingbeats. Nests in burned-out, 

 hollow tree trunks, mostly redwoods. 



In summer found along the coast 

 from Santa Cruz Co. northward and 

 occasionally in the Sierra. M. through- 

 out, including Sierra. C. V. to Yosemite 

 region. Recorded in Yosemite Valley. 



BLACK SWIFT (Nephoecetes ni- 

 ger): 7 in. General coloration black; 

 at close range small amount of white 

 may be seen about face; undersides of 

 wings may appear silvery at certain 

 angles; slender curving wings; tail 

 slightly forked. Voice a high-pitched 

 twitter. Nests in cliffs near waterfalls 

 or in sea-bluffs. 



S. v., breeding in the Transition life- 

 zone of the central coast of California, 

 and the central and southern Sierra 

 Nevada. Seen in Yosemite Valley and 

 found nesting in Tenaya Canyon. 



WHITE-THROATED SWIFT 

 ( Aeronautes saxatalis) : 6/2-7 in. Chin, 

 throat, breast, middle line of belly, and 

 patches on flanks white; flank patches 

 show from above; rest of plumage es- 

 sentially black; tail slightly forked; 

 wings long and slender. In flight, one 

 sees flashes of white on breast and 

 rump. Song, a twittering series of de- 

 scending notes resembling song of a 

 canyon wren. A remarkably fast flier. 



Frequents the yicinity of cliffs (often 

 of granite) where it roosts and nests. 

 Breeds chiefly in the Lower and Upper 

 Sonoran life-zones and into the Tran- 

 sition zone. S. V. in the Yosemite re- 

 i:;ion, usually near sheer cliffs. Common 

 about Yosemite Valley. 



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