THE BIRO BOOK 



\.^ 



L - ' 



420 — 421 



of gray, brown and lilac. 



420c. Sennett's NiGHTHAvvK, 



CordeMes virginianus senneiti. 

 Range. — A very pale species with little or 

 no tawny; found in the Great Plains from 

 Texas north to the Saskatchewan; winters 

 south of the United States. 



421. TkXAS NiGIITHAWK. 



Chordeiles acutipevnis li'.rcnsis. 



Range. — Mexico and Central America, breed 

 ing north to southern Utah and California. 



The pattern of the 

 marking of this species 

 is finer and more mot- 

 tled with rusty than 

 the Nighthawk. Its 

 habits do not differ to 

 any extent from those 

 of the preceding spe- 

 cies; they lay their two 

 mottled gray eggs up- 

 on the bare ground, often on the dry sand and 

 in arid regions - _^_ . 



where they are -481 



exposed, with '' ■ 



no protection, 

 to the scorch- 

 ing rays of the 

 sun. The eggs 

 vary endlessly 

 in extent of 

 markings, some 

 being very pale 

 and others 

 very dark gray, 

 mottled with 

 various shades 

 Size 1.10 X. 75. 



Grayish white 



SWIFTS. Family MICROPODID^ 



422. JiLACK Swift. Cypscloidcs nigcr 

 horcaUs. 



Range. — Mountain ranges from Central Amer- 

 ica north to British Columbia, locally distribut- 

 ed throughout its range. 



The plumage of this Swift is entirely sooty 

 black, darkest above; the tail is slightly forked 

 and is without spines; lepgth of bird, 7 inches. 

 Although the general habits of this species are 

 well known, little is known of their nesting; 

 they are seen during the breeding season about 

 the higher ranges throughout their United 

 States habitat, and are supposed to nest in 

 crevices on the face of cliffs at a high altitude. 



268 



422—424 



