The Prairie Falcon 



Taken in Idaho 



NEST AND EGGS OF SAGE GROUSE: A DESERTED NEST 



Photo by H. J. Rust 



No. 319 



Prairie Falcon 



A. 0. U. No. 355. Falco mexicanus Schlegel. 



Synonyms. — Mexican Falcon. American Lanner Falcon. 



Description. — Adults: Upperparts ruddy grayish brown (nearly bister), the 

 feathers usually more or less tinged with rusty and chiefly bordered with pale clay-color, 

 or bluish gray — the general effect in high plumage being of a ruddy brown overspread 

 with ruddy glaucous reticulations; crown and upper back more blended, crown sharply 

 and heavily streaked with dusky shaft-lines, back and wings more lightly and sparingly 

 dusky-shaft-streaked; primaries darker brown, nearly uniform on exposed portions of 

 folded wing, but sharply and deeply indented or spotted on inner webs with white and 

 ochraceous; tail much paler brown on exposed portion, but similarly ochraceous- 

 whitish dented on inner webs; face narrowly (region about base of bill) white, flanked 

 by narrow ruddy black mustachios which proceed sharply downward from before eye; 

 cheeks white; auriculars like back; an obscure whitish line across occiput continuous 

 with equally obscure superciliaries, and another disconnected line across cervix; axillars 

 plain brown, the proximal portion of wing-lining brown centrally with white edging; 



1608 



