226 BULLETIN 50, UNITED STATES NATIONAL MUSEUM 



and auriculars paler than in male — pale pinkish buff barred narrowly 

 with buffy brown. 



Immature (sexes alike). — Similar to the adult female but paler, the 

 blackish marks on the upper parts smaller, the browns less ochraceous, 

 ashier, very pale buffy brown, the scapulars and the inner lesser and 

 median upper wing coverts with conspicuous white shaft stripes; rec- 

 trices pale buffy brown crossed by eight or more wavy white bars each 

 of which is margined narrowly by fuscous, the broad .brown interspaces 

 sparsely freckled and vermiculated with fuscous, the shafts dusky ; breast 

 as in adult female but the dark tips of the feathers paler, buffy brown; 

 abdomen paler — dark hair brown to chaetura drab and fuscous; under 

 tail coverts drab to dusky hair brown broadly tipped with whitish buffy, 

 the whitish areas banded sparingly with hair brown. 



Juvenal. — Similar to the immature but with the ground color of the 

 breast less buffy, more whitish ; the abdominal feathers tipped with white, 

 basally broadly dusky hair brown; the white shaft stripes of the feathers 

 of the upperparts more pronounced; the forehead, sides of head, and 

 superciliary area much paler — tilleul buff; the tail very different — the 

 shafts white terminally, bordered on each side with blackish, the edges 

 of the feathers broadly pale tawny olive freckled with blackish ; the white 

 shaft stripes spreading out into narrow terminal white fringes. 



Natal down. — "Crown, back, and rump are mottled and marbled with 

 black, dull browns, pale buff, and dull white; the sides of the head and 

 neck are boldly spotted and striped with black ; there are two large spots 

 of sayal brown bordered with black on the foreneck or chest; underparts 

 grayish white, suffused with buff on the chest. "^^ 



Adult male.—Wing 286-323 (303.9) ; tail 297-332 (315.3) ; culmen 

 from base 38.3-41.6 (40.1) ; tarsus 53.1-59.0 (56.3) ; middle toe without 

 claw 45.5-51.4 (48.0 mm.).^^ 



Adult female.— Wing 251-273 (260.6) ; tail 188-213 (198.9) ; culmen 

 from base 33.0-37.5 (35.0) ; tarsus 44.0-49.6 (47.2) ; middle toe without 

 claw 36.6-41.9 (40.3 mm.).28 



Range. — Originally resident in the prairie areas where the sagebrush 

 (Artemisia tridentata) grows ; now extirpated or greatly reduced in parts 

 of its range: Extreme western Kansas (formerly), extreme north- 

 western Nebraska (formerly), Colorado (formerly nearly everywhere 

 except high in the mountains, now found chiefly in Rio Blanco, Moffat, 

 Routt, and Jackson Counties), South Dakota (in western part), North 

 Dakota (still found in Billings County, south of Sentinel Butte) ; Wyo- 



« Ex Bent, U. S. Nat. Mus. Bull. 162, 1932, 304, 



" Seventeen specimens from Nebraska, Montana, Wyoming, Nevada, Oregon, and 

 Idaho. 

 " Ten specimens from Montana, Oregon, Nevada, and Wyoming. 



