SAGE GROUSE. 141 



CENTROCERCUS UROPHASIANUS. 



Geographical Distribution. — British Columbia and Assiniboia 

 in the north to New Mexico, Utah, and Nevada. East to the 

 Dakotas, Nebraska, and Colorado, and west to California, 

 Oregon, and Washington. 



Adult Male. — Upper parts, light brown or grayish, barred with 

 black, dark brown, and grayish, sometimes blotched with black; 

 wings, like the back, with borders of tertials. and central streaks 

 and bars of some of the coverts, white; primaries, grayish 

 brown, lighter on their outer webs; tail, composed of twenty 

 cuneate feathers, graduated to a filamentous point, the central 

 ones like the back, remainder black, barred with light buff for 

 two-thirds their length from the base; top of head and neck, 

 grayish buff, barred with black, chin, throat, and cheeks, white, 

 spotted on first with black, sometimes this part is all black; a 

 blackish line from mouth passes under the eye, and over the ear- 

 coverts; a white line extends from behind the eye down side of 

 neck; fore-neck, black, bordered with grayish white; chest, gray, 

 with the shafts of feathers very stiff and black; flanks, barred 

 broadly with blackish brown and buffy white, occasionally a buff 

 line in center of black bar, sometimes mottled with black; ab- 

 domen and rest of lower parts, jet-black; under tail-coverts, 

 black, broadly tipped with white; bill, black. Total length, 

 about 28 inches; wing, 13; tail, 13. Weight, 5 to 8 pounds. 



On sides of neck is a loose skin which, in the breeding season, 

 is inflated into two enormous yellow sacs, and by the exhaustion 

 of the air a loud, booming sound is produced. 



Adult Female. — Like the male, but much smaller, the chin 

 and throat, pure white. Total length, about 22 inches; wing, 

 10^; tail, 8i. 



Downy Youfig. — Upper parts, grayish brown, irregularly 

 marked and blotched with black, most conspicuous on the head. 

 Markings of lower parts indistinctly defined. 



