106 LIFE HISTOEIES OF NOETH AMERICAN BIRDS. 



they gather more aud more iirto flocks and become regular visitors to the 

 stubble fields, and in consequence regular articles of diet with the farmer." 



The nesting habits are similar to those of the Columbian Sharp-tailed 

 Grouse, and the average number of eggs about the same, from eleven to 

 fourteen. Their favorite nesting sites, according to Mr. W. M. Wolfe, are 

 usually along upland thickets or the edges of timber, near streams, and he 

 also states that occasionally two broods are raised in a season. He found 

 one nest on the bare ground under the shelter of a rock. 



Dr. T. E. Wilcox, assistant surgeon, U. S. Army, writes me from Fort 

 Niobrara, Nebraska: "In the spring of 1889 a nest of this species was found, 

 and the bird was incubating. Neatly coiled among the eggs was a fox 

 blacksnake. Coluber vulpinws, the death of which, perhaps, insured a success- 

 ful result of the effort to rear offspring. Here they nest usually in the sand- 

 hills, remote from water. Wild grapes, rose-hips, plums, sand-cherries, besides 

 grasses, the tops of plants, grasshoppers, and other insects afford them food." 



The nesting season varies according to latitude. In the more southeria 

 portions of its range it begins in April, usually about the latter half of tliis 

 month, and it is protracted to the middle of June occasionally, in the more 

 northern localities. 



Incubation lasts about three weeks, and usually but a single brood is 

 raised. The eggs, in shape and color, are exact counterparts of those of the 

 Columbian Sharp-tailed Grouse. They can not be distinguished from each 

 other with certainty. The average measurement of thirty-eight specimens 

 in the U. S. National Museum collection is 42.5 by 31.5 millimetres. The 

 largest egg measures 46 by 32.5, the smallest 40 by 30.5 millimetres. 



The type specimen, No. 16645 (PI. 3, Fig. 9), selected from an incomplete 

 set of three eggs, was taken by Dr. Elliott Coues, near Pembina, North 

 Dakota, June 6, 1873; No. 22829 (PI. 3, Fig. 10), from a partial set of 

 nine eggs, was collected by Mr. Ernest E. Thompson, in May, 1886, near 

 CarbeiTy, Manitoba. 



38. Centrocercus urophasianus (Bonaparte). 



SAGE GROUSE. 



Tetrao urophasianus Bonaparte, Zoological Journal, iii, 1827, 21.3. 

 Centrocercus urophasianus Swainson, Fauna Boreali Americana, 11, 1831, 497, PI. 58. 

 (B 462, C 382, R 479, C 560, U 309.) 



Geographical range : Sagebrush-covered plains of the interior, principally 

 within tlie United States from North Dakota, and southern Assiniboia to Washing- 

 ton, and casually (?) to southern British Columbia; south to northern New Mexico, 

 Utah, and Nevada ; west to Oregon and California ; east to Colorado, Nebraska, South 

 and North Dakota. 



The home of the Sage Grouse is found on the dry sagebrush-covered 

 plains and table lands of the western parts of the United States. Its breed- 

 ing range extends northward to our boundary, latitude 49°, from Avestern 



