THE SOOTY GROUSE. 49 



But one brood is raised in a season. Incubation lasts, according to differ- 

 ent observers, from eighteen to twenty-four days. Females seem to predominate 

 in numbers, but I do not tliink that these birds are polygamous. Their ordi- 

 nary note resembles the cackling of the domestic hen very much. The Indian 

 name of the Sooty Grrouse on the Northwest coast is " Ti/hee-CuUaw-CuUaiv," 

 " Chief Bird." 



According to my own observations, made in various portions of Oregon, 

 Washington, and Idaho, the usual number of eggs laid by the Sooty Grouse is 

 about eight, and occasionally as many as ten are found in a set. Prof. 0. B. 

 Johnson, of the University of Washington, Seattle, Washington, informs me, 

 however, that he found as many as sixteen eggs in a nest, and gives the average 

 number from eight to twelve. The former, I think, will as a rule, come 

 nearer to the correct average. 



The eggs are ovate in shape, and the ground color varies from pale cream 

 to a cream-buff, the latter being more common. In a single set before me it 

 is a pale cinnamon. The eggs are more or less spotted over their entire surface 

 with fine dots of chocolate or chestnut brown; these spots vary considerably 

 in size in different sets, ranging from the size of No.. 3 shot to that of mustard 

 seed. These markings are generally well rounded, regular in shape, and pretty 

 evenly distributed over the entire egg. They never run into irregular and 

 heavy blotches, such as are frequently found in the eggs of the Canada Grouse, 

 Demlragaims canadensis, which approach the pattern usually found among those 

 of the Willow Ptarmigan, Lagopus lagopus, much nearer than the former. All 

 of these markings can be readily washed off, as well as the overlying ground 

 color, while they are still quite fresh, leaving the shell a delicate pale creamy 

 white. In fact this coloring matter rubs off very readily, and occasionally 

 fresh eggs will not stand even a good wiping. An Qgg is usually deposited 

 daily and incubation does not begin until the set is completed, the male taking 

 apparently no part in this duty nor in the care of the young after they are 

 hatched. 



The average size of ninety-six specimens in the U. S. National Museum 

 collection is 48.5 by 34.5 millimetres. The largest Qgg of the series measures 

 52 by 37, the smallest 45 by 32.5 millimetres. 



The type specimens show the different variations found in the eggs of the 

 Sooty Grouse, and are all from the Bendire collection, having been col- 

 lected by the author. No. 21073 (PI. 1, Fig. 16), is from a set of ten, taken 

 near Camp Harney, Oregon, May 10, 1876 ; No. 21074 (PI. 1, Fig. 17), from 

 a set of eight collected on the Canyon City Mountain, Grant County, Ore- 

 gon, June 8, 1876; No. 21079 (PI. 1, Fig. 18), from a set of nine, taken May 

 10, 1877, near Camp Harney, Oregon, and No. 21080 (PI. 1, Fig. 19), from a 

 set of seven eggs found near Fort Klamath, Oregon, and taken May 22, 1883. 

 The majority of the eggs of this subspecies resemble the specimen figured on 

 PI. 1, Fig. 18, moi'e than the other types. 

 36957— Bull. 1 4 



