PRAIRIE SHARP-TAILED GROUSE 295 



articles of diet with the farmers until the first fall of snow buries their foraging 

 grounds and drives them en masse to the woods. 



Doctor Gross says in his notes : 



So far as my observation goes only one bird incubates and cares for the 

 young. I did not see the male about the nest at any time. The female is a 

 nervous, excitable creature and continually flits her tail when walking about 

 or approaching the nest. The tail is usually widespread and displaying the 

 patches, and the long tail feathers are held up in an upright position, making 

 a striking picture. 



Plumages. — Downy young sharptails are decidedly yellowish ; the 

 general color varies from " mustard yellow " above to " straw yellow " 

 below, washed on the crown and back with " ochraceous-tawny " ; 

 they are spotted on the crown and blotched or streaked on the back 

 with black; there is a black spot at the base of the culmen and a 

 black spot on the auriculars. 



As with all grouse, small chicks show the growth of juvenal plum- 

 age, beginning with the wings; before the young birds are half 

 grown they are fully feathered, and even before that they are able 

 to fly. In full juvenal plumage, in July, the crown and occiput are 

 " hazel," centrally black ; the feathers of the mantle and wing coverts 

 are brownish black, broadly tipped, barred, or notched with " ochra- 

 ceous-tawny " on the back and with " ochraceous-buff " on the coverts ; 

 the feathers of the mantle have a broad median white stripe; the 

 underparts are dull w T hite, spotted or barred on the breast and flanks 

 with " sepia " and " cinnamon-buff " ; the four central tail feathers 

 (sometimes nearly all of them) are patterned with "ochraceous- 

 buff " and black, with a broad median white stripe, and they are all 

 decidedly pointed; the chin and throat are "colonial buff." 



Within a month or so, during August, the postjuvenal molt takes 

 place. This is a complete molt, except that the outer primaries on 

 each wing are retained for a full year; it produces a first winter 

 plumage, which is practically adult in September. Adults may have 

 a partial prenuptial molt, about the head and neck. They have a 

 complete postnuptial molt, during July, August, and September. 

 The sharp-tailed grouse has several times been known to hybridize 

 with the prairie chicken. 



Food. — Dr. Sylvester D. Judd (1905a), by his examination of 43 

 stomachs of sharp-tailed grouse, showed that 



animal matter (insects) formed only 10.19 percent of the food, while vegetable 

 matter (seeds, fruit, and ' Browse ') made 89.81 percent. The insect matter con- 

 sists of bugs, 0.50 percent; grasshoppers, 4.62 percent; beetles, 2.86 percent, 

 and miscellaneous insects, 2.21 percent in a total of 10.19 percent of the 

 food. Vernon Bailey, of the Biological Survey, found that three birds shot by 

 him in Idaho August 29 had eaten chiefly insects, including grasshoppers, small 

 bugs, and small caterpillars. The young of the sharp-tailed grouse, like those 

 of other gallinaceous species, are highly insectivorous. A downy chick from 1 



