158 BULLETIN 50, UNITED STATES NATIONAL MUSEUM 



drab to whitish washed with pale vinaceous-buff ; under tail coverts 

 clay color to cinnamon-buff, broadly tipped with white, the white some- 

 times extending back in a narrow streak along the shaft, the brown parts 

 frequently with a few blackish spots ; under wing coverts sayal brown 

 to Saccardo's umber with whitish mesial streaks ; axillars white banded 

 broadly with sayal brown ; iris hazel ; bill dark brown ; feet dark grayish 

 olive with a brownish wash. 



Adult male (gray phase).— Similar to the red phase except that the 

 interscapulars, back, lower back, rump feathers, and upper wing coverts 

 have the brown areas vermiculated and irregularly banded with smoke 

 gray, the feathers completely margined with the same ; the upper tail 

 coverts and the rect rices have the rufescent replaced by smoke gray, which 

 is generally somewhat more abundantly flecked and vermiculated with 

 black than in the red phase ; the subterminal band is usually fuscous to 

 fuscous-black, but occasionally it is dark argus brown (in which examples 

 the ruffs are usually auburn with blackish tips) ; the outer margin of 

 the greater upper primary coverts paler — wood brown ; the sides, flanks, 

 and thighs ashier, and the brown on the under tail coverts reduced largely 

 to narrow, incomplete cross bars.^'^ 



Adult female (both phases). — Similar to the corresponding males but 

 averaging smaller with shorter ruffs, the gray phase females less pure 

 gray on the tail, more mixed or washed with rufescent than in gray males, 

 and the pectoral area in both phases more extensively tawny or hazel ; 

 the cordate spots on the feathers of the back and rump smaller than in 

 the males and also more washed with avellaneous to wood brown. 



Immature (both sexes). — Similar to the adults of the corresponding 

 sex and phase, but the ruffs slightly duller and slightly smaller; birds 

 in this stage may be told, however, chiefly by the fact that they have 

 the two outer primaries of the juvenal plumage, which differ from the 

 adult feathers in that their outer webs are not cartridge buff or whitish 

 marked with sayal brown but pale fuscous mottled and stippled with 

 pinkish buff to pale cinnamon-buff.^^ 



Juvenal (sexes alike). — Similar to the adult female but browner above, 

 more abundantly marked with sayal brown to Saccardo's umber on the 

 underparts, but these marks more irregularly disposed, not so clearly 

 forming bars, but something between bars and heavy transverse mottling ; 



"In winter, grouse (both sexes) differ from summer birds in the presence of 

 "snowshoes" caused by the growth of the hiteral scales on the toes, and also in 

 more extensive grayish tips and margins to the feathers which wear off by spring. 



"' In literature one finds statements to the effect that the juvenal primaries, such 

 as are retained in the immature plumage, are "light vinaceous cinnamon unmarked 

 except for a very fine sprinkling of a slightly darker shade . . .," but the only 

 difference between them and adult primaries is confined to their outer webs as 

 given above. 



