76 BIRDS OF SOUTH DAKOTA 
Grouse, measuring in length from eighteen to twenty inches. 
The back of the male is dark slate mixed with brown and gray; 
below it is light slate. The tail is dark slate fully barred on the 
back. Like all true Grouse it is feathered on the legs, but not 
so persistently as the Sharp-tailed Grouse. The Dusky Grouse is 
a bird of the mountains, usually found in the evergreen zone. 
It feeds on berries and insects. 
300b. GRAY RUFFED GROUSE (Bonasa umbellus umbelloides.) 
An annual resident and rather abundant in the Black 
Hills. This is the Partridge or Pheasant of wooded areas east 0’ 
Minnesota and the Mississippi River, except that its general - 
color is grayish instead of mixed rusty brown. About seventeen 
inches long; head slightly crested with gray; body gray, mixed 
with rufous and black; tail mixed gray with a wide slate colored 
band near the tip. Both male and female have back neck tufts, 
hence the name. , 
The male produces his drumming sound by rapidly beat- 
ing his wings, usually while perched on a log. They are fre- 
quently found in deep woods feeding on berries, buds and insects. 
305. PRAIRIE CHICKEN (Tympcanuchus americanus americanus.) 
The male is eighteen inches in length; female slightly 
smaller; alike in color; irregularly barred with black and rufous, 
with some white on wings and tail; under parts barred with 
white, dark brown and buff; front and side of legs covered with 
short, downy feathers; head slightly crested. On the sides of 
the neck there are tufts of feathers, which, when extended, re- 
semble small wings. These tufts cover a yellow, bare sac that 
is capable of being expanded by the male to the size of a small 
lemon. The function of this inflated sac is perhaps not definitely 
known but it is thought to connect by a canal with the windpipe 
and thus assist in producing that “booming” sound which is so 
often heard, especially during the early spring. 
Their nesting place is usually in meadows, but an un- 
plowed strip of wild hay land is sometimes preferred. 
A closed hunting season for a few years, and the creating 
of public sentiment for law enforcement, are much needed to in- 
crease Prairie Chickens in sufficient numbers to make them of 
economic importance, either as game birds or insect destroyers. 
