408 THE PRAIRIE CHICKEN, OR SHARPTAILED GROUSE. 
During the dance, the males strut as do most gallinaceous birds, 
with feathers all erect, the wings spread (not touching the ground), 
tail spread and upright, the head nearly touching the ground, the 
sacs on the neck inflated and displayed to their utmost ; thus the 
bird runs a few yards uttering a sort of bubbling crow, which 
sounds as if it came froin the air-sacs; after this they relax for a 
few moments, then repeat the performance ad lib. When disturbed 
they immediately take wing and scatter (not hide in the grass 
(Wilson), uttering as they rise a peculiar vibratory ‘“ cack,” ‘“ cack,” 
“cack,” almost like a cough. This is nearly always uttered simul- 
taneously with the beats of the wings, and so rarely heard except 
then that I at first supposed that it was caused by them, but since 
have heard the sound both when the bird was sailing and on the 
ground, besides seeing it whirr up without the note. They have 
also a peculiar call note, a whistle of three slurred notes. In the 
fall their common note is a sort of whistling grunt, which is joined 
in by the pack as they fly. The “crow” is heard only in spring, 
the grunt only in fall, but the cackle and the whistle always. 
Their flight is very strong and rapid, so much so that they can in 
winter escape by flight from the white owl. When sprung they rise 
with a loud whirr, beating rapidly but soon sail, flying and sailing 
alternately every fifty or one hundred yards. 
The hen nests in the long grass tangle, generally near cover or on 
the edge of timber. The nest is a slight hollow arched over by the 
grass, lined only with a few straws. She lays eight to sixteen eggs 
no larger than those of a pigeon. Just before being laid they are of 
a delicate sky-blue, on exposure they soon become a deep chocolate 
with a few dark spots. In a fortnight they are gradually changed 
to a dirty white, partly by bleaching, partly by the scratching of the 
mother’s bill in turning them. Common as addled or infertile eggs 
are in the barnyard, I never in nature found more than one, and 
that was of the present species. J found the nest in June; it had 
eight eggs (less than the complement); I left it untouched, and 
some weeks after returned to find all had hatched but one; this, on 
inspection, proved to be non-fertile. Assuming that they really and 
faithfully pair, it is accountable by supposing that the male was 
killed and the female laid her last egg unimpregnated and carried 
out her duties alone. 
