SHARP-TAILED GROUSE 255 
nearly horizontally and its tail perpendicularly, distends 
its air-sacs and erects its feathers, then rushes across 
the ‘floor,’ taking the shortest of steps, but stamping its 
feet so hard and rapidly that the sound is like that of a 
kettle drum; at the same time it utters a sort of bub- 
ling crow, which seems to come from the air-sacs, 
beats the air with its wings, and vibrates its tail, so 
that it produces a low, rustling noise, and thus con- 
trives at once to make as extraordinary a spectacle of 
itself and as much noise as possible. 
“As soon as one commences all join in, rattling, 
stamping, drumming, crowing and dancing together 
furiously ; louder and louder the noise, faster and faster 
the dance becomes, until at last, as they madly whirl 
about, the birds are leaping over each other in their 
excitement. After a brief spell the energy of the 
dancers begins to abate, and shortly afterward they 
cease and stand or move about very quietly, until they 
are again started by one of their number ‘leading off.’ 
“The whole performance reminds one so strongly 
of a Cree dance as to suggest the possibility of its 
being the prototype of the Indian exercise. The space 
occupied by the dancers is from 50 to 100 feet across. 
... The dancing is indulged in at any time of the 
morning or evening in May, but it is usually at its 
height before sunrise. Its erotic character can hardly 
be questioned, but I cannot fix its place or value in the 
nuptial ceremonies. The fact that I have several times 
noticed the birds join for a brief set-to, in the late 
fall, merely emphasizes its parallelism to the drumming 
