RUFFED GROUSE—PARTRIDGE 145 
ing like far-off thunder, is often heard in late summer 
and autumn. It is possible that this autumnal drum- 
ming is made by the young males, just as sometimes in 
autumn a young male songbird may be heard to prac- 
tice in low tones the lay which it will utter during the 
mating season of the following spring. A great variety 
of explanations have been given as to the method by 
which the drumming is produced. It is made by the 
wings, and the observations of ornithologists have es- 
tablished the fact that the sound is caused by the out- 
spread wings of the bird rapidly beating the air with- 
out striking the bird’s body or any other object. Pho- 
tographs taken by Professor Hodge show the wings 
beating in front of the breast as the bird sits upright 
during the act. The belief that the resonance of the 
sound is caused in part because, while drumming, the 
bird stands on a hollow log, was long ago abandoned. 
One of the best descriptions of the process of drum- 
ming is that given by Mr. Manly Hardy, of Brewer, 
Maine, who says: “The cock grouse usually selects 
a mossy log near some open hedge, clearing, or woods 
road, and partly screened by bushes, where he can see 
and not be seen. When about to drum he erects his 
neck feathers, spreads his tail, and with drooping wings 
steps with a jerky motion along a log for some distance 
each way from his drumming place, walking back and 
forth several times and looking sharply in every direc- 
tion. Then standing crosswise, he stretches himself to 
his fullest height and delivers the blows with his wings 
fully upon his sides, his wings being several inches clear 
