Ruffed Grouse drumming

A friend took me looking for Ruffed Grouse this summer and this time we witnessed this male Ruffed Grouse doing his drumming courtship display on a log in a wooded area of Calgary. The drumming sound, made by beating the air with its wings, feels as if it is vibrating through your body. Sounds very much like a motor starting up. Males and females look similar. Thanks, David, as always!