The use and function of the ruffed grouse (Bonasa umbellus) non-vocal drumming display across the breeding season

Abstract

The use of sonations in avian courtship displays is described for many species, however, the function and variation with these non-vocal acoustic displays has rarely been investigated. Perhaps the only well studied sonation used by a bird is the wing snap display of the golden-collared manakin. My thesis focuses on the use and function of a non-vocal drumming display used by male ruffed grouse during the breeding season. This thesis presents data that the non-vocal drumming display of the ruffed grouse is used in similar fashion to bird song and calls. That is, drumming peaks in activity during the morning hours much like a dawn chorus. Additionally drumming appears to function in part like a contact call, attracting potential mates and marking a male’s location within the environment. This is to the best of my knowledge, the first report of a daily change in a display performance reported for sonations.