Ruffed Grouse Drumming Sites in Northern Michigan

A study was made of 40 ruffed grouse (Bonasa umbellus) drumming logs known to be used one or more springs, 1951-59, in the Rifle River Area, Ogemaw County, Michigan. Thirty-four logs were old, decayed conifers. Logs had a mean height of 11.9 inches, a mean width of 13 inches, and a mean length of 19.8 feet. Minimum log sizes were 7.5 inches in diameter (height + width)/2 and 5.5 feet in length. No correlation existed between several log measurements (diameter, length, mass, or azimuth of log axis) and repeated annual use. Woody vegetation around the logs was divided into seven arbitrary size classes and studied by a system of ¼-milacre quadrats and 1/100-acre transects. Plants less than 2 feet high were significantly less dense near the logs than elsewhere in the cover, but those over 8 feet high were significantly more dense near the logs. There was no correlation between stem densities and the number of years the logs had been used for drumming. Thirty-seven woody plant species were tallied on the 360 quadrats used, and seven additional species were found on the 160 transects. In the large-shrub class, which furnished the most important grouse cover, 73.2 percent of the stems tallied were speckled alder (Alnus rugosa). This and other plant species supplying the necessary understory cover for grouse are unpalatable to deer. There is urgent need for deer control and habitat manipulation to supply adequate grouse cover, especially in upland areas.