The ruffed grouse (Bonasa umbellus) was designated the official state bird of Pennsylvania in 1931. Sometimes called the partridge, the ruffed grouse is one of 10 species of grouse native to North America, ranging mostly in regions where snow is an important part of the winter scene (consistently covering the ground from late November to at least late March). The ruffed grouse is a hardy bird which thrives during severe winters that decimate flocks of quail, pheasants, and turkeys.
Male ruffed grouse are aggressively territorial throughout their adult lives, defending a 6-10 acre piece of woodland shared with one or two hens. The male grouse proclaims his property rights by engaging in a "drumming" display (ruffed grouse drumming is shown near the end of the video below). This sound is made by beating his wings against the air to create a vacuum. The drummer usually stands on a log, stone or mound of dirt to drum; a stage for his display that enables a more distant view. Drumming occurs throughout the year, so long as his " drumming log" is not too deeply buried under snow. In spring, drumming becomes more frequent and prolonged as the ruffed grouse cock advertises his location to hens seeking a mate.
When snow covers the ground, ruffed grouse are almost exclusively "flower-eaters," living on the dormant flower buds or catkins of trees such as aspens, birches, cherries, ironwood and filberts. When the ground is bare of snow, they feed on a variety of green leaves, fruits, and some insects (have also been known to eat snakes, frogs and salamanders).