Ruffed Grouse Flight Capability over Water

Game bird flight capabilities have received little attention, undoubtedly because this aspect of behavior usually has little bearing on species management. As Leopold (1933) points out, this knowledge is important only when it is desirable or necessary to eliminate interchange between different isolated populations. The Michigan Department of Conservation recently established ruffed grouse (Bonasa umbellus) on several Great Lakes islands (Ammann and Palmer, 1958). In most cases wild, live-trapped grouse were used to establish populations. On one island we have attempted to establish a population of diseasefree hand-reared birds. We obviously hope that each population remains isolated from the others. Since some of our islands are separated by only 1 mile of water, the question naturally arose regarding the distance ruffed grouse can fly. This paper reports the results of tests performed to ascertain the flight capabilities of grouse over water. It also sheds light on some contributing factors affecting distribution of animals on islands. Compared with most birds, those in the superfamily Phasianoidea are relatively sedentary. No species, for example, is migratory. However, several species in this superfamily are, if necessary, capable of quite long single flights. Prairie grouse, including prairie chicken (Tympanuchus cupido), sharp-tailed grouse (Pediocetes phasianellus), and red grouse (Lagopus scoticus) are examples of powerful fliers, and reportedly are capable of flights of several miles (Leopold, 1933). Data on ruffed grouse flight capabilities are particularly scanty. Perhaps this is understandable. Because of the bird's habitat requirements and its tendency to fly toward denser cover when flushed, few firsthand observations have been made of long flights. It would seem logical to derive further insight into ruffed grouse flight capability by analyzing origins of populations on islands. Bump, et al. (1947) used this approach and apparently concluded that flights over several miles of water are possible. As regards islands referred to by these authors, this conclusion is tenable, but my familiarity with grouse distribution on Michigan's Great Lakes islands makes me suspicious of such circumstantial evidence. Along the shoreline of Michigan's Great Lakes, ruffed grouse are absent from islands more than a half mile from the mainland. To our knowledge ruffed grouse have populated only Grand Island in Lake Superior, and Sugar and Neebish Islands in St. Mary's River between Lakes Superior and Huron. These islands are about :/2 mile from shore. All of our other islands, including Drummond, which lies only 1 mile from the eastern tip of the Upper Peninsula, had no ruffed grouse prior to recent introductions. This evidence, contrary to the opinion offered by Bump, et al. (1947), suggests that long-distance flights are unlikely. I decided to test-fly several grouse by releasing them from a boat at considerable distances from shore. I wish to thank the following biologists of the Michigan Department of Conservation for their assistance in the tests: Thomas Prawdzik, Peter F. Olsen, Jerry Duvendeck, Herbert Johnson, and John Kadlec. I also appreciated C. T. Black's comments and suggestions on presentation of this report.