Where Have All The Ruffed Grouse Gone?
By Tom Allen
Research on one of West Virginia's most prized game birds began in the summer of 1995 because of a concern over low or dwindling ruffed grouse populations throughout the state. Biologists designed a project to investigate the bird's mortality factors, survival, production, and habitat preferences. Because wildlife agencies in surrounding states expressed an interest in the same information, West Virginia chose to do a pilot study to determine the feasibility of such an in-depth undertaking.
A study area was selected on the Westvaco Ecosystem Research Forest in Adolph, Randolph County. Initially, 36 birds were captured and fitted with small radio transmitters around their necks during the summer of 1995. Once the year-long pilot study was completed, four other states (Maryland, Virginia, Kentucky and Ohio) joined the project in 1996. At that time a joint study was designed to run for six years, from 1996 to 2002. During that period every aspect of grouse biology would be studied in some fashion.
The ruffed grouse is a bird of young forest communities. Its favorite haunts are the thick, impenetrable thickets associated with clear cuts or other forms of timber removal, and old stripped sites from mining operations. Here the bird spends its life dodging predators and raising its young. Many hunters have found this secretive and wary adversary to be a formidable target during their fall and winter hunts. Grouse are omnivorous, feeding on insects, plants and fruits during spring and summer, and switching to almost entirely fruits and buds of trees during the winter months.
During the harshest weather the birds seek out the thickest cover and remain there for the duration. Coniferous trees, rhododendron thickets, and blow-downs are often used in periods of heavy snows. Grouse may also snow roost by diving into deep snow and remaining there to prevent the loss of body heat during extreme weather conditions.
During spring and early fall grouse are the most susceptible to trapping efforts. It is at these times when biologists set traps to capture grouse. They are captured in a ground trap comprised of a wire cage at each end of a 50-foot chicken wire lead which funnels the birds into the trap at either end. Once in the trap the birds cannot escape. The traps are checked twice each day, at noon and before dark. Captured birds are removed from the traps and a number of biological parameters are recorded before they are equipped with radio transmitters and released at the capture site. Such information as weight, sex, age and feather molt patterns are collected. Once released, the birds are given a seven-day adjustment period before data collection begins. A total of 40-50 birds are captured on each of the two sites in West Virginia during the fall and supplemented by spring trapping efforts to bring the numbers of birds radioed back up to that level.
Data collected on each bird involves locating the bird from three predetermined stations and taking a compass bearing on its direction. The bird's location is recorded where these bearings intersect. From this information biologists determined the bird's home range, the habitat type and forest growth stage that it is using, and its interaction with other birds and predators. Personnel locate dead birds, record the cause of death, and recover the transmitters. From this data, researchers obtain insight into the types of mortality that impact grouse, the times of the year when mortality is most severe and how hunting fits into the mortality picture. Thus far researchers have found that avian predators cause the greatest mortality and that mammal predation ranks a close second. Hunting averages about 15 percent of the total mortality.
During the spring nesting season female grouse are monitored closely in order to locate the nests and determine egg counts, hatching dates and nest success. Brood counts are done on each female when the chicks reach three weeks of age and again at five weeks of age. These counts determine the nest success and the recruitment of young birds into the population in the fall.
West Virginia's survival of young birds appears to be lower than grouse populations in the northern states, so studies are now being aimed at determining the mortality parameters affecting chicks. Graduate research programs are looking at the types of mortality impacting chicks, the condition of the hens going into the nesting season, the weather patterns at the time of hatch and shortly thereafter, and the availability of insects for the chicks during the first few weeks of life. All these can affect the success of grouse production in any given year.
As this program moved into the second and third years other states became interested and joined the project. Eight states are now involved in this research, with the addition of Pennsylvania, Rhode Island, North Carolina and Tennessee, and a total of 12 study areas are distributed throughout the Appalachian region. At the end of the first phase of the project (the first three years) a total of more than 1,200 grouse had been radioed and studied in the region. By the end of the project that number should be doubled. The second three-year phase is aimed at investigating the impacts of hunting as well as continuing the ongoing studies. Three study areas, one in Virginia, West Virginia and Kentucky, have been closed to hunting to see if survival changes on these sites.When completed this project should produce the most in-depth current information known on the Appalachian ruffed grouse.
This multi-state project is funded by the various state wildlife agencies and research grants from the US Fish and Wildlife Service. In addition, the Richard King Melon Foundation, The Ruffed Grouse Society, Westvaco Corporation, The U.S. Forest Service, Coweeta Hydrologic Laboratory, and the various colleges and universities throughout the region help to fund this project. In West Virginia, The West Virginia Trophy Hunters Association and the West Virginia Chapter of The Ruffed Grouse Society have donated money to this project.
Tom Allen is a former research wildlife biologist stationed in Elkins.