- Minnesota, Wisconsin, and Michigan Departments of Natural Resources recently announced results of the first year of coordinated West Nile Virus (WNV) sampling efforts for ruffed grouse in their state
- Rates of WNV antibodies in ruffed grouse varied from around 13 percent in Minnesota and Michigan, and 29 percent in Wisconsin
- Ruffed Grouse Society continues to emphasize habitat management as the “solution” for WNV, and aid in coordinating surveillance efforts in all 3 states
October 22, 2019
For Immediate Release
Coraopolis, Pa. – The Departments of Natural Resources in Minnesota, Wisconsin, and Michigan recently announced results of West Nile Virus (WNV) testing of hunter submitted samples from the 2018 hunting seasons.
Results are the first in a three-year study conducted through a partnership among the Ruffed Grouse Society (RGS) and each state agency. The coordinated effort was planned to better understand ruffed grouse exposure to WNV in the region. Results already demonstrate that some grouse survive exposure to WNV and are not sick when harvested in the fall.
“We still have much to learn about the effects of West Nile Virus across the range of ruffed grouse,” noted RGS President and CEO Ben Jones, “but one thing we do know is an abundance of good habitat buffers grouse populations against disease and other stressors.”
RGS members and other hunters submitted samples from ruffed grouse harvested in Michigan, Minnesota and Wisconsin during the 2018 hunting season. Samples were ultimately sent to the Southeastern Cooperative Wildlife Disease Study in Athens, Georgia, to be analyzed. Blood samples were examined for presence of antibodies that suggest exposure to WNV after previously being bitten by an infected mosquito. A total of 720 samples were submitted (273 from Minnesota, 235 from Wisconsin, and 212 from Michigan). Results indicated 12.5 percent of sampled ruffed grouse in Minnesota were previously exposed to WNV, compared to 29 percent in Wisconsin and 13 percent in Michigan.
Prior research regarding the effect of WNV on ruffed grouse populations in other states emphasizes the importance of high-quality young forest habitat at a landscape scale. Individual ruffed grouse have a higher rate of survival – and populations recover faster and are more likely to persist – in regions with high-quality, abundant habitat.
WNV, previously known from Europe, Africa and Asia, was first detected in North America in New York State in 1999. It was confirmed as infecting wild grouse in that state the following year. All three Great Lakes states had previously confirmed ruffed grouse exposure to WNV (Minnesota in 2005, Wisconsin in early 2019, and Michigan in 2017). The recent efforts by RGS, the state agencies, and especially the hunters that have committed their time to assist in collecting samples have resulted in expanded and coordinated regional testing beyond ruffed grouse submitted by members of the public in each state that were found dead or exhibiting signs of illness. Ongoing WNV surveillance in the region is being coordinated during the current hunting season among agencies in Minnesota, Wisconsin, and Michigan.
There is no evidence WNV can be spread by handling dead birds or by consuming properly cooked game. Signs of WNV infection can range from no clinical disease or illness to heart lesions and inflammation of the brain, the lining of the brain and of the spinal cord. Many factors can influence how severely the virus affects an individual bird. Testing noticeably sick or dead birds provides an important way to confirm WNV presence, but the hunter-supported sampling effort is a new approach aimed at understanding prevalence of the disease among ruffed grouse across the landscape. RGS will continue to communicate with members and the public in the region as results are reported, and as efforts proceed for future years of the project.
Established in 1961, the Ruffed Grouse Society/American Woodcock Society is North America’s foremost conservation organization dedicated to preserving our sporting traditions by creating healthy forest habitat for ruffed grouse, American woodcock and other wildlife. RGS/AWS works with landowners and government agencies to develop critical habitat utilizing scientific management practices.
Information on RGS/AWS, its mission, management projects and membership can be found on the web at: www.ruffedgrousesociety.org.
RGS/AWS Chief Conservation and Legislative Officer