Michigan testing ruffed grouse to gauge West Nile exposure

Evan James Carter
The Detroit News

If you hunt grouse, the Michigan Department of Natural Resources wants your birds.

DNR biologists and veterinarians are collaborating with scientists in two other Great Lakes states to research West Nile virus exposure and infection in ruffed grouse.

Thanks to their coloration and slow, deliberate movements, ruffed grouse can be difficult to spot as they forage on the forest floor.

The Michigan DNR became interested in testing ruffed grouse for West Nile virus after a rise in the number of the bird species testing positive for the disease in recent years, including 2017, when DNR biologists identified West Nile in 12 ruffed grouse found in the state.

West Nile virus cannot be translated directly from ruffed grouse to humans. But Kelly Straka, a wildlife veterinarian with the Michigan DNR's Wildlife Disease Laboratory, said wildlife surveillance can "alert the Department of Health (and Human Services) about the prevalence of West Nile in the state."

In 2018, Michigan recorded nine human deaths related to West Nile in Michigan. The state hasn't identified any cases of West Nile in humans in 2019.

Straka said Michigan's grouse hunters play an important role in the research effort by providing the carcasses.

"They can breast (the grouse) out and keep the meat," Straka said.

Under the program, now in its second year, researchers in Michigan, Minnesota and Wisconsin collect the carcasses of ruffed grouse along with blood samples from the birds during the states' respective grouse seasons.

 Each state's DNR searches the birds' organs for signs of West Nile and sends the blood samples to the Southeastern Cooperative Wildlife Disease Study group at the University of Georgia for further testing.

The data collected by the group then helps researchers evaluate the effects of West Nile on grouse populations throughout Michigan, Minnesota and Wisconsin. 

In Michigan, grouse season runs from Sept. 15 to Nov. 14, with a break at the beginning of deer hunting season, and then resumes from Dec. 1 to Jan. 1. The Michigan DNR hopes to collect 400 grouse samples this year.

The DNR collected 209 samples during the 2018 grouse season. The final test results from 2018 are still are being analyzed and are expected by early fall of this year.

The state department will collect samples throughout the year, even outside of grouse season, Straka said. 

The Michigan DNR has not documented any unexpected declines in grouse populations across the state and has no data suggesting the state’s populations are in peril.

Further information on West Nile in ruffed grouse and how to obtain sampling kits in Michigan can be found on the Michigan DNR’s West Nile virus and Ruffed Grouse FAQ sheet.