Minnesota’s spring population of ruffed grouse appeared to be about the same this year as in 2019, according to the annual drumming survey conducted by the Department of Natural Resources.
The average count this spring was 1.6 drums per location, about the same as 2019. That’s up a tad from 1.5 in 2018 but down from the recent high of 2.1 drums per location in 2017.
Those numbers are all within the usual variation of grouse drumming counts, where wildlife experts stop along predetermined routes to listen for male grouse to beat their wings, or drum, in mating ritual. Drumming numbers usually range from lows of around 0.6 drums per location during low-population years to highs of just over 2 drums per location during high-population years.
Due to staff work restrictions because of COVID-19, the survey was not conducted in the southeastern corner of the state, where drumming occurred when state workers were still kept at home. But most routes in the northern grouse range did get surveyed thanks to some help from tribal and other agencies.
“In a typical year, we have 16 cooperating organizations providing folks to help us count grouse drumming,” Charlotte Roy, the DNR’s grouse project leader, said. “We are grateful to our federal and tribal partners, some of whom conducted extra routes to get surveys completed during the pandemic.”
This year’s count was 1.7 drums per stop in the northeast survey region, up from 1.6 last year. Counts were 1.2 drums per stop in the northwest, down significantly from 2.1 last year, and 1.2 drums per location in the central hardwoods, up from 0.8 last year.
While spring drumming counts produced similar results as last year, only having counts from the northern region — which has more forest and holds more grouse — likely means the statewide index is higher than it would be if the southeastern region, which usually has the fewest birds, was included.
The drumming count is a rough indication of grouse population trends, but not necessarily of what hunters will see in the woods this autumn during the hunting season that starts Sep. 19. Weather conditions during the spring hatching season play a key role in the survival of young grouse which make up a large portion of each year’s fall population. Female grouse may start with as many as a dozen chicks but end up with only a few remaining by October due to weather and predators.
Biologists were not able to collect sharp-tailed grouse survey data this year during the pandemic.
West Nile virus results
Test results from the second year of a study on West Nile virus in ruffed grouse showed similar results to the previous year. Antibodies consistent with virus exposure were detected in 12.3% of the 317 grouse samples submitted by hunters in 2019. This compares with a 12.5% antibody rate in the 273 samples submitted by hunters in 2018.
West Nile virus is carried by infected mosquitoes. Not all people or animals bitten by an infected mosquito will contract West Nile virus. There have been no documented cases of people contracting West Nile virus from consuming properly cooked meat.
West Nile virus has been present in Minnesota since the early 2000s, but interest in effects on ruffed grouse increased following a study in Pennsylvania documenting relationships between lower grouse numbers and virus exposure, especially in areas of poor habitat. Minnesota officials speculate that West Nile may be having a smaller impact on grouse here because of better grouse habitat overall.