Ruffed grouse drumming counts up 41% statewide

Ruffed grouse drumming increased 41% statewide this spring in Wisconsin, according to an annual survey coordinated by the Department of Natural Resources.

Notably, drumming was up 48% in the northern region, home to the state's best grouse habitat and highest grouse population.

The 2019 results are a reversal from the previous year, when statewide counts unexpectedly fell 34% and the northern region dropped 38%.

While biologists lack an explanation for the 2018 decline, this spring's counts appear to put Wisconsin back on track for approaching the next cyclical high in the ruffed grouse population, according to the DNR.

Ruffed grouse populations traditionally rise and fall over a nine to 11-year cycle, and the last peak in Wisconsin occurred in 2011.

Drumming declines were noted in 2012, 2013, 2014 and 2015, followed by a slight increase in 2016 and a substantial increase in 2017 before the unanticipated drop in 2018.

The 2019 statewide drums per stop of 0.89 was still lower than 2017 (0.96), but the change in trend was welcomed by grouse hunters and others.

"As we enter the brood rearing season, weather conditions over the coming weeks will be critical in determining what grouse enthusiasts see in the grouse woods this fall, but increased drumming activity is a good sign that there were more breeding grouse on the landscape this year," said Mark Witecha, DNR upland wildlife ecologist.

Roadside surveys to monitor the number of breeding grouse have been conducted in Wisconsin since 1964 by the DNR, U.S. Forest Service, tribal employees and grouse enthusiasts and volunteers. 

The surveys begin 30 minutes before sunrise and consist of 10 stops at assigned points. Surveyors listen for four minutes at each stop for the distinctive thumping sounds made by drumming male grouse. 

One hundred sixteen routes were used this spring to produce the statewide drumming index, according to the DNR's report.

The regional averages were 1.89 drums per stop in the north (48% increase from 2018), 0.81 in the central (up 35%), 0.10 in the southwest (down 17%) and 0.01 in the southeast (down 50%).

Weather can influence drumming activity by male grouse but conditions were similar in 2018 and 2019, according to the report.

Overall survey conditions were "excellent" on 62% of transects run in 2019, compared to 64% in 2018, while "fair, the lowest available weather condition rating, was noted 4% of the time in 2019 and 2% in 2018.

While grouse numbers recede and rise on a nine to eleven-year cycle, an overriding downward trend can be noted for the Wisconsin grouse population since the inception of the survey. 

Grouse highs are not as high as they have been in the past and the amplitude of the change from low to high seems to be decreasing, according to the report. Changing land use patterns and the long-term aging of Wisconsin’s forest are likely playing a role in these changes, the DNR said.

Concern over the unexpected decrease in 2018 drumming counts in part led the Natural Resources Board to use an emergency rule to shorten the 2018 grouse hunting season by one month.

The rule has since expired.

The 2019 Wisconsin ruffed grouse hunting seasons are scheduled to run Sept. 14 to Jan. 31 in Zone A and Oct. 19 to Dec. 8 in Zone B.

West Nile Virus testing update: With the assistance of hunters, the DNR last fall submitted 238 ruffed grouse samples to be tested for West Nile Virus. 

The test results are expected to be available in late July or early August, Witecha said. The laboratory conducting the analysis is also working on samples from Michigan, Minnesota and some northeastern states.

The work is part of a three-year study commenced in 2018. Separate testing found WNV in three of 16 ruffed grouse found sick or dead last fall in Wisconsin and submitted to the DNR for evaluation, the first time the disease had been documented in grouse in the state.

Hunters in Wisconsin will once again be asked to contribute grouse samples to the study; the DNR will likely send out information in late July or early August.