Wisconsin Ruffed Grouse Numbers on the Decline After Peak in Population Cycle
Ruffed grouse populations in Wisconsin follow a fairly steady 10-year population cycle.
Through decades of surveys, the Wisconsin DNR has found the population usually peaks in years that end in 9, 0, or 1.
This spring’s drumming survey found a 6% decline in breeding males overall in the state. Drumming is the beating sound males’ wings make during mating season.
The northern half of the state saw a 7% decline. The central region saw no change. The driftless area saw a 33% increase.
Alaina Gerrits is the Assistant Upland Wildlife Ecologist with the DNR. She says that decline is nothing out of the usual.
“Now we’re just kind of going down that very characteristic downslide and it’s a typical normal thing. I think that 6% decrease isn’t anything we should be really concerned about. It’s something we were anticipating,” said Gerrits.
She said this means the population likely peaked last year or the year before.
The DNR doesn’t know for certain since it wasn’t able to the survey last spring due to the pandemic.
“It’s a little frustrating for sure because we’ve been doing these surveys for decades. To have one year missing is really atypical,” said Gerrits.
While the DNR doesn’t have the drumming surveys from last spring, it does have harvest data from last year’s hunt.
In 2020, there was an increase in harvested grouse.
“That’s kind of a piece of evidence that leads me to believe that we did peak last year,” said Gerrits. “Once we can have harvest information after this season is over in 2021, we’ll kind of be able to use that as a little bit of an index to see where the population is at as well.”
Gerrits said Wisconsin is home to a robust ruffed grouse population. For perspective, roughly 200,000 grouse were harvested last year.
While the current population is doing well, the state has seen a decline in the population over the decades.
Grouse used to roam just about the entire state. Now, majority of the population lives in the northern half.
Gerrits points to a loss of young forest habitat in the southern and central portions of the state as a big driver of the decline.
“There’s a lot of misconceptions out there, especially among forest landowners, that timber harvest is bad or detrimental to wildlife and it’s actually incredibly important, especially for things like ruffed grouse, deer, and turkey. They really rely on that young forest habitat for food and cover and things like that,” said Gerrits.
Roadside surveys to monitor the number of breeding grouse have been conducted by staff from the DNR, U.S. Forest Service, tribal employees and numerous volunteers since 1964.
You can view the full results of this year’s survey here.