After two years of large increases in Minnesota's ruffed grouse drumming counts, this year's counts showed little change from last year.
The Minnesota Department of Natural Resources released results of its annual spring drumming counts on Friday. Counts were up about 8 percent statewide and 9 percent in the Northeast survey region, said Mike Larson, DNR grouse research biologist in Grand Rapids.
"That's consistent with a positive trend in the population since 2005," Larson said.
The news comes after disappointment last fall among some hunters who didn't find as many grouse during the hunting season as they hoped to find. Spring drumming counts were up 40 percent last year and 37 percent in 2006 in Northeastern Minnesota.
The grouse population in Minnesota typically rises and falls on a 10-year cycle, and it had been low for at least three years before the 2006 increase.
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Some hunters wondered last fall if last spring's hatch or chick survival had been poor. This spring's drumming counts don't provide conclusive evidence about that, Larson said.
"All the drumming counts can tell us is it wasn't a complete failure of production and recruitment. The only way to have a higher population this spring than we had last spring, which is what the drumming counts indicate, is to have had some production and some recruitment last year," he said.
Last fall's grouse harvest figures, based on a survey of hunters, will shed more light on what may have happened with the population last fall. But those figures won't be available until early August.
If the harvest dropped last year compared to the twoprevious years, that would indicate that the size of the grouse population going into the fall may have been lower than expected, Larson said.
"I take this as very positive news," said Wayne Jacobson of Grand Rapids, who is national president of the Ruffed Grouse Society and a founder of the National Grouse and Woodcock Hunt, held each October in Grand Rapids. "We suspect something must have happened to the hatch [last year]. I take this as very encouraging. The cause of that cycle must still be in play."
It is not unusual to have a year or two of modest drumming-count increases as the grouse population heads toward the peak of its cycle, Larson said. The third year of increasing populations in the past two 10-year cycles was similar to this year's numbers, he said.
"From 1987 to 1988 and from 1995 to 1996, there was an increase of drums-per-stop [on the survey] but it was statistically not that significant," Larson said.
Grouse populations usually peak in years ending with a nine or a zero, then decrease toward the middle of the decade.
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The mean number of drums-per-stop along survey routes statewide went from 1.3 last year to 1.4 this year, Larson said. In the Northeast, it went from 1.5 last year to 1.6 this year.
Typically, drums per stop range from 0.8 in the low-population years to about 1.9 in the high years, Larson said.
Wisconsin's spring drumming counts were up 12 percent in the north region and 7 percent statewide this spring.
Grouse chicks typically hatch the first week of June at this latitude, Larson said. Until the past few days, weather has not been good for grouse chicks, he said.
"That second Tuesday of the month [June 10] we had good, heavy rain and temperatures not much above 40," Larson said. "That's pretty borderline. They can handle the rain OK. They can handle the cool. But combine the two, and that can be bad."
Nesting and hatching is spread over several weeks, so not all grouse may have been affected adversely, he said.
