Grouse survey shows slight decline
Madison — Ruffed grouse populations in Wisconsin have shown another slight decline this spring, according to results of the recently completed annual roadside ruffed grouse survey.
“The index that Wisconsin uses to track ruffed grouse decreased 9 percent between 2012 and 2013,” said Brian Dhuey, DNR wildlife surveys coordinator. “This decrease isn’t unexpected at this point in the population cycle. Ruffed grouse populations are known to boom and bust over a nine- to 11-year cycle. Grouse populations in Wisconsin tend to be at their peak in years ending in a nine or zero.”
The roadside survey to monitor the number of breeding grouse has been conducted by staff from the DNR, U.S. Forest Service, tribal employees, and numerous grouse enthusiasts and volunteers since 1964. Surveyors begin 30 minutes before sunrise and drive along established routes, making 10 stops at assigned points and listening for four minutes for the distinctive “thump, thump, thump” sounds made by drumming male grouse. Results from this survey help DNR biologists monitor the cyclic population dynamics of ruffed grouse in the state.
The number of drums heard per stop in 2013 was down 9 percent statewide from the previous year. One of the primary regions for grouse in the state, the Central Forest Region, showed an 18-percent drop in the number of drums heard per stop, yet the other primary region in the north showed a 2-percent increase.
Intensive surveys also were conducted at two research areas. The Sandhill Wildlife Area in Wood County showed a decline of 5 percent. The Stone Lake Experimental Area in Oneida County showed an increase of 2 percent.
According to Scott Walter, DNR upland wildlife ecologist, maturation of southern Wisconsin’s forest community in recent decades, and the resulting loss of dense, brushy areas that grouse need for cover, has contributed to lower numbers of grouse.
“Ruffed grouse are closely linked to young forest habitats that develop following large disturbances, notably logging activities,” Walter said. “While we often focus as hunters on grouse numbers in a single year, it’s important to remember that the long-term health of grouse and other early successional wildlife is dependent upon our ability to create the dense, young cover they require. Lacking significant, broad-scale forms of natural disturbance such as fire, we need to ensure that intensive timber harvests remain a component of our forest management activities.”
In regard to the slight increase in northern Wisconsin, Gary Zimmer, coordinating biologist for the Ruffed Grouse Society and the newest member of the Natural Resources Board, points to the weather.
“Weather, especially during the brood-rearing period in late May and early June, plays an important role in ruffed grouse numbers,” Zimmer said. “The slight increase shown in this spring’s Northern Forest Region drumming counts, even in a downward cycle, can definitely be tied to 2012’s excellent brood-rearing conditions with its lengthy dry, warm period in June.
“Unfortunately, this spring’s weather is not following the same pattern, and it is doubtful fall grouse numbers will be comparable to last year in the Northwoods. However, even with lower populations, Wisconsin still has some of the best grouse hunting in the country,” Zimmer said.
Complete survey results can be found by searching the DNR website for “wildlife reports.”