Roadside ruffed grouse surveys completed this spring show that ruffed grouse enthusiasts should expect bird encounters similar to those experienced in 2015 as the population cycle begins to trend upward.
“While statewide trends were essentially stable, the two regions that make up the primary grouse habitat in the state showed increased drumming activity in 2016,” said Wisconsin Department of Natural Resources wildlife survey coordinator Brian Dhuey. “Ruffed grouse populations are known to rise and fall over a nine- to 11-year cycle, and the last peak in Wisconsin’s cycle occurred in 2011. Survey results suggest that we have reached the low point in the population cycle and may have started the increasing phase, which should continue the next few years as the grouse population moves toward the next peak.”
Roadside surveys to monitor the number of breeding grouse have been conducted by staff from the department, U.S. Forest Service, tribal employees and numerous grouse enthusiasts and volunteers since 1964. Surveys begin 30 minutes before sunrise and consist of 10 stops at assigned points. Surveyors listen for four minutes for the distinctive thumping sounds made by drumming male grouse. Surveyors monitored 99 routes this year.
While the number of drums heard per stop statewide in 2016 was similar to last year, there were some notable differences among regions. Both the northern and central forest regions showed increases in drumming activity. The largest increase occurred in the central forest, with an eight percent increase, followed by the Northern forest regions with a four percent increase. The southwest region saw the largest decline at 67 percent. Declines in the southwest part of the state are more than likely driven by aging forest and the loss of prime grouse breeding habitat.
Weather conditions influence drumming activity by male grouse, and most observers felt weather conditions were conducive to accurate surveys this spring. Surveyors rated the overall survey conditions as “excellent” on 45 percent of transects runs, compared to 65 percent in 2015. Surveyors rated 2016 conditions as “fair,” the lowest available weather condition rating, seven percent of the time in 2016, compared to five percent in 2015.
Results from the 2015 survey show that grouse populations in both the southwest and southeast region remain well below historic levels. According to DNR Upland Wildlife Ecologist, Mark Witecha, maturation of southern Wisconsin’s forest community and the resulting loss of dense, brushy areas that grouse need for cover has resulted in lower numbers of grouse in the region in recent decades.
“Ruffed grouse are closely associated with dense, young forest cover,” said Witecha. “Young forests are generally the result of some disturbance, like logging or intense wildfires. Forest management and fire prevalence in southern Wisconsin have declined in recent decades, leading to more mature forest communities that are not as suitable for grouse.”