Ruffed grouse numbers appear to be down
ST. PAUL - Minnesota's ruffed grouse spring drumming counts were lower than last year across most of the bird's range, according to a survey conducted by the Minnesota Department of Natural Resources (DNR).
Compared with drumming counts conducted in 2011, 2012 survey results showed an average decline of 24 to 60 percent, to 1.1 drums per stop, in the northeast survey region, which is the core and bulk of grouse range in Minnesota. Drumming counts in the northwest declined 33 to 73 percent to 0.9 drums per stop. Drumming counts did not change significantly in the central hardwoods or southeast, which had averages of 0.6 and 0.7 drums per stop, respectively.
"The grouse population is in the declining phase of its 10-year cycle," said Mike Larson, DNR wildlife research group leader and grouse biologist. "The most recent peak in drum counts was during 2009, but hunter harvests remained relatively high through at least 2010."
Ruffed grouse populations, which tend to rise and fall on a 10-year cycle, are surveyed by counting the number of male ruffed grouse heard drumming on established routes throughout the state's forested regions. This year observers recorded 1.0 drums per stop statewide. The averages during 2010 and 2011 were 1.5 and 1.7 drums per stop, respectively. Counts vary from about 0.8 drums per stop during years of low grouse abundance to about 1.9 during years of high abundance.
Drumming counts are an indicator of the ruffed grouse breeding population. The number of birds present during the fall hunting season also depends upon nesting success and chick survival during the spring and summer.
Minnesota frequently is the nation's top ruffed grouse producer. On average, 115,000 hunters harvest 545,000 ruffed grouse in Minnesota each year, also making it the state's most popular game bird. During the peak years of 1971 and 1989, hunters harvested more than 1 million ruffed grouse. Michigan and Wisconsin, which frequently field more hunters than Minnesota, round out the top three states in ruffed grouse harvest.
One reason for Minnesota's status as a top grouse producer is an abundance of aspen and other ruffed grouse habitat, much of it located on county, state and national forests, where public hunting is allowed. An estimated 11.5 million of the state's 16.3 million acres of forest are grouse habitat.
For the past 63 years, DNR biologists have monitored ruffed grouse populations. This year DNR staff and cooperators surveyed 126 routes across the state.
Sharp-tailed grouse counts in the northwest survey region decreased approximately 18 percent between 2011 and 2012, Larson said. Counts in the east-central region declined approximately 33 percent.
Observers look for male sharptails displaying on traditional mating areas, called leks or dancing grounds. Despite three years of declines, this year's statewide average of 9.2 grouse counted per dancing ground was similar to the long-term average since 1980. The 2009 average of 13.6 was as high as during any year since 1980. During the last 25 years, the sharp-tailed grouse index has been as low as seven birds counted per dancing ground.
Overall, sharptail populations appear to have declined over the long term as a result of habitat deterioration. In recent years the DNR has increased prescribed burning and shearing that keep trees from overtaking the open brush lands that sharp-tailed grouse need to thrive.
The DNR's 2012 grouse survey report, which contains information on ruffed grouse and sharp-tailed grouse, will be available soon online at www.mndnr.gov/hunting/ grouse.