Grouse counts decline, later spring nesting may help hatch

(Released July 15, 2013)

Ruffed grouse drumming counts were down across most of the bird’s range, according to the annual survey conducted by the Minnesota Department of Natural Resources (DNR).

“This decrease was not unexpected because the ruffed grouse population is still in the declining phase of its 10-year cycle,” said Charlotte Roy, DNR grouse biologist. “Drum counts peaked most recently in 2009.”

Drumming counts dropped from 1.1 to 0.9 per stop in the northeast, which is the forest bird’s core range in Minnesota. Counts in the northwest declined from 0.9 in 2012 to 0.7 drums per stop in 2013. Drumming counts did not change significantly in the central hardwoods or southeast, with an average of 0.9 and 0.4 drums per stop, respectively.

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. Drumming counts are an indicator of the ruffed grouse breeding population.

This year, observers recorded 0.9 drums per stop statewide. The averages during 2011 and 2012 were 1.7 and 1.0 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.

The number of birds present during the fall hunting season also depends upon nesting success and chick survival during the spring and summer. Drumming did occur later this year because of the late spring, suggesting that nesting likely occurred later than normal.

“Later nesting would have pushed the hatch out a bit, hopefully beyond the spring rains,” Roy said. “Time will tell if that occurred and the impact on production.”

Minnesota frequently is the nation’s top ruffed grouse producer. On average, 115,000 hunters harvest 545,000 ruffed grouse in the state each year, 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 the 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 64 years, DNR biologists have monitored ruffed grouse populations. This year,
DNR staff and cooperators from 14 organizations surveyed 117 routes across the state.

Sharp-tailed grouse counts decrease slightly
Sharp-tailed grouse counts in the northwest, the bird’s primary range in Minnesota, were similar to 2012. Counts in the east-central region declined significantly.

Observers look for male sharptails displaying on traditional mating areas, called leks or dancing grounds.

Despite several years of declining numbers, 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 2013 grouse survey report, which contains information on ruffed grouse and sharp-tailed grouse, is available online.