Written by Glen Schmitt
The Department of Natural Resources has monitored the ruffed grouse population in Minnesota for more than 60 years. Part of that process involves driving established routes in the forested region and counting the number of male grouse heard drumming each spring.
Those drumming counts are used as an indicator of the ruffed grouse breeding population, which tends to rise and fall on a 10-year cycle. Results from this year’s survey showed that drumming counts were down for the second consecutive year and that ruffed grouse numbers are likely at the low end of that natural cycle.
In the northeast, which is considered the state’s premier ruffed grouse range, drumming counts dropped from 1.1 to 0.9 per stop. Counts in the northwest dipped from 0.9 last spring to 0.7 drums per stop this year, while drumming counts showed little change from a year ago in the central hardwoods and southeast with an average of 0.9 and 0.4 drums per stop, respectively.
According to Charlotte Roy, DNR grouse biologist, the decrease in drumming counts this spring was not unexpected since the ruffed grouse population is still in the declining phase of its cyclical pattern.
“We’re near or at the bottom of the cycle and I don’t think there’s anything to worry about,” Roy said. “Historically, you can see that it takes three or four years to rebound so it wasn’t surprising to see the counts down this year.”
Counts vary from about 0.8 drums per stop in years when grouse abundance is low and as high as 1.9 drums per stop when the grouse population is up. Drumming counts spiked last in the spring of 2009.
The peak of spring drumming efforts usually occurs somewhere during the first few days in May. The median date this year was later, around May 10, likely the result of lagging cold and snow in the state’s core ruffed grouse range.
Roy pointed out that she asked DNR officials and volunteers that were counting drums across the 117 surveyed routes to do so when they thought drumming was at its peak. Most of them indicated that drumming peaked later than usual.