Ruffie drumming counts up in Minnesota
Minnesota's ruffed grouse spring drumming counts were up 18 percent statewide this year compared to last year, according to a survey conducted by the Minnesota Department of Natural Resources.
"Ruffed grouse populations tend to rise and fall on a 10-year cycle and counts this year are typical of what we expect during the rising phase of the cycle, which we are seeing now," said Charlotte Roy, DNR grouse project leader.
Drumming is a low sound produced by males as they beat their wings rapidly and in increasing frequency to signal the location of their territory. Drumming displays also attract females that are ready to begin nesting. Ruffed grouse populations 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. The number of birds present during the fall hunting season also depends upon nesting success and chick survival during the spring and summer. For the past 67 years, DNR biologists have monitored ruffed grouse populations. This year, DNR staff and cooperators from 14 organizations surveyed 126 routes across the state.
The 2016 survey results for ruffed grouse were 1.3 drums per stop statewide. The averages during 2013 and 2014 and 2015 were 0.9 and 1.1 and 1.1, respectively. Counts vary from about 0.6 drums per stop during years of low grouse abundance to about 2.0 during years of high abundance.
Results this year follow a year of no change from 2014 to 2015. While it can be difficult to explain year-to-year variation, the lack of change in last year's results followed a cold, wet spring of 2014, which may have hurt grouse production.
In the northeast survey region, which is the core of Minnesota's grouse range, counts were 1.5 drums per stop; in the northwest there were 1.1 drums per stop; in the central hardwoods, 0.8 drums per stop; and in the southeast, 0.8 drums per stop.
Sharp-tailed grouse counts down slightly
To count sharp-tailed grouse, observers look for males displaying on traditional mating areas, which are called leks or dancing grounds.
"The data on sharp-tailed grouse take some interpretation, because survey results can be influenced by how many leks are counted or changes in how many birds are at each lek year to year," Roy said. "The average number of sharp-tailed grouse was similar this year compared to 2015, but we may be looking at a decline when considering changes in the number of leks counted or changes at the same leks counted in both years."
Comparisons of the same leks counted in both years indicate that counts per lek were down in the northwest region and statewide. In the east-central region, birds counted per lek was statistically unchanged, but fewer leks were counted, likely indicating that birds are combining into fewer lek's but maintaining the average lek size.
This year's statewide average of 9.5 sharp-tailed grouse per lek 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.