From: Rick Horton
Date: Fri Jun 11, 2004
To: "Rick Horton" <rgshort@uslink.net>
Subject: MN Grouse Counts

MN Grouse Enthusiasts:
 
The long-awaited results of the DNR's drumming surveys are in.  Unfortunately it isn't good news.  Despite excellent winter conditions and no sign of large numbers of predators, the grouse count declined 11% statewide.  DNR biologist John Erb isn't certain what happened, but suspects that the abnormally cool spring weather may have inhibited drumming or delayed the peak until after most routes had been run.  In some cases, disbelieving managers reran drumming routes in better weather and found higher numbers of birds.  But the survey protocol doesn't allow them to submit the later data.  Erb cautions that this data is most valuable as a long-term trend indicator and that year-to-year changes should be interpreted cautiously.
 
Regionally, we see that the Northwest declined 8% to 1.1 drums per stop (d/s).  The decline is surprising, but this region still has the highest drumming density in the state.  The Northeast region, covering the Arrowhead of Minnesota, declined 17% from last year's already low count, to 0.5 d/s.  This low level is not unusual for the boreal forest region, which has routinely seen dips as low as 0.3 and 0.4 d/s in the past.  The North-Central  and the Central Hardwoods regions remained stable, at 0.9 and 0.8 d/s, respectively.  In another surprising development, the Southeast region showed an increase, up 17% to 0.7 d/s.  This is the highest the area has been since 1991!
 
This downturn when we thought the population was recovering is not unusual - similar patterns are seen in 2 of the past three cycles - the early 70's and early 80's dips.  Whatever the cause may be, we have to remember that our worst years are still better than the rest of the country's best years.
 
In other news, sharptailed grouse numbers are up, snowshoe hares are down and the Superior National Forest has confirmed lynx breeding in Minnesota by finding a den with three healthy kittens.
 
Attached is the DNR's full report for those interested.
 
Rick Horton
Ruffed Grouse Society
218-327-2524

MN DNR> News >
News Releases
Ruffed grouse count decline may be related to survey conditions (2004-06-08)

Wildlife biologists with the Minnesota Department of Natural Resources (DNR) say an unexpected decline in ruffed grouse survey numbers may be related to inclement spring weather during the time when counts were conducted.
Ruffed grouse populations are surveyed by counting the number of ruffed grouse drums heard by DNR staff and volunteers along specified routes in the state?s ruffed grouse range. Male ruffed grouse loudly beat their wings in mating displays each spring.
According to John Erb, a wildlife research biologist in Grand Rapids, the survey indicated an 8 percent decline in drums heard on routes in the northwest and a 17 percent decline in the northeast, while the north-central and central hardwoods regional counts remained stable. In southeastern Minnesota, drumming counts increased 17 percent.
For the past 55 years, DNR biologists have tracked ruffed grouse populations as they rise and fall in an approximate 10-year cycle. Drumming counts had increased slightly last year, prompting hope that the cycle was on the upswing. Statewide, drumming counts were down 11 percent compared with last year.
"It remains unclear whether the lack of an apparent increase in northern zones represents a real change in the population or whether it is just a result of sampling variability," Erb said. "Overall, winter conditions did not appear detrimental to ruffed grouse and historic patterns suggest we should have begun the increase in the grouse cycle. It is possible that the inclement spring weather may have simply delayed or reduced drumming intensity in many areas."
Erb said that this uncertainty highlights the fact that the drumming count survey is most valuable as a long-term trend indicator, and that year-to-year changes should be interpreted cautiously.
Minnesota continues as a leader in grouse hunting opportunities, with cyclic population lows often exceeding grouse peaks in other regions. The ruffed grouse 10-year population cycle occurs naturally. However, hunters have helped enhance populations overall through hunting license fees that help fund DNR habitat programs to provide grouse with improved food and cover. One such program is cooperative work between DNR wildlife managers and foresters to improve grouse habitat in state forests.
SHARP-TAILED GROUSE NUMBERS INCREASE
Erb also reported that sharp-tailed grouse numbers increased in both the northwest and east-central parts of their range. Observers look for male sharptails dancing on traditional mating areas, called leks. For comparable leks monitored in 2003 and 2004, surveyors counted 15 percent more birds in the east-central range and 31 percent more in the northwest range.
Throughout the past 15 years, sharptail population fluctuations have mirrored the ruffed grouse population cycle. However, superimposed on these periodic changes, sharptail populations appear to have declined over the long haul as a result of habitat deterioration. In recent years, the DNR has increased prescribed burning and shearing that keeps trees from overtaking the open brushlands that sharp-tailed grouse need to survive.
In addition, the Conservation Reserve Program (CRP) appears to be benefiting sharptails in the northwest, perhaps evidenced by the record number of males per lek observed there this spring.