Ruffed grouse success will fluctuate based on hunting spot

We are just about a month away from the ruffed grouse opener and early indicators suggest this season will be on par with what hunters saw during the fall of 2019

Whether that is a good thing mostly depends on where you hunt as hunters reported less than stellar action last year despite hopeful pre-seasons predictions.

The ruffed grouse season opens on Sept. 19 and runs through Dec. 31.

Northeastern Minnesota is home to some of the best grouse habitat in the state and a popular destination for hunters looking to bag a few birds each fall.

According to the Minnesota Department of Natural Resources, the ruffed grouse is the most popular game bird in Minnesota, with an annual harvest of 200,000 to 500,000 birds and hunter numbers have been as high as 92,000 during the last decade.

Grouse numbers rise and fall on a 10-year cycle and the DNR has been tracking that information for 71 years and normally, when the population is near its peak and opportunities are ample, more hunters are out and about.

But two things have changed over the last few years in relation to that: Hunter numbers did not peak in 2017, when the population cycle supposedly reached its peak, and the grouse numbers didn’t crash at the tail end of the decade, which is typically what would happen.

And DNR wildlife officials aren’t exactly sure why either of those things occurred.

Still, despite that mystery, grouse counts remain a viable indicator of the population.

The Minnesota DNR coordinates grouse surveys each year to monitor changes in grouse populations through time. These surveys provide a reasonable index to population trends, when the primary source of variation in counts among years is change in densities.

While there are various things that affect the count, like weather and habitat, and make short-term predictions tough, over the long-term the spring surveys provide fairly accurate evidence that the ruffed grouse population cycles at approximately 10-year intervals.

According to the DNR, the spring survey data also correlated strongly with the fall harvest before the early 2000s, but in recent decades, this relationship has weakened.

The first surveys of ruffed grouse in Minnesota occurred in the mid-1930s, and the first spring survey routes were established along roadsides in 1949.

By the mid-1950s, some 50 routes were established with 70 more routes added during the late-1970s and early-1980s.

Since then, staff and cooperators have conducted spring drumming counts annually to survey ruffed grouse in the forested regions of the state where ruffed grouse habitat occurs.

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.

These drumming displays also attract females that are ready to begin nesting, so the frequency of drumming increases in the spring during the breeding season.

The sound produced when male grouse drum is easy to hear and thus drumming counts are a convenient way to survey ruffed grouse populations in the spring.

This year, because of COVID-19 and the restrictions that followed, getting an accurate count proved to be a challenge.

There were no drumming counts done in southeastern Minnesota, but wildlife officials were still able to get out in the woods in May in the northern part of the state, where grouse breeding usually occurs later.

Because of the situation – only recording northern Minnesota counts – it is quite likely the numbers are a little higher statewide, according to the DNR.

The 2020 survey results for ruffed grouse were 1.6 drums per stop. The averages during 2015, 2016, 2017, 2018 and 2019 were 1.1, 1.3, 2.1, 1.5 and 1.6 respectively.

Counts vary from about 0.6 drums per stop during the years of cyclical low grouse abundance to about 2.0 during years of high abundance.

Drum counts were 1.7 drums per stop in the northeast survey region; counts were 1.2 drums per stop in the northwest; 1.2 drums per stop in the central hardwoods; and no routes were completed during the appropriate survey window in the southeast survey region.

While drumming counts are an indicator of the ruffed grouse breeding population, the actual number of birds present during the fall hunting season also depends upon nesting success and chick survival during the spring and summer.

Tom Rusch, DNR Wildlife Manager for the Tower area (most of northeastern Minnesota), said this week that drumming and breeding in our area peaks in April, nesting is in May, broods hatch in early June, and the early flight stage is usually in July.

Weather conditions this spring, he added, were good for all of those stages.

“Our extremely dry May and June were excellent for ruffed grouse broods,” he said. “For the second year, we are doing ruffed grouse brood monitoring. I have not seen a ruffed grouse brood all summer. (But) I still think production was good with the excellent nesting conditions. Time will tell.”

Part of the reason for that is spotting the most ground based bird known to be quite jumpy when approached by anything is not easy to see in the summer.

“I saw good ruffed grouse numbers throughout late winter an early Spring. With State COVID-19 restrictions and wildlife staff vacancies, I worked alone on Wildlife Management Areas quite a bit since March,” Rusch said. “I have not seen many adults this summer. That is not atypical for me. In the thick cover it is just tough to see (them).”

West Nile Virus Results

Test results in from the second year of a study on West Nile virus in ruffed grouse showed similar results to the previous year.

Antibodies consistent with virus exposure were detected in 12.3 percent of the 317 samples submitted by hunters in 2019.

This compares with a 12.5 percent antibody rate in the 273 samples submitted by hunters in 2018.

The bottom line: West Nile virus exposure is lower in Minnesota than in other states where exposure has been studied, which may reflect the abundance and quality of grouse habitat in Minnesota, DNR officials say.

West Nile virus is carried by infected mosquitoes.

Not all people or animals bitten by an infected mosquito will contract West Nile virus.

There have been no documented cases of people contracting West Nile virus from consuming properly cooked meat.

West Nile virus has been present in Minnesota since the early 2000s, but interest in effects on ruffed grouse increased following a study in Pennsylvania documenting relationships between habitat quality, populations and virus exposure.

Some bird species recover quickly and become tolerant to the virus while others, such as blue jays and crows, suffer higher rates of mortality.

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