Tuesday, August 11, 2020
Minnesota 2020 Ruffed grouse counts similar to last year
Minnesota’s ruffed grouse spring population counts are similar to last year and likely are following the 10-year cycle of rise and fall—a predictable pattern recorded for 71 years. Due to COVID-related restrictions, this past spring’s drumming counts in southeastern Minnesota were not conducted as planned.
As the DNR was able to resume more field operations in May, there was still time to conduct drumming counts in more northerly portions of the state, where grouse breeding occurs later.
While spring drumming counts that were conducted produced similar results as last year, only having counts from the northern region—which has more forest and holds more grouse—likely means the statewide index is higher than it would be if the southeastern region was included.
Some consider the ruffed grouse the “king of game birds” because it’s a challenge to pursue, a thrill to witness on the wing and a delicious wild game entrée when served. These birds are native to Minnesota—the top ruffed grouse-producing state in the coterminous United States, with millions of acres of public land for hunters and their dogs to explore.
Drumming counts are an indicator of the ruffed grouse breeding population. However, the number of birds present during the fall hunting season also depends upon nesting success and chick survival during the spring and summer.
The number of birds present during the fall hunting season also depends upon nesting success and chick survival during the spring and summer.
If production of young birds is low during the summer months, hunters may see fewer birds than expected based on counts of drumming males in the spring. Conversely, when production of young is high, hunters may see more birds in the fall.
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.
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.
“In a typical year we have 16 cooperating organizations providing folks to help us count grouse drumming,” Roy said. “We are grateful to our federal and tribal partners, some of whom conducted extra routes to get surveys completed during the pandemic.”
Biologists were not able to collect sharp-tailed grouse survey data this year during the pandemic.
The Minnesota grouse hunting season opens on Saturday, Sept. 19. More information about ruffed grouse hunting and sampling, the grouse survey report and West Nile virus is available on the DNR grouse hunting page.
RESULTS & DISCUSSION Ruffed GrouseObservers from 11 cooperating organizations surveyed 102 routes (80% of all routes) between 21 April and 13 May 2020, with 84% of northern routes completed and 42% of southern routes completed. Most routes (89%) were surveyed between 21 April and 10 May, with a median survey date of May 6, which is similar to last year (May 4) and the median survey date for the most recent 10 years (May 3). Observers reported Excellent (61%), Good (37%), and Fair (2%) survey conditions for 95 routes reporting conditions.
Statewide counts of ruffed grouse drums averaged 1.6 dps (95% confidence interval = 1.2–1.9dps) during 2020 (Figure 3). Drum counts were 1.7 (1.3–2.0) dps in the Northeast survey region (n = 92 routes), 1.2 (1.0–1.3) dps in the Northwest survey region (n = 5), 1.2 (0.4–2.2) dps in the Central Hardwoods survey region (n = 10), and no routes were completed during the appropriate survey window in the Southeast survey region (Figure 4a-d).
Statewide drum counts were similar to last year. I received 5 surveys from 2019 after the report was written last year, and updated results are included here. The southern survey regions tend to have lower average counts than the northern regions each year, and because southern regions were not surveyed in 2020, the statewide index is likely higher than it would be if southern routes were included. In the Northeast and Northwest, counts were similar to or down from last year, respectively. In the Central Hardwoods, observers surveyed only the northern portion of the region where counts tend to be higher, which likely explains the slightly higher, although not statistically different, dps in this region in 2020 compared to 2019. The most recent peak in the 10-year cycle occurred in 2017. Although peaks in the cycle occur on average approximately every 10 years, they vary from 8 to 11 years apart (Figure 3). Recent survey data indicate that ruffed grouse are in the declining phase of the 10-year cycle in Minnesota.
Read the original DNR Article
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