The Ruffed Grouse share my love of a long winter with a lot of snow. For them, however, this is critical to their survival. Deep (about 10-inches), powdery snow provides excellent conditions for burrowing where the grouse can be hidden from predators and can receive thermal protection from freezing temperatures.
Studies prove when winters are long and have a sufficient snow-depth with temperatures remaining below freezing, grouse have a much higher survival rate than in winters without much snow or when temperatures fluctuate above freezing thus melting the snow. Gordon Gullion provides one such comparison in his book The Ruffed Grouse:
” … For examples, I’ll compare the favorable winter of 1969-70 to 1972-73 when grouse numbers plummeted. From 1969 to 1970, adult male survival was 61 percent, and the breeding population on the Cloquet Forest increased from 71 to 106 birds. Conversely, from 1972 to 1973, adult male survival was only 31 percent and population declined from 187 to 101 breeding males…
In 1969-70, snow cover lasted 149 days, from November 11 to April 10, while in 1972-73 now covered the ground for 130 days, from November 14 to March 27. In the good year, there were 66 days of satisfactory conditions for snow-burrow roosting, and only eight days in 1972-73. …”
When I think of the states with the highest grouse populations, such as Minnesota, Wisconsin, Maine, etc., I certainly think of long winters with lots of snow. Of course, the habitat to attract the grouse and sustain them throughout the rest of the year must be there in the first place, but they need long-lasting, sufficient depths of snow to get them through winter when cover from predators is almost non-existent and to keep them from freezing. So when we are complaining about more snow on the way, let us remember that the King of upland birds needs it to survive!
Gullion, Gordon. The Ruffed Grouse (Minocqua: NorthWord Press, Inc., 1989), 100.
Get yourself a copy here: The Ruffed Grouse