The northern forest of Minnesota has had a record breaking and extremely mild winter thus far with very little snow. As temperatures dropped today to below 0˙ F, this sleeping ruffed grouse rests on the ground since there has not been enough snow cover for its preferred roost under the snow in cold temps.
Ruffed grouse are able to use snow roosts when light and fluffy snow conditions reach 8" or more. The grouse dives into the powdery snow from a headlong flight. Once inside the snowpack, they burrow a few feet further looking for a comfortable, well-hidden roost like the accompanying photograph shows. Here a grouse had penetrated the show then burrowed and stuck its head out a couple times, then exited after a sleep.
In years of deep snow, the inside temperature of a snow roost can be as much as 50˙ F warmer than the outside temperatures. A snow roost gives the grouse an additional advantage of being hidden from view of predators such as hawks, owls, fox, wolves, coyotes and lynx. The metabolic energy they conserve allows them to spend less time foraging, further reducing their exposure to attack. In years like this with little snow and cold temps as we see now, the grouse population suffers.