I have been spending a lot of time snowshoeing this winter. The conditions are ideal for snowshoeing, which is one of my favorite wintertime activities.
My destination all winter long has been on the miles of spacious hiking trails throughout La Salle Lake State Recreation Area and the adjacent La Salle Lake Scientific and Natural Area. The trails are perfect for snowshoers like me.
One recent evening while snowshoeing a trail adjacent to a mixed forest of mostly mature aspen, I was startled by a sudden rush of feathers and fury that exploded from the snow just inches from the tip of one of my snowshoes as I plodded briskly on my hike.
In a cloud of snow dust, a ruffed grouse flushed from its snug and warm snow roost underneath about a foot of powdery snow. The bird zigzagged through the forest understory and landed in a nearby spruce tree.
Recovering from the jolt and surprise that the flushing grouse caused me, I examined the bird’s now vacant snow roost. The grouse had evidently been inside its burrow for a while, as a few droppings covered the bottom of the burrow. Just large enough for the grouse to fit in, I couldn’t help but think of what it must be like to spend the night underneath the snow.
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Indeed, one of the most interesting behaviors that ruffed grouse and other members of the grouse family share with one another, is how they thermoregulate their bodies.
Put another way, how grouse stay warm in the winter during the coldest days and nights and when stormy weather occurs. In the case of snow roosts, the unique strategy takes full advantage of the insulative qualities that snow provides.
Somehow eons ago grouse figured out that burrowing into snow provided superior protection from inclement weather and predators. Indeed, inside the confines of a snow roost can be as much as 50 degrees warmer than the outside ambient temperature, not to mention the snow roost provides grouse complete protection from dangerous wind chill.
So how do grouse make a snow roost? Improbably — and one would think dangerously and maladaptively — grouse fly at relatively high speed headfirst into snowbanks or into blankets of snow that’s deep enough.
Can you imagine flying headfirst into a snowbank!? Yet grouse routinely do this many times throughout Minnesota’s long, cold winters in order to survive. The snow has to be of the right consistency and deep enough, about 10 inches of fluffy snow.
After a grouse launches itself from a nearby perch in a tree and dives headfirst into the snow, the bird doesn’t stop there. Once safely underneath the snow, a grouse will create about a 4-inch burrow and sometimes will work themselves through the snow by as much as a few to 10 feet before stopping and hollowing out a small and snug cavity where the grouse settles into.
Generally, when a grouse utilizes a snow roost it’s for just an overnight stay, but there are times when an overnighter extends into the next day or longer when made necessary by storms.
In these latter cases, grouse will have hopefully filled their crops with plenty of food, otherwise, hunger can cause them to leave a snow roost earlier than what might be safe for the bird.
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As already described, grouse evacuate their snow roost in as dramatic a fashion as they created their roosts. If ever you have stumbled upon a roosting grouse while out in the woods in the wintertime, you will likely never forget the ensuing explosion of feathers in a puff of snow dust as the bird flushes.
And if you examine the exit hole, you should also be able to locate the cavity where the grouse spent time in, which is evidenced by not only a grouse-size hollow, you’ll also observe a few droppings or a rather large pile depending on the amount of time the bird occupied its snow roost.
There is so much more to grouse than their physical beauty. Behaviors, how they survive and adapt in their environments, are truly one of Nature’s many wonders, as we get out and enjoy the great outdoors.
Blane Klemek is a Minnesota DNR wildlife manager. He can be reached at bklemek@yahoo.com.
