The Grouse in Winter

When the snow gets deep, ruffed grouse head under the snow. Photo: Ben Amstutz  under a Creative Commons license

When the snow gets deep, ruffed grouse head under the snow. Photo: Ben Amstutz under a Creative Commons license

By Matt Miller, senior science writer

When the snow starts falling, many wild creatures start moving towards more benign environments.

Not so with certain grouse species. They’re adapted to thrive in deep snow and cold weather – provided they have healthy habitat.

Given the interest in the recent blog explaining how the polar vortex affected wildlife, this week I’ll look at how three North American grouse species survive the deepest snows and coldest temperatures.

Ruffed Grouse

Snow hole and wing marks: signs of a ruffed grouse shelter. Photo: Cephas under a Creative Commons license.

Snow hole and wing marks: signs of a ruffed grouse shelter. Photo: Cephas under a Creative Commons license.

As is the case with skiers, ruffed grouse love powder. When the snow is fluffy, this bird creates one of winter’s most unusual wildlife shelters.

Forget moving out of the snow; ruffed grouse plunge into it.

The ruffed grouse flies along and dive bombs head first into deep, fluffy snow – completely submerging itself. Its body heat then creates a sealed dome under the snow: essentially, its own igloo.

This structure allows the grouse to stay warm even in the most inclement conditions. Research shows that the snow shelter can warm to 32 degrees Fahrenheit, and rarely drops below 20 degrees — even when it’s much colder outside.

The ruffed grouse is found in many forested areas of North America, so it’s the grouse you’re most likely to see on winter wanderings.

In fact, numerous stories exist of grouse “exploding” out of the snow when a skier or snowshoer approaches – surely a dramatic sight, and one I always hope to see on my own winter outings. However, I’ve never seen a firsthand report, so it’s unclear how often this really happens.

Unfortunately, a snow shelter is not without risks for ruffed grouse. Researchers have found instances when a crust forms on the snow, trapping the grouse inside. If the crust lasts too long, the grouse is unable to escape and dies.

Grouse do have other adaptations for surviving the winter: in September, they grow extended scales on their toes, functioning as snowshoes when the snow is deep. These scales fall of in the spring.

Dusky Grouse

Dusky grouse move to areas with higher elevations (and deeper snow) for the winter. Photo: National Park Service

Dusky grouse move to areas with higher elevations (and deeper snow) for the winter. Photo: National Park Service

When you picture winter wildlife migrations, you probably see wildlife moving away from heavy snow and cold temperatures. Birds and dragonflies head south for the winter. Elk and mule deer move from high to low elevations.

But dusky grouse do the reverse. They actually migrate to high altitudes and heavy snows.

These grouse are found in the Rocky Mountains and western Canada. In the summer, they feed on forbs and insects in low elevation foothills. As winter approaches, they start heading high up into the mountains.

There, they’ll live in the boughs of pine trees. And while their summer diet is diverse, in winter they’ll exclusively dine on pine and fir needles (and only the outer two-thirds of the needles).

Why would an animal move to snowy and harsh conditions? It’s likely to avoid competition. Lots of species take refuge in the valleys and foothills, and they compete for precious calories to survive the winter. In the high mountains, dusky grouse have an untapped nutritional source all to themselves.

Sage Grouse

Male sage grouse begin their dramatic display before the snow melts. Photo: Bob Griffith

Male sage grouse begin their dramatic display before the snow melts. Photo: Bob Griffith

This one is simple: Sage grouse need sagebrush. Period.

Sagebrush is important to sage grouse all year. In winter, it’s critical for survival, as the grouse eat sagebrush almost exclusively. It’s a highly nutritious plant (and not just for sage grouse; mule deer, elk and pronghorn also rely on it).

Some range managers still believe the myth that sagebrush gets “decadent.” Essentially, they think it the plant gets too big and thick. But big, “decadent” sagebrush provides important shelter for grouse under its branches, protecting them from snow, ice and wind.

Sage grouse begin their dramatic spring courtship display before the snow melts across much of their range in the American West.

The loss of sagebrush habitat has led to the sage grouse’s well-publicized decline. That’s why the Sage Grouse Initiative focuses on proactive methods, partnering with ranchers, to protect sage grouse habitat—ensuring that the birds have the food and cover they need year round.

Opinions expressed on Cool Green Science and in any corresponding comments are the personal opinions of the original authors and do not necessarily reflect the views of The Nature Conservancy.

Posted In: Birds

Matt Miller is a senior science writer for the Conservancy. He writes features and blogs about the conservation research being conducted by the Conservancy’s 550 scientists. Matt previously worked for nearly 11 years as director of communications for the Conservancy’s Idaho program. He has served on the national board of directors of the Outdoor Writers Association of America, and has published widely on conservation, nature and outdoor sports. He has held two Coda fellowships, assisting conservation programs in Colombia and Micronesia. An avid naturalist and outdoorsman, Matt has traveled the world in search of wildlife and stories.

Comments: The Grouse in Winter

  •  Comment from TimBoucher

    Awesome post! Very interesting! (birds are so cool!)

  •  Comment from Paul F. Vang

    As a big fan of wild grouse,thanks for this post. Grouse are interesting birds and their adaption to specific habitat is always a moral lesson in preserving a quality environment for wildlife.

  •  Comment from Ken Miracle

    Love grouse. Do not recommend eating a dusky after they have switched to a pine needle diet … think turpentine. I do disagree that sage brush getting decadent is a myth. If a stand of sage brush gets to large and thick with no understory then the forbes and grasses disappear and also the non-winter cover and food source. You will find very few sage grouse in that habitat. Mixed mosaic sage stands are the best for the birds. Also in the winter you will find them near and in low black sage whenever they can find it that is their preferred winter food not the big tall sage.

  •  Comment from Heather

    Nice to see ruffed grouse winter behaviour getting some attention. The shelter you describe actually has a name. It’s called a kieppi. It’s a Finnish word. I have found several over the years and have had one experience of a grouse exploding out of the snow in front of me when I was taking a nighttime snowshoe. Definitely gets the heart pumping.

  •  Comment from Mary O. Fitzgerald

    While reading the interesting Grouse article, a pair of Pileated Woodpeckers flew onto 2 of our backyard trees. We live on the edge of Prince William forest, fortunately, as otherwise, I don’t think I’d get this opportunity. I haven’t seen a Pileated since vacationing in the Wisconsin Peninsula State Park near Fish Creek, WI North of Green Bay in 1995. Really made my day!

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