Subnivian, subnivian, That’s what we’ve all been livin’ in…. By we, I mean us little guys,
We’re hidden from the winter skies. Down in between the snow and ground,
We insects and we mice have found A habitat that’s kind of nice,
Protected from the wind and ice. -from Subnivian Samba by Deb Gerace
Boulder is in the grip of cold and snow. I admit that this is not my favorite time of year. At the urging of snow-loving Mandy the dog we trudged out to Chautauqua Meadow yesterday for a frigid hike. I did manage to capture yet another image of The Flatirons before my fingers went numb and I ran back to the warm car feeling like a whimpy human…
When I looked at the blanket of snow in this picture I thought about surviving outside in this bitter cold weather and I remembered learning about the subnivean (under the snow) zone. Many small animals and even some insects take shelter in the space between the warm earth and a hardened snow ceiling. Here are some interesting facts about life under the snow…
-Thanks to the remarkable insulating nature of snow, in winter regions that don’t have permafrost, the subnivean zone maintains a temperature of close to 32 °F (0 °C) regardless of the temperature above the snow cover, once the snow cover has reached a depth of six inches (15 cm).
-Animals weighing about seven ounces or less tend to live in the subnivean zone and squirrels are the largest mammal found there.
-Larger carnivores, like wolves, coyotes and foxes, listen for small mammals rustling around beneath the snow and then pounce, crashing rudely into the quiet and protective realm of the subnivean zone.
-Resident birds also use subnivean spaces for protection against cold. Chickadees congregate in pairs and groups beneath the snow maintaining precious body heat. Larger birds including ptarmigan and grouse will submerge their bodies in snow to insulate themselves while resting. They often keep their heads above the snow to watch and listen for predators like hawks and owls.
-The demands of winter may find some species abandoning their solitary lives to practice communal living. In the subnivean world, voles and mice stay warm by huddling together in grassy nests.
-The subnivean environment is very humid. Under thin snow packs in spring, light levels permit limited photosynthesis for lichens and evergreen tundra shrubs. This is an important adaptation given the short growing season. Plants in the “greenhouse of snow” created by the subnivean cavity can start to grow weeks before neighbouring plants covered by deep snow.
-For nearly half the year, plants and small animals find heavenly habitat sequestered beneath the snow in their subnivean world. So don’t think of a blanket of snow as a casket for the dead of winter, but as a warm, protective comforter for a universe of winter wildlife. –Eric Orff, Wildife Biologist
So I guess I should stop being so whimpy about the cold and just try to adapt.