Life snowed under
A week of storms leaves piles of half-cleared snow everywhere. Hidden doorways peer out between mounds of shoveled-off decks. Roofs creak under accumulated layers that creep slowly over gutters to join mounds growing up from hastily plowed driveways.For a few days our homes join the subnivean habitat.The below snow habitat is an interesting and vital one for many of the smaller animals that survive the winter with us up here in the mountains. The sensible animals survive the season by migrating to warmer climes. We have our own migration of sorts, too. It’s just the wrong way as the seasonal snow sports “bum” or “winter sports service professional” moves here for the fun and money a ski resort provides.The animals that stay survive with behavioral and physiological changes that soften winter’s chill and demands. Communal nesting is a common behavioral thermoregulation mechanism for many small animals. Seasonal winter professionals have also seen some advantages to this behavior, as any landlord can testify. My dogs indulge themselves, too, stretching out and hogging the communal nest of my bed by morning.This year’s snowfall is a great start for the subnivean animals. Warm fall temperatures then a quick few feet to insulate them before the cold weather arrives. Once under a blanket of insulating snow the mice. Voles and gophers are in a stable and not-too -cold climate with a surprising amount of mobility.Early in the season you see lots of holes created by voles. The moist environment releases carbon dioxide, which pools in hollows and they need these holes for ventilation. In spring you can see other evidence for how active these below snow critters are. Patches of clipped grass, nest balls, piles of droppings and those mysterious tubes of dirt (gopher eskers). These earth tubes are the remains of snow tunnels filled with excavated dirt as the gophers burrow around.The temperature stays around freezing, which is relatively warm, as anyone who has left their semi-subnivean dwelling these past few days knows. It’s cold up there on the mountain (-20 F on one thermometer!), and few have mastered the adaptations or desire needed for skiing.On Wednesday Vail Mountain sported the rare sight of untracked powder under blue skies for the whole day. A few powder predators floated around like owls and lynxes feasting on fresh tracks while benefiting from their behavioral adaptations of extra batteries for boot heaters or Jaeger shots at mid-Vail. Both seemed to work OK.Compacted snow has its advantages, too, which anyone who’s struggled to follow a poorly packed path on snow shoes knows. No one wants to be the first to pack the trail. Snowshoers hate every snowmobile except the first one. Hares and coyotes are the same, following trails, either their own or someone else’s, to save energy.Mule deer can’t cope with snow deeper than 18 inches. Elk have longer legs that can go a bit deeper, but they also break through crusts easily and move to valley sites (like your yard) as the snow deepens. Herds have a behavior appropriately called yarding. They gather in a forest clearing and trample and flatten the snow so they can stand and move around comfortably. Loose dogs have a habit of chasing resting herds out of these yards into deep snow, which exhausts the elk and is an unaffordable waste of energy for the elk.Since we now live more and more where the elk used to winter, keeping dogs leashed becomes very important from the elk’s point of view. If you’re lucky, a leashed dog may even break the trail and pull you forward. Mine won’t, choosing instead to follow their wild coyote instinct, preferring that I pack it down for them. This also gives them the chance to stand on the back of the snowshoes and trip me up – a favorite canine game involving happy wags and licks at “master’s” muttering prostrate form. Another time while walking under an I-70 overpass, a snowplow blasting snow approached and we ran – in different directions, ending up going nowhere before getting covered. Now a snowplow elicits warning barks and a dropped leash.Dogs give a little window into the subnivean world as they stop, cock their heads and listen to the scurryings going on beneath the snow. I try not to let them pounce, it doesn’t seem fair to harass wild animals trying to make a go of it in a harsh winter world with semi-useless, subsidized predators that haven’t a clue, really.Pets are parodies of their wild relatives: the wolves, foxes and lynxes that stare regally out from wildlife calendars on our walls. “Hmmm, not so,” our dogs snootily reply while eyeing the cinnamon bun they’ve tracked down on the coffee table. “We prefer to think of ourselves as sponsored instead of subsidized,” they think as they lounge in front of the fire in their den – and I try to make it less subnivean by shoveling snow off the roof.Alan Braunholtz of Vail writes a weekly column for the Daily.