I WONDER…. How do mountain animals survive the harsh winter?

Many of us delight in winter play days in the mountains, enjoying skiing and other snowy adventures or just taking in the peaceful stillness of the season. Afterwards, it’s also fun to shake off the chill cuddling up with a cup of cocoa or a cozy blanket in front of the fireplace.

 But what’s life like for high-elevation wildlife when instead of fun, winter brings hardship? Creatures of the high country must cope with bitter temperatures, fierce storms, little access to food, and some of the highest snow accumulations in the country. How do they do it?

Seasonal migrations from snow country 

For some animals, the answer is easy – as days grow shorter, they head downhill, hoofing it from the mountains or winging their way south. Deer and elk undertake “vertical migrations,” moving to lower elevations where they can graze on snow-free fields. Many birds, such as warblers, bluebirds, and swallows, are true “snowbirds,” making more ambitious trips to Central or South America so they may enjoy year-round summer to satisfy their appetites for bugs or fruit.

A deep winter’s sleep

Not all animals can escape winter weather, so some cope by going into a state of hibernation, napping away in underground dens. Marmots, ground squirrels, and chipmunks are among the most hard-core hibernators. During its seven-month sleep, a marmot’s body temperature drops to just above freezing and its heart rate slows to just four beats per minute. It doesn’t eat or drink, instead living off the pounds packed on during the summer feeding frenzy when it adds as much as fifty percent to its bodyweight. A marmot will awake periodically during hibernation to defecate but won’t leave its burrow until the first shoots peek through spring’s snowmelt.

In contrast, a hibernating black bear’s large size, thick fur, and the close confines of its den prevent heat loss so its body temperature will only drop about ten degrees. This allows a bear to awaken from its torpor relatively quickly if disturbed or to provide care for cubs delivered in the den. While denning, a bear’s metabolic rate drops by about fifty percent so it can make it through the winter without eating or drinking, slowly living off fat gained in the summer.

Black bear packing on pounds for winter

A community under the snow

Not all animals under the snow nap away the winter. Pika remain active in the darkness of their talus slope tunnels, surviving on grasses and flowers harvested and stored in “haypiles” during the summer. And a dynamic community of creatures is active where the snow meets soil. In this subnivean zone, the insulating protection of the snow keeps temperatures much warmer than at the surface – right around freezing. Here, small mammals, such as mice, voles, and shrews create extensive tunnels for foraging on grasses and seeds and accessing stored food. When the snow melts, look for the remains of their remarkable tunnel systems winding around the meadows and imagine all the activity going unnoticed under your snowshoes.

Weathering the elements

While most animals migrate or hunker under the snow to make it through winter, some can be seen out and about, even where dozens of feet of snow blanket the meadows. Corvids – members of the crow and jay family – have amazing spatial memories and cope with the lack of food by consuming seeds they’ve hidden in caches over the summer. Clark’s nutcrackers are the seed-storing champions. It’s estimated one bird can remember as many as 20,000 different locations where it has seeds tucked away! Stellar’s jays, Canada jays, and ravens also store food and are easy to spot year-round.

Keeping warm is another must for coping with winter’s chill if you’re out in the elements. Predatory mammals such as foxes and weasels grow a thick layer of warm fur. Birds benefit from the incredible insulating power of their feathers, just like a down coat keeps you toasty by trapping warm air around your body. During a storm, mountain birds will fluff up and hide deep in the branches out of the wind. The white-tailed ptarmigan takes winter living to an extreme: it sports thickly feathered feet that serve as snowshoes and gains white plumage to camouflage among the drifts

Whether they’re boldly shaking off winter’s chill or coping with cold through a long winter’s sleep, all mountain creatures are tough and resilient. Think of them the next time you’re enjoying some winter adventure and marvel at the wonder of nature’s super-survivors!