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THE ARRIVAL of the first fluffy flakes each autumn are an
occasion, especially when you're a seven-year-old, gazing dreamily out the
classroom window on a grey afternoon. As winter plods on and snow accumulates,
most of us begin to regard snowdrifts with a shudder and a twinge in the lower
back. Yet many animals cope quite well with the annual blanket of white.
Like enthusiastic children, some birds actually seem to
welcome the first snowfall and become animated when it arrives. Ravens,
ptarmigan, owls, finches and others enjoy a fluttering, flapping snow bath,
just as birds bathe in dust in summer. Others make use of the snow in a
different way.
If you've ever had the heart-stopping experience of a grouse
exploding from the snow nearly beneath your feet, you may have paused to wonder
why it had buried itself. By tunneling into the snow for the night or during a
storm, ruffed grouse and ptarmigan can reduce their heat loss by up to 45
percent, staying warmer and conserving valuable energy resources. When out
foraging, grouse make use of fringed toes that can grip slippery surfaces, such
as snow-covered branches, while ptarmigan bobble along over the snow on thickly
feathered feet.
As with ptarmigan feathers, the snowshoe hare's camouflage
coat turns from summer brown to winter white, cued by dwindling hours of
daylight. More snow actually makes it easier for the hare to reach food,
raising the little browser up to the tender, tasty branches. The hare's big
feet let it travel effortlessly across even soft snow. An adult person would
need feet about 30 centimetres (12 inches) wide and 76 cm (30 inches) long to
move through snow as easily as the hare. One of the hare's main predators, the
lynx (Felis lynx) pictured above, also has oversized paws, allowing it to
traverse the same areas as its prey.
The subnivean (beneath the snow) empire exists unseen.
Amidst a labyrinth of tunnels, mice, shrews and voles scurry between food
caches and nests. Without this windless, stable refuge, few small rodents could
survive the winter. They are less visible to predators here, and their energy
costs are 15 to 50 percent less than they would be in the open air.
Plants also benefit from snow. A thick snow cover reduces
temperature extremes and helps prevent frost heave, which can thrust roots from
the soil. The snow layer also keeps humidity levels relatively constant,
preventing dessication. Here on the Prairies, where the chinooks - literally
"snow eaters" - come blasting through, the presence or absence of snow may
determine whether plants live or die.
Not all of us will become chionophiles (snow lovers).
Indeed, some may be chionophobes. Still, we can muster some appreciation for a
white winter. This winter, the white stuff has stretched from coast to coast to
coast, while ignoring some spots.
Here's a bit of snow trivia to consider the next time you're
out in very cold weather, with snow squeaking beneath your boots. During the
golden years of radio, sound effects experts replicated the sound of someone
walking through snow by twisting and squeezing boxes of cornstarch. That's snow
business!
- REBECCA L. GRAMBO
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