Life Under the Snow
(This
column was first published in the January 7, 2002 Buffalo News.)
The response to snow
differs among us humans from individual to individual. Some of us are delighted
to see the falling flakes. We have visions of skiing, snowshoeing, sledding or
snowmobiling. Others among us are less enthusiastic. Our thinking focuses on
shoveling and hazardous driving.
Just so is it among the
animals. Some, like rabbits and deer, are threatened by snow. It will be harder
for them to forage and hunters – coyotes, foxes, hawks and owls as well
as humans -- can better follow their trails. But for other animals the snow
will bring protection from the cold and from at least some of their many
predators.
On our closely manicured
lawns the snow piles up directly on the ground, but in the longer grass of
meadows and on leafy forest floors a quite different process ensues. Not all of
the snow reaches the ground. The leaves and branches of living and dead
wildflowers and grasses form tiny roofs that hold the snow a few centimeters
above the soil. Natural passages are formed through which mice, shrews, voles,
lemmings and even chipmunks and weasels can make their way. The Inuit name for
this complex layer of ice crystals and open space at the base of the snowpack
is pukak.
Imagine for a moment that,
like Alice in Wonderland, we can shrink ourselves down to an inch in height in
order to enter this subnivean world. We'll need to carry flashlights because
very little light penetrates that thick ceiling of snow. The animals that
inhabit these passages have much better eyesight than we do and their other
senses, especially their better ability to smell and hear, serve them well
here.
We find ourselves in a
complex system of caves in which it will be very easy to get lost. Some of the
openings have been enlarged by the bodies of mice and other animals forcing
their way through, however, and we can more easily follow one of them.
Surprisingly, because the
snow serves as a kind of blanket and the ground below our feet radiates some
warmth, the temperature is a degree or two above freezing. This causes slow but
constant melting and refreezing so all around us are ice formations that mimic
the stalagmites and stalactites of mineral caves.
When we wander through this
wonderland, we find much that serves as food for the inhabitants of the pukak.
Everywhere our light discloses living as well as dead plants and fungi on which
we occasionally see flies, beetles, springtails and aphids feeding. These
insects are fed upon in turn -- predatory beetles, mites, spiders and wasps
make meals of them.
And now we must realize
that our size threatens us as well. We too could serve as prey for a mouse,
shrew or weasel wandering through these passages. When we hear crashing noises
approaching, we had better recall the magic incantation that will return us,
bursting up through the snow cover, to retain our original size.
Surprisingly, more than a
dozen species of small mammals spend much of their time through the winter in
these passageways. Among the mice and voles, only the jumping mice are not to
be found. They, like the woodchuck and the little brown bat, are true
hibernators and they spend the entire winter curled up in their nests soundly
sleeping. Far and away the most common of the denizens of the pukak are the
voles, little "meadow mice" that seem designed to serve as food for
our carnivores.
Recall the next time you
trudge across a snow-covered field that each of your steps capsizes
a little of that world under the snow.-- Gerry Rising
Much of the information for this column was taken from an excellent article by Jon Nelson entitled "Pukak: Life Under the Snow" that appeared in the Winter 1966 issue of The Boundary Waters Journal. The article was forwarded to me some time ago by my good friend and companion of many years camping in the Minnesota Boundary Waters Canoe Area, Wally Neal.