George Washington, Abraham Lincoln, Charles Darwin and my wife all were born in
February. That said, I am unable to find any further redeeming quality in this month; its
only saving grace is that it's short. It's a cold, gloomy, depressing time. For animals,
the readily available food was eaten earlier, and they walk on a razor's edge between
survival and starvation. It affects people, too; in northern European countries, where the
whole winter is like that, such weather generates some of the world's highest rates of
alcoholism and suicide. You can understand why the Vikings came south on their raids; the
mystery is why they ever went back.
Years ago when I took my first field biology courses in graduate school, my major
professor, Dr. Schwartz, put great emphasis on the Law of Tolerance. That "Law" is really
a generalization stated by the pioneering ecologist, Victor Shelford, in 1913; it states
that it is the extremes of environmental factors like temperature, not the averages, that
determine whether an animal can survive. Dr. Schwartz told us we would never really
understand the problems animals face in surviving the extremes of the environment unless
we experienced them ourselves; and we quickly got used to coming home from field trips
frozen and soaked to the skin. I knew intuitively that Dr. Schwartz was right, but my wife
never bought into it. She thought the whole idea was demented, although she never quite
got up nerve enough to confront him about it. (She was younger then. A lot younger.)
By preference, I'm a warm-weather person. I hate to be cold, and the logical
inclination is to stay indoors when it is acting like winter outside. But sometimes, logic
runs afoul of guilt. When I began teaching my own ecology course, I had to make a decision
the first time it rained on field trip day. I could have cancelled the lab (a sure road to
popularity with the students), or invented some make-work lessons to be done inside (a
logical formula for keeping the Dean happy); but there in the back of my mind was Dr.
Schwartz, watching. Guilt prevailed; we went out in the rain, and a precedent was born.
Initially it resulted in some grumbling in the ranks, but it never led to open revolt; and
the next year, the word was out. Students knew getting cold and wet was part of the
bargain when they signed up for the course. My wife continued to disapprove, but the
students soon developed a sort of macho attitude about the field trips; even the girls
made wildly exaggerated boasts of the rigors endured while climbing College Mountain in a
blizzard to measure trees, or wading through swamps in a hurricane to see the last
surviving patch of Lycopodium on campus.
After I retired, my wife assumed age and decrepitude would combine with logic to put an
end to such nonsense. However, that winter it rained on the day of the Christmas bird
count, and when she voiced her assumption that I would stay home, the specter of Dr.
Schwartz reappeared. Guilt prevailed again, as it has several times since. The controversy
is reborn if there happens to be a snow flurry when I suit up to go on one of my regular
birdwatching jaunts in the winter. Even walking to the post office in a mild drizzle, as
the English would do without a second thought, leads to discussions on the distinction
between sanity and senility.
All of this came to mind because I walked to the post office in about 6 inches of new
snow one day last month. One of the houses along my route has an old-fashioned wooden
picket fence, and as I walked past, the corner of my eye caught a blur of gray at the
bottom of the fence. It was a mouse, and if I had been a predator it would have been in
serious trouble. The snow was packed too densely for it to burrow in quickly, so it did
the next best thing; it dived behind one of the pickets and hunkered down, motionless, as
I peered over the fence at it. It was shivering, partly from being forced to sit still in
the shade, but mainly from nervous tension. I did not move, and after 3 or 4 minutes, it
poked its head out and looked around. Another few minutes passed, and it decided that
either I had gone away or I was not a threat; it darted back to its original location and
resumed its business.
It was not the common gray house mouse; its white feet and belly indicated that it was
either a deer mouse or white-footed mouse (hard to tell apart unless you have them in your
hand). Sitting up like a squirrel, it selected a maple seed from the leaf litter where the
snow had been removed, peeled off the covering, and munched away, all the while peering
nervously about for signs of danger. I watched it eat for another 5 minutes or so before
The temperature was below freezing, and the mouse did not like the cold any more than I
did, but neither of us was uncomfortable. Both of us have adapted. My adaptation is
cultural; it consists of a complex infrastructure that provides me with a wool cap, a down
jacket, gloves and boots, and, if it gets too bad to be outside, a snug house supplied
with food, natural gas and electricity. The mouse has adapted ecologically; millennia of
evolution have provided it with a fur coat, some insulating fat, and a metabolic rate that
generates heat like a little furnace. The entrance to its nest tunnel was nearby-I spotted
it while I was watching-and if it got chilled, it could duck back inside where there was a
grass-lined nest, and, probably, a hoard of maple seeds.
The mouse's survival depends on only a few simple but ironclad mouse rules: don't let
your insulating fur get wet; eat as constantly as possible to keep the internal furnace
stoked; and watch the ground and the sky so you don't get eaten yourself.
The same rules apply to the birds at my feeder. They fear only extreme conditions such
as prolonged ice storms; as long as they can find food, stay dry and keep out of strong
winds, they can endure much lower temperatures than those normally found in Emmitsburg. In
fact, the only wild animals around here that suffer much from ordinary winter temperatures
are possums. The warming climates of the past century have lured them to move north from
their original Dixie-land home, and they are ill equipped for winter-poorly insulated and
unable to hibernate. Like homeless people in cities, even an ordinary winter is a time of
misery for them, and February is the worst of times.
The mouse returned to its nest. I went home and sat by the kitchen window, watching the
bird feeder and remembering old Victor Shelford and Dr. Schwartz. February will be over
soon. If the rest of it is an average month, we'll survive.