Life in the Snow 
Animals react to the season of winter in many
different ways. Some animals store up food in the form of fat reserves.
In this situation they will often sleep the winter away in a state
of 'hibernation'. Others may choose to search out new resting sites,
new food sources
and warmer temperatures. This technique is known as
'migration'. Adaptation to the season of winter is another
technique which some animals demonstrate. This is often known
as 'over-wintering'. If an animal remains active through the winter, it must be able to
be overcome the extremes weather.
Cold temperatures require an animal to exert more energy in order to keep
its body temperature at safe level. The animal must
fuel its energy stores with a constant supply of food. Problems
occur when there is deep snow or a covering of ice, and food sources
are reduced. Animals which travel over the ground, as opposed
to tunneling or flying creatures, find it difficult to hunt
for their prey when the snow depth is extreme.
Since the temperature beneath the surface of the snow or ice is
actually warmer than the ground level temperature, tunnelling
animals are well adapted to deep snow. In this case, snow acts
as an insulator. Beneath the snow surface there are many
creatures who remain active. Between the snow and
the earth the temperature remains fairly constant at 0oC (zero degrees
Celsius) while above the snow surface wind chill could drive the
thermometre to extremes of -30oC (minus thirty degrees
Celsius)! In order to create the insulating effect a minimum of 15 cm of snow is
required.
Hidden under the leaves which fell in the autumn season is a whole
world. This tiny micro world is given the term:
subnivean.
Just when you thought that everything beneath the snow was frozen
and silent,
you suddenly discover that there is a network of activity below your
snowshoes!
Insects: Most insects spend the winter in
a resting phase called diapause. The insect could be at any
life stage (egg, larva, pupa, or adult) during the diapause rest. Some
insects do remain active during the
winter such as the "Snow Flea". This tiny grey-black insect is only 3-5 mm in length. During warmer
spring weather of early February they can be seen as pepper grains on
the surface of the snow. If you take the time to look closely
you can see them springing and bouncing. It is from the
grouping of insects known as a springtail. It moves by using a powerful forked tail as a
spring for locomotion. These insects eat algae, pollen,
and leaf mould found in the leaf layer.
The next time you are out cross-country
skiing, tobogganing or walking, remember that we are not
the only animal that must endure the trials and
tribulations of a long, cold winter, and surprisingly,
the world around you is not as peaceful as it looks.
FURTHER READING 1. A Guide to Nature in Winter Donald
W. Stokes, Little Brown & Co., Ltd., Boston, 1976. 2.
Life in the Snow W.O. Pruitt, Jr., Nature Canada Vol. 4,
1975 3. The Mammals of Canada A.W.F. Banfield, University
of Toronto Press Toronto, 1974.
Down To Earth