Winter in the Natural World

by Susan Streich-Boldt

Susan Stretch-Boldt, currently an environmental education consultant, served as the director of two Youth Conservation Corps camps for the Addison Park District. She recently developed and wrote an environmental education grant for the Illinois Institute of Natural Resources. An amateur sports car racing enthusiast, Streich-Boldt won the 1979 Midwestern Council Showroom Stock "C" Road Racing Championship. When not behind the wheel she enjoys nature photography, swimming, and cross country skiing.

Winter is an ideal season to observe the natural world. A winter landscape with its contrasting whites, browns and blacks can reveal some of the interrelationships which tie nature together. Activities of animals and plants during this time beautifully illustrate the "form fits function" quality of life in the natural world. Careful observation is a must to see these relationships in such a visually simplified environment.

Adaptation is one of the important keys to survival in both the plant and animal worlds. Faced with the physical change of water to ice, nature adjusts her growing schedule and growth patterns.

Trees control their growth in winter. Next year's leaves are stored in winter buds and protected by moisture-conserving scales, for winter is a time of drought for plants. These same trees often thought dead are continually growing by responding to light and temperature changes. Winter tree identification can be a challenge using silhouettes, types of buds, bark, branching and seeds instead of the usual leaves.

Animals are confronted with the problems of preventing their appendages from freezing, keeping their bodies warm and finding food. In meeting these challenges animals leave stories to be read in the snow. These stories can be found in animals' tracks, diggings, food scraps and droppings.

Track prints and patterns can be found anywhere. Common places are along "edges," i.e. diverse habitats consisting of the transition between two different plant communities such as woodland and meadow. Open water will attract birds and animals.

Tracks too can tell us something about the animals. First, their existence suggests that few animals actually hibernate. Tracks can indicate speed and direction of travel as well as mode of locomotion. There are four general patterns based on the normal gait the animals use. Single prints in a nearly straight line are produced by walking or trotting animals (dogs, cats, fox, deer). Evenly spaced pairs are imprinted by bounding animals with short legs and long bodies (weasel family). Galloping animals land with their hind legs ahead of their front legs (rabbits, squirrels, mice and shrews). Waddling animals (raccoon, muskrat, opposum) create two types of track simultaneously.

Tracks will often lead an observer to the animal's food source or to its shelter. Notice the location of the shelter (below the ground, on the ground, in a low shrub, or in a tall tree), the number and the size of the entrances. Please do not disturb the animals, however! Ask yourself the following questions. Did the animals build the shelter? Can the animal watch you without being seen? What special adaptations must the animals have and use to reach their shelter? Can you find the animal's food source nearby?

Look for other signs as indicators of the animal's daily activities: stray feathers, drops of blood, twigs chewed, bark gnawed, diggings in ground and holes in the ice.

Close inspection of trees and plants yields further evidence of winter life. Insect tunnels in trees and galls on plants are two examples. Beetle tunnels are engraved on the surface wood of dead trees and in live trees between the bark and the wood, and into the wood itself. The exact location and type of tree carved depends on the species of beetle, but each carving will give you clues about the beetle's lives as well as a visual treat.

The mouse is a sober citizen who knows that grass grows in order that mice may store it as underground haystacks and that snowfalls in order that mice may build subways from stack to stack: supply, demand, and transport all neatly organized. To the mouse, snow means freedom from want and fear.

The rough-leg has no opinion why grass grows, but he is well aware that snow melts in order that hawks may again catch mice. He came down out of the Arctic in the hope of thaws, for to him a thaw means freedom from want and fear. Aldo Leopold, A Sand County Almanac, Oxford University Press, New York, 1966, p. 4.

Illinois Parks and Recreation 8 January/February, 1980

Adapted by Kirn Gress from A Field Guide to Animal Tracks, O.L. Murie, author.

A gall is a deformity on a plant caused by an insect to provide food and protection for the developing insect. Galls can be found in varying sizes and shapes on branches and twigs of plants. Two common shapes are spherical and elliptical galls. Upon opening a gall, you might find a mass of insect eggs, insect larvae, or even a group of wintering adult insects.

Some insects remain active during the winter months. Springtails, small gray insects, can be found jumping at the base of trees on sunny winter days. Stoneflies can be found crawling over rocks and snow at a stream's edge, feeding on algae.

Snow itself affects the lives of plants and animals. It protects some, such as the meadow mice and shrews from predators, by hiding them under its blanket. If you carefully brush the snow aside, exposing a small section of ground, you might find a flurry of activity. Some plants and dormant insects benefit from the layer of insulation it provides. At the same time, snow hinders seed-seekers in search of food by covering the visible food sources. Snow serves as a limiting factor directly controlling the population and the diversity of plant and animal life in an area, protecting some and hindering others.

The snow can also teach a lesson in diversity as snow can have different physical characteristics. It can be fluffy, wind-packed, wet, thinly crusted, glazed, dry and drifting. Carefully examine it to determine how each of these qualities can help or hurt plant and animal life.

As you can see, winter has much to offer and can provide many hours of enjoyment in the natural world. The simplicity of a winter landscape can introduce even the casual observer to the many wonders of nature. All that is really needed is a little time, patience, and a desire to see. Sources:

Stokes, D., A Guide to Nature in Winter, Little Brown, 1976.

Murie, O.L., A Field Guide to Animal Tracks, Houghton Mifflin, 1954.

Peterson, R., A Field Guide to Wildflowers, Houghton Mifflin, 1968.

Teale, E., Strange Lives of Familiar Insects, Dodd, Mead & Co., 1962.

Illinois Parks and Recreation 9 January/February, 1980