Outdoor Notebook: How animals survive the cold
Following the past several winters that were extremely mild, it hurts when we venture outdoors when we are experiencing sub-zero temperatures. Some of us forgot the feeling of those cold winds on bare skin. We have been spending several days on the ice of some of our lakes and notice that ice thickness increased quite rapidly. Presently, it is not unusual to drill holes through ice that is 18 inches thick. The advice from many sources is that there is no such thing as safe ice. I continue with my practice to never make the first tracks over any ice. That practice is particularly employed when I am in the pick-up.
During the several weeks when we were experiencing these cold temperatures, numerous questions have been posed regarding how animals survive the cold. All of us who enjoy having a dog around the house and yard have been encouraged to bring dogs into the house or have a good dog house lined with straw for the dog to lie on. When we enjoyed the company of a dog at our house, they would always be very anxious to come back in any time the thermometer hovered near zero. When it was relatively warm, they seemed to enjoy rolling in the snow.
While discussing the weather with numerous area residents, the topic of how wild animals cope with the very cold weather has come up. That topic can go on and on, but let us look at how some of the wildlife in our area survives.
One wild animal that I enjoy watching and hunting is the partridge or ruffed grouse. Birds have the ability to fluff out their feathers to increase the insulating qualities of the feathers. When we have a covering of soft fluffy snow, the grouse will dive into the snow and cover itself with snow. I have read that the temperature in the soft snow may be as much as 20 degrees warmer than it will be in the open. When there is very little snow or a crust on the snow, grouse may spend time in evergreens away from the wind. During late afternoons, grouse may be observed eating buds in popple trees. I have read that they prefer the buds of the male popples. The mystery remains, how can they tell a male popple from a female popple tree?
It appears that the turkeys in the area are busy digging through the snow to get at acorns. Recently we have seen quite a few turkeys on farm fields as we drive through farm areas.
Perhaps the animal that gets the most attention is the whitetail deer. In winter, the whitetail’s coat consists of stiff, hollow guard hairs that are quite long, dark in color, and a very fine but deeper, wooly underfur. The thickness of this protection varies from one part of the deer’s body to another, providing better covering on the animal’s back and sides than on the lower portion of its legs. Although the guard hairs tend to absorb some solar radiation because of their dark color, it is the extreme density of the underfur that makes the whitetail’s winter coat so highly insulated.
During times of extreme cold, deer have the ability to increase the insulating qualities even more by contracting skin muscles attached to the hair shaft, causing the hair to stand erect. This process, called piloerection, helps to trap air near the skin surface.
When cold temperatures and wind chills become more severe, whitetails in our area of northern Wisconsin burn more calories in daily maintenance than they take in as food, requiring deer to live on accumulated body reserves. When this takes place, deer tend to lose weight.
The whitetails’ red summer coat has no underfur, only relatively thin, short guard hairs, and its ears, that may serve as radiators, have an especially sparse hair covering.
In our part of the whitetails’ range, the deer tend to move toward deer yards in the winter. These yards generally are thick swamps that protect the deer from cold winds. If there is a logging job nearby, it will attract good numbers of deer as winter progresses, where they can eat the tender tips of trees that have been cut down.
The 37th Rhinelander Lions Club Ice Fisheree is being held on the ice of Boom Lake this weekend. This annual event is a lot of fun and is always well attended. There is a $500 cash prize each day for the largest northern.
Longtime Northwoods outdoors personality Roger Sabota writes a bi-monthly column for the Star Journal.