As I sit in my warm office in Michigan today, I look out at snow and ice. My outdoor thermometer registers -8 degrees, and I wonder how the ducks on the river, the squirrels on the ground, and the birds in the air handle these frigid temperatures. I enjoy watching the birds on my bird feeders and the squirrels chasing each other in the oak trees, but I wonder how they survive. Then I apply my knowledge of physics, and I understand animal survival in the cold.
I always enjoyed teaching the heat and thermodynamics section of my high school physics class. One of my lines that always got a laugh was, “Why do we need to wear clothes to survive, outside of the obvious one.” The point is that our skin is not very good insulation against the cold. In winter, we pick clothes with air spaces within the fabric because air is a very poor conductor of heat, so it insulates us from the cold. We use coats stuffed with goosedown or some facsimile to be well protected from the cold. Goosedown also insulates sleeping bags and quilts.
Chickadees visit my bird feeders regularly. They usually are relatively sleek birds that fly smoothly and efficiently. As I look at my chickadees on this day of -8 degrees, they are almost round. Their feathers are fluffed up to trap air, so the birds are well insulated for survival in the cold. They don’t fly as smoothly as they do in summer. They crowd my feeders and would sit there without moving if they could.
Squirrels have a different problem. Their coats give them some protection, but getting food is an issue when heavy snow covers everything. They need to keep warm but avoid activities that would sap their reserve of nutrition. My gaze goes to the top of the oak trees, and I see a large round ball of leaves and twigs. Many years ago, to expand our church parking lot, we had to take down a tree with a large round ball of leaves and twigs near the top. As the tree came down, a squirrel ran out of the ball. I put my hand into the nest to see what was inside. Even though the air temperature was 20 degrees, it was very warm inside the ball of leaves and squirrel hair.
God has equipped His creatures for survival in the cold, and His design enables our Michigan winter to throb with animal activity. Trial and error explanations are weak because survival errors are lethal. We can see design in the natural world that speaks of God’s wisdom and planning. The evidence allows us to “know there is a God through the things He has made” (Romans 1:20). Watching animals thrive in very cold conditions is an excellent example of that evidence.
— John N. Clayton © 2024