by Emily Stone
Cable Natural History Museum
Steely cold seeped through my gloved fingers as they gripped the lock on my front door. The chill of winter had found an easy path through this dense metal, and gave me a frosty preview of what waited outside. Pulling my hand back, I zipped my jacket higher, pulled my hat lower, and looked at the thermometer: 14 degrees. With a burst of resolve, I flipped the lock and braced for impact.
The frosty air I had so dreaded was bracing and fresh on my face, and pale, rising sunshine painted an ever-changing water color behind the lace of trees. With a deep breath, I relaxed, and had myself a very enjoyable hike. I love winter, but it still takes some willpower to leave the warm cocoon of my house.
Animals, including humans, have three basic options for dealing with winter: migrate, hibernate, or stay active. That third one can feel daunting, but getting outside and getting your heart rate up is also incredibly valuable for our mental and physical health. Maybe we can gain some inspiration with a little help from our wild friends. What do they have to teach us about staying active in winter?
The key to my winter happiness—whether indoors or out—is having warm feet. I achieve this through wool-blend socks and insulated boots; but rough-legged hawks, who breed in the Arctic and who fly “south” to Wisconsin for the winter, simply grow feathers all the way down their legs and along their toes. In comparison to the bare, scaly talons of other hawks, their legs look “rough.” Golden eagles share this adaptation, as do snowy owls, great gray owls, and northern hawk owls. I’d be jealous, but then I also have down booties keeping my tootsies warm right now.
Birds don’t have a monopoly on warm feet. Thick fur covers the foot pads of red foxes. This makes their tracks look fuzzy. Coyotes have less foot-hair, and so the tracks they make are more precise. That’s one characteristic I use to try to figure out who’s been walking up and down my driveway at night.
Of course, just having warm feet isn’t enough when the sidewalks and trails are covered in a perilous patina. Then we need traction, too. Earlier this fall, I watched a forlorn duck traversing thin ice in order to reach open water. Each foot slid as it landed on the water-glazed surface, and slipped again as it tried to push off. This continued until the ice broke and the duck plopped into a belly-sized hole. Webbed feet have their advantages, and disadvantages, too. Luckily, most ducks migrate to regions where the water stays in liquid form.
On the other hand, ruffed grouse thrive in the land of ice and snow. The secret? They produce their own combo of snowshoes and Yaktrax traction cleats. Every fall, the scales on a grouse’s feet expand out to the sides, until they have a comb-like fringe decorating all their toes. These pectinations—from the Latin word for comb—distribute the grouse’s weight onto a bigger surface area to help them walk on top of the snow. The projections also help grouse get a good grip on the ice-encased twigs of aspen trees while they nibble on the tender flower buds—their most important winter food.
As long as my feet are warm and I’m not falling over, my next goal in winter is to make sure that I don’t get too hot. Yep, you read that right. I find it pretty easy to stay warm in the winter—just layer up with all of those cozy, puffy layers, and get moving. But as soon as I’m moving, my metabolism kicks up and I become a furnace. If I’m not careful, my base layers become damp with sweat. The liquid interferes with the insulating properties of fabric, and also initiates evaporative cooling. This is an unfortunate part of being human. Hardly any other animals sweat. The purpose of sweat is to cool us down, and it works…sometimes too well. So, I’ve learned to dress lightly, and in layers that I can take off to prevent overheating.
Moose have a more troubling problem. Hollow, insulating hair in their winter coat and a huge body mass make sub-zero temperatures a non-issue. But moose can’t take off a layer like I can, and they also can’t sweat, so when the mercury rises to 23 degrees Fahrenheit, they start exhibiting heat stress. Their behavior mimics ours in the dog-days of summer: seek shade, find a cooling breeze, lie down, and eat less.
That last item is a problem because, for Northwoods winter residents, the most important factor in staying warm is eating enough food. (Remember that on Thanksgiving Day!) Animals who can’t find food migrate or hibernate. Up north, chickadees gorge on fatty seeds; golden-crowned kinglets spend every second of daylight searching for juicy caterpillars frozen to twigs; wolves stuff up to 20 pounds of venison into their bellies at a single meal; snowshoe hares nibble constantly on twigs and consume their food twice to extract all of the calories.
For Northwoods humans, it’s a great idea to keep a candy bar in your jacket pocket and a thermos of hot chocolate in your backpack. What a treat! With those calories to ward off the cold, plus proper footwear to keep you upright, I think nature is telling us that it’s time to get outside!