STRONG WINDS and lower temperatures have finally arrived. My horse and his “mini” friend live a very outdoor life, with three-sided shelters from direct wind and precipitation. They have access to water at all times via a heated water tub — the most important thing in winter for livestock to help regulate internal temperature — and they get multiple feedings of hay which generates heat from the inside out.
As a long-time horse caregiver and a certified veterinary technician, I know how horses keep warm — double-layered insulating coats, a long distance for cold air to travel and warm before it hits the lungs, and a digestive system that operates through heat-generating fermentation, to name just a few things. But how do other animals living 24/7 outside survive the winter?
Last week on my way to work a weasel, decked out in winter white with the classic black-tipped tail, ran across the road in front of me. Camouflage is one way it thwarts predators in (snowy) winter and it does help them hunt more effectively, but what do weasels do to keep warm?
According to northernwoodlands.org, hibernation wouldn’t work for weasels: “(D)ue to their elongated bodies and lack of fat, they do not retain heat effectively. They keep warm by eating 40 percent of their weight in food daily.” They also rob other animals’ dens, store food for later in dens and hollow logs, and save energy when it’s too cold. Females can even delay embryo implantation until they have more reserves for having and feeding babies.
An article on MyNorth.com, “Winter Survival Strategies for a Grouse, a Weasel, and a Flea” by Cara McDonald (Feb. 24, 2014), has some interesting tidbits on winter survival strategies employed by ruffed grouse. First, the grouse is thrilled to have fewer predators and less competition for food, the article points out. They also adapt their diet to whatever they can find. And they stay warm by eating 20% of their body weight daily and maintaining a high metabolism.
The other interesting thing that the grouse does, the article describes, is something referred to as snow roosting. “(T)hey fly straight up into the air, scope out an open space full of drifts and free of obstacles, and dive bomb into the snow. From their initial landing, they’ll wriggle another 10 to 20 feet” to distance themselves from their entry point which is visible to predators. Under the snow, the article states, air pockets can help maintain a temperature as much as 70 degrees higher than the air.
One of my favorite books, “Winter World” by Bernd Heinrich, deals in great detail about what animals do in winter to survive life outdoors. Where humans have adapted by changing our environment — crank up the woodstove, build as airtight of a house as we can, and put on temporary (for hours not whole seasons) extra layers of clothing — wild animals have had to let evolution help them with winter survival. And evolve they have.
The tiny golden kinglet, a favorite bird of Heinrich’s, and many small birds that winter in northern New England utilize excessive food consumption by day (hidden bugs and caterpillars) and shivering and fluffing feathers at night. They tuck their heads under their upper wing in order to limit the loss of heat through their eyes and bill which, Heinrich says, are where most heat loss takes place in birds.
And lastly, I wonder about one of my favorite mammals, the porcupine. I have regular porcupine pals who live under the barn. When there is snow, I see Roger’s (so I named the current big fella) tracks leaving the barn almost nightly. Sometimes I even see Roger himself on his way out on the town when I do the last feeding of the night to the horses. I have in fact almost stepped down on top of Roger when I go out the back door. We have startled each other more than once. Porcupines have thick coats in the winter and they will even den up together (although not in tight-knit groups like squirrels for obvious reasons) if it is particularly cold. They are capable of eating evergreen needles that are toxic to other animals giving them an edge when it comes to winter foraging.
I know that as I bundle up in a snowsuit and mittens and extra thick socks and even a heated vest at times just to go out for 20 minutes in single-digit temps and wind chills below zero, I will always marvel at how wild animals make it through a winter night. And how much they must appreciate the sun on a winter day.
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Cheryl Kimball is a freelance writer who lives north of Rochester. Email her at naturetalksck@gmail.com.
