The landscape can look lonely during the winter months. Many commonly observed animals from summer seem to simply disappear during winter — when the season rolls around, animals basically have three options: migrate, hibernate, or stay and endure it.
Many of our small mammals will reduce their activity during winter months, resting during the colder period and being more active during warmer conditions. Our squirrels (red, fox, and gray), prairie dogs, rabbits, badgers, skunks, and raccoons generally take this approach. Odds are that we won't see them during the cold spells, but they will come out during warmer weather.
Mice, voles, shrews, and pocket gophers spend the winter under the snow in the subnivean world — the environment between fallen snow and terrain. They are actually quite active under the snow. Some are even mating and rearing young during winter. We may occasionally see their tracks going across a snowy surface, but they are more vulnerable to predators when they are on the snow. So whatever they do, they better do it quickly.
Beavers and muskrats, of course, are active throughout the winter, but mostly under the ice and in the safety of their lodges.
It might surprise you, but relatively few mammals native to North Dakota hibernate. Ground squirrels do, and they must go on a feeding binge to store up enough fat to get them through the winter. And of course, finding a warm and safe place to hibernate has its challenges.
Most birds do not stay here through the winter. For those that do, however, winter obviously requires some adjustments. They have a variety of physiological and behavioral modifications. A good roosting site is important, and they may stash food in a roost for use during a cold period or storm.
Some insects spend the winter in their larval stage, others as adults, some in a hibernation-like state called diapause. They also have evolved mechanisms, such as anti-freeze substances and proteins to prevent freezing to death at temperatures below the freezing point of water.
Many of the animals we see are probably much like us — active throughout the winter, but not nearly as active as during the summer months, and much more prone during cold spells to hold up at home.
