Snow on the ground in the past week sends a clear and cold signal to the residents of Northfield: winter is fast approaching. Boots are retrieved from closet corners, shovels extricated from the garage, thin socks switched out for the woolen thick as we feel the sting of air temperature dipping dangerously close to the single digits. And, of course, the Arboretum is feeling it too.
A familiar question for Student Naturalists this time of year is the oft-asked “How does (blank) survive the winter?” The dark part of the year in Minnesota may seem impossibly inhospitable without an HVAC system, and it is endlessly fascinating to wonder how the little ones stay warm, or even alive, through the cold.
The answers vary. Beavers spend the fall building lodges out of sticks and mud where they will spend the winter insulated from predators and temperature, gnawing on strategically frozen wood as their only food source. White-footed mice find abandoned goldfinch nests which they “dome over” with plant fibers and fuzz to make warm winter homes.
For mammals like us, winter may only be a tribulation to endure. For some species, however, a midwestern winter is crucial to their life cycle. Most prairie plant seeds require several months of “cold stratification” in order to germinate. In other words, without the many weeks of freezing and thawing and freezing again, the prairie will not sprout come spring.
Overwintering in Northfield looks different for us all. For some, it is hunkering indoors with fireplaces and warm drinks, like beavers in their lodges or mice in their stolen nests. For others, it is actively braving the cold with snowshoes or skis, like seeds embracing the snow under open sky. For others still, it is studying abroad in the southern hemisphere, like bluebirds migrating to warmer climes for the season. But no matter how you get through the winter here, remember you are not alone: the Arb is patiently getting through it too.