< in Minnesota is unpredictable—one week at Carleton you need a parka, hat, scarf, and mittens just to avoid frostbite while walking to class, and the next week you’re getting rained on and you contemplate busting out a pair of shorts. Weather, without a doubt, is a big part of Carleton campus, dictating whether we’re playing frisbee or broomball, eating a picnic lunch on the Bald Spot or staying in the dorms, huddled next to our radiators.
But humans are not the only ones impacted by this environment’s weather—organisms big and small also undergo change to survive through the Minnesota winter. We can think of the more visible changes—deer grow more hair to insulate themselves, certain birds fly to warmer abodes, and deciduous trees lose their leaves—but there are other, more difficult-to-spot organisms with their own great winter survival stories.
Take the snow flea, for example. It’s not a well-known creature—few people associate snow with having fleas as if it were someone’s Labrador. But these tiny creatures do exist, and if you look at the base of a tree on one of these warmer winter days, you’ll see specks that look like pepper or ash which are actually little 1-2 millimeter-long snow fleas, who are probably munching away at decaying plant material or tree sap.
These critters aren’t, however, actual fleas. They are scientifically named Hypogastrura harveyi or Hypogastrura nivicola, and are kinds of arthropods in the order Collembola, or springtails. Springtails have an abdominal appendage called the furca that acts as a loaded spring that they can use to launch themselves when threatened.
So how do such tiny, seemingly delicate arthropods survive our harsh winters? Though they lack parkas or warm fur, snow fleas have found a very clever way of keeping themselves from freezing to death. Snow fleas can survive in sub-zero environments because they possess an anti-freeze-like protein that prevents ice crystal formation in their tissues. Wouldn’t we all like to have some of that protein in our systems while walking around campus?
On the next warmer day (believe me, they do happen!) take a good look at the ground around some of the trees on campus or in the arb—you might just get a peek at one of the best-equipped creatures for a climate which those who come from warmer areas might think is, at times, inhabitable.
