Photo Courtesy of D. Gordon and E. Robertson
You can download and/or listen to the audio of this episode here!
Snow falls, snow melts, water drips from roof edges. Night falls, temperatures plummet, drips freeze and elongate, then melt and crash in the morning sun. Welcome to The Nature of Phenology where we share the cycles and seasons of the outdoors. I’m your host, Hazel Stark.
Weather and snow conditions have become even more unpredictable in recent years, especially at the beginning of December. Something we can rely on a bit more are the habits of certain wildlife that accomplish their necessary survival tasks based more on the hours of daylight that cue a seasonal shift than the particular weather. At the end of October, we told you about the winter preparation activities of beavers who were working especially hard to cache food and repair their lodges so they would be ready whenever their home river, pond, or lake froze up—locking them under the ice until the next thaw. A close relative of the beaver that shares their habitat did not have to fuss about storing enough food for winter, however. These musky-smelling rat-tailed rodents are the topic of today’s episode: muskrats.
For most of my life, my nearest neighbors have not been humans. I have been fortunate to live in places where barred owls have lulled me to sleep, noisy porcupine conflicts have woken me up at midnight, and a moose snoring has awoken me in the morning. When the other writer for this show, Joe, and I were working as caretakers of a Maine island for a couple seasons, we represented one of only two terrestrial mammal species on the island—the other species being the muskrat. Apparently the two-mile open ocean swim did not deter these typically freshwater swimmers from the appeal of an island full of vegetation for them to eat. And, given that muskrats exemplify that classic rodent penchant for reproducing by being able to have fifteen babies per year, once a couple settled on this island, their population exploded. During our first season there, a pair of great-horned owls was able to stay well-fed on these slow and abundant rodents. But the owls moved on the second season, making for no muskrat predators. Wherever we went on the island that summer, we would often step in muskrat scat and nearly trip over the bumbling critters crisscrossing the hiking trails, observing first-hand just how poor their vision is. So when I started to look into how these clumsy creatures of habit survive winter, it was no surprise to learn that they really just keep on doing what they do best—swim, munch, rest, and repeat.
Unlike beavers, muskrats are happy with a much more varied diet. In addition to the aquatic vegetation that they eat the most, they will also eat fish, frogs, salamanders, and shellfish. It’s funny how a small and fluffy animal suddenly becomes a lot less cute when you find out it eats other animals, but it’s a great adaptation for when vegetation is hard to find. Rather than working extra hard in the fall to store enough food for winter, as beavers do, muskrats can simply maintain a fairly consistent level of effort year-round.
Muskrats also build little pop-up shelters on frozen waterways where they can catch their breaths and eat. They chisel through the ice and push mud and plant matter up through it to make a miniature shelter that does just the trick. Little did we know that ice fishermen were just copying muskrats when they bring their shacks onto the ice in the winter. Too bad those shacks are not as biodegradable as muskrat shacks when some inevitably fall through thin ice in the spring.
So as you settle deeper into the reality of winter, you can consider whether you prefer to spend the season like a muskrat, eating a varied diet and putting in a daily effort for it, or like the beaver, just going to the pantry every now and then and otherwise relaxing due to your fall efforts.
You can find a link to the full transcript of this show as well as references, contact information, and accompanying photos by visiting archives.weru.org. You can also listen to or download our features or subscribe to podcasts. Theme music was by a pileated woodpecker, made available by the US Fish and Wildlife Service. Thanks for listening and please join us next week for another dive into The Nature of Phenology.
Caduto, M. J. (2009, March 16). In Homes on Ice, Muskrats Endure the Season | The Outside Story. Retrieved November 21, 2018, from https://northernwoodlands.org/outside_story/article/in_homes_on_ice_muskrats_endure_the_season
Muskrats. (2018). Retrieved November 21, 2018, from https://www.maine.gov/ifw/fish-wildlife/wildlife/wildlife-human-issues/living-with-wildlife/muskrats.html