As the nights get longer and the days (finally) get colder, most Oles have pulled out their sweaters, puffy coats, and warm hats. It actually feels good to get to class, where it’s warm, and the soup in Stav is almost appealing. For animals in the natural lands, winter at St. Olaf looks a bit different. They don’t have sweaters, coats or hats to put on, nor is there a place serving them warm food, but they do have adaptations to help them survive the winter. 

For some animals, it is simply too cold to remain in Minnesota for the winter, and they migrate south. Monarch butterflies will travel up to 3,000 miles in the fall to overwinter in Mexico. Researchers think they use the magnetic pull of the earth, among other things, to find the oyamel fir forests where they roost for the winter. Thousands of butterflies will cling to one tree, where the humidity allows them to conserve energy without drying out. Other animals that migrate include song birds, Canada geese, and ducks. 

Other animals have adaptations to help them survive the winter here. Red foxes, White-Tailed deer, and Gray squirrels all have doubly insulated fur to help keep them warm. The outer layer helps catch warmth from the sun, while the thick inner layer traps their body heat. Red foxes continue hunting throughout the winter, and they have fur on their paws to keep them warm while out in the snow. Gray squirrels hide nuts in different places during the fall, which they can eat over the winter. Other animals that spend the winter here include some Canada geese, beavers, and rabbits.

Some animals who stay in Minnesota for the winter conserve energy by entering into a state of dormancy. Painted turtles hibernate, which is a type of dormancy that is voluntary and can last for many months. These turtles bury into the mud at the bottom of ponds, and absorb oxygen through the posterior cavity of their intestines. If they run out of oxygen, they can use anaerobic respiration. By reducing their metabolic rates, these turtles require very small amounts of oxygen to stay alive over the winter. Woolly bear caterpillars enter into a similar state called quiescence, where they stop moving and their body temperature drops. It’s even possible for their blood to form ice crystals.

Garter snakes and Brown snakes also go dormant for the winter. They find a hole in the ground, beneath the frost line, and enter into a state of brumation, where their body functions slow down to conserve energy. Unlike in hibernation, Garter snakes are awake the whole time, and they need to keep their body temperature above zero so they can metabolize their food. 

While we don’t see as many animals out and about in the winter because many have migrated south, or are dormant, I encourage you to think about them the next time you put your puffy coat on or eat a hot meal in Stav. In the end, we’re all just out here trying to survive the winter. 

Sources:

https://www.fs.usda.gov/wildflowers/pollinators/Monarch_Butterfly/migration/index.shtml

https://www.sierraclub.org/minnesota/blog/2023/02/winter-adaptations

https://www.voyageurs.org/news/winteradaptations

Click to access janfeb2020_young_naturalists.pdf

https://www.weather.gov/arx/woollybear#:~:text=Once%20settled%20in%2C%20the%20caterpillars,low%20as%20%2D90oF

https://wildlifeinwinter.com/common-garter-snake/#:~:text=As%20fall%20weather%20cools%2C%20it,in%20September%20or%20early%20November

Image sources:

https://www.nationalgeographic.com/animals/article/migratory-eastern-monarchs-mexico-decline

https://mnmammals.d.umn.edu/red-fox