On an unseasonably warm day for this time of year in Wisconsin, our group enjoyed an Arboretum hike in 40-degree weather. The sun was shining, too, so we really lucked out considering the many cloudy gray days over the last few months. We had to use great caution on the trails as there were many icy patches. The rangers have been marking unsafe trails, so some were closed due to icy and wet conditions. It was good we all had proper footwear, as we also encountered a lot of mud along the way. Mud happens to be an excellent way to detect animal activity thanks to their tracks, and we talked about which animals are adapted to surviving Wisconsin winters.
The first animal we sought out was the wild turkey (Meleagris gallopavo)—a hardy bird well suited for Wisconsin winters and usually easy to spot around the Arboretum. These animals endure cold winter temperatures like champs. Feathers effectively trap heat, keeping the bird warm, and that is why birds appear to be “poofy” (a very scientific term) in the winter, as they “poof” out their feathers to maximize heat retaining potential. We trotted into Longenecker Horticultural Gardens to spy them near the pine trees where they roost at night. These tall pines give us another clue as to how the turkeys stay comfortable in the below-freezing temperatures Wisconsin regularly gets in the winter. Every evening the turkeys fly up into the pine branches to settle in for a night’s sleep. One reason they choose these cover-providing trees is to protect themselves from predators, but there is also some protection from the wind and cold in these evergreens (compared to a bare-leaved winter maple tree). If you have ever stood underneath a pine tree on a cold and windy day, you can attest that it is at least slightly warmer in the protection of pine coverage.
Next we journeyed to Icke Boardwalk, where a muskrat lodge is easily visible, to check out how the muskrat (Ondatra zibethicus) survives the winter. These mammals feed on plant tubers, roots, and other foods available under the water. Their lodge (this one constructed in the fall) not only provides them with shelter from the cold but also access to food in the water that would otherwise be inaccessible under the ice. Truly though, it is muskrats’ waterproof fur coat that keeps these rodents comfortable in cold winter temps. On a side note, according to the Wisconsin Department of Natural Resources, the muskrat is the most valuable of the Wisconsin fur bearing animals.
Looking out over the prairie along our walk, we couldn’t ignore the lack of snow cover we usually see this time of year. This observation led to a discussion about how mice and voles fare in the winter. Without that snow cover it is difficult to say how they are doing—these small animals rely on a layer of snowpack to protect them from cold and predators as they travel through their tunnels insulated beneath the snow. Frozen ground and a lack of subnivian space (the area between the snow and the ground) could certainly mean death for these little critters.
We thought about many other Wisconsin resident animals on our hike and how they tackle the cold, like bears, deer, a variety of birds and other mammals, amphibians, reptiles, and insects.