Minnesota Department of Natural Resources question of the week
Q: How does the winter cold and snow affect deer, and how do they survive Minnesota’s winter weather?
A: Wildlife in Minnesota must be able to withstand a wide variety of environmental conditions, which provides a niche for cold-adapted species that may otherwise be outcompeted by species that cannot survive the winter.
White tailed deer are found throughout North America and Central America, but also exhibit some winter adaptations. The heavy fur on the outside of a deer’s coat is hollow. The air stored inside each hair serves as an insulator that buffers the deer’s warm body from colder outside temperatures, much like the insulation inside a house’s wall traps warm air.
Snow affects deer in many ways. Like the hair on a deer’s back, fluffy snow can also trap air and provide good insulation for any animal that beds down in a deep snow drift. Snow can also be a detriment to deer because it can make food more difficult to find.
In winter, deer often shift from typical grazers feeding on grasses and herbaceous plants to browsers that feed on buds and rely on fat reserves gained during the summer.
Deep snow can also make travel more difficult for deer, meaning that they may alter their movement patterns or try to find areas where food and cover from wind are nearby one another. This can cause deer to “herd up” in winter as they congregate near an available source of food or a windbreak.
-Charlie Tucker, assistant manager, Red Lake Wildlife Management Area.