I know not all of our readers are currently shut-in for the blizzard blowing its way through parts of Nebraska. I am however and while the drifts in northeast Nebraska continue to increase in depth I wonder how our prairie critters are managing.
It seems many of us consider hibernation synonymous with winter survival. While there are some true hibernators in the prairie our most commonly thought of and seen Nebraska animals do not hibernate but rather, go into torpor.
While hibernation is still a bit of a mystery to scientists, (side note: as are many things still are), hibernation is considered a deep sleep triggered by day length and hormone changes. It can be categorized by a significant drop in heart rate and body temperature for an extended period of time. Animals in hibernation can and do wake up to eat or dispose of their bodily waste but they rarely forage for food or leave their winter shelters. Woodchucks, ground squirrels and bats are a few of Nebraska’s true hibernators.
Torpor is, shall we say, a less committed form of hibernation. Torpor is also a deep sleep influenced by temperature and food availability. There is a drop in body temperature as well as metabolism, but as far as I can tell from my research, it seems to be far less dramatic than true hibernation. Raccoons, striped skunks and occasionally opossums are a few common Nebraska prairie inhabitants that enter torpor as a winter survival technique. Let’s check in, with just a little more detail, what it is these critters are doing to survive our winters.
Raccoons will fatten up during the summer using their stored body fat to survive from late fall to early spring. They shelter in hollowed trees or deserted homes vacated by their previous owners. They are also found in abandoned or not so abandonedbuildings. Once they are hunkered down out of the weather and air temperatures are below 25 degrees, raccoons enter torpor . During our winter warm spells they will venture out in search of food.
Like raccoons striped skunks too will survive on their winter coat of fat gained in the summer and late autumn months. Skunks raise their young in dens or burrows but will move to a den in a different location for the winter. While they are capable of digging their own burrows they save energy by reusing abandoned ones or seeking shelter under your porch or deck. Eek! I hope you have never had to experience this. Once set on a winter home, they block the entrance with dirt or other material. Unlike raccoons, skunks will share their burrows in the winter with other skunks utilizing…WAIT FOR IT…FANCY SCIENCE WORDS… social thermal regulation. Which simply means, shared regulation of body temperature.Opossums
Aw the poor opossum. By far this creature has the hardest time surviving a prairie winter. First of all, its naked ears and tail are susceptible to frost bite. Second, they don’t stock pile food or insulated their bodies with fat from late autumn feasting. They do line dens with grass or leaves for a bit of extra protection from harsh weather, but they tend to switch den sites several times a season while on the hunt for nourishment their non-existent fat stores can’t give them.
What observations have you made this or in winters past, about our prairie critters?
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