Don’t Poke a Bear
A few weeks ago, the temperature had not risen above 25oF for a week. Thus, everything must be shut down for winter, right? Our big puffball hats and trendy boots will allow us to last outside for a couple of hours if we’re lucky, but let’s give some credit to the animals who have learned to survive our harsh winters! Some migrate to warmer areas (our Floridian snowbirds have learned from the best); very few animals hibernate; and most animals have adaptations to help them survive cold temperatures.
A pet peeve of mine, and many naturalists, is the misconception that most animals hibernate during the winter. One of the only true hibernators that you’ll find around Cincinnati is Punxsutawney Phil’s cousin, the groundhog. Almost all other mammals decrease their physiological activity for short periods of time, a process known as torpor. Both torpor and hibernation involve a reduced body temperature and metabolic rate, but torpor is associated with temperature and food, while hibernation is associated with day length (photoperiod) and hormones. Animals that go through torpor utilize warmer winter days to collect food for energy and would wake up if you poked them during their snooze. Some “research” even claims that true hibernators, like the ground squirrel, would stay sleeping even if you juggled them. Please don’t do that. And don’t poke a “hibernating” bear, because they actually are in torpor and would wake up!
The inactivity of reptiles and amphibians during winter is known as brumation. It’s not called torpor because there are different mechanisms for changing body temperature in cold blooded (ectothermic) animals. During extremely cold temperatures, some reptiles and amphibians use supercooling or freeze tolerance. Natural antifreeze is used to lower their body temperature below the freezing point of their body tissues (ice crystals in the body-wow!). One of my favorite adaptations is the ability of aquatic turtles to bury themselves in the mud at the bottom of ponds or streams and breathe through their butts. Well technically it’s called their cloaca, but I’ll let you look up the details. Terrestrial reptiles and amphibians will find a hibernaculum such as rocks, bark, or leaf litter to bury underneath. Insects also have natural antifreeze and will use similar methods of surviving the cold, but you’re more likely to see them active on warmer winter days. Coyotes, foxes, and deer grow thick winter coats and are actively searching for food, even on some of the coldest days. Birds grow warm winter feathers and eat all day to store up enough energy to not freeze through the night. When they aren’t foraging for their buried nuts, squirrels are staying warm in their carefully crafted dreys and dens. And the list goes on and on.
Basically what I’m trying to say is quit using the excuse of hibernating animals to curl up in a blanket and sit on your couch binge-watching Netflix. Bundle up and go for a hike to look for evidence of these extraordinary overwintering techniques.