Did you know Harriet Alexander Nature Center (HANC) has a team of naturalists who lead tours, host hands-on classes, and help make visits more educational and enjoyable?
We asked Nature Center Supervisor and Naturalist Deon Haider, how do different animals survive our harsh Minnesota winters?
Deon: It depends on the type of animal. Reptiles like Frank, our nature center’s resident painted turtle, are cold-blooded. They don’t regulate their own body temperature in the same way mammals do. Aquatics turtles like this, which spend a lot of time in water, they have to go below the freeze line. A painted turtle will get down lower in the water and bury itself in some mud at the bottom of the lake, marsh, or pond.
They will actually breathe in a different way than they normally do. Rather than breathing from the head end, they breathe from the tail end in a process called cloacal respiration. Turtles have a multipurpose opening under their tails known as a cloaca, which is used for reproduction, expelling waste and this form of respiration. They take in water through the cloaca and filter dissolved oxygen from the water that they use to breathe. It’s a great adaption to allow them to survive in the wintertime. Their metabolism also slows down greatly. They are not eating in the winter and their body temperature drops.
How do other reptiles including snakes make it through the winter?
Deon: Snakes in Minnesota are not so water-orientated. Common species include garter snakes and brown snakes. They will find a spot like an old animal burrow to hide away in. Similar to turtles, they will drop their body temperature and their metabolism goes way down; it’s called brumation.
Do any animals actually hibernate in Minnesota?
Deon: Some of our rodents are true hibernators meaning they will spend pretty much the whole winter sleeping. When animals can’t find calories in the winter, that’s one of the biggest reasons they hibernate. True hibernation is staying in a state of dormancy for that whole winter period. Chipmunks and ground squirrels will hibernate. Chipmunks will find little burrows and hidden spots away from predators.
Do black bears also hibernate?
Deon: Not quite, Black bears go into a state of torpor, which is a lighter sleep. It’s not that deep hibernating sleep. They can still awaken if there’s a predator or if there’s a nice warm day and there’s a chance to find food. They do not have to stay asleep all winter, but torpor is still an involuntary process where they start to drop their metabolism and they go into a sleeping period.
Are there any animals that are active during the winter?
Deon: Tree squirrels are active in the winter. They are notorious for hiding food for the wintertime. Gray squirrels are scatter hoarders, so they will collect and hide food in a variety of places. While we like to joke about squirrels losing their acorns, some studies show they have over a 90 percent recovery rate for the nuts they hide. Our red squirrels are what we call larder-hoarders. They will hide food in one spot and they will defend it. Red squirrels have this reputation of being a bit more feisty and that’s, in part, due to defending their hoard.
Of course, some animals are just not adapted to the Minnesota winter. Some of our birds and insects migrate or move on. The monarch butterfly has a generation that will migrate. Some insects do overwinter here in a larval stage or just a few survivors will overwinter. Some bees buzz in their hive to keep warm. It’s all about keeping yourself warm in whatever way you can!
Click here to learn more about the Harriet Alexander Nature Center and its fall programs.