Northland Nature: Snakes move to winter sites
Retired teacher Larry Weber, a Barnum resident, is the author of several books, including “Butterflies of the North Woods,” “Spiders of the North Woods,” “Webwood” and “In a Patch of Goldenrods.” Contact him via Katie Rohman at email@example.com.
By the time we reach this date in October, local wildlife are preparing for the impending winter. Those that have been living here will need to deal with the cold season. There are basically four ways to cope with winter: migrate, hibernate, die or stay active. And we can see examples of all of these happening now.
Those that choose to migrate are taking the route of going somewhere else, someplace where this difficult season is not as severe, mostly further to the south. The most obvious ones to use this method of wintering are birds. Many avian species that nested here in the warm months, now go other places, some quite far. Mostly, it is those that have a diet of insects, which are not available in the cold.
For some northern birds, their wintering site will be here. We see this with various finches that may be at our feeders or perhaps owls that leave their boreal world to winter nearby. Now, in October, we may be noting some birds, such as sparrows, as they pass through the region from further north to further south.
A few mammals, mainly bats, will migrate, as do a couple kinds of insects. The best-known insect migrant is the monarch butterfly, but they are not alone. The large, green darner dragonflies have a fall flight as well. More limited in their migration is that of snakes.
Snakes use hibernation to cope with winter as do many other cold-blooded animals, such as frogs (most of our local frogs hibernate on land); insects, including some butterflies; and a few warm-blooded mammals. But before the snakes can hibernate, they need to travel to get to the proper sites for wintering. Such places are known as hibernacula and when there, snakes will form a conglomeration, curling below the frost line. (We have only two kinds of snakes common in the region: garter snake and red-bellied snake. A third one, the ring-necked snake, is seen occasionally.)
During these autumn days, snakes will travel to their hibernacula that they left last spring. This trekking route, a form of migration, may take them over roads and trails, exposing themselves to danger, but also allowing us to see them and just how common they are at this time. Autumn sunshine on a paved road must feel good to a passing snake and some will want to bask a while, even though it can be hazardous. Roadkill snakes tell of this situation. When walking or biking in much of October, I expect to see some of these reptiles.
The critters that die as cold and daylight lessens do so after laying eggs to assure a population next spring. We see this mostly with insects. I note many grasshoppers, locusts, moths, meadowhawk dragonflies and hornets all active as the days get chilly and they succumb to the cold.
Those that remain active all winter often need to make changes in how they live and what they eat to survive. Mostly, these are birds and mammals, many of which spent summer with us. Food and shelter are very important in this season, but they can make adaptations to handle the Northland winter.
We might be seeing this preparation now. We can watch squirrels gathering nuts and acorns or beavers caching food near their lodges. Others are growing thicker coats or changing colors. Birds that ate insects last summer are switching to a diet of seeds. All of these wintering techniques are now seen in the local wildlife.