Going Nature's Way
It’s been nearly 20 years since we have faced this kind of extended cold weather. And I don’t ever recall it being compared with the temperature on the surface of Mars, but apparently there are places near that planet’s equator where minus 36F is common. Talk about bragging rights! Even for those of us who actually like winter, these kinds of dangerously cold temperatures are hard to celebrate, but I am trying to look for the silver lining.
Just when it seemed we’d finished with and recovered some from Dutch elm disease, here comes another pest. I’m sure you have heard about the emerald ash borer — an insect from Asia that showed up in our state in 2009 and rapidly began to spread, mainly through the transportation of firewood from one part of the state to another. While the bugs haven’t yet been recorded in Pine or Carlton counties, they are headed our way and this may be the bitter pill we have to swallow to stop their progress.
These temperatures are killing lots and lots of emerald ash borers. They are an especially voracious invasive insect that is attacking Minnesota ash trees, which number more than in any other state. Unfortunately, these trees appear to be completely defenseless against this invasive pest. Like many insects, the emerald ash borer survives winter as larvae, burrowed under the bark of the tree, but here’s the good news. Not having the type of natural antifreeze that some of our trees contain, cold temperatures kill the larvae. Each dip in the thermometer equals a rise in the percentage of ash borer’s killed. When it reaches 30 below zero, almost all the larvae die.
There are other blights on our forests, such as the spruce bud worm and the birch borer that may also suffer losses with this Arctic blast. We can only hope so, because with the milder winters we’ve had in recent years, up until this one, those bugs have been having a hay day at the expense of our iconic north woods trees.
The trees in this part of the state, however, have adapted through the centuries to such extreme cold. They have a built-in defense of natural antifreeze in their cells — a glycose base that resists freezing. It still can happen and that is when you will hear the exploding pops of trunks splitting and see the resulting scars in their sides, but for the most part, they can weather even these types of injuries better than they can the slow death by insect.
Any of us that love wildlife cringe each time we hear another report of dropping temperatures and deadly windchills. We know that the birds and mammals have faced these kinds of conditions in the past, but that doesn’t prevent us from empathizing when we contemplate what it must be like to spend entire days and nights exposed.
The mammals in this region have all developed nice thick, multi-layered coats, which trap air next to their bodies and acts as insulation. The same is true for birds and their layers of feathers, which they can fluff up to varying degrees depending on the temperature. Most mammals will find either burrows, cavities in trees or other shelters where they can get away from the worst of the wind and weather. Finding food is their biggest challenge. Most of the smaller mammals that they would eat are safely hidden away under that thick layer of snow, where they build runways to and from their burrows. The ruffed grouse will also take advantage of that deep snow and plunge into it to escape the cold and danger. It may not make sense to us to go into the snow to stay warm, but again, because it traps air, the temperature below can be well above the air temperature.
Birds on the other hand, will roost in dense shrubbery and pine boughs for the most part, although some will find those empty tree cavities and cluster there. Feeding the birds is never more important than during one of these bitter, painful cold spells. If you can, fill the feeders or spread the seed on the ground more than once a day and as early in the morning as possible. During the day the birds generate heat by flying around, but during the night, shivering is the only way to replace body heat and that is a quick way to deplete energy (fat) reserves.
We will make it through this January freeze, with higher fuel bills to be sure, but with an increased awareness of our inability to control nature. And renewed pride in our tough, long-suffering Minnesotan character. Garrison Keillor will be able to weave this winter into his Lake Woebegone stories for a long time to come.