More Winter Adaptations

The dead of winter is nigh upon us. It had been relatively mild where I am, despite a colder fall than usual. Unlike this time last year, we are having some temperatures above freezing. I deal with the cold by putting on this flannel,

but how are some more of out animal friends coping?
The wood frog survives by going into suspended animation while buried in mud or leaf litter. For all intents and purposes, it is dead. It survives the cold (and insect-free) winter because it produces a natural antifreeze that keep the water in its cells from freezing and bursting.

Wood frog (MN Dept. of Natural Resources)

Deciduous trees also have to work around internal ice causing cells to burst. In late summer they prepare for winter by shedding their leaves, which reduces the surface area that snow and ice can accumulate on. That protects branches from breaking. They also drastically reduce water consumption. It won't be needed without photosynthesis happening, and less water stores in the trunk is less risk of water freezing and causing a rupture.

Leafless trees that gave up drinking

Snapping turtles survive by spending the winter underwater. Lucky for them, water freezes from the top down rather than from the bottom up. The cold water and lack of oxygen may seem less than ideal living conditions but somehow the turtles survive by changing their blood chemistry to compensate for increasing levels of acid.

Snapping Turtle (Missouri Dept. of Conservation)

Insects also are able to adapt to winter conditions. I always assumed they flew south ahead of the birds or just did when I was younger. Some use the same antifreeze method as the wood frog. Others allow themselves to freeze without becoming ice, a process known as supercooling. Supercooled fluids remain liquid at temperatures below freezing. But the risk is always there that a single particle could allow ice crystals to form. Once that happens it's game over.  The fluid instantly iced over, killing the insect.

Supercooled stonefly (Scientific American)

While you are enjoying the snow from inside your cozy house, just be thankful you don't have to rely on chemistry or dehydration to make it through the winter. And next time you need a snack, it probably won't be your last for a few months.
This week's information comes from the Minnesota Department of Natural Resources and Bernd Heinrich's book "Winter World".