Snow

Snow is an incredibly important part of nature.  Without sufficient snowpack, a pika can actually freeze to death. Snow provides insulation from the colder air temperatures above it.)  Snow hides animals that turn white in the winter (more on them later), and provides a chance for mice and other small creatures to create a secret tunnel system hidden from predators--visually hidden that is, unfortunately for the mice, owls have excellent hearing.  AND snow splits the ground into 3 layers that have great scientific names: the Sub-nivean (under the snow, like a hibernating bug), the nivean (in the snow, like a mouse), and supra-nivean (on top of the snow, like you snowshoeing while dressed as a superhero).  Yes, snow is pretty darn cool.

Arctic hare in snow and bushes lepus arcticus public domain image picture

About animals that change color in the winter:  If you are a little tan weasel running all over the place in a field or forest, you will be sure to stand out once the ground turns white.  Standing out in nature is usually fatal.  It's like a chocolate-ship cookie on a white plate.  It's going to be spotted quickly, and once it is spotted it will be eaten.  The solution?  Change your coat.  Short-tailed weasels (ermines), some ptarmigans, the ridiculously cute-looking little arctic fox, and others all change the color of their coats (or plumage) to be better camouflaged in winter.

These were the thoughts that ran through my head when I saw the snow this morning, and my resultign questions was how do animals change the color of their fur?

Here is what I found:

      Mammals that change color do not change the color of pre-existing fur.  They shed out their old coat (think of how much fur a dog leaves around the house at the start of summer) and when the new one grows in, it grows in as a different color.  I am still looking for a satisfactory answer as to how (on a more cellular level) their body produces a different fur color.  Perhaps, I'll answer that question next time.  Now, it's time to go play in the snow!

Like a security blanket,

The snow has dropped from the sky,

Tucking us in, thick and white.

Now the pikas need not freeze,

And the mice may travel in tunnel-- 

Just in time, for owl breeding has begun.

Now the skiers may coast,

And the dreamers may dream,

And adventurers may follow soft-edged trails,

Secret stories in the snow.

Who is running?

Who is hiding?

Who fell in just here?

They are busy,

We are busy,

Wide awake in the new found snow.

ECO