Wednesday, October 14, 2009

Mouse, Mole or Vole? Learning Your Adirondack Small Mammals

star nosed molePeople in any field (medicine, education, engineering, archaeology, etc.) become so used to their chosen area of expertise that they soon come to believe that certain things are universal knowledge, even if they aren’t.

Natural history is no exception. Sure, we naturalists figure that most people know a tree from a shrub, but we also expect they know the difference between a mouse and a vole. After twenty years in this field, however, I’ve come to accept that what is obvious to me may not be obvious to everyone else.
Let’s take a look at mice, voles and moles. They are all different animals, but more often than not, when I mention the word “vole” I get the following reaction: “Vole? Do you mean mole?” While mice and voles can understandably be confused with each other, moles are so much different that it used to boggle my mind that people would mix the two up. Then I came to realize that it wasn’t the animals they were mixing up, but the words. We’ve all heard of mice, and we’ve all heard of moles, but voles are in that shady area where most people don’t venture. Well, now is the time to bravely step into that unknown territory and learn the differences.

We’ll start off with the easy one: the mouse. Here in the Adirondacks we have deer mice, white-footed mice, meadow jumping mice and woodland jumping mice. Who knew there could be such variety? They are all rodents, and what they have in common is long tails. The deer and white-footed mice also have very large ears and beautiful large (some would say almost buggy) eyes. In fact, these two look so much alike that it can be quite difficult to tell them apart. But you’ll never confuse them with jumping mice, for the latter have very long hind feet to go with their very long tails – all the better to jump with, my dear. Mice are primarily herbivorous – seeds, grains and plants make up the vast majority of their diet.

Voles, on the other hand, look different. We have meadow voles (sometimes incorrectly called meadow mice), rock voles, woodland voles, and the southern red-backed vole. Voles collectively have short tails, small ears and small eyes. At one place where I used to work we told people that if you compared a mouse to a hamburger, then a vole would be a quarter-pounder (or a quarter-pounder with fleas).

Voles are larger, although not by much; a few grams, give or take. Voles, like mice, are rodents. All rodents have incisors that continuously grow, which is why they are always gnawing on things, be they mice, rats, voles, porcupines or beavers. If they didn’t gnaw, those teeth would grow so long that eventually they would curve around the skull and pierce it (I’ve seen a skull where just this very thing happened – it was pretty cool). If the animal didn’t die of starvation first, it would die from the tooth puncturing the brain. Like mice, voles are almost exclusively herbivorous.

Moles, however, are an entirely different ball of fur. Moles are not rodents. They are in the Order Insectivora, making them more closely related to shrews (which are also not rodents; we’ll discuss shrews another day). We have two species of moles in the Adirondacks: hairy-tailed and star-nosed. Both are fossorial animals, meaning they spend most of their lives underground, where they dig tunnels in search of food. And what are they eating? You should’ve guessed this one: insects.

Moles have very sharp pointy teeth, specially designed to grab insects and crunch through their exoskeletons. They’ll also take down worms and other invertebrates they encounter. But what really makes moles stand out are their front feet, which are large, broad, and turned in such a way that if you were to have them clap their hands, the backs of their hands would hit each other, not their palms. These feet are built for digging and pushing large quantities of soil out of the way. Nothing else works quite so well.

Moles also have other adaptations that make their underground lifestyles work: no external ear flaps (just fur-covered holes in the head), itty bitty eyes (can’t really see in the dark anyway), and non-directional fur (it doesn’t lay down in any one direction, so crawling around underground will not result in a bad hair day). And if all that wasn’t cool enough, star-nosed moles have an additional feature: twenty-two fleshy tentacles on their snouts that are super-sensitive and feel out prey at lightning speed.

So there you have it, in a figurative nutshell, three types of small mammals that call the Adirondacks home: mice, voles and moles. From this day forward, you should never again confuse the three. They are apples and oranges (and bananas). And now that you have mastered them, you can set yourself to learning to tell one mouse from another, and one vole from the next. Before long, you, too, will come to believe that knowing a mouse from a vole is common knowledge.

Photo: star nosed mole (courtesy National Park Service).

Related Stories

Ellen Rathbone is by her own admission a "certified nature nut." She began contributing to the Adirondack Almanack while living in Newcomb, when she was an environmental educator for the Adirondack Park Agency's Visitor Interpretive Centers for nearly ten years.

Ellen graduated from SUNY ESF in 1988 with a BS in forestry and biology and has worked as a naturalist in New York, New Jersey, and Vermont.

In 2010 her work took her to Michigan, where she currently resides and serves as Education Director of the Dahlem Conservancy just outside Jackson, Michigan.

She also writes her own blog about her Michigan adventures.

One Response

  1. Woodswalker says:

Wait! Before you go:

Catch up on all your Adirondack
news, delivered weekly to your inbox