Wildlife Wednesday -- Shrews
By Andy Ames
If you see some teeny tiny tracks in the snow, you may just be looking at the path of a shrew. Shrews are our smallest mammals, many weighing less than 5 grams, about the weight of a nickel. To satisfy their voracious appetite, shrews speed through the forest litter in search of food. In fact, a shrew needs to consume at least its body weight in food daily to avoid starvation. Shrews are considered insectivores, feeding mainly in insects, spiders, worms, and larvae. Shrews also consume seeds, lichen, fungi, and even carrion. This high energy lifestyle comes at a cost, however, as few live longer than a year. While we are rarely lucky enough to see one of these little wonders in person, winter gives us the opportunity to see where they live and travel.
With its long nose and whiskers, shrews detect prey mainly by scent and touch. Body length is generally about two to two and a half inches with the tail adding on other inch and a half, depending of the species.
A tiny set of shrew tracks with the front tracks below and rear above indicating a direction of travel from bottom to top. I don’t carry a ruler with me but the gloved finger is less than one inch wide for comparison. Unlike mice, chipmunks, and squirrels, shrews have 5 toes on front and rear feet. You can just make out the toes and heal of the rear tracks in this photo. Unfortunately, due to our dry conditions we rarely get surfaces that allow good definition of these small tracks.
Shrews forage in the surface litter using shallow runways or tunnels made by other animals. During the winter they are subnivean, living below the snow. In shallow snow you may be able to see their path below the surface. On occasion, they may travel on the top of the snow, too.
Most often I see shrew tracks in a bounding pattern similar to mice, and like mice their tail may or may not leave an impression. In this photo, it looks like a shrew was traveling in a bounding gate at the top and then slowed to a trot, indicated by the offset tracks.