As I searched the snow for movement, a very small mammal popped out of a snow tunnel, but then quickly disappeared below the surface of the snow. A moment later, I saw it again, but about three feet away. The little furry creature was none other than a shrew, a pygmy shrew, one of several species of shrews that call Minnesota home.
Though mouse-like or vole-like in appearance, shrews are more closely related to moles than mice or voles. Both shrews and moles belong to the mammalian order Insectivora and, accordingly, eat mostly insects. Insectivores are believed to be the most primitive of contemporary mammals.
Yet as is the case with most creatures of the animal kingdom, plenty of exceptions exist amongst those that we humans have lumped into orderly classification schemes. While the diets of the ten species that reside in north-central United States are comprised of mostly insects, the diets of other species of shrews aren’t as restricted.
The northern short-tailed shrew, for example, and the largest of our local shrews that can weigh a little over one ounce, is known to hunt, kill, and eat mice and voles. Amazingly, the saliva of the northern short-tailed shrew is toxic. Put another way, this species is venomous. One well-placed bite helps to subdue or kill larger prey such as mice and voles. Additional items on the menu of some shrews include snails and slugs as well as fungi, animal matter, and plant material including seeds and fruit.
Another highly interesting trait of short-tailed shrews is the ability to echo-locate. Aside from bats, which are of course aerial mammals that use echolocation to locate food and navigate, the short-tailed shrew (and a few other shrew species) is the only known terrestrial mammal that can echo-locate. By emitting series of ultrasonic squeaks, these shrews are able to orientate themselves in close-range situations. Put another way, these shrews use their squeaks to help them negotiate their environment -- or habitat -- not to locate food.
On the opposite end of the size-scale for shrews is the diminutive, and aptly named, pygmy shrew. This little fellow at its heaviest tips the scale at a whopping four grams. Generally too small to be taken by the conventional mousetrap if you have one in your house, this miniature mammal, cute as it is, is more easily captured by glue traps. An accomplished burrower underneath the snow, I observed with interest one evening many years ago this very species of shrew performing its amazing burrowing feats.
Other Minnesota shrews include the arctic shrew, masked shrew, and water shrew. There are also records of shrews inhabiting the extreme southeastern portion of the state. Whereas the arctic shrew inhabits a large range and occurs over most of Minnesota and other northern tier states and Canada.
Another species, the water shrew, lives out its life in and near water. Not only does this species swim and dive extremely well as it hunts for aquatic insects on the bottoms of streams and wetlands, they reportedly possess the ability to run short distances on the surface of water too.
Shrews are fascinating, tiny Minnesota mammals. Most are active at night and have poor eyesight, but all have exceptional senses of smell and touch. Quite vocal, in fact their squeaks are audible to our own ears, shrews are everywhere though rarely observed as we get out and enjoy the great outdoors.
Blane Klemek is a Minnesota DNR wildlife manager. He can be reached at bklemek@yahoo.com.
The Link LonkJanuary 16, 2021 at 09:00PM
https://www.bemidjipioneer.com/northland-outdoors/6840621-BLANE-KLEMEK-OUTDOORS-Shrews-are-interesting-little-creatures
BLANE KLEMEK OUTDOORS: Shrews are interesting little creatures - Bemidji Pioneer
https://news.google.com/search?q=little&hl=en-US&gl=US&ceid=US:en
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