Underground Neighbors

There is likely a venomous creature lurking around in your backyard and you may not even know it. [Cue the shark music.] Worse, even if you saw it, you might mistake it for the wrong animal. Your identification mistake would cost you precious seconds, just time enough for the wild beast to rush on you, back you into a corner and then … oh, wait, we’ll come back to that at the end of this blog.

Of course, I am talking about one of our most common and least familiar mammals in Virginia, the Short-tailed Shrew (Blarina brevicauda). Man, are these guys fascinating! As a front-desk coordinator at the Wildlife Center, I have learned that the general public has just about exactly two mental categories for all our smallest furry mammals: the mouse category or the mole category. So when I get a phone call that starts off with “Hi, I have an odd-looking injured mouse …” then I am pretty sure what the caller really has is either a vole, a mole, or a shrew.

Last week, we had two dog-attacked young shrews come to the Wildlife Center. I asked the caller to send a photo showing the feet of the animals so I could make sure it was not a mole. This is the picture she sent:


“Help! I’ve fallen and I can’t get up!” Blurry, but cute!

So, why did I need to know if the caller had a mole versus a shrew? If it was injured, it should come to the Center either way, right? True, but shrews eat up to three times their bodyweight in food every day. Shrews typically eat for an hour, then sleep an hour, then eat, then sleep like that around the clock 24 hours a day! If they miss a meal, they can actually die. So, shrews and hummingbirds are the ONLY two species we actually advise rescuers to feed before the animal arrives at the Center. Therefore, it is important for us to get the identification of mole, shrew, mouse, or vole correct over the phone so we can tell the caller to start offering food!

What kind of food do shrews eat? Mostly earthworms, snails, insects, spiders, seeds, and nuts, but also small birds and small mammals like mice and rabbits. Watch this great video to see a shrew take on a garter snake!

 


In the first sentence of this blog, I mentioned the single coolest thing about shrews: they are the only venomous mammal in Virginia! Shews actually paralyze their prey by creating a venom in the salivary glands in their lower jaws. When the venom is injected into the victim via a bite, it kills the victim by lowering its blood pressure, respiration, and heartbeat. If a human is gets bitten by a shrew, it can cause painful swelling. So even though you now probably love shrews as much as I do, it’s probably best to not handle them directly –no “taming of the shrews”, please. Besides, they stress out easily, and we don’t want stressed shrews. (Try saying that five times fast.)

More cool shrew facts:

  • The Least Shrew is the smallest Virginia mammal, about the size of your thumb. The Least Shrew adult is about the size of this juvenile Short-tailed Shrew pictured below.

         

  • Some shrew species use echolocation squeaks to navigate dark underground tunnels and avoid large objects like rocks.
  • Shrews don’t taste good. Lots of animals like cats, fox, and weasels catch and kill them, but leave them uneaten. Shrews have musky glands that make them smell unappetizing.
  • Shrews are not rodents, they are in their own Order: Soricomorpha.
  • Shrews are really common, and there may be up to 25 shrews per acre (usually less). They are a staple in the food web which anyone who ever dissected an owl pellet can probably tell you. [You have dissected an owl pellet, right? If not, you should and you may get your very own shrew skull to display in your living room! Get owl pellets at http://www.pelletsinc.com. The Wildlife Center sells pellets to schools, although ours are probably lacking in the shrew-skull department!]

But don’t just read about shrews— go look for them! Now! Go to your nearest woods and lift up some fallen leaves to look for tunnels and trails that are about one-inch in diameter. If you don’t find some at the first spot, move about 30 feet away and try again. Here’s a shrew hole (left) and trail (right) that I just found. You can do it, too.

 

Last thing, one really excellent movie is The Killer Shrews. I cannot vouch for its scientific accuracy, but the plot is that some people are trapped during a hurricane on an island where scientific research is being done and the shrews get big, mean, and start eating people. Don’t base your total impression of shrews just from this one movie, however, because the shrews in this movie look a lot like a Golden Retriever/Warthog mix. Usually shrews don’t look like that in real life.

More real science? Click here!
 

--Kate
Front-Desk Coordinator

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