Log Cabin Chronicles

Beth Girdler

Fierce, Hungry & Tiny
or
Look what the cat dragged in

BETH GIRDLER

Every now and then domestic cats will present their owners with a gift. This gift can arrive in the form of a tattered bird but more often than not what you get is a mouse or vole, nicely chewed and temptingly displayed. Yummy.

Most people don't mind these presents because the corpse is proof the cat is earning its keep. (I only let my cat out at night so she can't catch the birds that come to our feeder.)

One morning I found myself looking at the body of an animal many people don't even know exists. There at my feet was a short-tailed shrew (Blarina brevicauda) -- Canada's only venomous mammal.

Shrews are in the family Soricidae. If you've never seen one, I'm not surprised. They are small mouse-like creatures with long snouts, sharp dark teeth, tiny black eyes, very short tails, and gorgeous velvety fur. They travel mostly at night, often through runways and burrows made by other small animals, giving high frequency calls as a form of echolocation. This is probably how my cat found her catch.

Shrews are one of the fiercest creatures on earth. With the highest surface area relative to body mass of all mammals, shrews have an extremely high metabolic rate and therefore need a continuous supply of food. They eat everything -- seeds, insects, worms, fish, frogs, and carrion.

I have always had a fascination for shrews, ever since I managed to trap one live in a coffee can when I was 10. I took it home and read about shrews in my science book. When I learned they have to eat constantly, I dropped in a huge dew worm, bigger than the shrew. The result was carnage! That worm was gone in seconds. I was impressed. I let the little terror go right away.

Shrews will attack and consume animals many times their size, even small rabbits. (Imagine sitting down to a half a side of beef and for afters, the other half.) It's a good thing the largest North American shrew weighs no more than a whopping 0.63 ounces. Let's hope the species doesn't mutate.

The short-tailed shrew produces venom. Their neurotoxic saliva is strong enough to kill garter snakes and young rabbits and can cause swelling and localized pain in humans. Don't worry, though; unless you grab one with your bare hands (definitely not advised!) you will never be bitten.

I often see dead shrews in the winter when I am out walking or cross-country skiing. Like my cat, predators such as mink, fox, and coyotes may catch and kill shrews but very rarely eat them, possibly due to a foul odor released from special glands.

The short-tailed shrew is only one of five species found in our area. There can be as many as 80 short-tailed shrews per acre. Be thankful. Half of every shrew's total diet consists of mice and voles and since they eat continuously, they control our rodent population far better than your average house cat, or mine.

If you have any nature questions or observations please contact me and I will be glad to share them with readers.

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Copyright © 1999 Beth Girdler/Log Cabin Chronicles/12.99