Tiny terrors - informative article on the shrew covering habitat, diet, defenses, etc

Ranger Rick, Dec, 1996

Do you have a shrew in your backyard? You may not know it if you do. These secretive animals live in burrows and under leaves in almost every part of the world. They're tiny and fierce. In fact, they're strong enough to kill animals twice their size!

The short-tailed shrew shown in the photo on the left lives in the eastern half of the United States. It weighs about as much as a toothbrush. But you should see how much it can eat!

Shrews are almost always on the run, looking for food. They usually snatch small snacks like earthworms, snails, berries, and lots of different insects. But they also will tear into mice much bigger than themselves and gobble them in a flash.

A huge appetite isn't the only thing that makes a short-tailed shrew such a tiny terror. It is one of the few mammals with a poisonous bite. These mammals aren't dangerous to humans. But the poison in their saliva paralyzes their victims so they can't move. Just a bite or two from a short-tailed shrew, and lunch is ready to eat!

If shrews don't eat their prey right away, they hide them. Because of the paralyzing poison, the prey can't get away. So the poisoned animals usually stay put until the shrews get around to eating them.

ON THE PROWL

Shrews have poor eyesight. So how do they find their food? Their senses of smell, touch, and hearing are terror-ific! These talents all work together to help shrews catch animals day and night.

Some scientists think that shrews send out super-high squeals the way bats do. When the sounds bounce back from nearby plants, animals, and rocks, the shrews may be able to find their way and discover what's around them.

Shrews don't hibernate in cold weather. During the coldest part of the winter, they still have to eat. Even heavy snow doesn't stop a shrew--the animal just digs a tunnel under the snow and keeps on hunting!

SPEEDY INSIDES

Why does a shrew eat so much? It has to in order to stay alive. Shrews have a fast metabolism (muh-TAB-uh-lizum). That means that everything going on inside a shrew happens really quickly. For example, in the time it takes for you to breathe in and out once, a shrew breathes 10 times. Its heart speeds along at around 700 beats a minute (about 10 times faster than yours). And when the shrew is frightened, its heart rate can double.

Very small mammals such as shrews need lots of energy just to keep warm. And they get that energy from eating. A shrew eats from one-half to twice its body weight daily. Let's say, for example, that you weigh 70 pounds. If you ate like a shrew, you'd gulp down as many as 560 quarter-pound hamburger patties a day!

WHAT'S THAT SMELL?

Shrews may be tiny terrors, but that doesn't stop them from getting eaten by larger animals. The shrews don't give up without a fight, though.

Besides having a poisonous bite to protect themselves, they also give off a strong odor. Some people say it smells like rotting garlic--yuck!

The odor is enough to make a hungry bobcat or coyote think twice about having a shrew for supper. But birds such as owls probably can't smell well. Many a shrew is gobbled up during an owl's nighttime hunt.

Shrews may be tough, but they can be pretty jittery. Believe it or not, a clap of thunder or other loud noise sometimes kills them. That's right, they can die of fright!

HIDDEN FROM VIEW

Even though many shrews get eaten, there are still plenty of them around. Then why don't you see them? If they do come out, it's usually at night. But most of the time these mighty mites scoot around in tunnels they've made in the soil or under snow or leaves. They use the ready-made holes of mice, rats, and moles too.

NEW SHREWS

Most female short-tailed shrews make their nests in hidden spots. They tuck them under rotting logs or in tunnels. And sometimes they make the nests deep underground. They line their nests with bits of grass, leaves, and other plants. Shrew moms may have from three to ten babies at a time. And most females have more than one family a year.

Baby shrews grow up quickly. They leave the nest when they're three weeks old, and a few days later, they're on their own. By the time a female is six weeks old, she's ready to mate and start her own family. When you're a shrew, every- thing happens fast!

OWLS HELP STUDY SHREWS

This saw-whet owl has caught a short-tailed shrew. It'll swallow the shrew whole--bones, fur, and all. After it has eaten several animals, it'll spit up a pellet full of things it can't digest.

Scientists collect owl pellets and take them apart. By checking out the bones in each pellet, they can tell what kinds of little animals the bird ate.

What does it mean when the scientists find lots of shrew parts in the pellets? It means that there must be plenty of shrews around for the owl to have caught so many.

WORLD WIDE WONDERS

There are nearly 300 different species (kinds) of shrews in the world, and they live on almost every continent. Most live on land. But there are also water shrews that feed on fish and other water creatures.

More than 25 species of shrews live in North America. Many of them burrow in damp places; others scamper around deserts. There are shrews that live in cold Arctic lands and shrews in the warm South.