The Shrews: Our tiniest mammals

By Al Lowe
Contributor

Probably a great many of you have never even seen a shrew. First, they are very small. Second, when you go tramping through the woods, your footsteps sound like explosions to these tiny animals, so they wisely stay put.
It may surprise you to know that we, in Northern Ontario, have six species of these miniature carnivores. The bodies of shrews run from about 2 1/2 inches to maybe 4 inches at the most, and that doesn't count the animals tail.
Because these animals are so small, size affects their lives in many ways. Almost all of their waking hours are spent looking for food. The smaller the animal, the less food it can store away in its body to use as energy. Some species will starve to death in just a few hours. Their metabolic rate is more than twice that of man, and they breathe at a rate which is ten times ours.
Shrews are carnivores, which means that they live on meat. An earthworm is a wonderful meal for a shrew. But they will scour the surface of the earth to find any kind of insect, larva, worm or slug. A shrew will eat its own weight every day. Imagine that you, and average person of 150 pounds did that, you would eat your weight in groceries every day. Safeway would be overjoyed!
For their size, shrews are the most vicious animals on earth. A tiny shrew, lighting fast, can paralyze a mouse in seconds. Most shrews have poison glands in their lower jaws. These can immobilize a creature much larger than itself.
Besides that, they are fearless. They will eat anything they can handle, and will try to eat lots of things they can't like small rabbits or big toads. They will 'hamstring' a frog so he can't jump. The same goes for big jumping insects, grasshoppers or crickets. They attack the jumping legs first, then the meal has to stay where it is.
Shrews spend most of their time on the surface of the ground. They do, at times make use of the tunnels of other small mammals. Nests are made of grass and dried leaves, and they run to about two families a year.
Males and females get together only in the 'mating season,' which only lasts for about a day. It seems to be pretty effective though, since a litter usually has about 20 young in it.
Some of the Eskimo tribes are very much afraid of shrews. They believe that this tiny animals can burrow into a man's body, and enter his heart. When a hunter meets a shrew, he stops dead in his tracks until the wee animal has gone by.
The shrews we have in Northern Ontario are these. The Smoky and the Arctic Shrews always live in damp or wet places. The Masked Shrew lives in the woods and is very fond of the larvae of the Pine Sawfly. The Water Shrew, as its name indicates, is always close to water, swamps or bogs. The Pygmy Shrew is the smallest of the lot, being only about 3 inches long, including its tail. And the Short-tailed Shrew is the most abundant. It is almost the biggest, and has been known to attack garter snakes and even young rabbits.
Some day, when you are out in the woods, just stand or sit still for a few minutes. Chances are that one of these tiny animals will run near you, at the blistering speed, and squeaking all the time. You'll get a glimpse of one of our fiercest, tiny mammals.