PA Keystone Wildnotes - Spring 2006 Edition

Creatures & Features

Tiny Terrors

Pennsylvania's seven shrew species are out there but out of sight. Their tiny size, mostly nocturnal habits and underground or "under ground litter" habitat have limited researchers' ability to study these fascinating creatures.

These mouselike creatures have pointed snouts, extremely sharp teeth, tiny eyes, five clawed toes on each foot and fur that can lie either forward or backward. The latter two traits enhance a shrew's ability to create and move through their burrows.

Extremely high metabolisms force shrews to be constantly in search of their next meal. While shrews (and moles) belong to the Order Insectivora, shrews' menu also includes small mammals, plants and fungi.

Their voracious appetites and tendency to savagely defend their territory have earned shrews a ferocious reputation.

Here is a list of Pennsylvania's shrews. Are you 'shrewd enough' to match them up with their descriptions?

Least Shrew
Masked Shrew
Pygmy Shrew
Rock Shrew
Short-tailed Shrew
Smoky Shrew
Water Shrew

A. This solid gray shrew, the largest in North America, grows up to 5.5 inches long from the tip of its nose to the tip of its tail and weighs a whopping -- at least for shrews -- 0.5 ounces. It is found in woods and wet areas as well as in cities, and is one of the continent's most common mammals. This shrew, known for its ferociousness and poisonous saliva, bites its prey in the throat or face, and sometimes eats its victim while it is still alive. It eats insect and other invertebrates and will occasionally eat small mice or other shrews.

B. This shrew has a dark or black back and white to gray belly. It lives among the boulders along mountain streams. Unlike other shrews, its hind feet are fringed with feathery fur, which help the animal paddle while swimming as well as allow it to walk on water. This shrew can dive, but as soon as it stops paddling, air trapped in its fur will force the creature to pop to the surface. It eats mayfly and stonefly nymphs, as well as trout eggs. It is preyed upon by weasels and minks, and large bass and trout.

C. This shrew is one of North America's rarest mammals, as well as its tiniest, with a body length of 31/8 to 37/8 inches and a tail length of 11/8 to 13/8. It weighs 0.125 ounces -- about the same as a dime. Its has a brown to gray back and a silvery belly. It is found in deep woods, fields and mossy bogs and is thought to eat insect larvae, small worms, spiders and centipedes. "Mammals of Pennsylvania," which is published by the Game Commission, notes that the only record of this rare creature in the state is a skull found in the stomach of a red fox.

D. This nocturnal shrew with a brown back and gray belly is rarely seen. It lives in bogs, marshes and woods. Its metabolism is so fast that it must eat its weight or more per day of slugs, snails, spiders and moth or beetle larvae. It will starve to death in hours and captives kept in the same cage have been known to eat each other.

E. This rare, dark gray creature is also known as the long-tailed shrew. It is found in moist crevices among boulders or talus slopes near streams in coniferous mountain forests. It eats spiders, centipedes and beetles. This slender shrew's snout is longer and slimmer than its cousins.

F. This shrew has a gray or brown back and pale belly. It is also the only shrew besides the short-tailed shrew to have a short tail. It is found in grassy or weedy fields. Because of its high metabolism, it must constantly eat: larvae, worms, spiders and the internal organs of grasshoppers and crickets. Unlike other shrews, which are solitary, this shrew is quite social, and several adults have been found sharing one nest.

G. This shrew sports a brownish coat in the summer and a grayish coat in winter, when it is still active. It lives in cool, moist wooded areas; swamps; edge habitat; and along streams. It eats worms, sowbugs and centipedes.