Popular Science Monthly/Volume 36/March 1890/Concerning Shrews
By FREDERIK A. FERNALD.
THE shrews, or shrew mice, as they are often called from their mouse-like size and general appearance, are nearly related to the moles, but may be distinguished from them by their distinct outer ear and the moderate size of their fore-paws, which are not usually employed in digging. They have a long, pointed muzzle, with two very long cutting teeth in each jaw—the upper much curved and the lower nearly horizontal. Their other teeth are many-pointed, being thus adapted to seizing the worms and crushing the hard wing-cases of the beetles which form their food. They also sometimes destroy small vertebrates and devour each other. Most species of shrews live on the surface of the ground, and a few in burrows. They do not hibernate. They take their food at night. They are spread over the northern hemisphere, sometimes going very far north, and the smaller species enduring severe cold. The sub-family Soricina is the only one represented in North America; other sub-families are found in Europe, Asia, the East Indies, and in south and central Africa; none as yet have been detected in South America. Most of the American species belong to the genus Sorex (Linnæus). Prof. Spencer F. Baird described twelve species, varying in length from three to four and a half inches, in Vol. VIII of the Pacific Railroad Reports. In color they range from blackish and brownish to grayish above and lighter to whitish beneath. Most of the species belong on the Pacific coast or in the Northwestern States and Territories. The S. personatus is the least of the American shrews, and among the smallest of the quadrupeds of this country, being not . quite three inches long; it belongs in the South Atlantic Fig. 1.—Mole Shrew. States. In the genus Blarina (Gray) the body is stout, the tail shorter than the head; the skull is short and broad, and the fore-paws are large in proportion to the hind-paws. This genus is peculiar to America. The mole shrew (B. talpoides, Gray), the largest of the American shrews, four and a half inches long, is found from Nova Scotia to Lake Superior, and southward to Georgia. It is dark, ashy gray above and paler below, with whitish feet. Several other species are described by Baird, of which two are in Mexico and Texas.
Four species of shrew are mentioned by Wood as inhabiting the British Isles: the erd shrew, the water shrew, the oared shrew, and the rustic shrew. The erd shrew, also called the shrew mouse, is the common shrew of England, and is found also all over Europe, Unlike most animals, they are often found dead; though, owing to their nocturnal habits, they are seldom seen alive. Aubyn Battye writes in "Longman's Magazine": "Every countryman is familiar with the sight of shrew mice lying dead on autumn footpaths and by sides of roads. The hot, dry English September weather presses very hardly on this class of animals. Worms retire then a long way below ground, and even the strong mole often can not follow them in the hard-baked ground, and has to trust to slugs for maintenance. The damp, dead leaves of the hedge-bottom, which were once the shrew's best hunting-ground, are dry and deserted now—a fatal change of things. Yes, dead we often see the shrew; and picking him up we hold in our hand a little creature of an oddly quaint and old-world appearance, with a coat like velvet, brownish black above and grayish white beneath. But the two ends of him strike us most; a long, pink-tipped snout, and a blunt, four-sided tail." Shrews are accustomed to eating much and often, which doubtless accounts for their dying so speedily when food becomes scarce. The reason why their bodies are seen lying about instead of being devoured by flesh-eating creatures is probably because they secrete a strong scent that does not seem to please the palate of cat or weasel. Cats will catch them to play with, and finally kill them, but will not eat them. Owls eat them, however, and so does the kestrel falcon. On account of this scent, the animal is known in some parts of England by the name of fetid shrew. In Scotland it is called the ranny. The Latin term araneus, or spider-like, has Fig. 2.—Common European Shrew (Sorex araneus). been applied to this creature by several writers, because it was said to bite poisonously like a spider. The body of the shrew is not much over two inches long, and its whole length from the snout to the tip of the tail is about four inches. It lives in little tunnels which it digs in the earth, and which serve also as a hunting-ground. The nest in which the young shrews are brought forth is not made in the burrow, but in some little hollow or a hole in a bank. It is composed of leaves and like substances and is entered by a hole at the side. The young are from five to seven in number, and are generally born in the spring.
The word shrew applied to a scolding woman has a different derivation, according to the dictionaries, from the name of our little insect-hunter. But it is no libel on the animal to give its name to a vixen even of a more unconquerable sort than is represented in Shakespeare's "Taming of the Shrew," as the following character which Wood gives it abundantly shows:
"Sometimes the shrews mutually kill each other, for they are most pugnacious little beings, and on small ground of quarrel enter into persevering and deadly combats; which, if they took place between larger animals, would be terrifically grand, but in such little creatures appear almost ludicrous. They hold with their rows of bristling teeth with the pertinacity of bull-dogs, and, heedless of everything but the paroxysm of their blind fury, roll over each other on the ground, locked in spiteful embrace and uttering a rapid succession of shrill cries, which pierce the ears like needles of sound. It is a most fortunate circumstance that the larger animals are not so vindictively pugnacious as the moles and the shrews; for it would be a very hard case if we were unable to put two horses or two cows in the same field without the certainty of immediate fight, and the probability that one of the combatants would lose its life in the struggle."
The bite of such a little creature obviously need not be feared by a human being, though ancient prejudice attributes to it such venomous properties that in many districts in England the viper is no more dreaded than the shrew. Even the touch of the animal's tiny foot was believed to cause pains which could only be relieved on the "like cures like" principle.
The following curious account of this latter superstition is from Gilbert White's "Natural History of Selborne": "At the fourth corner of the Plestor, or area, near the church, there stood about twenty years ago a very old, grotesque, hollow pollard ash, which for ages had been looked on with no small veneration as a shrew ash. Now a shrew ash is an ash whose twigs or branches, when gently applied to the limbs of cattle, will immediately relieve the pains which a beast suffers from the running of a shrew mouse over the part affected; for it is supposed that a shrew mouse is of so baneful and deleterious a nature that wherever it creeps over a beast, be it horse, cow, or sheep, the suffering animal is afflicted with cruel anguish, and threatened with the loss of the use of the limb. Against this accident, to which they were continually liable, our provident forefathers always kept a shrew ash at hand, which, when once medicated, would maintain its virtue forever. A shrew ash was made thus: Into the body of the tree a deep hole was bored with an auger, and a poor devoted shrew mouse was thrust in alive and plugged in, no doubt with several quaint incantations long since forgotten."
The shrew is often seen near reposing cattle, and this habit probably gave the chance for putting upon it any unexplained malady that the cattle might suffer. But it has been well suggested that the shrew goes to domestic animals for the insects which light upon them. From the fact that the shrew will eat one of its own species, if slain in battle, it is evident that insects and worms do not form its whole diet. "One of these little creatures," says Wood, "has been discovered and killed while grasping a frog by the hind-leg; and so firmly did it maintain its grasp, that even after its death the sharp teeth still clung to the limb of the frog. Whether the creature intended to eat the frog, or whether it was urged to this act by revenge or other motive, is uncertain."
The water shrew is much like the erd shrew in general appearance, but its fur is nearly black on the upper parts of the body, instead of the reddish-brown color which marks its relative. On the under parts its fur is beautifully white. The fur is very silky and has the useful property of repelling water. When swimming, the parts of the body which are submerged appear to be sprinkled with tiny silver beads, which give the animal a very brilliant appearance. This phenomenon is due to air-bubbles that cling to the fur. Water shrews are fond of pools and streams that are pretty well open to the sunlight.
The following account of them is given by the writer in "Longman's," already quoted: "See these water shrews, how they chase one another in the pool! Out of the water their fur is black and soft, but under it a thousand air-bubbles clothe them round till they flash like silver fishes in the sun. In and out of the weeds they swim, picking off the fresh-water shrimps from under the leaves. No sea otter is more at home under the water than they. Yet are their feet not webbed, but only fringed about with stiff white hairs. Instead of swimming with the direct motion of the water rat, the water shrew appears to move alternately both its feet on either side. Unlike the common shrew, which rears its young near the surface of the ground, often in the old nest of a field mouse, the water shrew nests in holes under the bank. It generally, I think always, appropriates some existing hole, which it no doubt improves to. its liking."
Fig. 3.—Water Shrew (Crossopits fodiens).
Besides catching aquatic insects, the water shrew roots out larvae from the muddy banks with its long snout, and does not hesitate to eat moths and other like insects which fall into the water and drown. The ears of this creature are peculiarly adapted to prevent the entrance of water. When it goes beneath the surface, the pressure of the water folds together three small valves, which effectually close the opening of the ear. "The total length of the water shrew is not quite four inches and a half, the length of the head and body being a little more than three inches, and that of the tail being about two inches. Its snout, although long, is not quite so narrow and pointed as that of the erd shrew, and its ears are remarkably small. When it swims, it has a curious habit of spreading out its sides, so as to flatten its body as it floats upon the water" (Wood).
Another kind of shrew which frequents the water is the oared shrew, so called from the oar-like shape of the feet and tail. It is the largest of the British shrews, its total length to the tip of the tail being about five inches and a quarter. The fur on its back is sprinkled with white hairs, and that on the flanks and belly is blackish gray, tinged with yellow. On account of the general dark appearance of its fur, it is sometimes called the "black water shrew." The rustic shrew (Corsira rustica) is found in many parts of England, while in Ireland it replaces the erd shrew.
The smallest mammal known to exist is found among the shrews. This is the Etruscan shrew, and it is found in Italy. Its head and body measure only an inch and a half in length, and its tail adds about an inch more.