Part 10

The vizcacheras are different from other underground animal cities; some of the burrows are large, others are small. Most of them open into a subterranean main-street at from four to six feet from the entrance; from this street other streets wind and turn in all directions, like a man-made subway, and many of them extend clear into other streets or subways, thus forming a complete network of underground passageways. All the tunnelled-out dirt is brought to the surface and forms a large mound to prevent the water from entering the cities.

According to W. H. Hudson, in The Naturalist in La Plata, "in some directions a person might ride five hundred miles and never advance half a mile without seeing one or more of them. In districts where, as far as the eye can see, the plains are as level and smooth as a bowling-green, especially in winter when the grass is close-cropped, and where the rough giant-thistle has not sprung up, these mounds appear like brown or dark spots on a green surface. They are the only irregularities that occur to catch the eye, and consequently form an important feature in the scenery. In some places they are so near together that a person on horseback may count a hundred of them from one point of view."

Unlike some burrowing animals, the vizcacha does not select a spot where there is a bank or depression in the soil, or roots of trees, or even tall grass; knowing that they only attract the opossum, skunk, armadillo, and weasel, he chooses an open level plot of ground where he can watch in all directions for enemies while he works.

The great or main entrance to some of these underground cities is sometimes four to six feet in diameter. A small man stands shoulder deep in them. The going and coming of these little vizcachas would almost lead one to believe that they have a primitive city government, and are ruled according to definite laws. Their cities stand for generations, and many of the old human inhabitants tell of certain vizcacheras around them which existed when their parents were living. The founder of a new village is usually a male; and he goes only a short distance from the other villages to establish his new colony.

These cities are by no means occupied by their builders alone, but have their undesirables within their borders. The unique style of burrowing which the vizcachas employ benefits several kinds of birds, especially the Minerva, and one species of the swallows, which build their nests in the bank-like holes in the sides of the vizcacha's cities. Several insects, among which may be mentioned a large nocturnal bug, with red wings and shiny black body, also seek the same shelter; another foreign inhabitant is a night-roaming cincindela, with dark green wing-cases and pale red legs, which remind one of oriental jewels. There are also no less than six species of wingless wasps, beautifully coloured in red, black, and white. Dozens of spiders and smaller insects that live in and near the vizcacheras, which are everywhere sprinkled over the pampas, pass in and out among the streets recognising their respective friends and enemies.

The home life in these communities is most interesting. The burrowers remain indoors until late in the evening during the winter, but in summer appear before the sun sets. One of the larger males is the first to appear, as if to see if everything is safe from danger; if it is, others immediately pop up and take their places at the entrance to the burrow. The females are smaller than the males, and stand up that they may see everything that happens. Curiosity struggling within them for mastery is often the cause of their death. Tiny swallows hover over the entrances, like myriads of large moths, with never-ending low, mournful cries.

Of all the incongruous inhabitants of the vizcacheras, the fox is the most dreaded and the least welcome. To appease his growls and snarls the vizcachas are sometimes forced to let him occupy one of their rooms for a season, or even permanently. During a part of the year he appears quite unassuming and indifferent to the general affairs of the household, and he really goes quite unnoticed, even though he may be sitting on the mound in the family group. But when the vizcachas appear in the spring, the fox begins to become interested in the nursery and as soon as the older animals are away he devours the young. Occasionally, if the fox is hungry, or if he has another friend to aid him, he will hunt the vizcachera from end to end, battling with the old, and usually killing all the young. It often happens that the mother vizcacha, when her babes are large enough to follow her, will take them away to another place that is safer.

The language of these city-builders is most unusual; the males frequently utter the most varied and astonishing cries. They are jarring in the extreme, and are produced in the most leisurely manner, growing louder and louder and finally ending with a slow quaver. At other times, they grunt like small pigs. Hudson says that any quick noise, like the report of a gun, produces a most startling effect among these little animals. As soon as the report is broken on the stillness of the night a perfect furore of cries issues forth from every direction. In a few seconds it ceases for a momentary lull, and then suddenly breaks forth again, louder than before. The tones of the different ones are so different that the cries of nearby individuals may be plainly distinguished amidst the babel of voices coming from the distance. It sounds as if thousands upon thousands of them were striving to express every emotion with their tiny tenor voices. No words can describe the effect that these sounds produce. One of the most peculiar calls is the special alarm-note, which is sharp, sudden, and shrill. It is reported from one to another until every vizcacha is safe in his burrow.

But with all the kind and sociable qualities of these little animals, they have characteristics which seem rather paradoxical, and chief among these is their resentment of any intrusion of neighbours into their burrows. Although a number of individuals may reside in adjoining compartments in the same burrow, yet if one enters a burrow not his own--woe is he! Even when pursued by fierce dogs a vizcacha will rarely enter a room of another. If he does, he is immediately pounced upon by the angry owner, and is usually driven clear out of the burrow. These animals are undoubtedly far the most versatile and intelligent rodents in the world.

A most unusual miner and underground dweller is the pocket gopher of North and Central America. He is a rat-like animal, and is most plentiful on the plains of the Mississippi region. He is unusual in appearance, dressed in brown and grey fur, with tiny white feet, small eyes and ears, and a short stubby tail. His feet are wonderfully strong, and his fore-paws are armed with strong, curved claws. But he is famed for his wonderful fur-lined pouches which open inside his cheeks and serve a peculiar use.

His entire life, with rare exceptions, is spent underground. There he makes long tunnels for the purpose of securing tender roots for food; these tunnels are about twelve to eighteen inches below the surface, and usually wind under the foot of a tree where a sinking passage goes down four to five feet further and leads to a large living-room. This is the family nest and nursery, lined with grass and soft fur which Mrs. Gopher has taken from her own body. Adjoining the living-room is a storage bin filled with nuts, dried bits of roots, tobacco, and potatoes.

Much that is exaggerated has been said in regard to the adaptability of the gopher for his work. But it is a fact that he is of all the diggers best suited for his task. He uses his strong teeth, like a trench-digger uses a pick, to loosen the earth; and while his fore-feet are kept constantly at work in digging and pressing the dirt back under the body, the hind feet also aid in shovelling it still farther back. When a sufficient amount has heaped up behind him, he performs the strangest of all his feats--he turns around, and places his hands vertically against his chin, thus forcing himself backwards, pushing the dirt ahead of himself until it is forced out of the tunnel. At the outer end of the tunnel is formed a little hillock.

Dr. Merriam has made a special study of the gopher, and in speaking of the strange habit of running backwards, he says that even in carrying food to one of his barns or storehouses the gopher rarely turns round but usually runs backwards and forwards, over and over again like a shuttle on its track.

The gopher uses his pouches for carrying food, not dirt. When he has eaten a sufficient amount of food, he fills his pouches. If a potato is too large to be carried in this way, he trims it off to the right size. His method of emptying his pouches is most interesting; with his two tiny paws he delicately presses the food from his cheeks.

The woodchuck is an American basement-dweller of considerable renown. His peculiar whistling cry has won for him from the French the name of siffleur; and we sometimes call him by the very inappropriate name of ground-hog. He is a skilled weather prophet, and his appearance in the early spring signifies that the winter is over. He never shows himself until the cold is gone.

The home of the woodchuck is usually found under a hill, with a sheltering rock to protect the entrance, which leads into a tunnel, from twenty to thirty feet in length, finally ending by entering his home proper. The tunnel descends obliquely for several feet, and again rises towards the surface. His nest is rather large, and nicely lined with dry grass and leaves, which serve as a carpet for the young woodchucks when they come into the world. The young remain in the underground home until they are about five months old, then they go out into the world for themselves.

The ground squirrel long ago decided that he would rather have a dwelling under the ground than in the tree-tops, for in an underground home he would have more protection, a better place for storing food, and a far safer nursery for rearing his precious babes. So snug, cosy and hidden are the tiny quarters to which his runs or subways lead that his family is quite safe against most enemies. The ingenuity and skill shown in the construction of his home entitles him to rank among the leading animal miners and excavators.

The most unusual of all the underground and basement dwellers is the polar bear. This wise inhabitant of the Far North has long ago learned that no animal needs to freeze to death in the snow. To him the snow is a constant means of warmth and protection, and as winter approaches, he seeks a position, usually near a big rock, where he digs out a hole of small dimensions, and allows the snow to cover his body. Strangely enough it is only the female bear that seeks this permanent snow hut; the males do not care to spend so much time in seclusion. The same is true of the unmated females. But the mated females always have snow huts in which they give birth to their young, and where they reside until early spring; then the mother bear comes forth with them to seek food and teach them the ways of the world.

TO THE POLAR BEAR THE ICE AND SNOW OF THE FAR NORTH MEAN WARMTH AND PROTECTION. THE MOTHER BEAR DIGS HERSELF INTO A SNOWBANK, WHERE SHE LIVES QUITE COMFORTABLY THROUGHOUT THE WINTER.]

There is no danger that the bears will stifle for air under the snow, because the warmth of their breath always keeps a small hole open at the top of the snow-cell. This snow-house increases as time goes on, the heat exhaled from their bodies gradually melting the snow. Often Mrs. Bear's home is discovered by means of the tiny hole in the roof around which is collected quantities of hoar frost.

Hibernation is one of the strangest phenomena of the animal world, and bears, especially the white bear of the polar regions, the black bear of North America, and the brown bear of Europe, agree in the curious habit of semi-hibernation. In the late fall of the season, the bears begin to eat heavily and soon become enormously fat, preparatory for the long winter of semi-sleep.

During the winter, at least for three months, the polar bear takes no food, but lives entirely upon the store of fat which her body had accumulated before she went into retirement. The same is true of many hibernating animals, but in case of the bears it is more remarkable because the mother bear must not only support herself but nourish her young for a long period without taking any food for herself.

Another good example of a ground-dweller is the aard vark of Southern Africa. He is as curious as his name, and scoops out immense quantities of earth to form his home. This dwelling might be termed a cave, as he heaps up the earth in the shape of a mammoth artificial ant-hill; on one side is the entrance, which is so skilfully formed that it looks far more like the work of man than of an animal.

His name is Dutch and means earth-hog. It is applied to him because his head looks somewhat like that of a pig. His claws are powerful and enormous, and with them he is able to dig into the hardest soil, and to destroy the giant ant-hills which are dotted over the plains of South Africa, and which can withstand the weight of a dozen men.

This strange creature sleeps during the day, and comes forth at evening to seek his food. The first thing he does is to burst a hole in the stony side of an ant-hill, to the utter dismay of its tiny inhabitants. As they run among the ruins of their fallen city, he throws out his slimy tongue and catches them by the hundreds. In a short time only the shell of a half-destroyed wall remains.

These once stately ant-homes metamorphosed into caves, form homes for the jackals and large serpents of the plains. The Kaffirs of Africa use them as vaults into which are thrown their dead. The aard vark outrivals, with his great claws, the most skilled burrowing tools of man. These animals are therefore rarely captured. It is not uncommon for a horse to fall into their excavations and be killed.

Miners, excavators, and underground dwellers teach us the great lesson that, while many of them sought the ground as a protection, and found there many difficulties to overcome, they not only have won in the great struggle of life but have so skilfully adapted themselves to their environment and surroundings as to become entire masters, even artists, in their methods of living.

ANIMAL MATHEMATICIANS