The Human Side of Animals: Chapter 10 - Animals Architects, Engineers, and House Builders

"The heart is hard that is not pleased
With sight of animals enjoying life,
Nor feels their happiness augment his own."

The most popular and perhaps the most interesting department of natural-history study is that which treats of the manner in which animals utilise the various materials of the universe for purposes of protection, for war and defence, for raiment, food, and even the luxuries of life. Man, by his superior power of adaptation, excels the lower animals in providing for the comforts of life; but, on the other hand, in such practical arts as engineering and domestic architecture man frequently finds himself an amateur in comparison. With all man's inventions he has not been able to equal some of the remarkable results produced by some animals. The beaver, for example, shows a more profound knowledge of hydraulics than man himself. The power possessed by these craftsmen, not only in felling trees, but in duly selecting the best places for making homes and in appropriating substances suitable for their needs, is a never-ending marvel!

Nowhere can we find a greater animal-workman than the beaver. He belongs to the great burrowing family, and is also extremely graceful in the water. Long ago he learned the advantages of co-operation, and he unites with his fellows in building dams of felled trees, which have been cut up into suitable length for use in damming up water places. These are skilfully placed, and with the aid of mud, control the level of the water in selected places as efficiently as man could do. As a social animal, the beaver should be ranked among the first; of course, the various marmots are extremely sociable, but they ordinarily live quite independently of each other, except in cases where they chance to congregate because of favourable conditions. The beavers, on the other hand, thoroughly understand the benefits of united labour, and work together for the good of the community.

Beavers, if their skill were generally known, would have a great reputation among their human friends. Recently, at the New York Zoological Gardens, a visitor was pointing out different animals to his little son, and when he came to the beaver pond, referred to two of these dam-builders and tree-cutters, which were swimming through the water with large sticks in their mouths, as big rats!

Young beavers make their appearance in May, and there are usually from four to eight to a family. These kittens, as they are called, are odd looking little fellows, with big heads, large sharp teeth, flat tails, like little fat paddles, and delicate, soft, mouse-like fur, not at all coarse like that of their parents. If taken at an early age they make nice pets and are easily domesticated. In the early days of American history it was not uncommon to see one running around an Indian lodge, playing like a child with the little Indians, and frequently receiving with the papoose nourishment from the mother's breast. Strangely enough, the cry of the young beaver is exactly like that of the baby child. One of my friends in Michigan recently stopped at an Indian's house to see a real live baby beaver. "He cry all same as papoose," remarked the squaw, as she brought the young beaver out of the house, giving him a little slap to start him crying—and cry he did!

The body of a grown beaver is usually about thirty inches long, and something over eleven inches wide; it weighs about sixty pounds. The fore-paws are quite small in comparison with the rest of the body; the hind feet are larger, webbed like a duck's feet, and are the principal motive power in swimming. The most unique feature of the animal's body is the famous mud-plastering tail, which is oft-times a foot long, five inches in width, and an inch in thickness. The colour of the beaver varies; there are black beavers, white beavers, and brown beavers. The black are the best known.

The beaver is well equipped for defending himself, and for carrying out his architectural schemes. His jet black tail, which is like a large paddle, covered with horny scales, he uses in many ways. With it he turns the body in any desired direction while swimming and diving, and, in time of danger, employs it as a sound board, or paddle. When alarmed at night, he dives into the water, and, by means of his tail, splashes so violently as to give warning to all beavers within a half-mile distance. The stroke of the tail sounds not unlike a pistol shot. As soon as a beaver sounds the alarm all others dive underneath the water. His teeth are expressly suited by nature for cutting and chiselling out trees.

The dam is the beaver's masterpiece. In the alder or birch swamps, where he usually lives, he oft-times builds from six to eight little dams from knoll to knoll, and in this way makes a pond sufficiently large for his purposes. The average beaver dam is from twenty to thirty feet long; but they differ greatly in size. There is one on a branch of Arnold's River in Canada, where the stream is twenty-one feet wide and two feet deep, which is especially well built. The dam is seven feet high, and rises five to six feet above the pool. It is constructed mainly of alder poles, which are arranged side by side, and their length is parallel with the direction of the current. To create a pond for himself and provide against drought is the chief aim of the beaver in building his dam.

Just how these dams are built; who plans the job; who sees that it is carried out; whether each works under his own impulse or whether they co-operate; when they begin and how they finish; all these things are unknown to man. The investigation of such questions is almost impossible. It is generally believed, however, that beavers work in gangs under a common "boss" or "overseer," and it is a known fact that they work only at night. During a dark, rainy night they accomplish twice as much as on a moonlight night. No doubt the darkness gives them a sense of security which aids their work. Anyway, in the completed job, we see the evidences of a skilled engineer and architect, and one who knew thoroughly what he was about.

The size of a dam depends entirely upon the wishes of its builders and location and general conditions of land and water. Sometimes the more ambitious beavers build a dam a quarter of a mile in length. They employ exactly the same principle as is used in making a mill-dam. Beavers, however, were building dams long before millers came into existence, and their methods are fully as scientific as those of man. Mill-dams usually run straight across a stream, while beaver-dams are so curved that the water is gently turned to each side. In this way the beaver-dams are capable of resisting immense quantities of water which in its impetuous rush would carry away the ordinary mill-dam. Many scientific thinkers claim that the beaver employs this principle of construction without knowing it. How absurd! Who can be sure that he doesn't know it? Scientists of the old school desire proof before they will accept anything as a fact, yet they themselves repeatedly make wild statements without proper substantiation.

It is not unusual for a beaver family to select a home on the bank of a pond, lake, or stream whose waters are sufficiently deep and abundant for all their needs. In such a case dams are not needed, and regulation beaver houses are rarely constructed. Instead, apartment houses are hollowed out from the banks. But in the ease of a town-site on shallow, narrow waters, dams are absolutely necessary to insure sufficient depth to conceal the beavers, and to prevent obstruction by ice. The entrance to the beaver's home is almost always under the water. This arrangement safeguards the home from predatory enemies.

During the summer months, beavers are inclined to live alone, except when a new home occupies their attention; but when autumn comes, the various families of a neighbourhood meet and remain together through the following spring. In the latter part of August the busy season begins, and each and every beaver, old and young, aids in repairing the dam and dwellings, which have been allowed to fall into decay. The cutting and felling of trees is the first important work to be done.

These interesting "tree-cutters" usually work in pairs, and are sometimes assisted by younger beavers; thus the family works together in cutting and felling the trees, but in other forms of labour it seems that several families work together. If only two are engaged in felling a tree, they work by turns, and alternately keep guard; this is a well-known practice of many animals both in work and play. As soon as the tree begins to bend and crack, they cease cutting and make sure of their definite direction of escape, then they continue to gnaw until it begins to fall, whereupon they plunge into the stream, usually, where they remain for some time lest the noise of the falling tree attract the attention of enemies.

Their next work is to cut up the tree into sections which they can remove. If the tree is not too large and has already fallen in the water, they take it as it is, otherwise it must be cut up and conveyed to the dam. No professional lumberman better understands how to transport lumber to a desired place than beavers. They realise the value of water transportation and thoroughly appreciate that trees can only be removed downhill. From tame beavers we have learned that they remove smaller limbs by seizing them with their teeth, throwing the loose end over their shoulder, and then dragging them to their destination.

These water-loving animals rely mainly upon their native element for the movement of lumber and food, and to aid this they employ engineering skill that is rivalled only by their feats of tree-cutting and dam-building. This constructive faculty is shown largely in their canal-digging. From one small stream to another, or from one lake to another, they excavate canals from three to four feet in width, with a water depth of two feet, and occasionally one hundred and fifty to two hundred feet in length. The amount of labour they perform is almost unbelievable; every particle of dirt is carried away between their chin and fore-paws. This earth is sometimes used in plastering up a nearby dam or repairing their winter home. Small and tender twigs are transported to the vicinity of their lodges, and then sunk for winter food.

Mr. Morgan has made a close study of these canals, and in speaking of them he says that when he first saw them, and heard them called canals, he doubted their artificial origin; but upon examination he found that they were unquestionably beaver excavations. He considers these artificial canals, by means of which the beavers carry their wood to their lodges, the supreme act of intelligence on the part of these wise animals. Even the dam, remarkable as it is, does not show evidence of greater skill than that displayed in the making of these canals. No one who has ever understood the ways of the beaver can believe that he is not exceedingly intelligent. The banks of these canals soon become covered with growing plants and moss, and they look not unlike slow sluggish streams winding through the marshy lands.

THE BEAVER IS THE GREATEST OF ALL ANIMAL ARCHITECTS. HIS SKILL IS EQUALLED ONLY BY HIS PATIENCE.

The beaver huts, or "lodges" as they are usually called, look not unlike beehives, somewhat broader at the base, with thick walls and roof, four to six feet in thickness. They are formed of numbers of poles, twigs, and small branches of trees, woven together and plastered with mud, in the same way that the dams are made. Inside the house are circular chambers formed of mud, which have been smoothed and polished like waxed floors by the feet of the occupants. Around the outer border of each polished floor is dry grass used for Mrs. Beaver's nursery, and here the young beavers sleep and play.

From the outside these beaver huts resemble Esquimaux snow-houses, being almost circular in form, and domed. The walls are quite thick enough to keep out the cold, but with all the beaver's ingenuity, he is helpless against trappers. Summer and winter they are hunted, until now they are fast becoming extinct. How few people seem fully to realise and care what is being done to wild animals! They do not seem to know that it is a crime to take the life of a being unnecessarily. Only human life is sacred to them! To realize the wonderful work of beavers, and then to act as we do toward them is unworthy of our civilisation.

An interesting cousin of the beaver, the musquash or muskrat, and called by the Indians the beaver's "little brother," is also a house-builder and engineer of no mean abilities. He is at home throughout the greater part of North America, and, like the beaver, frequents the regions of slowly flowing streams and large, reed-bordered ponds. Here he mingles in groups of his own kin, and together they build houses, work and play, dive and swim, with almost as much skill as their big beaver brothers.

The muskrat is a skilled engineer, and delights in tunnelling. His home consists of a large rounded chamber which is reached by a long burrow from the side of a stream. From his main living-room are oftentimes found a number of smaller chambers or galleries, and these are used to store food in the form of delicate roots and bits of bark. Some of the more ambitious muskrats build large houses on piles of mud which rise out of the water. These houses are usually made of heaps of dead grass and weeds which are cemented together with mud and clay; at other times they contain no mud or clay, and seem to be only piles of tender roots and swamp grasses to be used for food during the long, cold winters.

From his physical appearance, the muskrat is well prepared to do his work: he is stoutly built, with a body about a foot in length, not including the tail; has small eyes, and tiny ears, partly covered with fur. In the winter, as food gets scarce, he begins to eat even the walls of his house, and by the time his home is gone—spring has arrived!

A most unusual family of skilled house-builders are the brush-tailed rat-kangaroos, or Jerboa kangaroos of Australia and Tasmania. They are no larger than an ordinary rabbit, but they have cousins who are as large as a man. These rat-kangaroos have most interesting tails, covered with long hair which forms itself into a crest near the tip. Their homes are found among small grassy hills, where there are a few trees and bushes. They scratch out a small hole in the ground, near a tuft of tall grass, and so bend the grass as to form a complete roof to the house, which is rather poorly constructed, and whose chief interest lies in the unusual way the kangaroos have of carrying all the building materials, like tiny bundles of hay, held compactly in their tails. There is no other workman among the animals that employs quite this method of transporting materials.

The rat-kangaroos have a dainty little brown cousin that lives in Africa, and who is occasionally seen jumping around on the ground, underneath bushes, and near damp springs. He is very small, not over three inches in length, and is like a miniature kangaroo, except for his long tail. Like their great cousins—the kangaroos—Mrs. Jerboa often carries her babies on her back when she goes out to seek food.

In the Great Sahara Desert, parched and dry, are found numerous cities of these little animals. With the exception of a few birds, reptiles, jackals and hyenas, they are the only inhabitants of this barren and desolate land. From the Arabs we learn that these little animals have extensive and intricate burrows, consisting of innumerable passages tunnelled out in the hard, dry soil. And these tunnels are the result of combined labour on the part of the entire community. The least alarm causes them to scuffle away into their underground homes.

One of the larger species of Central Asia employs a stratagem that is remarkable. Like their cousins of Africa, they live in a great underground city which is a perfect network of burrows which end in a large central chamber. From this chamber a long winding tunnel terminates very near the surface of the ground, and it is a long distance from the other burrows. No sign of its existence appears from above the surface of the earth, but if an enemy invades the burrow, away the jerboas rush for this secret exit and break through to the surface out of reach of the trouble, and escape.

These African jerboas are exceedingly odd in appearance, and they are two-legged in their habits of walk, and never go on all-fours. They walk by placing one hind foot alternately before the other; and they run in the same way. They can leap an extraordinary distance.

Frogs and toads, as a class, are not so skilled in house-building as some of their higher relations, but there is one of their number—the Hyla faber—that is remarkably gifted in building mud houses. He lives in Brazil, and the natives call him the ferreiro, or smith, and he is indeed the master-builder of his family. Mrs. Hyla is really the gifted member of the tribe, and it is during the breeding season that she diligently dives underneath the water, digs up handfuls of mud, and builds on the bottom a small circular wall, which encloses a space about ten to fourteen inches in diameter. This wall is continued until it reaches about four inches above the surface of the water. It looks not unlike a small volcano, and the inside is skilfully smoothed. This has been done by Mrs. Frog's artistic hands. When the house is entirely completed, Mrs. Frog lays a great number of eggs, and here they are quite safe from enemies both as eggs and baby tadpoles.

Mr. Frog seems little concerned in the building of the home, but he does take pleasure in croaking for Mrs. Frog while she works. Perhaps this is to her heart genuine music, and his faithful attention to their children makes up for his love of idleness!

Perhaps the strangest animal engineer in the world is found in Madagascar and Australia. It is the duckbill or duckmole, and is scientifically known as the Ornithorhynchus paradoxus. The natives of Australia call it by several names: Mallangong, Tambreet, and not a few call it, Tohunbuck.

This odd little aquatic engineer digs long tunnels of great intricacy in the bands of lazy rivers, and because of its paradoxical nature and appearance has caused many strange stories to originate about its habits and methods of propagation. It has the beak of a duck and waddles not unlike this bird, but, like other mammals, it gives birth to its young, and does not lay eggs, as is so often claimed for it. When swimming it looks like a bunch of floating weeds or grass.

Its home is always on the banks of a stream, and is always provided with two entrances: one below the surface of the water, and the other above. This insures escape in case of enemies. The main tunnel or road to the home is sometimes fifty feet in length, and no engineer could devise a more deceptive approach; it winds up and down like a huge serpent, to the right, and to the left, and is so annoyingly variable in its sinuous course that even the natives have great trouble in digging the duckbill out of its nest.

The nest is oval in form, and is well-carpeted with dry weeds and grass. Here the young reside on soft beds until they are large enough to care for themselves. There are from one to four in each nest.

There are no greater architects in the universe than may be found among the coral-polypes. These interesting little animals of the deep have been much misunderstood, and have sometimes had the erroneous designation of "insect" bestowed upon them. The word "insect" has been applied in a very loose and general sense in other days; but naturalists and scientists should see to it that the use of this term be corrected in reference to these wonderful coral-architects, and that no informed person refer to them except as animals. Even poets have been guilty of propagating the most erroneous ideas about the nature and works of these sea-builders. Montgomery, in his Pelican Island, makes statements that are shocking to an intelligent thinker, and which no scientist can excuse on the ground of poetical license. "The poetry of this excellent author," says Dana, "is good, but the facts nearly all errors—if literature allows of such an incongruity." Think of coral-animals as being referred to as shapeless worms that "writhe and shrink their tortuous bodies to grotesque dimensions"! These deep-sea builders manufacture or secrete from their own bodies the coral substance out of which the great reefs are built. It is a part of their life work and nature, as a flower produces its own colours and shapes; it is amusing to know that it has only been about one hundred and fifty years since it was discovered not to be a plant but an animal! Even Ovid states the popular belief of the classic period when he speaks of the coral as a seaweed "which existed in a soft state as long as it remained in the sea, but had the curious property of becoming hard on exposure to the air."

These strange coral-producing animals of the deep demand two especially important conditions only under which they will thrive: namely, a certain depth of water and a certain temperature. Thus it is seen that the warmth of the sea determines the distribution of the corals; the geography of these animals is defined by degrees of temperature. Only in equatorial seas may reef-building corals be found; and if we select the "Equator as a natural centre of the globe, and measure off a band of 1800 miles in breadth on each side of that line," we will find that it will include the chief coral regions of the earth.

The work of the corals is most interesting. Small as are these tiny workmen, each and every one does his bit and, speck by speck, adds his minute contribution to the growing mass of coral until entire islands are surrounded by extensive reefs. Tahiti, for example, is surrounded by a barrier reef which is really an immense wall. The large barrier reef on the northeast coast of Australia extends in a continuous line for 1,000 miles, and varies from 10 to 90 miles in breadth. Some reefs are mere fringes which simply skirt the coast lands, and seem to be mere extensions of the beach. Still another variety of reef is known as the "atoll" or "lagoon" reef. This latter form is seen in circular rings of coral of various breadths which enclose a body of still water—the lagoon. There are many of these coral islands in the Indian and Pacific Oceans. Keeling or Cocos Atoll, of the Indian Ocean, is 9½ miles in its greatest width; Bow Island is 30 miles in length, and 6 miles wide; while in the Maldive Archipelago one island measures 88 geographical miles in length, and in some places is 20 miles wide. When one beholds a large coral ring, covered with rich soil and tropical vegetation, and "protecting a quiet lake-haven from the restless ocean without, it is little to be wondered at that the earlier voyagers recorded their surprise that the apparently insignificant architects of such an erection are able to withstand the force of the waves and to preserve their works among the continual attacks of the sea." As Pyrard de Laval truly said, "It is a marvel to see each of these atollons surrounded on all sides by a great bank of stone—walls such as no human hands could build on the space of earth allotted to them.... Being in the middle of an atollon, you see all around you this great stone bank, which surrounds and protects the island from the waves; but it is a formidable attempt, even for the boldest, to approach the bank and watch the waves roll in, and break with fury upon the shore."

As to the explanation of the modes of formation of these coral-reefs, the scientists have long been propounding theories which are sometimes amusing. Strangely enough they have nearly all explained that coral-polypes aggregate themselves in the forms of atolls and barrier-reefs by a mysterious "instinct," mediocrity's only term for screening its ignorance, and which is also given as the cause for their secreting lime. Flinders says that they form a great protecting reef in order that they may be protected by its shelter, and that the leeward aspect of the reef forms a nursery for their infant colonies.

Thus we see that these same scientists are accrediting these little architects with the possession of a great intelligence, and they are thought to co-operate together in a manner expressive of the greatest degree of efficiency and brotherly feeling. Each of these scientists gives a theory that leaves untouched the essential question of the causes for coral-reefs assuming their various shapes; and it is reasonable to believe that they work according to a divine wisdom and plan, and that mankind does not yet understand their strange ways, which give us a higher conception of the universe than that held by the ancients. Science has come to the point where it must recognise the perfect unity of all life, and that our fellow-architects, engineers, and house-builders in the animal world also fill an important place in Nature's great scheme.

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