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.