BEAVER, a large aquatic rodent animal of the northern part of the world named by Linnaeus Castor fiber, and representing the family Castoridee. Some naturalists maintain that the American beaver is specifically differ ent from that of the Old World, and is there fore entitled to its specific name of Castor cane densis. All varieties agree so closely that there is little need of any such classification. It is distinguished from its nearest relatives, the marmots, not only by adaptation to an aquatic life, and the possession of large, fully webbed hind feet, which form the principal instrument for swimming, but especially by its extraor dinary tail, which is exceedingly broad and coy ered with a horny integument resembling scales. A large beaver is about two feet in length from the root of the tail to the nose, and the tail will be nearly a foot long. Such a one will weight about 35 pounds. Its flesh is edible, but not particularly good. The fin- i,s exceedingly close and fine, and when freed from the long hairs that are scattered through it and overlie the under coat, forms one of the most valuable furs of commerce and one which figured largely in the early history of North America. It is owing, indeed, to the eagerness with which men have sought for this valuable commodity, going farther and farther into the wilderness in search of the animal, that the beaver has almost disappeared from large re gions where it was once numerous. Originally it was widespread throughout Europe and northern Asia, but became extinct in the British Islands iti the 12th century, and it remains else where in Europe only in a few of the wilder streams of Norway and some of the tributaries of the Rhone and the Danube, where it is under royal protection. In some cases colonies of cap tives have re-established themselves in parks, notably that of Lord Bute, in England. It stilt exists, however, in eastern Siberia, whence a large ntunber of its skins are annually sent to market.
When America was first entered by Euro peans, the beaver was found inhabiting almost all of the woodland streams of the whole north ern continent, from the Arctic Circle down to central Mexico. Its temperament and manner of life made it.an easy prey and prevented it from adapting itself to changed conditions as did its neighbor, the muskrat. It rapidly dis appeared, therefore, wherever civilization pro gressed or trapping was systematically carried on, and now no beavers are to be found south of the rivers that flow into Hudson Bay, except in the northern parts of the Rocky Mountains and in a few remote and scattered places like the forests of Maine and the Lake Superior region, where they are more or less protected by law. A few survive, nevertheless, in the wild ranges of the southern Alleghenies and along the borders of Mexico. The principal use to which beaver fur was put was for the making of hats; and it is probable that had not the method of making hat-coverings from silk been discovered, the animal would long ago have become extinct, and also its South American substitute, the coypu or nutria.
The life of the beaver is remarkably inter esting on account of the skilful structures by which it keeps itself 'surrounded with a suffi cient depth of water, and so maintains access to a continuous supply of food. The food of the beaver consists mainly of the bark of hard wood trees, such as the maple, linden, birch, poplar and the lilce. It never eats the bark of the coniferous trees, and beavers are not found living in forests composed entirety of conifer ous trees, nor are beavers able to live in a treeless country. They are gregarious and dwell in colonies, which in favorable circumstances may persist for centuries. From time to time a pair of young beavers will wander away from such a colony and seek a new place in which to start afresh. They will choose a sluggish stream in the woods, preferably where the ground is low and level, and there will dig for themselves a burrow in the bank, the entrance of which is below the surface of the water. The tunnel will lead upward into the earth above the level of high water, and there be enlarged into a chamber in which viill be placed a bedding of grass, etc. They are likely to make an opening from this chamber into the air, and, as if for defense or concealment, will pile over this open ing a little heap of brush, in which perhaps may be seen the germ of the architectural ability which the species have so highly developed. It
is necessary to their scheme of life that the water in the stream should never fall so low in summer as to expose the entrance of the bur row; moreover, it is necessary that this water should be so deep that in winter the ice will not freeze to the bottom, but that, on the contrary, there shall remain room enough between the ice and the bed of the creek for them to store there a supply of winter food. In order to maintain this requisite level of water the beav ers throw a dam across the stream below their settlement, holding the water back to a sufficient height For this purpose they choose a place where the water is not more than 2Y2 feet deep and the bottom is firm, and beginning in the centre of the channel they place there, length wise of the current, a number of long sticks which they hold down by piling upon them mud and stones, moved into place with their dex terous fore feet They procure these poles by cutting off small trees with their front teeth, which are exceedingly large and strong and are faced with a hard yellow enamel. As the back part of the tooth consists of softer ma terial, it wears away more rapidly, leaving the front with a chisel-like edge, which is always sharp. Standing on their hind feet, they gnaw round and round the stem of a tree until it falls; and are able to cut down trees 18 inches in diameter, but this is only done in procuring their winter supplies. From its fonodation in the centre the dam is c.arried each way to the shore. As the beavers increase in ntunber and the young ones grow up, they settle in the immediate neighborhood until after a few years a considerable colony will have arisen. During all this time work progresses upon the dam, each beaver gathering drift-wood, branches and logs from the shore, stones, mud, pieces of sod and everything available for the purpose, and working it into the structure of the dam. The work is carried on only at night and especially on pleasant moonlight nights, when they seem to be extremely busy from sunset till sunrise_ There is no superintendence, but each one pos sessed with an instinct for industry does what ever seems to it best. The result is a mere tangled heap, having a long slope and com paratively tight surface on the upper side, which sometimes in a low, swampy region, will stretch for several hundred feet and hold back a large pond or morass, largely grown up to grass, but having many channels running through it_ Meanwhile each family of beavers has erected for itself upon the bank of the pond or upon some islet adjacent to one of the channels, a conical house or' lodge, the interior of which may be a room six or seven feet in breadth, which has no opening into the air, but is entered from beneath the water by two channels, one of which is commonly used, while the other forrns a means of escape in case of invasion by a mink or some other aquatic enemy. These houses are mare solidly constructed than even the dam; and when frozen in winter are so thick and strong that nothing less than a bear is able to break into them. These houses are largest and strongest in the cold northern regions. During the summer beavers go ashore and obtain from time to time such bark as they want for food, and also feed largely upon the roots and stems of the flags, lilies and other water plants. In winter, however, when the pond is covered with ice and the banks with snow, the beavers would be unable to obtain such food, and to escape starvation are obliged to store in the autumn a sufficient supply to last them through the winter. They do this by felling large trees near the water's edge and cutting them up into such portions as they can manage to roll or drag into the water. These are floated away and sunk at the doors of their houses, where they are weighted or stuck into the mud to prevent their floating away, until a sufficient pile has been procured. Piece b.y piece this store is talcen into the house during the winter, and, the bark having been eaten off, the sticks are thrown out to be used in the spring as material for repairing and extend ing the dam.