BEAVER, in Zoology, the English name of the CASTOR Fiber of systematic naturalists. The gene ric and specific differences of the beaver tribe, and the peculiarities of structure that distinguish the common bearer from other quadrupeds, will be given under MAMMALIA ; but in the present article we propose to describe the manners and habits of this singular animal ; and, as far as possible, to correct the errors into which writers have fallen with re spect to its economy.
Of no animal have the accounts given by natural ists and travellers been more extraordinary, or more marvellous. The beaver has been elevated, in point of intellect and foresight, to a rank scarcely, if at all, inferior to the human race. It has been de scribed as raising works, and constructing habita tions, which appear altogether impracticable by an animal whose utmost length does not exceed three feet, whose paws are seldom larger than a crown piece, and whose tail, though broad and flat, naturally such an inclination downwards, that it can scarcely be brought on a line with the back. Yet it has been asserted that, with such small and unma nageable instruments, these animals are capable of driving stakes six feet long, and as thick as a man's leg, three feet deep into the ground ; of watling these stakes into a kind of basket work with twigs ; of building huts consisting of several apartments, and even several floors, the latter being supported on notches cut in the upright stakes, and of plastering the walls and ceilings of these apartments with mud, so as to form a smooth and uniform surface. Incre dible as these assertions may appear, they were not unsupported by testimony; but this testimony seems to nave been the result of hasty observation, assisted by that love of the marvellous, so natural to a lively traveller; and it has been flatly contradicted by later observers of equal credibility, and apparently of more experience. Still, however, though we abandon these questionable parts of the natural history- of the bea ver, enough remains abundantly to excite our inte rest and admiration.
Beavers are found in most of the northern regions of Europe and Asia, and were formerly not uncom mon in Britain. At present, they are met with in the greatest numbers in North America, where the hunting these animals, and collecting their furs, form a very important object of commercial traffic. In their natural state, they subsist entirely on vegelable food, such as roots, young wood, and the bark of trees ; and as, during summer, these are to be obtain ed in great abundance, the beavers pass that season in wandering, dispersed about the meadows and thickets that border the lakes and rivers which abound in North America. Here they ramble at their ease, reti
ring, for occasional shelter or repose, to the covert of bushes ; and when any sudden noise indicates the approach of danger, of which they receive notice by proper centinels, they seek a sure retreat in the neighbouring waters.
Towards autumn they quit their roving way of life, form themselves into communities, and, instruct ed by that admirable instinct, of which we have so many examples in the history of the animal creation, begin to provide for the wants of a season, whose duration and inclemency would effectually preclude a regular supply of their accustomed nourishment. On the approach of winter, those beavers which con stitute an established society retire to their old habi tations, while such as have formed new colonies set about constructing cabins for themselves.
The winter quarters of the beavers are situated on the bank of a river or a creek, or, where these are not to be found, on the edge of a lake or pond. In selecting the exact spot where they may form their houses, they appear to be guided by two considera tions, viz. a sufficient depth of water, to prevent its being completely frozen, and the existence of a cur rent, by means of which they can readily convey wood and bark to their habitations. To prevent the water from being drained off, when the frost has stopped the current towards its source, the beavers construct a dam across the stream; and in this work they certainly display wonderful sagacity, skill, and perseverance. The dam is of drift wood, branches of willows, birch, poplars, stones, and mud, brought by the beavers in their mouths, or be tween their paws, and not, as many have asserted, on their tails. These materials are ,not arranged in any particular order, but are placed indiscriminately in such a manner as to stem the current to the best advantage. If the current be slow, the dam runs straight across; butt if the stream be rapid, the dam is formed with a regular curve, having the convexity towards the current, so as effectually to resist' the force of the water and ice that rush down during the storms of winter, or the thaws that take place iu spring. These dams are several feet in thickness, and of such strength, when completely formed, that man may walk along them with perfect safety. As these dams are of the highest importance, the beavers are careful to keep constant repair; and if, by any accident, or the mischievous curiosity of human intruders, a part of this essential wall should give way, they immediately collect all their forces, and stop the fatal breach.