Dam (animal)

“ If the dam turns round and approaches it from even a very short distance, it will start back and run from her in fear, and will not understand her voice when she bleats to it: at the same time it will confidently follow after a man, dog, horse, or any other animal moving from it. ”

“ These stones weigh from one to six pounds, and are carried by the beavers in the same way as they carry their mud—namely, by walking on their hind legs while holding their burden against the chest with their fore-paws. The solid dams are much firmer in their consistence than the stick dams; for while a horse might walk across the former, the weight of a man would be too great to be sustained by the latter. Each kind of dam is adapted to the locality in which it is built, the difference between the two kinds being due to the following cause. ”

“ The stream itself, at the point where the dam intersects it, may only be a few yards in breadth, but as the mass of the flowing water cannot penetrate the solid embankment of mud and sticks which the beavers have made, it broadens out and begins to make a way on either side of it. ”

“ This extra flow disturbed both the colour and the temperature of the clear amber water of the pond. It lifted heavily against the ice, pressed up the tunnels to the very edge of the dry chamber of the lodge, and thrust ponderously at the outlets of the dam. Understanding the peril, the wise little dam-builders sallied forth in a flurry, and with [Pg 249] skilful tooth and claw lost no time in enlarging the outlets. They were much too intelligent to let the flood escape by a single outlet, lest the concentrated flow should become too heavy for them to control it. ”

“ They had reached the dam by this time; it seemed to Phil like a thick hedgerow on a solid bank, for not only were the willow branches in full leaf, but the poplars and birches, used to repair it from time to time, had taken root also.
"If the snow on the mountains melts too rapidly, and flows down to the river in torrents, the water behind our dam is still quite calm, and our houses, built in its shelter, are undisturbed. We must always have a deep body of water in which to build our lodges ”

“ The canoe in which I was, in passing over a wounded one, elicited a distinct grunting, though the animal lay entirely under water.
The young, when very little, take their stand on the neck of the dam, and the small head, rising above the large, comes soonest to the surface. The dam, knowing the more urgent need of her calf, comes more frequently to the surface when it is in her care. ”

“ He says that the largest dam he has himself seen measured 650 feet in length, and 31⁄2 feet in height, with a small number of lodges in the vicinity of the pond. The number of lodges is always thus very small in proportion to the size of the dam, the greatest number of lodges that he has observed upon one pond being five. It is evident from this that beavers are not really gregarious in their habits, and that their dams and canals 'are the work of a comparatively small number of animals ”

“ They also fill up all the gaps between them with mud, and so hard do they work that by the time the dam is finished it is often two hundred yards long, fifteen or even twenty feet thick at the bottom, and six or eight feet high. And when the river runs swiftly, they are clever enough to make their dam in the form of a curve, so that it may be better able to resist the force of the current. ”

“ The mud used is dug out of the bottom and sides of his pond, and carried, while swimming, between his paws, with his front feet holding it against his breast. The sticks used in the dam are thrust endwise into the mud on top of the dam, and the mud used is patted down with his fore feet. The tail is not used as a trowel, but in swimming it is the Beaver’s propeller.
In captivity the Beaver is not wholly a satisfactory animal. Like some human craftsmen, he positively declines to work under observation, and performs nearly all his tasks at night. ”

“ Sometimes after cutting a large limb into the right length to be used in the construction of a dam, the animal, finding he does not need it immediately, floats it out into the middle of a stream and sinks it to the bottom. ”

“ And when the dam is pronounced finished, the overseer or head beaver goes carefully over every part, to see that it is the proper shape and exactly smooth and even, for beavers cannot bear bad work, and would punish any of their tribe who were lazy or careless. ”

“ The materials being prepared in the manner I have previously described, the animals make ready to establish their dyke. They intermix their materials — driftwood, green willows, birch, poplars, etc. — in the bed of the river, with mud and stones, so making a solid bank, capable of resisting a great force of water; sometimes the trees will shoot up forming a hedge. The dam has a thickness of from three to four metres at the base, and about sixty centimetres at the upper part. The wall facing up-stream is sloping, that directed down-stream is vertical ”

“ As soon as a dam is completed, it becomes a wilderness highway. It is used day and night. Across it go bears and lions, rabbits and wolves, mice and porcupines; chipmunks use it for a bridge, birds alight upon it, trout attempt to leap it, and in the evening the graceful deer cast their reflections with the willows in its quiet pond. Across it dash pursuer and pursued. Upon it take place battles and courtships. Often it is torn by hoof and claw. Death struggles stain it with blood. Many a drama, romantic and picturesque, fierce and wild, is staged upon the beaver dam. ”

“ So they all started, carrying sticks and bark with them, the water-rat and all. But as they swam under an old oak-tree's root, the water-rat stopped in the darkness, and then he quietly turned round and went back to the hut. "It will be hard work," said he "and there are enough of them." There were enough of them. They mended the dam by working all night and by working all day. [191] But, as they came back, a great wave of the freshet came pouring over the dam and, though the dam stood firm, the beavers were swept away,—away and away, down the river into the sea, and they died there. ”

“ A few oar-strokes distant lies a dam or water-break, where the whole lake is held under control by certain distant mills, towards which a sluggish stream goes winding on through miles of water-lilies. The old gray timbers of the dam are the natural resort of every boy or boatman within their reach; some come in pursuit of pickerel, some of turtles, some of bull-frogs, some of lilies, some of bathing. ”

“ By night and by day the river leans heavily against the dam. Tiny, sharp currents, like fingers, tear constantly at the structure, working always underneath. Hidden and undreamed-of eddies burrow beneath the dam; little river animals undermine it, ever so slightly, with tooth and claw.
At last an imperceptible opening is made. Streams rush down from the mountain to join the river; even raindrops lend their individually insignificant aid. All the forces of nature are subtly arrayed against the obstruction in the river channel. ”

“ In its downward course the brook irrigates many water meadows, and to drive the stream out upon them there are great wooden hatches. Sometimes a gang of men, discovering that there is a quantity of fish thereabouts, will force down a hatch, which at once shuts off or greatly diminishes the volume of water flowing down the brook, and then rapidly construct a dam across the current below it with the mud of the shore. Above this dam they thrash the water with poles and drive all the fish towards it, and then make a second dam above the first so as to enclose them in a short space. ”

“ For a little way above the dam the waters lay still and deep, with patches of long mosses, vines and rushes, waving in its quiet clearness—forming shadowy dens for lusty trout, while the open places—shining fields and lanes—reflected, as a mirror, the steep green-clad bluff, and the trees that bent far over until their drooping branches touched the gleaming surface. ”

“ The summer air was full to brimming over with sound––with the roar of the furious little torrent beneath, with the thunder of the sheet of cream and amber water falling over the face of the dam some fifty yards above, with the hiss and shriek of the saws in the big sawmill perched beside the dam. Yet through all the interwoven tissue of noise the note of the cow-bell made itself heard in the cabin. From behind the cabin arose a sonorous cry of hong-ka, honk-a-honk, and the snaky 24 black head of a big Canada goose appeared inquiringly around the corner. ”

“ This bank was carried out a dozen feet or more on either side of the stream, the ends being bent forward (toward the pond above) so as to make a very fine concave arch. On a small or quiet stream like this, beavers almost invariably build a straight dam; and where swift water calls for a stronger or curving structure, they present the convex side to the current; but here they had [300] reversed both rules, for some reason or impulse which I could not fathom,—except on the improbable assumption that the animals could foresee the end of their work from the beginning. ”

“ The long shallow dam is succeeded by pools to the old ford, above which is a rocky stretch, and then more pools, some floored with mud and shingle, others with naked rock. Coppices fringe one side of the stream the whole way, and the lavish falls from their overhanging branches go some way towards attracting large fish to these haunts. At flood-time few anglers are disappointed of heavy panniers, but the chief repute of the water is for evening fishing. ”

“ This undertow, meeting the next surface-wave on the bar which itself has made, forms part of the dam over which the latter breaks, as over an upright wall. The sea thus plays with the land, holding a sand-bar in its mouth awhile before it swallows it, as a cat plays with a mouse; but the fatal gripe is sure to come at last. The sea sends its rapacious east-wind to rob the land, but before the former has got far with its prey, the land sends its honest west-wind to recover some of its own. ”

“ When the dam is finished, not a drop of water escapes; their work is always well done."
"Nurse, do not beavers, and otters, and musk rats feel cold while living in the water; and do they not get wet?"
"No, my dear; they do not feel cold, and cannot get wet, for the thick coating of hair and down keeps them warm, and these animals, like ducks and geese, and all kinds of water-fowls, are supplied with a bag of oil, with which they dress their coats, and that throws off the moisture; for you know, Lady Mary, that oil and water will not mix. ”

“ They build very well arranged dwellings, although at first sight they look like mere piles of twigs, branches, and logs, heaped in disorder on a small dome of mud. At the edge of a pond each raises his own lodge, and there is no work by the colony in common. If, however, there is a question of inhabiting the bank of a shallow stream, certain preliminary works become necessary. The rodents establish a dam, so that they may possess a large sheet of water which may be of fair depth, and above all constant, not at the mercy of the rise and fall of the stream. ”

“ A dam has been driven across a perfectly limpid mountain stream; a wide open area has been cleared, levelled, strengthened with masonry, and divided into deep basins or reservoirs, through which the current continually flows. Hedges of hibiscus shine with crimson blossoms. Innumerable humming-birds glance to and fro among the trees and shrubs, and gardens and ponds are overhung by magnificent bamboos, which so astonished me by their size that I inquired if their height had been measured. ”

“ Even overnight, even in a few short hours, a stream has been known to swell from sudden rains or snow, bringing the water with a rush down steep mountain sides and carrying with it the logs that were left strewn on the slopes or near the bank. Men work with feverish haste to roll the logs into the stream. The whole is swept into the dam, the trigger is released at the right moment and the rush of water with its freight of logs sweeps through the open gate with a mighty roar, carrying its cargo for miles on down to the river. ”

“ When one, two, or more have arrived at the dam, the head of the raft is brought close to the sluice—the gate is opened—and away darts the raft, with a loud noise and fracas—dashing against the rocks—each joint, as it passes over the dam, rising up like the dorsal fin of a huge whale rolling about in the sea. In this way they are conveyed from the mountains to the Rhine—the raftlets augmenting in breadth, or number of trees, in proportion as the stream augments and enlarges into a river. As every mountain must have a valley, so every valley must have a rivulet. ”

“ And the dam over which I am driving now! This dam that erstwhile was a very blasphemy, an obscenity flung on the marshy meadows with their reeds, their cat-tails, and their wide-leaved swamp-dock clusters! It had been used by the winds as a veritable dumping ground for obnoxious weeds which grew and thrived on the marly clay while every other plant despised it! Not that I mean to decry weeds—far be it from me. When the goldenrod flings its velvet cushions along the edge of the copses, or when the dandelion spangles the meadows, they are things of beauty as well as any tulip or tiger-lily. ”