Part 15
The answer is, probably, that instinct has nothing to do with the matter; so we may as well put that prejudice out of our heads and open our eyes. Instincts are fairly constant, so far as we know them, while floods and lodges are endlessly variable. The height of a beaver’s lodge is largely the result of observation, I think, and of very simple observation. It is noticeable that, when lodges are built by different beaver families on the lower part of a stream, they are all comparatively high; but when they appear on the head-waters of the same stream, they are uniformly low. This because the spring rise of water at the mouth of a brook is commonly much greater than at its source.
Take your stand now at either place, and look keenly about. See those frayed alders; see that level line of gray spots where living trees have been barked by floating logs; see that other line of jetsam on the shore. Here, plain as your nose, are the high-water marks of this particular locality. Every spring these marks are renewed, and the highest is ever the most conspicuous. If you can see such signs, so also can a beaver, who has excellent eyes, and who is accustomed to use them in the darkness as well as in the light. That he does see them and is guided by them is suggested by the fact that Hamoosabik’s lodge, wherever you find it, has a dome which rises just above the high-water mark of the surrounding country. Again and again I have laid a straight stick as a level on top of a beaver house, turning it in different directions and sighting along it; and almost invariably, in one direction or another, I found my glance passing just above some striking line of barked trees or drift stuff which showed where the floods had reached their height.
A beaver does not use an artificial level, to be sure; but it is doubtless as easy for him as for anyone else to know, when he sits on a hummock, whether he is above or below the level of a plain mark confronting him. Such is the probability, since all creatures have subconscious powers of coördination. The probability increases when you observe the beaver at his building operations.
One evening, just after sundown, I had the luck to watch a family of beavers at work on their winter lodge. The place was solitary; the animals had long been undisturbed, and they were hurrying the last part of their work by day as well as by night, as they do in lonely regions. As they are very shy in the light (at night they will come within reach of your paddle, if you sit motionless in your canoe), I dared not approach near enough to follow the details of their work; but this much I saw plainly, that while four or five animals were industriously gathering material and piling it up, one large beaver sat almost constantly on top of the lodge. Occasionally he moved as if to receive a troublesome stick or place it properly; but for the most part he seemed to be doing nothing. Even when it became too dark to distinguish more than moving shadows, the silhouette of that quiet beaver stood out like a watchman against the twilight.
Simmo and Tomah both tell me that such a scene is typical of beaver families at work, and that the quiet animal I had noticed, far from doing nothing, was directing the whole job. These Indians can tell at a glance whether a dam was built by young or old beavers; and they say that, if the older members of a family are trapped or killed, the young make blundering attempt at providing winter quarters. If the family is undisturbed (a beaver family is made up, commonly, of three generations), one of the parent animals takes his place on top of any dam or lodge they are building, in order to direct the work and bring it to the right level. At the same time he acts as a watchman, his elevated position giving him advantage over the working beavers, which have the habit every few minutes of dropping whatever they may be doing and sitting up on their tails for a look all around.
It is very likely, therefore, that Hamoosabik does not follow a “blind” instinct when he can use his seeing eyes. While his lodge is rising he looks forth from the top of it, seeking familiar signs to guide him, and he keeps on looking as well as building until he knows that he is above the high-water mark of the neighborhood. And then, having reared his walls to clear the flood level, he lays the floor of his upper room and puts on the roof. If waters are normal, he will have a dry nest as long as he cares to use it; but if deep snows are followed by an unprecedented rise of water, he will probably be drowned out.
Such observation seems remarkable in a mere beast; but what shall we say of the beaver’s dam, of his transportation canal, of his channels scooped out of the bottom of a shallow pond, and of other works that deal intelligently with land or water levels? All these seem to call for eyes as well as instinct; and it is no more remarkable that a beaver should know, sitting on top of his lodge, that he is above or below a visible mark than that he should run a winding canal half a mile, as he often does, and keep the water level right at every point.
Even the simplest of the beaver’s works, his felling of trees, seems to indicate a measure of observation. When he cuts a leaning tree he always gnaws first and deepest on the leaning side, to which the tree will fall. But if the tree is straight up and down, like a clever cat’s tail, he cannot judge its inclination, and often makes a mistake, throwing the tree to the wrong side or “lodging” it against another tree, as the best woodsman may do now and then. When a beaver tackles such a doubtful tree, he gnaws evenly around the whole butt, sinking the cut deepest in the middle, shaping it like an hourglass. As he works, he often stops cutting to look aloft, raising himself with forepaws against the trunk or sitting erect at a little distance, studying the tree with unblinking eyes as if to learn for his own safety which way it intends to go. One who has ever seen an old beaver thus sitting up on his tail, apparently to get the slant of a towering poplar before he fells it, has no difficulty in accepting the notion that the same beaver will recognize high-water mark when it lies directly under his nose.
At times Hamoosabik must be sadly puzzled by his primitive observation, especially where man interferes with nature, leaving strange marks to which animals are not accustomed. Twice have I found surprising lodges built on the shore of artificial ponds, where a new high-water mark showed above the old flood level. These ponds had been made by lumbermen, who raised the water five or six feet in order to have a “head” for driving their logs. When their work ended they opened the gates of their dam and went away, leaving the pond to return to its former size. Then beavers came back to the solitude, and used the pond for a winter home. When they examined the shores before building their lodge (it is their habit to explore a place thoroughly), they must have seen the dead trees, the barked trees, the line of jetsam high and dry, all plainly indicating where the flood had been. But there was nothing to tell the beavers why the water had risen so much higher here than in other lakes, and they were evidently guided by such signs as they could understand. In each case they built their lodge not on low swampy ground, as they habitually do, but on a dry bank, and the dome of the lodge rose just above the artificial water level.
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Another question meets you when you examine Hamoosabik’s digging operations, especially his canals, which are the most intelligent of all his works. It is noticeable that beavers cut their food-wood above their storehouse whenever that is possible, and so make use of the current in transportation; but when the selected grove of poplars stands back from the shore, then the beavers dig a canal from their pond or stream to their source of supply. And a very remarkable canal it is, with clean-cut sides, about two feet wide and a little less in depth, in which the water stands quiet, showing a perfect level.
Such a canal goes straight as a string in one place, or winds around an obstruction in another, always following the most even ground; and it ends at the beaver’s grove, or as near as he can get and bring the water with him. He is a powerful worker, handling logs of astonishing size with the help of his mate; but you will not catch him rolling or dragging a thing if he can possibly float it. Even the stones which he uses in weighting his dam are moved under water, where they are much lighter than on land.
It is commonly assumed that Hamoosabik digs a canal in order to have an easy way of transporting his wood. He certainly uses it for that purpose; but he has another end in view, I think, when he begins his digging. It should be remembered that beavers, though tireless workers, like to loaf and play as well as other wood folk. They never work for the sake of working; yet one often sees a canal that represents an enormous amount of labor, so apparently superfluous that one wonders what the animals were thinking of. It is not merely the length of such a canal which puzzles one, but the roundabout course it must follow in order to keep on level ground. It sometimes happens, when food-wood stands on a hillock within a few rods of the pond, that the beavers will run their canal four or five times that distance, avoiding the rising ground and approaching the hill from the farther side. Your first thought, when you meet such a work, is that the animals could have hauled their wood down the easy slope in half the time they spent preparing for water transportation.
I recall one canal on which a deal of labor, the most skillful I ever saw in an animal, had been expended for what seemed a very small result. The beavers were building a dam on a trout stream bordered by primeval forest. About two hundred yards west of the stream the forest opened upon a little swale, in which grew plentiful alders, the beavers’ favorite building material. Evidently they found the alders when they explored the neighborhood, and decided they must have them. Their dam was a small one, and it would have been a simple matter to drag a sufficient supply of brush through the woods; but the beavers chose the harder task of digging a six-hundred-foot canal from the stream to the alder swale.
That canal was an amazing piece of work. Not ten yards of it were straight, and could not be straight because of trees or other obstacles; yet it held a course true as a compass from the pool above the dam to the objective point, which was hidden from sight in the big woods. In one place it ran under an immense tree that stood on a hummock. The central roots were cut away; but other great roots were left arching down on either side, supporting the tree as a living bridge. In another place a pine log twenty-inches thick, its heart still sound, was encountered beneath the mossy mold, squarely athwart the course of the canal. The beavers had cut through other logs that lay on the surface; but the buried pine did not interfere with their plan or purpose, apparently. After clearing away the earth on top of the log, they dug an opening beneath it and continued their ditch on the other side, thus allowing the water to flow over and under the obstruction. When the time came for towing their material through the canal, the slippery top of the pine offered hardly more resistance than the water itself.
Here the beavers had not only spared themselves unnecessary labor, but had shown a rare degree of intelligence in the process. So the question arises, Why did they bother with a canal at all, since they move material overland on occasion, and they could have dragged a supply of alders to the stream with half the effort required for their extraordinary digging?
I had camped weeks near this beaver family, puzzled by their work, before answer came from an unexpected actor. Lynxes were uncommonly abundant; they prowl by night, when the beaver works, and they are ravenously fond of young-beaver meat. They suggest the fact that all the beaver’s works are intended primarily for security, and that the element of safety is probably uppermost in his mind when he digs a canal. On land he is slow, clumsy, almost defenseless; in the water he is at home, a match for any animal at either swimming or fighting. Undoubtedly he feels safer in his canal, where he can defend himself or get away under water, than he can possibly feel in woods or meadows that offer him no refuge from his enemies. So he always starts digging at the stream’s edge, and works toward his grove of wood (never in the opposite direction, from grove to stream), and so the friendly water goes with him, filling his canal as fast as he digs it, offering him a way of escape at every instant.
It is significant, in this connection, that beavers do not use a pond that has no outlet or inlet. Hundreds of such spring-fed ponds are scattered through the north, some of them desirable from a beaver’s viewpoint; yet I have never found a sign to indicate that Hamoosabik has visited them. But if the pond have even a trickle of water running out of it, he will surely find it, no matter how distant it may be. The method is very simple, I think. Swimming up or down river on his endless exploration (for Hamoosabik is the pioneer among wood folk, forever pushing out himself or sending forth his progeny to new regions), he catches a flavor of different water, and follows it from river to brook, from brook to runlet, till he finds the pond it came from. And if he likes the place, after exploring all its watershed, he will bring his mate or family there for winter quarters.
In his journeying from place to place, likewise, Hamoosabik invariably follows the watercourses. His objective may be only a mile away in a direct line; but to reach it he will travel five or ten times that distance, making his way down one brook or river and up another to the pond he is seeking. If a brook is shallow, the beavers hurry over it, leaving only a few tracks to mark their passing; but if they intend to use the brook again, either for gathering building material or as a trail between their new home and the colony from which they came, they deepen the channel here and there by dam or excavation. And commonly at such places there is a hidden burrow, with entrance under water, in which the beavers may take refuge if surprised by their enemies.
These emergency burrows, which Hamoosabik prepares beside a regular trail or near the site of his lodge, always start from the bottom of the pond or stream, and slant upward to a spot under a tree’s roots, above high-water level. There he excavates a rough den, a little den if he has only a mate to consider, or a big den if he has brought a family with him. Finding such a refuge with its secret approach, one is reminded of New England pioneers, who built hiding places in their chimneys or cellars as a precaution against Indian attack.
When Hamoosabik needs deeper water for storing his winter food, he makes a pond by damming the stream below his lodge; but if he finds plentiful food near a natural lake having depth enough for safety, he uses that lake just as it is, thus avoiding the difficult job of building a dam. If he makes a pond that proves too shallow for his need or too slow in filling (the latter occurs frequently in dry weather), instead of running the risk of being frozen in before he is ready for winter he will dig channels in the bottom of his pond, and so provide the needed depth of water in another way. For winter lodging he must have a solid structure of two rooms, lower entrance hall and upper living room, with a stairway between;[3] but when he occasionally builds a house for summer use he is content with a simpler shack, as if it were not worth while to build solidly for a few weeks of pleasant weather.
The walls of a summer house are lightly constructed of grass and mud, over which a few weathered sticks may be thrown for the apparent purpose of concealment. The interior is a single large room, with a floor that either slants upward from the front or water side or else is arranged in two distinct levels or benches. The slanting floor is the work of a young pair of beavers, as a rule; the two-bench arrangement indicates that the lodge is used by more experienced builders. From the lower bench a passage through the wall opens directly on the air, at the brink of the stream; from the upper bench a hidden tunnel leads down through the bank, and emerges in deep water.
One curious fact about these summer houses is that a beaver always enters by the open door, and always comes out by the subaqueous tunnel. One can understand why he should enter by the door, because he stops just within to let water drain from his outer coat before climbing to his dry nest. The tunnel goes direct to the sleeping bench; if he entered by that route, he must drag a lot of water into his bed. But that Hamoosabik should refuse to go out of his open door appears as an oddity, until by long watching you become acquainted with his cautious habits. Thus, if you surprise him outside his summer house, he will not enter it (showing you where it is) so long as you remain in the neighborhood, but will hide in one of his refuge burrows. And if you surprise him at home, he will make an unseen exit under your very eyes. This is the method of it, when you watch from your canoe in the summer twilight:
During the day the family sleep in their nests of grass on the upper bench, all but one old beaver, who is on guard near the entrance; for that open door of the summer house (a winter lodge has no opening in the walls) may invite an intruder or an enemy. As the shadows deepen into dusk, and waters fill with soft colors of the afterglow, the watchman bestirs himself for his night’s work; but still he is careful not to show himself at the open door. Instead of making the easy and obvious exit, he climbs the sleeping bench, slips down through the tunnel, and lifts eyes and ears among the shadows under the bank, where he cannot be seen. After watching there awhile, he sinks without a sound and swims away under water. You are watching the lodge keenly when your eye catches a ripple breaking the reflection of sky and sleeping woods, or your ear hears a low call, like the flutter of a dry leaf in the wind. There is your beaver, at last, not where you looked for him at the door of his lodge, but far away on the other side of your canoe!
Again, as showing the beaver’s grasp of a natural situation, when he finds a wild meadow with a stream meandering through it, and decides to use it for winter quarters, his work is so simple as to appear like play. That meadow was once, undoubtedly, the bed of a beaver pond; it became a meadow because of rich soil which the stream brought down in flood, year after year, filling the pond and giving wild grasses a chance to root and blossom there. The beaver may not know this ancient history, that the perfect place he selects was made perfect by an ancestor who pioneered this region long ago; but he does know, or soon finds out, that water, soil, food-wood, building material,--everything is precisely suited to his needs. After locating his grove of poplar, he goes down to the foot of the meadow and builds a dam across the stream. Since he is careful to pick the best spot for building, the chances are that he will place the dam where his unknown ancestor placed it; if you dig beneath the new structure, you will find the solid foundation of the old. As the water flows back, being checked in its onward course by the dam, the grasses slowly disappear until their heads are covered, and presently the meadow is a beaver pond once more. Then without hurry or anxiety a goodly store of food is gathered, a lodge rises on the shore, and the family have all things ready before winter comes and the ice locks them in.
It is a different story when Hamoosabik settles in a new place, which no beaver ever used before, and then you see what pioneer stuff is in him. What with building his dam (always a troublesome element in a new place), or getting the right level to his pond or the proper height to his lodge, or running safety burrows and transportation canal through soil that may show rocks or clay where he expected easy digging, our little settler is up to his ears in work, and faces a new problem every evening. He is still working and planning, adding a last stick to the food pile or putting a spillway on the dam, which already gives him more water than he needs, when as he rises from his tunnel on a nipping night he bumps his head against the top of his pond, and knows that he is frozen in. Then, seeing he has done all a beaver can do, he settles down with pioneer courage to face the winter, the lazy winter, when from dawn to dusk he will be sociable with his family, and from dusk to dawn they will all sleep without fear in their warm living room.
What a curious life they live for six long months every year! By night the lodge and tunnel must be places of almost absolute darkness; yet even after nightfall, should the need arise, beavers go to every part of their pond and return, finding their way without seeing, I think, by their unerring sense of locality. By day a little light filters through the walls of the lodge, enough to make the gloom visible, and then the beavers use their eyes once more,--wonderful eyes, which adapt themselves alternately to thick darkness and the blinding glare of sunlight on pure snow.
No sooner does the sun rise than beavers, young and old, are all stirring eagerly, cleaning their house, exploring the pond under the ice for a relish of lily roots, bringing in their daily fare of bark, and finally, when hunger and need of exercise are satisfied, gathering in the big living room for an hour of sociability. At such a time, if you approach softly from leeward and lay your ear to the lodge, you may hear a low, rapidly whispered _thup-a, thup-a, thup-a, thup-a_, which is made by the vibration of a beaver’s lips when he is surprised or pleased. There is a moment of silence after the call, then a babel of voices, squeaky or whining or bumbling voices, as if little and big beavers were talking all at once.
As the short winter day fades into the long night, the gloom thickens in the arched living room. Voices are hushed; not a sound comes from the lodge, which is covered with a blanket of snow. In the forest an owl hoots, or a wolf wails to the sky, or a stealthy tread is heard as some night prowler climbs the lodge for a sniff at the ventilator. That hungry beast is only three or four feet away; but the beavers care not; their house is burglar-proof. Its one doorway leads down through the bank to water under the ice, and no enemy can come from that direction. When the prowler goes away, an old beaver stirs himself; like a watchman he goes down the stairway to the tunnel, finds the water at its safe level, comes back whining a low call, and curls up in his bed with a satisfied grunt. Then the family fall asleep, each in his own nest; in their ears is a little song, the endless song of the spillway with its quieting burden, _All’s well with our world; all’s well!_