Part 17
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!_
Yes, a curious life, monotonous and dismal, or cheery and forever expectant, according as you view it from without or from within. Coming upon the lodge now, you see only a mound of white swelling above the expanse of pond or beaver meadow, and beyond stand ranks of evergreen, dark and silent. That mound is as dull or dead as anything else in the somber landscape until, as you pass indifferently, your eye catches a wisp of vapor, like a breath, or your ear detects a faint _plop, plop_, as bodies slide down into the tunnel one after another. In an instant the whole landscape changes, as it always does change, and glow and fall away into the golden frame of a picture, when a living creature moves across the face of it. The mound is no longer a dull mass, but the fascinating abode of life; the wilderness sun rises or sets not on snow and ice, but on work, play, companionship, and all else that makes life the one interesting and eternally mysterious thing in the universe.
So when my friend of the telescope looks in, as I write this, and tries to stir my lagging enthusiasm for the satellites of Jupiter or the vastness of the Milky Way, I find myself thinking that Jupiter might allure me if there were a beaver lodge on its meadows, and that I shall never feel any human interest in stars or interstellar spaces until someone discovers a squirrel track on the Milky Way.
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[Illustration]
COMEDIANS ALL
While watching a chipmunk one summer, a fascinating little fellow whom I had tamed till he would sit on my knee to beg with eloquent eyes for nuts or rice or sweet chocolate, I learned first the location of his den, and then, when he abandoned it for a roomy winter storehouse, the whole secret of his building.
For years our naturalists have debated the mystery of the squirrel’s digging, how he can excavate den or tunnel without leaving fresh earth at the entrance to betray him; but when I was a boy any farmer’s lad in the countryside could have given instant explanation. “How does a chipmunk dig a hole without leaving any earth at the entrance? Why, very simply; he begins at the other end.” And though the answer is true, beyond cavil or gainsaying, some doubting Thomas who clothes all animal action in a mysterious fog of instinct is bound to make hocus-pocus of the chipmunk’s art by demanding, “But how does he get to the other end?”
That also is simple; but you will not appreciate the answer till you know by observation that a chipmunk never digs a den. He trusts nature for that, contenting himself with furnishing a suitable tunnel and doorway.
In some way (probably by tapping the earth, as a woodpecker sounds a limb to see if it be hollow) Chick’weesep learns that there is a den under a certain tree or rock, a natural hollow engineered by frost or rain or settling earth, which by a little alteration may be made to serve his double need of room and safety. At any rate, it will do no harm to go down and have a look at it; he can find another if he is not satisfied.
Starting at a distance, for a chipmunk wants no sign of occupation near his den, he runs a slanting shaft down to the concealed hollow, throwing the earth from his excavation in a loose heap about the spot where he began to dig. Later he may scatter that heap if it looks conspicuous; but since he does not intend to use this shaft as an entrance, the disturbed earth gives him little concern. Next he modifies the natural hollow by a day’s or a week’s operations, making it over into a living room with two or three adjacent storerooms; and the final step is to run a tunnel from the finished den upward to the air. The first or exploration shaft is as straight as he can make it; but the new tunnel takes a devious course, following under roots where digging is very easy or where there is sometimes no digging at all. Also it heads well away from the den, so that when it reaches the surface the outlet is far from the scene of the first digging. A part of the earth from this tunnel is thrown back into the den, and from there is pushed into the working shaft, which is always filled solidly from end to end. The finished den has but one entrance, therefore; and there is no earth about the doorway for the simple reason that the whole tunnel was excavated from below.
Such is the process in our cleared lands, where Chick’weesep’s doorway may be in the middle of a lawn, while his storehouse is far away in a hidden drain or under a buried bowlder. On such lands, if you find the squirrel’s doorway and search the ground in all directions, you may discover at a considerable distance a flattened heap of earth, which will mean nothing unless you know the chipmunk’s secret. That heap speaks of the time when he ran an exploration shaft down to his unseen den; it tells also, if you listen to it, of the sad way in which civilization has interfered with the perfection of the squirrel’s craft. He must leave that plain sign of his work and presence (unwillingly, I think) because so much clearing has been done without consulting his small needs that he can find no convenient place to hide a quantity of fresh earth.
In the deep woods, where Chick’weesep’s ancestors learned to construct winter quarters, such a telltale sign is never found. The forest floor offers him a thousand hiding places; before beginning to dig he slips under a root or rock or moldering log, and from there runs a shaft to his objective point. The earth from his digging is packed away under mossy logs, where no eyes but his ever see it; and when the den is ready the working shaft is filled by earth from a new tunnel, as Chick’weesep bores his way toward the point where he intends to have his doorway. Like the beaver, he seems to have a perfect sense of direction; engineering his tunnel under the earth, turning this way or that to follow a friendly root, he seems to know precisely where he is coming out. From watching him several times when he was busy about his den, I think that he selects a spot for his doorway before starting his tunnel; but that is a doubtful matter of which no man has any assurance.
To fashion such a den and fill its storeroom to overflowing in the beautiful autumn days must be a joyous experience, I fancy, even to an unthinking squirrel. On a farm the happiest days of the year are not those of spring planting (for sowing of seeds is an artificial work, the result of our thought and calculation), but rather in the rewardful autumn, when man’s primitive instincts are stirred as he gathers the fruits of the earth into his winter storehouse. Likewise in the wilderness, the happiest days which ever come to a man are those in which he builds a shack by the labor of his hands, fashions a rude fireplace of rock or clay, lays in his provisions, and then, with eager anticipation of snappy days afield or stormy nights before the fire, looks upon his finished work and says in his heart, “Now welcome, winter!” If spoiled man can feel this instinctive joy of providing for creature comfort, why not an unspoiled squirrel also? In the woods all natural creatures, man included, seem to be made of the same happy, elemental stuff.