The Project Gutenberg eBook, In Beaver World, by Enos Abijah Mills

IN BEAVER WORLD
ENOS A. MILLS

BEAVER WORLD

In Beaver World

By
Enos A. Mills

With Illustrations from Photographs
by the Author

Boston and New York
Houghton Mifflin Company
The Riverside Press Cambridge
Mdccccxiii

COPYRIGHT, 1913, BY ENOS A. MILLS
ALL RIGHTS RESERVED
Published March 1913

To
J. Horace McFarland

Preface

This book is the result of beaver studies which cover a period of twenty-seven years. During these years I have rambled through every State in the Union and visited Mexico, Canada, and Alaska. In the course of these rambles notice was taken of trees, birds, flowers, glaciers, and bears, and studious attention devoted to the beaver. No opportunity for beaver study was missed, and many a long journey was made for the purpose of investigating the conditions in live colonies or in making measurements in the ruins of old ones. These investigations were made during every season of the year, and often a week was spent in one colony. I have seen beaver at work scores of times, and on a few occasions dozens at one time.

Beaver have been my neighbors since I was a boy. At any time during the past twenty-five years I could go from my cabin on the slope of Long’s Peak, Colorado, to a number of colonies within fifteen minutes. Studies were carried on in these near-by colonies in spring, summer, autumn, and winter.

One autumn my entire time was spent in making observations and watching the activities of beaver in fourteen colonies. Sixty-four days in succession I visited these colonies, three of them twice daily. These daily investigations enabled me to see the preparations for winter from beginning to end. They also enabled me to understand details which with infrequent visits I could not have even discovered. During this autumn I saw two houses built and a number of old ones repaired and plastered. I also saw the digging of one canal, the repairing of a number of old dams, and the building of two new ones. In three of these colonies I tallied each day the additional number of trees cut for harvest. I saw many trees felled, and noted the manner in which they were moved by land and floated by water.

The greater number of the papers in this book were written especially for it. Parts of the others have been used in my books Wild Life on the Rockies and The Spell of the Rockies. “The Beaver’s Engineering” appeared in the Saturday Evening Post, and I am indebted to McClure’s for permission to use “Beaver Pioneers.”

Beaver works are of economical and educational value besides adding a charm to the wilds. The beaver is a persistent practicer of conservation and should not perish from the hills and mountains of our land. Altogether the beaver has so many interesting ways, is so useful, skillful, practical, and picturesque that his life and his deeds deserve a larger place in literature and in our hearts.

E. A. M.

Contents

Illustrations

Working like a Beaver

One September day I saw a number of beaver at work upon a half-finished house. One part of the house had been carried up about two feet above the water, and against this were leaned numerous sticks, which stood upon the top of the foundation just above water-level. After these sticks were arranged, they were covered with turf and mud which the beaver scooped from the bottom of the pond. In bringing this earth covering up, the beaver invariably came out of the water at a given point, and over a short slide worn on the side of the house climbed up to the height where they were to deposit their load, which was carried in the fore paws. Then they edged round and put the mud-ball upon the house. From this point they descended directly to the water, but when they emerged with the next handful, they came out at the bottom of the slide, and again climbed up it.

The beaver often does a large amount of work in a short time. A small dam may be built up in a few nights, or a number of trees felled, or possibly a long burrow or tunnel clawed in the earth during a brief period. In most cases, however, beaver works of magnitude are monuments of old days, and have required a long time to construct, being probably the work of more than one generation. It is rare for a large dam or canal to be constructed in one season. A thousand feet of dam is the accumulated work of years. An aged beaver may have lived all his life in one locality, born in the house in which his parents were born, and he might rise upon the thousand-foot dam which held his pond and say, “My grandparents half a dozen centuries ago commenced this dam, and I do not know which one of my ancestors completed it.”

Although the beaver is a tireless and an effective worker, he does not work unless there is need to do so. Usually his summer is a rambling vacation spent away from home. His longest period of labor is during September and October, when the harvest is gathered and general preparations made for the long winter. Baby beavers take part in the harvest-getting, though probably without accomplishing very much. During most winters he has weeks of routine in the house and ponds with nothing urgent to do except sleep and eat.

He works not only tooth and nail, but tooth and tail. The tail is one of the most conspicuous organs of the beaver. Volumes have been written concerning it. It is nearly flat, is black in color, and is a convenient and much-used appendage. It serves for a rudder, a stool, a prop, a scull, and a signal club. It may be used for a trowel, but I have never seen it so used. It serves one purpose that apparently has not been discussed in print; on a few occasions I have seen a beaver carry a small daub of mud or some sticks clasped between the tail and the belly. It gives this awkward animal increased awkwardness and even an uncouth appearance to see him humped up, with tail tucked between his legs, in order to clasp something between it and his belly.

He is accomplished in the use of arms and hands. With hands he is able to hold sticks and handle them with great dexterity. Like any clawing animal he uses his hands or fore paws, to dig holes or tunnels and to excavate burrows and water-basins. His hind feet are the chief propelling power in swimming, although the tail, which may be turned almost on edge and is capable of diagonal movement, is sometimes brought into play as a scull when the beaver is at his swiftest. In the water beaver move about freely and apparently with the greatest enjoyment. They are delightfully swift and agile swimmers, in decided contrast with their awkward slowness upon the ground. They can swim two hundred yards under water without once coming to the surface, and have the ability to remain under water from five to ten minutes. On one occasion a beaver remained under water longer than eleven minutes, and came to the top none the worse, apparently, for this long period of suspended breathing.

It is in standing erect that the beaver is at his best. In this attitude the awkwardness and the dull appearance of all-fours are absent, and he is a statue of alertness. With feet parallel and in line, tail at right angles to the body and resting horizontally on the ground, and hands held against the breast, he has the happy and childish eagerness of a standing chipmunk, and the alert and capable attitude of an erect and listening grizzly bear.

A YOUNG BEAVER ON THE SIDE OF A BEAVER HOUSE

The beaver is larger than most people imagine. Mature male specimens are about thirty-eight inches in length and weigh about thirty-eight pounds, but occasionally one is found that weighs seventy or more pounds. Ten mature males which I measured in the Rocky Mountains showed an average length of forty inches, with an average weight of forty-seven pounds. The tails of these ten averaged ten inches in length, four and a half inches in width across the centre, and one inch in thickness. Behind the shoulders the average circumference was twenty-one inches, and around the abdomen twenty-eight. Ten mature females which I measured were only a trifle smaller.

There are twenty teeth; in each jaw there are eight molars and two incisors. The four front teeth of the beaver are large, orange-colored, strong, and have a self-sharpening edge of enamel. The ears are very short and rounded. The sense of smell appears to be the most highly developed of the beaver’s senses. Next to this, that of hearing appears to be the most informational. The eyes are weak. The hind feet are large and webbed, and resemble those of a goose. The second claw of each hind foot is double, and is used in combing the fur and in dislodging the parasites from the skin. The fore paws of the beaver are handlike, and have long, strong claws. They are used very much after the fashion in which monkeys use their hands, and serve a number of purposes.

The color of the beaver is a reddish brown, sometimes shading into a very dark brown. Occasional specimens are white or black. The beaver is not a handsome animal, and when in action on the land he is awkward. The black skin which covers his tail appears to be covered with scales; the skin merely has this form and appearance, the scales do not exist. The tail somewhat resembles the end of an oar.

The all-important tools of this workman are his four orange-colored front teeth. These are edge-tools that are adaptable and self-sharpening. They are set in strong jaws and operated by powerful muscles. Thus equipped, he can easily cut wood. These teeth grow with surprising rapidity. If accident befalls them, so that the upper and the lower fail to bear and wear, they will grow by each other and in a short time become of an uncanny length. I have found several dead beaver who had apparently died of starvation; their teeth overlapped with jaws wide open and thus prevented their procuring food. For a time I possessed an overgrown tooth that was crescent-shaped and a trifle more than six inches long.

Pounds considered, the beaver is a powerful animal, and over a rough trail will drag objects of twice his own weight or roll a log-section of gigantic size. Up a strong current he will tow an eighty- or one-hundred-pound sapling without apparent effort. Three or four have rolled a one-hundred-and-twenty-pound boulder into place in the dam. Commonly he does things at opportune times and in the easiest way. His energy is not wasted in building a dam where one is not needed nor in constructive work in times of high water. He accepts deep water as a matter of fact and constructs dams to make shallow places deep.

Beaver food is largely inner bark of deciduous or broad-leaved trees. Foremost among these trees which they use for food is the aspen, although the cottonwood and willow are eaten almost as freely. The bark of the birch, alder, maple, box-elder, and a number of other trees is also used. Except in times of dire emergency the beaver will not eat the bark of the pine, spruce, or fir tree. It is fortunate that the trees which the beaver fell and use for food or building purposes are water-loving trees, which not only sprout from both stump and root, but grow with exceeding rapidity. Among other lesser foods used are berries, mushrooms, sedge, grass, and the leaves and stalks of a number of plants. In winter dried grass and leaves are sometimes used, and in this season the rootstocks of the pond-lily and the roots of the willow, alder, birch, and other water-loving trees that may be got from the bottom of the pond. Beaver are vegetarians; they do not eat fish or flesh.

Apparently beaver prefer to cut trees that are less than six inches in diameter, and where slender poles abound it is rare for anything to be cut of more than four inches. But it is not uncommon to see trees felled that are from twelve to fifteen inches in diameter. In my possession are three beaver-cut stumps each of which has a greater diameter than eighteen inches, the largest being thirty-four inches. The largest beaver-cut stump that I have ever measured was on the Jefferson River in Montana, near the mouth of Pipestone Creek. This was three feet six inches in diameter.

The beaver sits upright with fore paws against the tree, or clasping it; half squatting on his hind legs, with tail either extending behind as a prop or folded beneath him as a seat, he tilts his head from side to side and makes deep bites into the tree about sixteen inches above the ground. In the overwhelming majority of beaver-cut trees that I have seen, most of the cutting was done from one side,—from one seat as it were. Though the notch taken out was rudely done, it was after the fashion of the axe-man. The beaver bites above and below, then, driving his teeth behind the piece thus cut off, will wedge, pry, or pull out the chip. Ofttimes in doing this he appears to use his jaw as a lever. With the aspen, or with other trees equally soft, about one hour is required to gnaw down a four-inch sapling. With one bite he will snip off a limb from half to three quarters of an inch in diameter.

After a tree is felled on land, the limbs are cut off and the trunk is gnawed into sections. The length of these sections appears to depend upon the size of the tree-trunk and also the distance to the water, the number of beaver to assist in its transportation, and the character of the trail. Commonly a six- or eight-inch tree is cut into lengths of about four to six feet. If the tree falls into the water of the pond or the canal, it is, if the limbs are not too long, transported butt foremost to the desired spot in its uncut, untrimmed entirety. Ofttimes with a large tree the trunk is left and only the limbs taken.

The green wood which the beaver uses for his winter’s food-supply is stored on the bottom of the pond. How does he sink it to the bottom? There is an old and oft-repeated tale which says that the beaver sucks the air from the green wood so as to sink it promptly. Another tale has it that the beaver dives to the bottom carrying with him a green stick which he thrusts into the mud and it is thus anchored. Apparently the method is a simple one. The green wood stored is almost as heavy as water, and once in the pond it becomes water-logged and sinks in a short time; however, the first pieces stored are commonly large, heavy chunks, which are forced to the bottom by piling others on top of them. Frequently the first few pieces of the food-pile consist of entire trees, limbs and all. These usually are placed in a rude circle with butts inward and tops outward. This forms an entangling foundation which holds in place the smaller stuff piled thereon.

Most willows by beaver colonies are small and comparatively light. These do not sink readily, are not easily managed, and are rarely used in the bottom of the pile. Commonly, when these light cuttings are gathered into the food-pile, they are laid on top, where numerous up-thrusting limbs entangle and hold them. The foundation and larger portion of the food-pile are formed of heavy pieces of aspen, alder, or some other stream-side tree, which cannot be moved out of place by an ordinary wind or water-current and which quickly sink to the bottom.

Among enemies of this fur-clad fellow are the wolverine, the otter, the lion, the lynx, the coyote, the wolf, and the bear. Hawks and owls occasionally capture a young beaver. Beaver spend much time dressing their fur and bathing, as they are harassed by lice and other parasites. At rare intervals they are afflicted with disease. They live from twelve to fifteen years and sometimes longer. Man is the worst enemy of the beaver.

A thousand trappers unite to tell the same pitiable tale of a trapped beaver’s last moments. If the animal has not succeeded in drowning himself or tearing off a foot and escaping, the trapper smashes the beaver’s head with his hatchet. The beaver, instead of trying to rend the man with sharp cutting teeth, raises himself and with upraised hand tries to ward off the death-blow. Instead of one blow, a young trapper frequently has to give two or three, but the beaver receives them without a struggle or a sound, and dies while vainly trying to shield his head with both hands.

Justly renowned for his industry, the beaver is a master of the fine art of rest. He has many a vacation and conserves his energies. He keeps his fur clean and his house in a sanitary condition. Ever in good condition, he is ready at all times for hard work and is capable of efficient work over long periods. He is ready for emergencies.

As animal life goes, that of the beaver stands among the best. His life is full of industry and is rich in repose. He is home-loving and avoids fighting. His lot is cast in poetic places.

The beaver has a rich birthright, though born in a windowless hut of mud. Close to the primeval place of his birth the wild folk of both woods and water meet and often mingle. Around are the ever-changing and never-ending scenes and silences of the water or the shore. Beaver grow up with the many-sided wild, playing amid the brilliant flowers and great boulders, in the piles of driftwood and among the fallen logs on the forest’s mysterious edge. They learn to swim and slide, to dive quickly and deeply from sight, to sleep, and to rest moveless in the sunshine; ever listening to the strong, harmonious stir of wind and water, living with the stars in the sky and the stars in the pond; beginning serious life when brilliant clouds of color enrich autumn’s hills; helping to harvest the trees that wear the robes of gold, while the birds go by for the southland in the reflective autumn days. If Mother Nature should ever call me to live upon another planet, I could wish that I might be born a beaver, to inhabit a house in the water.

Our Friend the Beaver

One bright autumn afternoon I peered down into a little meadow by a beaver pond. This meadow was grass-covered and free from willows. In it seven or eight beaver were at work along a new canal. Each kept his place and appeared to have a section in which he did his digging. For more than half an hour I watched them clawing out the earth and grass-roots and lifting it out in double handfuls and piling it in an orderly line along the canal-bank. While I was watching a worker at one end of this line, two others clinched in a fight. The fighters made no sound except a subdued guttural mumbling as they rolled about in a struggle. The other workers, to my astonishment, paid not the slightest attention to this fight, but each attended to his own affairs. After two or three minutes the belligerents broke away; one squatted down breathing heavily, while the other, with bloody tail, dragged himself off and plunged into the pond. This was the first beaver fight that I had ever seen.

Beaver may well be called the silent workers. No matter how numerous, or crowded, or busy they are, their work goes on without a word and apparently without a sign. Although I have seen them at work scores of times, in the twilight and in the daylight, singly, in pairs, and by the dozens, doing the many kinds of work which beaver perform, yet this work has always gone quietly and without any visible evidences of management. Each one is capable of acting independently. Since the quality of his work improves as the beaver increases his experience, it appears natural and probable that each colony of beaver has a leader who plans and directs the work. I am familiar with a number of instances which strongly indicate leadership. In times of emergency, when an entire colony is forced to emigrate, a beaver—and usually an aged one—takes the lead, and wherever he goes the others willingly follow.

Whatever may have been the custom of beaver in the past, at present large numbers sometimes coöperate in accomplishing community work. It used to be believed, and possibly it was true, that only the members of a family, or the beaver of one house, united in doing the general work of the colony. It was a common belief that seven beaver inhabited a house; perhaps eight was the number of the Rocky Mountain region. At the present time the number in a house is from one to thirty.

Beaver have been driven from most of the streams and lake-shores, and now maintain themselves with difficulty in the places which they inhabit. In surviving they probably have had to sacrifice a few old customs and to adopt some new ones, and it is likely that these changes sometimes call for larger houses so as to care for the increased number of beaver which conditions now compel to live in one locality. A number of instances have come under my notice where beaver were driven from their colony either by fire or by the aggressiveness of trappers; these moved on to other scenes, where they cast their lot with the beaver of another colony, and apparently were received with every welcome. Immediately after the arrival of the immigrants, enlargements were at once commenced, apparently to accommodate the new-comers permanently.

One autumn, while following the Lewis and Clark trail with a pack horse in western Montana, I made camp one evening with a trapper who gave me a young beaver. He was about one month old, and ate twigs and bark as naturally as though he had long eaten them. I named him “Diver,” and in a short time he was as chummy as a young puppy. Of an evening he played about the camp and often swam in the near-by water. At times he played at dam-building, and frequently displayed his accomplishment of felling wonderful trees that were about the size of a lead pencil. He never failed to come promptly when I whistled for him. At night he crouched near my camp, usually packing himself under the edge of the canvas on which I spread my bedding. Atop the pack on the horse’s back he traveled,—a ride which he evidently enjoyed. He was never in a hurry to be taken off, and at moving time he was always waiting eagerly to be lifted on. As soon as he noticed me arranging the pack, he came close, and before I was quite ready for him, he rose up, extending his hands in rapid succession beggingly, and with a whining sort of muttering pleaded to be lifted at once to his seat on the pack.

A YOUNG BEAVER SUNNING HIMSELF

He had a bad fright one evening. About one hour before sundown we had encamped as usual alongside a stream. He entered the water and after swimming about for a time, taking a dozen or so merry dives, he crossed to the opposite side. In plain view, only fifty feet away, I watched him as he busily dug out roots of the Oregon grape and then stopped leisurely to eat them. While he was thus engaged, a coyote made a dash for him from behind a boulder. Diver dodged, and the coyote missed. Giving a wail like a frightened child, my youngster rolled into the stream and dived. Presently he scrambled out of the water near me and made haste to crawl under my coat-tail behind the log on which I sat.

The nearest beaver pond was a quarter of a mile upstream, yet less than five minutes had elapsed from the time of Diver’s cry when two beaver appeared, swimming low and cautiously in the stream before me. A minute later another came in sight from downstream. All circled about, swimming cautiously with heads held low in the water. One scented the place where the coyote had attacked Diver, and waddled out and made a sniffing examination. Another came ashore at the spot where Diver came out to me. Apparently his eyes told him I was a part of the log, but his nose proclaimed danger. After three or four hesitating and ineffectual attempts to retreat, he plucked up courage and rose to full height on hind legs and tail to stare eagerly at me. With head well up and fore paws drooping, he held the gaze for several seconds and then gave a low whistle.

At this, Diver came forth from behind my coat to see what was going on. The old one started forward to meet him, but on having a good look at me whirled and made a jumping dive into the water, whacking the surface with his tail as he disappeared. Instantly there followed two or more splashes and a number of tail-whacks upon the water, as though a beaver rescue party were beating a retreat.

At the end of my outing Diver became the pet of two pioneer children on the bank of the Snake River. He followed the children about and romped with them. At three years of age he was shot by a visiting hunter.

My experience with Diver and other beaver pets leads me to believe that beaver are easily domesticated. One morning in northern Idaho, the family with whom I had spent the night took me out to see a beaver colony that was within a stone’s throw of their fireplace. Three beaver came out of the water within ten feet of us to eat scraps of bread which the children threw on the grass for them.

One day I placed myself between three young beaver, who were eating on land, and the river out of which they came. They were on one of the rocky borders of the Colorado River in the depths of the upper Grand Cañon. They attempted to get by me, but their efforts were not of the “do or die” nature. Presently their mother came to the rescue and attempted to attract my attention by floating in the water near me in a terribly crippled condition. I had seen many birds and a few beaver try that clever ruse; so I allowed it to go on, hoping to see another act. Another followed.

In it an old male beaver appeared. He swam easily downstream until within a few yards of me and then dived, apparently frightened. But presently he reappeared near by and dived again. While I was watching him, the youngsters edged a few yards nearer the river. To stop them and prolong the exhibition, I advanced close to them as though to grab them. At this the mother beaver struggled out of the water and set up a tumbling and rolling so close to me that I thought to catch her for examination. She dodged right and left and reached the water. While this was going on, the youngsters escaped into the river. Mother beaver instantly recovered, and as she dived gave the water a scornful whack with her tail.

The beaver is not often heard. He works in silence. When he pauses from his work, he sits meditatively, like a philosopher. At times, however, when, in traveling, beaver are separated from one another, they give a strange shrill whistle or call. Occasionally this whistle appears to be a call of alarm, suspicion, or warning. Sometimes when alarmed, a young beaver gives a shrill and frightened cry not unlike that of a lost human child. On a few occasions I have heard, while listening near a beaver house in the early summer, something of a subdued concert going on inside, a purring, rhythmic melody. They have a kind of love ditty also. This is a rhythmic murmur and sigh, very appealing, and it seems strangely elemental as it floats across the beaver pond in the twilight.

It is probable that beaver mate for life. All that is known concerning their ways indicates that they are good parents. The young are usually born during the month of April. The number varies from one to eight; probably four is the number most common. A short time before the birth of the youngsters, the mother invites the father to leave, or compels him to do so,—or he may go voluntarily,—and she has possession of the house or burrow, probably alone, at the time the youngsters are born. Their eyes are open from the beginning, and in less than two weeks they appear in the water accompanied by the mother. Often I have investigated beaver colonies endeavoring to determine the number of youngsters at a birth. Many times there were four of these furry, serious little fellows near the house on a log that was thrust up through the water. At other times from one to eight youngsters sunned themselves on the top of the rude home.

One May, in examining beaver colonies, I saw three sets of youngsters in the Moraine Colony. They numbered three, and two, and five. One mother in another colony proudly exhibited eight, while still another, who had been harassed all winter by trappers and who lived in a burrow in the bank, could display but one.

It is not uncommon for young orphan beavers to be cared for and adopted by another mother beaver. I have notes of three mothers who, with children of their own, at once took charge of orphans left by the death of a neighbor. One June a mother beaver was killed near my camp. Her children escaped. The following evening a new mother, with four children of her own adopted them and moved from her own home, a quarter of a mile distant, to the home of her dead neighbor and there brought all the youngsters up.

Beaver have great fun while growing up. Posted on the edge of the house, they nose and push each other about, ofttimes tumbling one another into the water. In the water they send a thousand merry ripples to the shore, as they race, wrestle, and dive in the pond. They play on the house, in the pond, and in the sunshine and shadows of the trees along the shore.

Beaver are mature the third summer of their lives, and at this time they commonly leave the parental home, pair, and begin life for themselves. There are stories to the effect that the parents of the youthful home-builders accompany the children to new scenes, help them select a building-site, and assist in the construction of the new house and dam. After this the parents return home. This probably is occasionally true. Anyway I once saw this program fairly well carried out, and at another time in a limited manner.

The beaver is practical, peaceful, and industrious. He builds a permanent house and keeps it clean and in repair. Beside it he stores food-supply for the long winter. He takes thought for the morrow. These and other commendable characteristics give him a place of honor among the hordes of homeless, hand-to-mouth folk of the wild. During the winter he has but little to do except bathe and eat his two or three meals a day from the food he has stored in the autumn. Towards spring, when his wild neighbors are lean, hungry, and cold, he is fat and comfortable. In the spring he emerges from the house, but then his only work is occasionally to cut a twig for food. In the summer he plays tourist. He visits other colonies, and wanders up and down streams, going miles from home. In the late summer or early autumn he returns, makes repairs, and harvests food for winter.

The beaver is a valuable conservationist, but there are localities in which he cannot be tolerated. Although dead wood is rarely cut by the beaver, many a homesteader has been disturbed by his cutting off and carrying away green fence posts. Recently beaver have returned to a few localities and got themselves into bad repute by felling fruit trees. Occasionally, too, in the West, they have lost caste by persistently damming an irrigation-ditch and diverting the water, despite the fact that a court has given both the title and the right to this water to some one else a mile or so down the ditch.

In all logging operations, beaver never fail—where there is opportunity—to cut trees upstream and float them down with the current. Tree-cutting is an interesting phase of beaver life. A beaver will go waddling dully from the water to a tree he is about to cut down. All will look about for enemies; one may be wise enough—but the majority will not do so—to look upward to see if the tree about to be felled is entangled at the top. All appear to choose a comfortable place on which to squat or sit while cutting.

Commonly when the tree begins to creak and settle, the beaver who has done the cutting thuds the ground a few times with his tail, and then scampers away, usually going into the water. Sometimes the near-by workers give the thudding signal in advance of the one who is doing the cutting. Now and then no warning signal is given, and the logging beaver occasionally fells his tree upon other workers with a fatal result. As with axe-men, the beaver doing the cutting is on rare occasions caught and killed by the tree which he fells.

Rarely does the beaver give any thought to the direction in which the tree will fall. In a few instances, however, I have seen what appeared to be an effort on the part of the beaver to fell a tree in a given direction. From an uncomfortable place he cut the lowest notch on the side on which he probably wanted the tree to fall. On one of these occasions, the aspen tree selected stood in an almost complete circle of pines. The beaver took pains to cut the first and lowest notch in this tree directly opposite the opening in the pines. I have seen a number of instances of this kind. And he will sometimes leave the windward side of a grove on a windy day, and cut on the leeward, so that the felled trees are not entangled in falling.

Rarely does more than one beaver work at the same time at a tree. In some instances, however, if the tree be large, two or even more beaver will work at once. But after the tree has been felled, ofttimes three or four beaver will unite to roll a large section to the water. In doing this, some may stand with paws against it and push, and others may put their sides or hips against it. On land, as in the water, small limb-covered trees are dragged butt foremost so as to meet the least resistance. Sometimes the beaver drags walking backwards; at other times he is alongside the tree carrying and dragging it forward.

IN THE HARVEST-FIELD
Aspens cut by beaver

Early explorers say that beaver do most of their work at night. In this they are practically unanimous. However, in Long’s Journal, written in 1820, beaver were reported at work in broad daylight. A few other early writers have also mentioned this daylight work. They probably work in darkness because that is the safest time for them to be out. During dozens of my visits to secluded localities,—localities which had not been visited by man, and certainly not by trappers,—I found beaver freely at work in broad daylight. I am inclined to think that day work was common during primeval times; and that, although the beaver now do and long have done most of their work at night, in localities where they are not in danger from man, they work freely during daytime.

Both the Indians and the trappers have a story that old beaver who will not work are driven from the colony and become morose outcasts, slowly living away the days by themselves in a burrow. I have no evidence to verify this statement, and am inclined to think that solitary beaver occasionally found in abandoned colony-sites and elsewhere are simply unfortunates, perhaps weighed down with age, unable to travel far, with teeth worn, the mate dead, without ambition to try, or without strength to emigrate. It is more likely that these aged ones voluntarily and sadly withdraw from their cheerful and industrious fellows, to spend their closing days alone. Although, too, there were among Indians and trappers stories of beaver slaves, I am without material for a story of this kind.

The beaver is peaceful. Although the males occasionally fight among themselves, the beaver avoids fighting, and plans his life so as to escape without it. Now and then in the water one closes with an otter in a desperate struggle, and when cornered on land one will sometimes turn upon a preying foe with such ferocity and skill that his assailant is glad to retreat. On two occasions I have known a beaver to kill a bobcat.

Beaver are not equally alert. In many cases this difference may be due to a difference in age or experience. Beaver have been caught with scars which show that they have been trapped before, a few even having lost two feet in escaping from traps. On the other hand, skillful trappers have found themselves after repeated trials, unable to catch a single beaver from a populous colony. Sometimes in colonies of this kind, the beaver even audaciously turned the traps upside down or contemptuously covered them with mud.

Nor is the work of all beaver alike. The ditches which one beaver digs, the house one builds, or the dam one makes, may be executed with much greater speed and with more skill than those of a neighboring beaver. Many houses are crude and unshapely masses, many dams haphazard in appearance, while a few canals are crooked and uneven. But the majority do good work, and are quick to take advantage of opportunity, quick to adjust themselves to new conditions, or to use the best means that is available. Beaver probably have made numbers of changes in their manners, habits, and customs, and those changes undoubtedly have enabled them to survive relentless pursuit, and to leave descendants upon the earth.

The industry of the beaver is proverbial, and it is to the credit of any person to have the distinction of working “like a beaver.” Most people have the idea that the beaver is always at work; not that he necessarily accomplishes much at this work, but that he is always doing something. The fact remains that under normal conditions he works less than half the time, and it is not uncommon for him to spend a large share of each year in what might be called play. He is physically capable of intense and prolonged application, and, being an intelligent worker, even though he works less than half the time he accomplishes large results.

The Beaver Past and Present

All Indian tribes in North America appear to have had one or more legends concerning the beaver. Most of these legends credit him with being a worthy and industrious fellow, and the Cherokees are said to trace their origin to a sacred and practical beaver. Many of the tribes had a legend which told that long, long ago the Great Waters surged around a shoreless world. These waters were peopled with beaver, beaver of a gigantic size. These, along with the Great Spirit, dived and brought up quantities of mud and shaped this into the hills and dales, the mountains where the cataracts plunged and sang, and all the caves and cañons. The scattered boulders and broken crags upon the earth were the missiles thrown by evil spirits, who in the beginning of things endeavored to hinder and prevent the constructive work of creation.

The beaver has been found in fossil both in Europe and in America. Remnants of the dugout and the teeth of beaver, together with rude stone implements of primitive man, have been found in England. Near Albany, New York, gnawed beaver wood and the remains of a mastodon were dug up from about forty feet below the surface in sediment and river ooze. Fossil beaver were of enormous size.

Coming down to comparatively modern times, the animal as we now know him appears to have been distributed over almost all Asia, Europe, and North America. There was no marked difference in the individuals that inhabited these three continents. The beaver is probably extinct in Europe, but in July, 1900, I found a piece of wood floating in the Seine that had been recently gnawed by a beaver. At this time I was assured that not even a tame beaver could be found in Europe. It is still found in parts of Siberia and Central Asia. That form which inhabits South America is very unlike those in the Northern Hemisphere, and may be called a link between the muskrat and the beaver.

Reference is made to the beaver in ancient Egyptian hieroglyphics, and Herodotus makes repeated mention of it. Pliny also gives a brief account of this animal. In Germany, in 1103, the right of hunting beaver was conferred along with other special hunting privileges; and a bull of Pope Lucius III, in 1182, gave to a monastery all the beaver found within the bounds of its property. A royal edict issued at Berlin in March, 1725, insisted upon the protection of beaver.

Before the white man came, beaver—Castor canadensis—were widely distributed over North America, perhaps more widely than any other animal. The beaver population was large, and probably was densest to the southwest of Hudson Bay and around the headwaters of the Missouri and Columbia rivers. Their scantiest population areas in the United States appear to have been southern Florida and the lower Mississippi Valley. This scantiness is attributed by early explorers to the aggressiveness of the alligators. All the southern half of Mexico appears to have been without a beaver population; but elsewhere over North America, wherever there were deciduous trees and water, and in a few treeless places where there were only water and grass, the beaver were found. Along the thousands of smaller streams throughout North America there was colony after colony, dam after dam, in close succession, as many as three hundred beaver ponds to the mile. Lewis and Clark mention the fact that near the Three Forks, Montana, the streams stretched away in a succession of beaver ponds as far as the eye could reach. The statements made by the early explorers, settlers, and trappers, together with my own observations,—which commenced in 1885, and which have extended pretty well over the country from northern Mexico into Alaska,—lead to the conclusion that the beaver population of North America at the beginning of the seventeenth century was upwards of one hundred million. The area occupied was approximately six million square miles, and probably two hundred beaver population per square mile would be a conservative number for the general average.

In the United States there are a number of counties and more than one hundred streams and lakes named for the beaver; upwards of fifty post-offices are plain Beaver, Beaver Pond, Beaver Meadow, or some other combination that proclaims the former prevalence of this widely distributed builder. The beaver is the national emblematic animal of Canada, and there, too, numerous post-offices, lakes, and streams are named for the beaver.

BEAVER PONDS

Beaver skins lured the hunter and trapper over all American wilds. These skins were one of the earliest mediums of exchange among the settlers of North America. For two hundred years they were one of the most important exports, and for a longer time they were also the chief commodity of trade on the frontier. A beaver skin was not only the standard by which other skins were measured in value, but also the standard of value by which guns, sugar, cattle, hatchets, and clothing were measured. Though freely used by the early settlers for clothing, they were especially valuable as raw material for the manufacture of hats, and for this purpose were largely exported.

From this animal were prepared many remedies which in former times were believed to have high medicinal value. Castoreum was the most popular of these, and from it was compounded the great cure-all. The skin of the beaver was thought to be an excellent preventive of colic and consumption; the fat of the beaver efficient in apoplexy and epilepsy, to stop spasms, and for various afflictions of the nerves. Powdered beaver teeth were often given in soup for the prevention of many diseases. The castoreum of the beaver was considered a most efficient remedy for earache, deafness, headache, and gout, for the restoring of the memory and the cure of insanity. Next in importance to its skin, the beaver was valued for the castoreum it yielded.

The old hunters, trappers, and first settlers forecast with confidence the weather from the actions of the beaver. This animal was credited with being weather-wise to a high degree. From his actions the nature of the oncoming winter was predicted, and plans to meet it were made accordingly. Faith in the beaver’s actions and activities as a basis for weather-forecasting was almost absolute. If the beaver began work early, the winter was to begin early. If the beaver laid up a large harvest, covered the house deeply with mud, and raised the water-level of the pond, the winter was, of course, to be a long and severe one.

Extensive autumn rambles in the mountains with especial attention to beaver customs compels me to conclude that as a basis for weather prediction beaverdom is not reliable. In the course of one autumn month in the mountains of Colorado more than one hundred colonies were observed. In many colonies work for the winter commenced early. In others, only a few miles distant, preparations for the winter did not begin until late. In some, extensive preparations were made for the winter. In a few the harvest laid up was exceedingly small. Thus in one month of the same year I saw some beaver colonies preparing for a long winter and others for a short one, many preparing for a hard winter and others almost unprepared for winter. From these varied and conflicting prognostications, how was one accurately to forecast the coming winter? The old prophets in one colony frequently disagreed with aged prophets who were similarly situated, but in a neighboring colony. At one place thirty or more beaver gathered an enormous quantity of food, sufficient, in fact, to have supplied twice that number for the longest and most severe winter. The winter which followed was as mild a one as had passed over the Rocky Mountains in fifty years. Not one tenth of the big food-pile was eaten.

I have not detected anything that indicates that the beaver ever plan for an especially hard winter. Goodly preparations are annually made for winter. Apparently the extent of the preparation in any colony is dependent almost entirely upon the number of beaver that are to winter in that colony. Winter preparations consist of gathering the food-harvest, repairing and sometimes raising the dam, and commonly covering the house with a layer of mud. Beaver display forethought, intelligence, and even wisdom, but being weather-wise is not one of their successful specialties. Local beaver now and then show unusual activity, and unusually large supplies are gathered and stored for the winter. This kind of work appears to be local, not general. The cases in which unusually large preparations were made for the winter could have been traced to an increased population of the colony that showed these activities. On the other hand, colonies with less preparations one year than on the preceding one probably had suffered a decrease of population. Increase of population in a beaver colony may be accounted for through the growing up of youngsters, or by the arrival of immigrants, or both; where the temporary inactivity of trappers in one locality might allow the beaver colony in that region to increase in numbers; or where the beaver population of that colony might be increased by the arrival of beaver driven from their homes by aggressive hunters and trappers in adjoining localities. At any rate, in the beaver world, some colonies each year commence work earlier than do others, and some colonies make extensive preparations for the winter, while others make but little preparation. This preparation appears to be determined chiefly by the number of colonists and the needs of the colony.

The beaver hastened, if it did not bring, the settlement of the country. Hunters and trappers blazed the trails, described the natural resources, and lured the permanent settlers to possess the land and build homes among the ruins left by the beaver. Early in the fur industry companies were formed, the Hudson’s Bay Company becoming the most influential and best known. Its charter was granted by Charles II of England on the 2d day of May, 1669. This company finally developed into one of the greatest commercial enterprises that America has ever known. The skin of the beaver furnished more than half its revenue. There are many features in the history of this company that have never been surpassed in any land. For more than two hundred years it held absolute sway over a country larger than Europe, and for the first one hundred and fifty years of its existence it was the government of the territory where it ruled, and thus determined the social and other standards of life within that territory. One of the early officials of this company declared that they were on the ground ahead of the missionaries, and said that the initials “H. B. C.” on the banner of the company might well be interpreted as “Here before Christ.”

Kingsford’s History of Canada says that in the eighteenth century, Canada exported a moderate quantity of timber, wheat, the herb called ginseng, and a few other commodities, but from first to last she lived chiefly on beaver skins. Horace T. Martin, formerly Secretary of Agriculture for Canada, calls the beaver’s part in Canadian development “a subject which has from the inception of civilization been associated with the industrial and commercial development, and indirectly with the social life, the romance, and to a considerable extent with the wars of Canada.”

The American Fur Company and the Northwestern Fur Company were two large fur-gathering enterprises whose trappers ranged afar and who left their mark in the history and the development of the Northwest. The colossal Astor fortune really had its beginning in the wealth which John Jacob Astor amassed chiefly through the gathering and the sale of beaver skins. Beaver skins are now economically unimportant in commerce, but their value has already led to the establishment of a few beaver farms.

To-day beaver are apparently extinct over the greater portion of the area which they formerly occupied, and are scarce over the remaining inhabited area. Scattered colonies are found in the Rocky Mountains and in the mountains of the Pacific Coast, and there are localities in Canada where they are still fairly abundant. In many places in the Grand Cañon of the Colorado they are common. A few are found in Michigan and Maine. Some years ago a few brooks in the Adirondacks were successfully colonized with these useful animals. They have reappeared in Pennsylvania, and there probably are straggling beaver all over the United States which, if protected, would increase.

There is a growing sentiment in favor of allowing the beaver to multiply. In 1877 Missouri passed a law protecting these animals; so did Maine in 1885 and Colorado in 1899. Other States to the total number of twenty-four have also legislated for their protection. The Canadian government has also passed protective laws. A noticeable increase has already occurred in a few localities. Beaver multiply rapidly under protection, as is shown in the National Parks of both Canada and the United States.

As Others See Him

For three hundred years the beaver has been a popular subject for discussion. Fabulous accounts have been given concerning his works, and that which he has done has been exaggerated beyond recognition. Many of the descriptions of him are grotesque, and many accounts of his works are uncanny. His tail has been made to do the work of a pile-driver, and some of the old accounts credit him with driving stakes into the ground that were as large as a man’s thigh and five or six feet long. Stories have been told that his tail was used as a trowel in plastering the house and the dam. A few writers have stated that he lived in a three-story lodge. More than a century ago Audubon called attention to the enormous mass of fabrications that had been written concerning this animal, and in 1771 Samuel Hearne of the Hudson’s Bay Company denounced a beaver nature-faker in the following terms: “The compiler of the Wonders of Nature and Art seems to have not only collected all the fictions into which other writers on the subject have run, but has so greatly improved on them that little remains to be added to his account of the beaver beside a vocabulary of their language, a code of their laws, and a sketch of their religion, to make it the most complete natural history of that animal.”

One might read almost the entire mass of printed matter concerning the beaver without obtaining correct information about his manners and customs or an accurate description of his works and without getting at the real character of this animal. The actual life and character of the beaver, however, the work which he does, the unusual things which he has accomplished, are really more interesting and place the beaver on a higher plane than do all the fictitious tales and exaggerated accounts written concerning him.

Mr. Lewis H. Morgan in his “American Beaver and his Works” says: “No other animal has attracted a larger share of attention or acquired by his intelligence a more respectable position in the public estimation. Around him are the dam, the lodge, the burrow, the tree-cutting, and the artificial canal, each testifying to his handiwork, and affording us an opportunity to see the application as well as the results of his mental and physical powers. There is no animal below man in the entire range of Mammalia which offers to our investigation such a series of works, or presents such remarkable material for study and illustration of animal psychology.”

Mr. Morgan was for years a capable and painstaking student of the beaver. That which he has written is so important a contribution concerning the beaver that no one interested in this animal can afford to be unacquainted with it. In the preface of his book he says: “I took up the subject as I did fishing, for summer recreation. In the year 1861, I had occasion to visit the Red River Settlement in the Hudson’s Bay Territory, and in 1862, to ascend the Missouri River to the Rocky Mountains, which enabled me to compare the works of the beaver in these localities with those on Lake Superior. At the outset I had no expectation of following up the subject year after year, but was led on, by the interest which it awakened, until the materials collected seemed to be worth arranging for publication.”

The greatest admirers of the beaver are those who know him best. He bears acquaintance. This cannot be had by merely looking at the animal, nor by sympathetically studying his monumental works. These works will of course impress one, but they give one at best only a traveler’s impression. Long and repeated visits to the colony in its busy season appear to be the best way to get at the character of the beaver. The cubical contents of a dam may not even suggest the obstacles overcome in its construction, the labor of getting the material, the dangers avoided, the numerous unexpected difficulties overcome. Five cords of green poles and limbs in a neat pile in the pond by the beaver house may tell that the harvest has been gathered, but it does not tell that a part of this harvest may have been gathered a mile away and skillfully transported to the house with difficulty and amid dangers. A part of the food-pile may have been dragged laboriously uphill and along trails which required months of labor to open; or numerous pieces in this pile may have been floated through a canal of such magnitude that a generation was required to construct it. Altogether, harvest-gathering is interesting and heroic work on the part of the beaver. In doing it he takes large risks, for the harvest is usually gathered far from the house and on the dangerous beaver frontier.

For more than a quarter of a century I have been a friendly visitor to his colonies, in which I have lingered long and lovingly. That he makes mistakes is certain, but that he is an intelligent, reasoning animal I have long firmly believed. As I said in “Wild Life on the Rockies,”—“I have so often seen him change his plans so wisely and meet emergencies so promptly and well that I can think of him only as a reasoner.”

As evidence that he sometimes reasons, it may be cited that he occasionally endeavors to fell trees in a given direction; that he often avoids cutting those entangled at the top; that sometimes he will, on a windy day, fell trees on the leeward side of a grove; that he commonly avoids felling trees in the heart of a grove, but cuts on the outskirts of it. He occasionally dams a stream, digs a canal, leads water to a dry place, and there forms and fills a reservoir and establishes a home. Often his house is built by a spring and thus the danger from thick ice avoided. These are some of the reasons for my believing him to be intelligent.

Morgan speaks of the beaver as “endowed with a mental principle which performs for him the same office that the human mind does for man,” and says, “The works of the beaver afford many interesting illustrations of his intelligence and reasoning capacity,” also, “In the capacity thereby displayed of adapting their works to the ever-varying circumstances in which they find themselves placed instead of following blindly an invariable type, some evidence of possession on their part of free intelligence is undoubtedly furnished.”

Mr. George J. Romanes has the following opinion of the beaver: “Most remarkable among rodents for instinct and intelligence, unquestionably stands the beaver. Indeed there is no animal—not even excepting the ants and bees—where instinct has risen to a higher level of far-reaching adaptation to certain constant conditions of environment, or where faculties, undoubtedly instinctive, are more puzzlingly wrought up with faculties no less undoubtedly intelligent.... It is truly an astonishing fact that animals should engage in such vast architectural labors with what appears to be the deliberate purpose of securing, by such artificial means, the special benefits that arise from their high engineering skill. So astonishing, indeed, does this fact appear, that as sober minded interpreters of fact we would fain look for some explanation which would not necessitate the inference that these actions are due to any intelligent appreciation, either of the benefits that arise from labor, or of the hydrostatic principles to which this labor so clearly refers.”

Mr. Alexander Majors, originator of the Pony Express, who lived a long, alert life in the wilds, pays the beaver the following peculiar tribute in his “Seventy Years on the Frontier”: “The beaver, considered as an engineer, is a remarkable animal. He can run a tunnel as direct as the best engineer could do with his instruments to guide him. I have seen where they have built a dam across a stream, and not having sufficient head water to keep their pond full, they would cross to a stream higher up the side of the mountain, and cut a ditch from the upper stream and connect it with the pond of the lower, and do it as neatly as an engineer with his tools could possibly do it. I have often said that the beaver in the Rocky Mountains had more engineering skill than the entire corps of engineers who were connected with General Grant’s army when he besieged Vicksburg on the banks of the Mississippi. The beaver would never have attempted to turn the Mississippi into a canal to change its channel without first making a dam across the channel below the point of starting the canal. The beaver, as I have said, rivals and sometimes even excels the ingenuity of man.”

Longfellow translates the spirit of the beaver world into words, and enables one in imagination to restore the primeval scenes wherein the beaver lived:—

“Should you ask me, whence these stories?

Whence these legends and traditions,

With the odors of the forest,

With the dew and damp of meadows,

·······

Should you ask where Nawadaha

Found these songs so wild and wayward,

Found these legends and traditions,

I should answer, I should tell you,

‘In the bird’s-nests of the forest,

In the lodges of the beaver.’”

And the cunning Pau-Puk-Keewis, fleeing from the wrath of Hiawatha, ran,—

“Till he came unto a streamlet

In the middle of the forest,

To a streamlet still and tranquil,

That had overflowed its margin,

To a dam made by the beavers,

To a pond of quiet water,

Where knee-deep the trees were standing,

Where the water-lilies floated,

Where the rushes waved and whispered.

On the dam stood Pau-Puk-Keewis,

On the dam of trunks and branches,

Through whose chinks the water spouted,

O’er whose summit flowed the streamlet.

From the bottom rose the beaver,

Looked with two great eyes of wonder,

Eyes that seemed to ask a question,

At the stranger Pau-Puk-Keewis.”

The Beaver Dam

Millions of beaver ponds graced America’s wild gardens at the time the first settlers came. These ragged and poetic ponds varied in length from a few feet to one mile, and in area they were from one hundred acres down to a miniature pond that half a dozen merry children might encircle. These ponds were formed by dams built by beaver, and the dams varied greatly in size and were made of poles variously combined with sticks, stones, trash, rushes, and earth.

In the Bad Lands of Dakota I saw two dams that were made of chunks of coal. This material had caved from a near-by bluff. I have noticed a few that were constructed of cobble-stones. The water-front of these dams was filled and covered with clay, and they were the work of “grass beavers,”—beaver that subsist chiefly on grass, and that live in localities almost destitute of trees.

It is doubtful if a dam is ever made by felling logs or large trees across the stream. I have, however, seen a few real log dams, but in these the logs were placed parallel to the flow of water. One of these was in the Sawtooth Mountains of Idaho. Here a snow-slide swept several hundred trees down the mountain. This wreckage was piled on the bank of a stream. Beaver in a colony a short distance away accepted this gift of the gods, and of these unwieldy logs built a dam about two hundred feet downstream from where the avalanche had piled the logs. This dam was a massive affair, about forty feet long and eight feet high. It really appeared more like a log jam than a dam, but it served the purpose intended and raised the level of the river so that the water overflowed to one side and spread in a broad sheet against a cliff and through a grove of aspens, which the beaver proceeded to harvest.

The majority of dams are made of slender green poles which are placed lengthwise with the flow for the bottom, and set braced with the end upstream a foot or so higher than the downstream end. With these there are occasionally used small limby trees. The large end of the tree is placed upstream, and the small bushy end downstream. If in a current these sometimes are weighed down with mud or stones. Short, stout sticks and long, slender poles are deftly mingled in the dam as it rises. The poles overlie, and many completed dams appear as though made of gigantic inclined half-closed shears and compasses of poles. Thus a dam is doubly braced. The weight against it is resisted both by the end-on poles that are parallel to the flow and by those set at an angle to it.

A NEW DAM

The shape and the material of a dam are dependent on a number of things: the nature of the place where built, the kind of materials available for its building, the purpose it is intended to serve, and the relation it may have to dams already constructed. Sometimes a small dam will be made—that may ultimately become a big one—by simply digging a ditch across the stream or basin and piling the excavated material into a dam.

Beaver, like men, are unequal in their skill, both in planning and in doing work, and the work of most beaver falls short of perfection. Errors are not uncommon. More than one colony has commenced a dam apparently without knowing that there was not sufficient available material to complete it. Others have built in the wrong places, and have thus failed to flood the area which they desired to reach or cover with water. Occasionally the difficulties of construction have been too great for the beaver who attempted it, and the dam has been abandoned in an incomplete state. Now and then a weak dam breaks, or a strong one is swept out by a flood.

But why do beaver need or want the pond which the dam forms? They need it for the purpose of maintaining water of sufficient depth and area to enable them to move about in safety, and to transport their food-supplies with the greatest ease. Above all, the pond is a place of refuge into which the beaver can constantly plunge and have security from his numerous and ever watchful enemies. The house-entrance must be kept water-covered. In the water the beaver is in his element. On the land he is a child lost in the wilds. He has extremely short legs and a heavy body. His make-up fits him for movement in the water. He is a graceful swimmer, and in the water can move easily and evade enemies; while on land he is an awkward lubber, moves slowly, and is easily overtaken. Water of sufficient depth and area, then, is essential to the life and happiness of the beaver. To have this at all times it is necessary, in localities where the supply is at times insufficient, to maintain it by means of dams and ponds.

Deep ponds are needed around the house; shallow ponds with shores in near-by groves facilitate far-away logging. Dams are placed across streams whose waters are to be led away through new channels and made to serve elsewhere in canals or ponds. Dams are made across inclined canals to catch and hold water in them. Streams are beaver’s avenues of travel. Along shallow streams in a beaver country it is not uncommon to see an occasional short dam which forms a deep hole, which apparently is maintained as a harbor or place of safety into which traveling beaver may dive and be made safe from pursuit.

Most beaver dams are built on the installment plan. They are the result of growth. The new dam is short and comparatively low. It is enlarged as conditions may require. As the trees in the edge of the pond are harvested, the dam is built higher and longer, so as to flood a larger area; or as sediment fills the pond, the dam is from time to time raised and lengthened in order to maintain the desired depth of water. Thus it may grow through the years until the possibilities of the locality are exhausted. The dam may then be abandoned. It may be used for a few years or it may be used for a century. A gigantic beaver dam may thus represent the work of several generations of beaver. It often occurs that one or more generations may use a dam and yearly add something to its size. By and by these beaver may die or emigrate. The old dam remains, falling to ruin in places. Years go by and other beaver come upon the scene. The old dam is then used for the foundation for a new one. The appearance of some old dams indicates that they have been repeatedly used and abandoned.

New dams, being made largely of coarse materials, appear very unlike old ones. Decay, settling, repairs, and other changes come rapidly. The dam is built of poles to-day; it speedily becomes earthy and is planted by nature to grass, willows, and flowers. On old, large dams it is not uncommon to see old forest-trees. The roots of these entangle the constructive materials, penetrate deeply, and help to anchor securely the entire dam.

In only a few cases are the water-fronts of dams at once plastered or filled in with mud. This is done only where there is a scarcity of water. It is the aim of the beaver to raise the water in the pond to a certain height and there maintain it, the chief purpose of the dam being to regulate the height or the depth of the water. The water, in streaming through new dams, deposits therein quantities of sticks, trash, and sediment, so that in a year or two these choke the holes, almost stop the leakage of the water, and help to solidify the dam. The discharge from dams is regulated by the beaver. In some instances water leaks through a dam in numerous places from bottom to top; in others it seeps through only close to the top; and in still others the dam is so solid that the water pours over the top in a thin sheet. In some cases, however, instead of the water pouring over the entire length of the dam the beaver force it to pour over in a given stretch at one end or the other, or sometimes through a hole or tunnel. The concentration of the overflow at some one point in the dam is commonly done either for the purpose of using it in transportation or to force the water to outpour on a spot where it will least erode the foundation of the dam. Occasionally beaver compel the water to flow round the end of a dam, which they raise sufficiently high for that purpose. Sometimes they dig a waste-way for the water.

European beaver appear to have barely developed to the dam-building stage. Rarely did they build even a small, unimportant dam. Nor did all the American beaver build dams. At the time the beaver population was most numerous and widely distributed, probably not more than half of them used the dam. However, those not using the dam were living in places where the dam and consequent pond were not needed. Dam-building enormously increased the habitable beaver area. There were, and are, thousands of brooks which each year cease to flow for a period, yet on these brooks are all other beaver requirements except a permanent, sufficient water-supply. By dam-building water is stored for to-morrow, or stream-courses changed, and with the assistance of canals water is diverted to a dry ravine where a colony is established.

The dam is the largest and in many respects the most influential beaver work. Across a stream it is an inviting thoroughfare for the folk of the wild. 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.

The beaver dam gives new character to the landscape. It frequently alters the course of a stream and changes the topography. It introduces water into the scene. It nourishes new plant-life. It brings new birds. It provides a harbor and a home for fish throughout the changing seasons. It seizes sediment and soil from the rushing waters, and it sends water through subterranean ways to form and feed springs which give bloom to terraces below. It is a distributor of the waters; and on days when dark clouds are shaken with heavy thunder, the beaver dam silently breasts, breaks, and delays the down-rushing flood waters, saves and stores them; then, through all the rainless days that follow, it slowly releases them.

Most old colonies have many dams and ponds. A dam is sometimes built for the purpose of forcing water back and to one side into a grove that is to be harvested for food. In many cases water flows round the end of a dam, and in making its way back to the main channel is intercepted by another dam, then another; and thus the water from one small brook maintains a cluster or chain of pondlets.

The majority of beaver dams are as crooked as a river’s course. Now and then one is straight. A few are built from shore to a boulder, from the boulder to a willow-clump, and finally, perhaps, from willow-clump to some outstretching peninsula on the further shore. It is not uncommon for a short dam to be built and afterwards lengthened with additions on each end which may curve either down or up stream. Sometimes a dam is built outward from opposite shores simultaneously by separate but coöperating crews of beaver. In swift water these ends are forced downstream in building, so that when they are finally joined midstream the dam curves noticeably downstream.

On one occasion I watched beaver commence and complete a dam in moderately swift water that when finished bowed strongly upstream. This, however, was not the intention of the builders. The material for this dam consisted of willow and alder poles that were cut some distance upstream. These were floated down as used. This dam was begun against a huge boulder near midstream, and built outward simultaneously toward both shores. Despite the repeated efforts of the builders to extend it in a straight line to the shore, the flow of the water pushed these outbuilding ends downward, and when they finally reached the shore this fifty-odd feet of dam with the boulder for a keystone had an arch that was about fifteen feet in advance of the bases.

Not far from where I lived in the mountains when a boy, the beaver built a dam. This had a slight arch upstream. A few years later the dam was doubled in length by building an extension on the end which bowed downstream. It thus stood a reverse curve. Later the dam was still further lengthened by a comparatively straight stretch on one end, and by a short, down-bowing stretch on the other. Recent additions to this dam consist of wings at the end which sweep upstream. The dam as it now stands reaches about three fourths of the way around the pond which it forms.

It is not uncommon for a dam to be planned and built with an arch against the current or against the water which it afterwards impounds. The most interesting dam of this kind that I ever saw was one across the narrow neck of a rudely bell-shaped basin that was about two hundred feet in length. The material for this dam came from a grove of aspens that extended into one side of the basin. The floor of this basin was partly covered with a few inches of water. In starting the dam the beaver evidently knew where they wanted to build it. This was not by the aspen grove where the materials were convenient, where the dam would need to be about one hundred and twenty feet long, but was about fifty feet farther on, where a dam of only forty feet was required. This dam when completed bowed seven feet against the enclosed water. The beaver commenced building at the end nearest the grove of aspens, pulling and dragging the poles the fifty feet to it. They laid these aspen poles, which were two to five inches in diameter and from four to twelve feet in length, at right angles to the length of the dam, and usually placed the large end upstream or against the current. But the water was shallow, and the transportation of these poles to the dam was difficult. Accordingly a ditch or canal was dug from the grove to the place by the dam where the work was going on. This ditch was about twenty-five inches wide and fifteen deep. The waters filled it and thereby afforded an easy means of floating or transporting the poles from the grove to the place where they were being used. This ditch was carried forward along the upper line of the dam, and several feet in advance of the spot where the outbuilding work was advancing. Upon the earth thrown up from this were laid the upper or high ends of the poles. When the dam was finally completed, it was approximately eight feet wide on the base and stood four feet high. As soon as it was completed, the beaver stuffed the water-front with mud and grass roots, which were obtained by digging from the construction ditch immediately in front of the dam. In other words, they enlarged their pole-floating ditch above the dam into a deeper and wider channel, and used this excavated material for strengthening and waterproofing the dam.

The longest beaver dam that I have ever seen or measured was on the Jefferson River near Three Forks, Montana. This was 2140 feet long. Most of it was old. More than half of it was less than six feet in height; two short sections of it, however, were twenty-three feet wide at the base, five on top, and fourteen feet high.

PART OF AN OLD DAM 1040 FEET LONG

Harvest Time with Beavers

One autumn I watched a beaver colony and observed the customs of its primitive inhabitants as they gathered their harvest for winter. It was the Spruce Tree Colony, the most attractive of the sixteen beaver municipalities on the big moraine on the slope of Long’s Peak.

The first evening I concealed myself close to the beaver house by the edge of the pond. Just at sunset a large, aged beaver of striking, patriarchal appearance rose in the water by the house, and swam slowly, silently round the pond. He kept close to the shore and appeared to be scouting to see if an enemy lurked near. On completing the circuit of the pond, he climbed upon the end of a log that was thrust a few feet out into the water. Presently several other beaver appeared in the water close to the house. A few of these at once left the pond and nosed quietly about on the shore. The others swam about for some minutes and then joined their comrades on land, where all rested for a time.

Meanwhile the aged beaver had lifted a small aspen limb out of the water and was squatted on the log, leisurely eating bark. Before many minutes elapsed the other beavers became restless and finally started up the slope in a runway. They traveled slowly in single file and one by one vanished amid the tall sedge. The old beaver slipped noiselessly into the water, and a series of low waves pointed toward the house. It was dark as I stole away in silence for the night, and Mars was gently throbbing in the black water.

This was an old beaver settlement, and the numerous harvests gathered by its inhabitants had long since exhausted the near-by growths of aspen, the bark of which is the favorite food of North American beaver, though the bark of the willow, cottonwood, alder, and birch is also eaten. An examination of the aspen supply, together with the lines of transportation,—the runways, canals, and ponds,—indicated that this year’s harvest would have to be brought a long distance. The place it would come from was an aspen grove far up the slope, about a quarter of a mile distant from the main house, and perhaps a hundred and twenty feet above it. In this grove I cut three notches in the trunks of several trees to enable me to identify them whether in the garnered pile by a house or along the line of transportation to it.

The grounds of this colony occupied several acres on a terraced, moderately steep slope of a mountain moraine. Along one side rushed a swift stream on which the colonists maintained three but little used ponds. On the opposite side were the slope and summit of the moraine. There was a large pond at the bottom, and one or two small ponds, or water-filled basins, dotted each of the five terraces which rose above. The entire grounds were perforated with subterranean passageways or tunnels.

Beaver commonly fill their ponds by damming a brook or a river. But this colony obtained most of its water-supply from springs which poured forth abundantly on the uppermost terrace, where the water was led into one pond and a number of basins. Overflowing from these, it either made a merry little cascade or went to lubricate a slide on the short slopes which led to the ponds on the terrace below. The waters from all terraces were gathered into a large pond at the bottom. This pond measured six hundred feet in circumference. The crooked and almost encircling grass-grown dam was six feet high and four hundred feet long. In its upper edge stood the main house, which was eight feet high and forty feet in circumference. There was also another house on one of the terraces.

After notching the aspens I spent some time exploring the colony grounds and did not return to the marked trees until forty-eight hours had elapsed. Harvest had begun, and one of the largest notched trees had been felled and removed. Its gnawed stump was six inches in diameter and stood fifteen inches high. The limbs had been trimmed off, and a number of these lay scattered about the stump. The trunk, which must have been about eighteen feet long, had disappeared, cut into lengths of from three to six feet, probably, and started toward the harvest pile. Wondering for which house these logs were intended, I followed, hoping to trace and trail them to the house, or find them en route. From the spot where they were cut, they had evidently been rolled down a steep, grassy seventy-foot slope, at the bottom of this dragged an equal distance over a level stretch among some lodge-pole pines, and then pushed or dragged along a narrow runway that had been cut through a rank growth of willows. Once through the willows, they were pushed into the uppermost pond. They were taken across this, forced over the dam on the opposite side, and shot down a slide into the pond which contained the smaller house. Only forty-eight hours before, the little logs which I was following were in a tree, and now I expected to find them by this house. It was good work to have got them here so quickly, I thought. But no logs could be found by the house or in the pond! The folks at this place had not yet laid up anything for winter. The logs must have gone farther.

On the opposite side of this pond I found where the logs had been dragged across the broad dam and then heaved into a long, wet slide which landed them in a small, shallow harbor in the grass. From this point a canal about eighty feet long ran around the brow of the terrace and ended at the top of a long slide which reached to the big pond. This canal was new and probably had been dug especially for this harvest. For sixty feet of its length it was quite regular in form and had an average width of thirty inches and a depth of fourteen. The mud dug in making it was piled evenly along the lower side. Altogether it looked more like the work of a careful man with a shovel than of beaver without tools. Seepage and overflow from the ponds above filled and flowed slowly through it and out at the farther end, where it swept down the long slide into the big pond. Through this canal the logs had been taken one by one. At the farther end I found the butt-end log. It probably had been too heavy to heave out of the canal, but tracks in the mud indicated that there was a hard tussle before it was abandoned.

The pile of winter supplies was started. Close to the big house a few aspen leaves fluttered on twigs in the water; evidently these twigs were attached to limbs or larger pieces of aspen that were piled beneath the surface. Could it be that the aspen which I had marked on the mountainside a quarter of a mile distant so short a time before, and which I had followed over slope and slide, through canal and basin, was now piled on the bottom of this pond? I waded out into the water, prodded about with a pole, and found several smaller logs. Dragging one of these to the surface, I found there were three notches in it.

Evidently these heavy green tree cuttings had been sunk to the bottom simply by the piling of other similar cuttings upon them. With this heavy material in the still water a slight contact with the bottom would prevent the drifting of accumulated cuttings until a heavy pile could be formed. However, in deep or swift water I have noticed that an anchorage for the first few pieces was secured by placing these upon the lower slope of the house or against the dam.

Scores of aspens were felled in the grove where the notched ones were. They were trimmed, cut into sections, and limbs, logs, and all taken over the route of the one I had followed, and at last placed in a pile beside the big house. This harvest-gathering went on for a month. All about was busy, earnest preparation for winter. The squirrels from the tree-tops kept a rattling rain of cones on the leaf-strewn forest floor, the cheery chipmunk foraged and frolicked among the withered leaves and plants, while aspens with leaves of gold fell before the ivory sickles of the beaver. Splendid glimpses, grand views, I had of this strange harvest-home. How busy the beavers were! They were busy in the grove on the steep mountainside; they tugged logs across the runways; they hurried them across the water-basins, wrestled with them in canals, and merrily piled them by the rude house in the water. And I watched them through the changing hours; I saw their shadowy activity in the starry, silent night; I saw them hopefully leave home for the harvest groves in the serene twilight, and I watched them working busily in the light of the noonday sun.

Most of the aspens were cut off between thirteen and fifteen inches above the ground. A few stumps were less than five inches high, while a number were four feet high. These high cuttings were probably made from reclining trunks of lodged aspens which were afterward removed. The average diameter of the aspens cut was four and one half inches at the top of the stump. Numerous seedlings of an inch diameter were cut, and the largest tree felled for this harvest measured fourteen inches across the stump. This had been laid low only a few hours before I found it, and a bushel of white chips and cuttings encircled the lifeless stump like a wreath. In falling, the top had become entangled in an alder thicket and lodged six feet from the ground. It remained in this position for several days and was apparently abandoned; but the last time I went to see it the alders which upheld it were being cut away. Although the alders were thick upon the ground, only those which had upheld the aspen had been cut. It may be that the beaver which felled them looked and thought before they went ahead with this cutting.

Why had this and several other large aspens been left uncut in a place where all were convenient for harvest? All other neighboring aspens were cut years ago. One explanation is that the beaver realized that the tops of the aspens were entangled and interlocked in the limbs of crowding spruces and would not fall if cut off at the bottom. This and one other aspen were the only large ones that were felled, and the tops of these had been recently released by the overturning of some spruces and the breaking of several branches on others. Other scattered large aspens were left uncut, but all of these were clasped in the arms of near-by spruces.

It was the habit of these colonists to transfer a tree to the harvest pile promptly after cutting it down. But one morning I found logs on slides and in canals, and unfinished work in the grove, as though everything had been suddenly dropped in the night when work was at its height. Coyotes had howled freely during the night, but this was not uncommon. In going over the grounds I found the explanation of this untidy work in a bear track and numerous wolf tracks, freshly moulded in the muddy places.

After the bulk of the harvest was gathered, I went one day to the opposite side of the moraine and briefly observed the methods of the Island beaver colony. The ways of the two colonies were in some things very different. In the Spruce Tree Colony the custom was to move the felled aspen promptly to the harvest pile. In the Island Colony the custom was to cut down most of the harvest before transporting any of it to the pile beside the house. Of the one hundred and sixty-two trees that had been felled for this harvest, one hundred and twenty-seven were still lying where they fell. However, the work of transporting was getting under way; a few logs were in the pile beside the house, and numerous others were scattered along the canals, runways, and slides between the house and the harvest grove.

THE SPRUCE TREE HOUSE AND FOOD-PILE, OCTOBER 12

There was more wasted labor, too, in the Island Colony. This was noticeable in the attempts that had been made to fell limb-entangled trees that could not fall. One five-inch aspen had three times been cut off at the bottom. The third cut was more than three feet from the ground, and was made by a beaver working from the top of a fallen log. Still this high-cut aspen refused to come down and there it hung like a collapsed balloon entangled in tree-tops.

Prowling hunters have compelled most beaver to work at night, but the Spruce Tree Colony was an isolated one, and occasionally its members worked and even played in the sunshine. Each day I secluded myself, kept still, and waited; and on a few occasions watched them as they worked in the light.

One windy day, just as I was unroping myself from the shaking limb of a spruce, I saw four beaver plodding along in single file beneath. They had come out of a hole between the roots of the spruce. At an aspen growth about fifty feet distant they separated. Though they had been closely assembled, each appeared utterly oblivious of the presence of the others. One squatted on the ground by an aspen, took a bite of bark out of it, and ate leisurely. By and by he rose, clasped the aspen with fore paws, and began to bite chips from it systematically. He was deliberately cutting it down. The most aged beaver waddled near an aspen, gazed into its top for a few seconds, then moved away about ten feet and started to fell a five-inch aspen. The one rejected was entangled at the top. Presently the third beaver selected a tree, and after some trouble in getting comfortably seated, or squatted, also began cutting. The fourth beaver disappeared and I did not see him again. While I was looking for this one the huge, aged beaver whose venerable appearance had impressed me the first evening appeared on the scene. He came out of a hole beneath some spruces about a hundred feet distant. He looked neither to right nor to left, nor up nor down, as he ambled toward the aspen growth. When about halfway there he wheeled suddenly and took an uneasy survey of the open he had traversed, as though he had heard an enemy behind. Then with apparently stolid indifference he went on leisurely, and for a time paused among the cutters, which did nothing to indicate that they realized his presence. He ate some bark from a green limb on the ground, moved on, and went into the hole beneath me. He appeared so large that I afterward measured the distance between the two aspens where he paused. He was not less than three and a half feet long and probably weighed fifty pounds. He had all his toes; there was no white spot on his body; in fact, there was neither mark nor blemish by which I could positively identify him. Yet I feel that in my month around the colony I beheld the patriarch of the first evening in several scenes of action.

Sixty-seven minutes after the second beaver began cutting he made a brief pause; then he suddenly thudded the ground with his tail, hurriedly took out a few more chips, and ran away, with the other two beaver a little in advance, just as his four-inch aspen settled over and fell. All paused for a time close to the hole beneath me, and then the old beaver returned to his work. The one that had felled his tree followed closely and at once began on another aspen. The other beaver, with his aspen half cut off, went into the hole and did not again come out. By and by an old and a young beaver came out of the hole. The young one at once began cutting limbs off the recently felled aspen, while the other began work on the half-cut tree; but he ignored the work already done, and finally severed the trunk about four inches above the cut made by the other. Suddenly the old beaver whacked the ground and ran, but at thirty feet distant he paused and nervously thumped the ground with his tail, as his aspen slowly settled and fell. Then he went into the hole beneath me.

This year’s harvest was so much larger than usual that it may be the population of this colony had been increased by the arrival of emigrants from a persecuted colony down in the valley. The total harvest numbered four hundred and forty-three trees. These made a harvest pile four feet high and ninety feet in circumference. A thick covering of willows was placed on top of the harvest pile,—I cannot tell for what reason unless it was to sink all the aspens below reach of the ice. This bulk of stores together with numerous roots of willow and water plants, which are eaten in the water from the bottom of the pond, would support a numerous beaver population through the days of ice and snow.

When I took my last tour through the colony everything was ready for the long and cold winter. Dams were in repair and ponds were brimming over with water, the fresh coats of mud on the houses were freezing to defy enemies, and a bountiful harvest was home. Harvest-gathering is full of hope and romance. What a joy it must be to every man or animal who has a hand in it! What a satisfaction, too, for all dependent upon a harvest, to know that there is abundance stored for all the frosty days!

The people of this wild, strange, picturesque colony had planned and prepared well. I wished them a winter unvisited by cruel fate or foe, and trusted that when June came again the fat and furry young beavers would play with the aged one amid the tiger lilies in the shadows of the big spruce trees.

Transportation Facilities

Two successive dry years had greatly reduced the water-level of Lily Lake, and the consequent shallowness of the water made a serious situation for its beaver inhabitants. This lake covered about ten acres, and was four feet deep in the deepest part, while over nine tenths of the area the water was two feet or less in depth. It was supplied by springs. Early in the autumn of 1911 the water completely disappeared from about one half of the area, and most of the remainder became so shallow that beaver could no longer swim beneath the surface. This condition exposed them to the attack of enemies and made the transportation of supplies to the house slow and difficult.

In the lake the beaver had dug an extensive system of deep canals,—the work of years. By means of these deep canals the beaver were able to use the place until the last, for these were full of water even after the lake-bed was completely exposed. One day in October while passing the lake, I noticed a coyote on the farther shore stop suddenly, prick up his ears, and give alert attention to an agitated forward movement in the shallow water of a canal. Then he plunged into the water and endeavored to seize a beaver that was struggling forward through water that was too shallow for his heavy body. Although this beaver made his escape, other members of the colony may not have been so fortunate.

The drouth continued and by mid-October the lake went entirely dry except in the canals. Off in one corner stood the beaver house, a tiny rounded and solitary hill in the miniature black plain of lake-bed. With one exception the beaver abandoned the site and moved on to other scenes, I know not where. One old beaver remained. Whether he did this through the fear of not being equal to the overland journey across the dry rocky ridge and down into Wind River, or whether from deep love of the old home associations, no one can say. But he remained and endeavored to make provision for the oncoming winter. Close to the house he dug or enlarged a well that was about six feet in diameter and four feet in depth. Seepage filled this hole, and into it he piled a number of green aspen chunks and cuttings, a meagre food-supply for the long, cold winter that followed. Extreme cold began in early November, and not until April was there a thaw.

LAKE-BED CANALS AT LILY LAKE, OCTOBER, 1911

SECTION OF A 750-FOOT CANAL AT LILY LAKE
Here five feet wide and three feet deep

Before the lake-bed was snow-covered, all the numerous canals and basins which the beaver had excavated could be plainly seen and examined. The magnitude of the work which the beaver had performed in making these is beyond comprehension. I took a series of photographs of these excavations and made numerous measurements. To the north of the house a pool had been dug that was three feet deep, thirty feet long, and about twenty wide. There extended from this a canal that was one hundred and fifty feet long. The food basin was thirty feet wide and four feet deep. This had a canal connection with the house. In the bottom of the basin was one of the feeble springs which supply the lake. Another canal, which extended three hundred and fifty feet in a northerly direction from the house, was from three to four feet wide and three feet deep. The largest ditch or canal was seven hundred and fifty feet long and three feet deep throughout. This extended eastward, then northeasterly, and for one hundred feet was five feet wide. In the remaining six hundred and fifty feet it was three to four feet wide. There were a number of minor ditches and canals connecting the larger ones, and altogether the extent of all made an impressive show in the empty lake-basin.

Meantime the old beaver had a hard winter. The cold weather persisted, and finally the well in which he had deposited winter food froze to the bottom. Even the entrance-holes into the house were frozen shut. This sealed him in. The old fellow, whose teeth were worn and whose claws were bad, apparently tried in vain to break out. On returning from three months’ absence, two friends and I investigated the old beaver’s condition. We broke through the frozen walls of the house and crawled in. The old fellow was still alive, though greatly emaciated. For some time—I know not how long—he had subsisted on the wood and the bark of some green sticks which had been built into an addition of the house during the autumn. We cut several green aspens into short lengths and threw them into the house. The broken hole was then closed. The old fellow accepted these cheerfully. For six weeks aspens were occasionally thrown to him, and at the end of this time the spring warmth had melted the deep snow. The water rose and filled the pond and unsealed the entrance to the house, and again the old fellow emerged into the water. The following summer he was joined, or rejoined, by a number of other beaver.

In many localities the canals or ditches dug and used by the beaver form their most necessary and extensive works. These canals require enormous labor and much skill. In point of interest they even excel the house and the dam. It is remarkable that of the thousands of stories concerning the beaver only a few have mentioned the beaver canals. These are labor-saving improvements, and not only enable the beaver to live easily and safely in places where he otherwise could not live at all, but apparently they allow him to live happily. The excavations made in taking material for house or dam commonly are turned to useful purpose. The beaver not only builds his mound-like house, but uses the basin thus formed in excavating earthy material for the house for a winter food depository. Ofttimes, too, in building the dam he does it by piling up the material dug from a ditch which runs parallel and close to the dam, and which is useful to him as a deep waterway after the dam is completed.

In transporting trees for food-supply, water transportation is so much easier and safer than land, that wherever the immediate surroundings of the pond are comparatively level the beaver endeavors to lead water out to tree groves by digging a canal from the edge of the pond to these groves. The felled trees are by this means easily floated into the pond. One of the simplest forms of beaver canal is a narrow, outward extension of the pond. This varies in length from a few yards to one hundred feet or more.

Another and fairly common form of canal is one that is built across low narrow necks of land which thrust out into large beaver ponds, or on narrow stretches of land around which crooked streams wander.

The majority of beaver ponds are comparatively shallow over the greater portion of their area. In many cases it is not easy, or even possible, to deepen them. They may be so shallow that the pond freezes to the bottom in winter except in its small deeper portion. The shallow ponds are made more usable by a number of canals in the bottom. These canals assure deep-water stretches under all conditions. Most beaver ponds have a canal that closely parallels the dam. In some instances this is extended around the pond a few yards inside the shore-line. Two canals usually extend from the house. One of these connects with the canal by the dam, the other runs to the place on the shore (commonly at the end of a trail or slide) most visited by the beaver.

In Jefferson Valley, Montana, not far from Three Forks, I enjoyed the examination of numerous beaver workings, and made measurements of the most interesting system of beaver canals that I have ever seen. The beaver house for which these canals did service was situated on the south bank of the river, about three feet above the summer level of the water and about two hundred feet north of the hilly edge of the valley. From the river a crescent-shaped canal, about thirty-five feet in length, had been dug halfway around the base of the house. Connected with this was a basin for winter food; this was five feet deep and thirty-five feet in diameter. From this a canal extended southward two hundred and seven feet. One hundred and ten feet distant from the house was a boulder that was about ten feet in diameter. This was imbedded in about two feet of soil. Around this boulder the canal made a detour, and then resumed its comparatively straight line southward.

Over the greater portion of its length this canal was four feet wide, and at no point was it narrower than three feet. Its average depth was twenty-eight inches. For one hundred and forty-seven feet it ran through an approximately level stretch of the valley, and seepage filled it with water. A low, semi-circular dam, about fifty feet in length, crossed it at the one hundred and forty-seven-foot mark, and served to catch and run seepage water into it, and also to act as a wall across the canal to hold the water. The most southerly sixty feet of this canal on the edge of the foothills ran uphill, and was about four feet deep at the upper end, four feet higher than the end by the house. The dam across it was supplemented by a wall forty-eight feet further on. This wall was simply a short dam across the canal, in a part that was inclined, and plainly for the purpose of retaining water in the canal. The upper part of the canal was filled with water by a streamlet from off the slope. Apparently this canal was old, for there was growing on its banks near the house, a spruce tree, four inches in diameter, that had grown since the canal was made.

Beaver Colony on Jefferson River near Three Forks, Montana
(Select to Enlarge)

The wall or small dam which beaver build across canals that are inclined represents an interesting phase of beaver development. That these walls are built for the purpose of retaining water in the canal appears certain. They are most numerous in canals of steepest incline, though rarely less than twenty feet apart. I have not seen a wall in an almost dead-level canal, except it was there for the purpose of raising the height of the water. This wall or buttress is after all but a dam, and like most dams it is built for the purpose of raising and maintaining the level of water.

Extending at right angles westward from the end of the old canal was a newer one of two hundred and twenty-one feet. A wall separated and united the two. One hundred and sixty feet of this new canal ran along the contour of a hill, approximately at a dead level. Then came a wall, and from this the last sixty-one feet extended southward up a shallow ravine. In this part there were two walls. The upper end of the sixty-one-foot extension was nine feet higher than the house, and four hundred and twenty-eight feet distant from it. The two-hundred-and-twenty-one-foot extension was from twenty-six to thirty-four inches wide, and averaged twenty-two inches deep. The entire new part was supplied with spring water, which the beaver had diverted from a ravine to the west and led by a seventy-foot ditch into the upper end of their canal. Thirty feet from the end of the canal were two burrows, evidently safe places into which the beaver could retreat in case of sudden attack from wolves or other foe. There were two other of these burrows, one at the outer end of the old canal and the other alongside the boulder one hundred and ten feet from the house.

At the time I saw these canals, the only trees near were those of an aspen grove which surrounded the extreme end. It was autumn, and on both tributary slopes by the end of the canal, aspens were being cut, dragged, and rolled down these slopes into the upper end of the canal, then floated through its waters, dragged over and across the walls, and at last piled up for winter food in the basin by the house. In all probability this long, large canal had been built a few yards at a time, being extended as the trees near-by were cut down and used.

Where beaver long inhabit a locality it is not uncommon for them to have two or three distinct and well-used trails from points on the water’s edge which lead into neighboring groves or tree-clumps. These are the beaten tracks traveled by the beaver as they go forth from the water for food, and over which they drag their trees and saplings into the water. On steep slopes by the water these are called slides. This name is also given to places in the dam over which beaver frequently pass in their outgoings and incomings. Commonly these trails avoid ridges and ground swells by keeping in the bottom of a ravine; logs are cut through and rolled out of the way, or a tunnel driven beneath; obstructions are removed, or a good way made round them. Their log roads compare favorably with the log roads of woodsmen who cut with steel instead of enamel.

In most old beaver colonies, where the character of the bottom of the pond permits it, there are two or more tunnels or subways beneath the floor of the principal pond. The main tunnel begins close to the foundation of the house, and penetrates the earth a foot or more beneath the water to a point on land a few feet beyond the shore-line. If there are a number of small ponds in a colony that are separated by fingers of land, it is not uncommon for these bits of land to be penetrated by a thoroughfare tunnel. These tunnels through the separating bits of land enable the beaver to go from one pond to another without exposing themselves to dangers on land, and also offer an easy means of intercommunication between ponds when these are ice-covered. Pond subways also afford a place of refuge or a means of escape in case the house is destroyed, the dam broken, or the pond drained, or in case the pond should freeze to the bottom. Commonly these are full of water, but some are empty. On the Missouri and other rivers, where there are several feet of cut banks above the water, beaver commonly dug a steeply inclined tunnel from the river’s edge to the top of a bank a few feet back.

Most of this tunnel work is hidden and remains unknown. A striking example was in the Spruce Tree Colony, elsewhere described. These colonists, apparently disgusted by having their ponds completely filled with sediment which came down as the result of a cloudburst, abandoned the old colony-site. A new site was selected on a moraine, only a short distance from the old one. Here in the sod a basin was scooped out, and a dam made with the excavated material. The waters from a spring which burst forth in the moraine, about two hundred yards up the slope and perhaps one hundred feet above, trickled down and in due time formed a pond. The following year this pond was enlarged, and another one built upon a terrace about one hundred feet up the slope. From year to year there were enlargements of the old pond and the building of new pondlets, until there were seven on the terraces of this moraine. These, together with the connecting slides and canals, required more water than the spring supplied, especially in the autumn when the beaver were floating their winter supplies from pond to pond. Within the colony area, too, were many water-filled underground passages or subway tunnels. One of these penetrated the turf beneath the willows for more than two hundred feet.

While watching the autumnal activities of this colony, as described in another chapter, I broke through the surface and plunged my leg into an underground channel or subway that was half filled with water. Taking pains to trace this stream downward, I found that it emptied into the uppermost of the ponds along with the waters from a small spring. Then, tracing the channel upwards, I found that, about one hundred and forty feet distant from the uppermost pond, it connected with the waters of the brook on which the old colony formerly had a place. This tunnel over most of its course was about two feet beneath the surface, was fourteen inches in diameter, and ran beneath the roots of spruce trees. The water which the tunnel led from the brook plainly was being used to increase the supply needed in the canals, ponds, and pools of the Spruce Tree Colony. The intake of this was in a tiny pond which the beaver had formed by a damlet across the brook. That this increased supply of water was of great advantage to the busy and populous Spruce Tree Colony, there can be no doubt. Was this tunnel planned and made for this especial purpose, or was the increased water-supply of the colony the result of accident by the brook’s breaking into this subway tunnel?

The canals which beaver dig, the slides which they use, the trails which they clear and establish, conclusively show that these animals appreciate the importance of good waterways and good roads,—in other words, good transportation facilities.

The Primitive House

The Lily Lake beaver house, in which the old beaver spent the drouthy winter, was a large roughly rounded affair that measured twenty-two feet in diameter. It rose only four feet above the normal water-line. This house had been three times altered and enlarged, and once raised in height. Its mud walls were heavily reinforced with polelike sticks, which were placed at the junctures of the enlargements. The one large room was more than twelve feet in diameter. Near the centre stood a support for the upper part of the house. This support was about one and a half by two and a half feet, and was composed for the most part of sticks. But few houses have this support; commonly the room is vaulted. The room itself averaged two and a half feet high. It had four entrances.

A house commonly has two entrances, but it may have only one or as many as five. Thus the way to the outer world from the inside of the house is through one or more inclined passageways or tunnels. The upper opening of these entrances is in the floor a few inches above the water-level, and the lower opening in the bottom of the pond under about three feet of water. These extend at an angle through the solid foundation of the house, are about one foot in diameter and four to fifteen feet long, and are full of water almost to floor-level. This dark, windowless hut has no other entrance.

Most beaver houses stand in a pond, though a number are built on the shore and partly in the water, and still others on the bank a few feet away from the water. The external appearance and internal construction of the houses are in a general way the same, regardless of the situation or size. Most beaver houses appear conical. Measured on the water-line, they are commonly found to be slightly elliptical. The diameter on the water-line is from five to thirty-five feet, and the height above water is from three to seven feet.

A house may be built almost entirely of sticks, or of a few sticks with a larger proportion of mud and turf. In building, a small opening is left,—or built around and over,—which is afterwards enlarged into a room.

Houses that are built in a pond usually stand in three or four feet of water. The foundation is laid on the bottom of the pond, of the size intended for the house, and built up a solid mass to a few inches above water-level. This island-like foundation is covered with a crude hemisphere or dome-shaped house, the central portion of the foundation forming the floor of the low-vaulted room which is enclosed by the thick house-walls. In building the house the beaver provide a temporary support for the combined roof and walls by piling in the centre of the floor a two-foot mound of mud. Over this is placed a somewhat flattened tepee- or cone-shaped frame of sticks and small poles. These stand on the outer part of the foundation and lean inward with upper ends meeting against and above the temporary support. The beaver then cover this framework with two or three feet of mud, brush, and turf, and thus make the walls and the roof of the house. When the outer part of the house is completed, they dig an inclined passageway, from the bottom of the pond up through the foundation, into the irregular space left between the supporting pile of mud and the walls. And of this space they shape a room, by clawing out the temporary support and gnawing off the intruding sticks. This represents the most highly developed type of beaver house.

In most houses the temporary support is not used, but a part of the wall is carried up to completion, and against it are leaned sticks, which rest upon the edge of the remaining foundation. A finished house of this kind has a slightly elliptical outline. However, many a house is a crude haphazard pile of material in which a room has been burrowed.

The room is from one to three feet high, and from three to twenty feet across. The room is a kind of a burrow and is without either door or window. Half-buried sticks make a comparatively dry floor, despite the fact that it is only a few inches above water-level. Beaver sleep on the floor, usually with tail bent along the side after the fashion of a dozing cat, in a nest of shredded wood, which they patiently make by thinly splitting and paring pieces of wood. Just why this kind of bedding is used cannot be said, but probably because this material dries more quickly, is more comfortable and more sanitary, and harbors fewer parasites. However, a few beds are made of grass, leaves, or moss.

But little earthy matter is used in the tip-top of the house, where the minute disjointed air-holes between the interlaced poles give the room scanty ventilation.

Except in a few cases where house-walls are overgrown with willows or grass, the erosive action of wind and water rapidly thins and weakens them. Hence the house must receive frequent repairs. Each autumn it is plastered or piled all over with sticks or mud. The mud covering varies in thickness from two to six inches. The mud for this purpose is usually dredged from the bottom of the pond close to the foundation of the house. It is carried up, a double handful at a time, the beaver waddling on his hind legs as he holds it with his fore paws against his breast. A half-dozen or more beaver may be carrying mud up at once. The covering not only thickens the walls and increases the warmth of the house, but also freezes and becomes an armor of stone that is impregnable to most beaver enemies. The “mudding” of the house is a part of the natural and necessary preparation for winter. It may also be a special means of protection deliberately carried out by the beaver. The fact that an occasional thick-walled or grass-covered beaver house was not thus plastered in autumn—perhaps because it did not need it—has led a few people to affirm that beaver houses are not mud-covered in the autumn. Many years of observation show that most beaver houses do receive an autumnal plastering, and the few that do not have this attention usually have thick, well-preserved walls and do not need it.

One autumn in Montana, of twenty-seven beaver houses which I examined, twenty-one received mud covering; three of the others were thickly overgrown with willows and two were grass-grown. Only one thin-walled house that needed reinforcement did not receive it; and this one, by the way, was broken into by a bear before the winter had got fairly under way.

AN UNPLASTERED AND A PLASTERED HOUSE

In the autumn of 1910 I made notes concerning eighteen houses. These I watched during October and November. Thirteen were plastered; a willow-grown one and a weed-grown one, both of which had thick walls, were not plastered. The remaining three were not greatly in need of additional thickness, so received only a scanty covering of sticks. Two of these were broken into by some animal during the winter, while none of the others were disturbed.

Beaver frequently show good judgment in that important matter of selecting a site for the house. Ice and sediment are two factors with which the beaver must constantly contend. In the pond the house is commonly placed in deep water, and apparently where the depth around it will not be rapidly reduced by the depositing of sediment. Keeping the house-entrance, the harvest-pile basin, and the canals from filling with sediment is one of the difficult problems of beaver life.

To guard against the rapid encroachments of the deposits of sediment, one group of beaver, apparently with forethought, built a dam that formed a pond from the waters of a small spring which carried but little or no sediment. I have noticed a number of instances in which a pond was made on a small streamlet with greater labor than it would have required to form a pond in a near-by brook. As there were a number of other conditions favorable to the brook situation of the house, the only conclusion I could reach was that these selections for colony-sites were made with the intention of avoiding the ever-encroaching sediment,—for in some beaver ponds this sediment is deposited annually to the depth of several inches.

Ice is one of the troubles of beaver existence. It is of the utmost importance to the beaver that he should have his house so situated that the ice of winter does not close the entrance to it, and also that the deep water in which his pile of green provisions is deposited does not freeze solid and thus exclude him from the food-supply. The ice fills the pond from the top and compels him to be constantly vigilant to save himself from its encroachments. Many a beaver home has been built alongside a spring, around which the beaver dredged a deep hole and in this deposited the winter food-supply. The constant flow of the spring water prevented thick ice from forming, both around the food-pile and between it and the house-entrance.

Large numbers of beaver do not possess a house. Beaver who live without a dam or pond commonly do not build a house, but are content with a burrow or a number of burrows in the banks of the waters which they inhabit. In the severe struggle to live, there is a tendency on the part of the beaver to avoid the building of dams and houses, as these reveal their presence and put the aggressive trapper on their trail.

Many colonies have both houses and burrows. Apparently the houses were used in the winter-time, the burrows in summer. One beaver burrow which I examined was about one foot above the level of the pond and twelve feet distant from it. The entrance tunnels were sixteen feet in length, and began a trifle more than three feet under water near the edge of the pond. This burrow measured five and a half feet long, about half as wide, and seventeen inches high. It was immediately beneath the outspreading roots of an Engelmann spruce. The majority of beaver burrows are about two thirds the size of this one.

One November I examined more than a score of beaver colonies. There was no snow, but recent cold had covered the pond with ice and solidified the miry surroundings. Over the frozen surface I moved easily about and made many measurements. One of these colonies was a fairly typical one. The colony was on a swift-running stream that came down from the snowy heights, three miles distant. The top of Long’s Peak and Mt. Meeker looked down upon the scene. The altitude of this colony was about nine thousand feet. The ponds were in part surrounded by semi-boggy willow flats, with here and there a high point or a stretch of bank that was covered with aspens. The tops of a few huge boulders thrust up through the water. All around stood guard a tall, dark forest of lodge-pole pines. These swept up the mountainside, where they were displaced by a growth of Engelmann spruce which reached up to timber-line on the heights above.

This colony had a number of ponds, with a few short canals extending outward from them. A conical house of mud and slender poles stood in the larger pond. Above this pond there were half a dozen pondlets, the uppermost of which was formed across the brook by a semi-circular dam. Over the outward ends of this dam the water flowed and was caught in other ponds; these in turn overflowed, the water traversing two other ponds, one below the other, just above the main one. Below the large pond were three smaller ones in close succession. The dam of each pond backed the water against the dam above it.

The dam of the main pond was two hundred and thirty feet long. Each end bent upward at a sharp angle and extended a number of yards upstream. This dam measured five feet at its highest point, but along the greater portion was only a trifle more than three feet high. The central part was overgrown with sedge and willows and appeared old; but the extreme ends appeared new, and probably had been in part constructed within a few weeks. The whole dam was formed of earth and slender poles. The pond formed by it was one hundred and eighty feet wide, and had an average length up and down stream of one hundred and ten feet. The average depth was only two feet.

Near the centre of this large pond stood the house, a trifle nearer to the dam than to the upper edge of the pond. I measured it on the water- or rather the ice-level. It took twenty-six feet of rope to go around it. The top of the house rose exactly five feet above the ice. The house was built of a mixture of sods and willow sticks. The ends of the sticks here and there thrust out through the three-or-four-inch covering of mud which the house had recently received. Wondering how much of the house was in the water below the level of the ice, I thought to measure the depth by thrusting a pole through the ice to the bottom. Holding it in an upright position, I raised it and brought it down with all my strength. The pole went through the ice and so did I. The water was three feet deep. This depth covered only a small area around the house and was maintained by frequent digging. The house is often plastered with this dredged material. Altogether, then, the house from its lowest foundation on the bottom of the pond to the conical top was eight feet high. The foundation of this house was made of turf, masses of grass roots, and a small percentage of mud thickly reinforced with numerous willow sticks. The floor was mostly sticks. As the entrance tunnels were filled with water to a point about three inches below the floor-level, and as these were the only entrances or openings into the house, friend or foe could enter only by coming up through one or the other of these water-filled tunnels from the bottom of the pond.

The single, circular, dome-like room of this house was four and a half feet in diameter and about two feet in height. Its ceiling was roughly formed by a confused interlacing of sticks, which stood at an angle. The spaces between were filled with root-matted mud. The walls were a trifle more than two feet thick, except around the conical top. Here was a small space, mostly of interlacing sticks, the thickness of which was but one foot. As very little mud had been used in this part, there were thus left a few tiny air-holes. As I approached, there could be seen arising from these holes the steamy and scented breath of the beaver inhabitants within. Since the ventilation of beaver houses is exceedingly poor, and as this animal probably does not suffer from tuberculosis, it is possible that ventilation is assisted, and some of the impure air absorbed by the water, which rises almost to the floor in the large entrance-holes.

The early trappers from time to time noted extended general movements or emigrations among beaver, which embraced an enormous area. They, as with human emigrants, probably were seeking a safer, better home. Some of these movements were upstream, others down; commonly away from civilization, but occasionally toward it. For this the Missouri River was the great highway. Limited emigrations of this kind still occasionally occur.

The annual migration is a different affair. This has been noted for some hundred and fifty years or more, and probably has gone on for centuries. This peculiar migration might be called a migratory outing. In it all members of the colony appear to have taken part, leaving home in June, scattering as the season advanced. Rambles were made up and down stream, other beaver settlements visited, brief stays made at lakes, adventures had up shallow brooks, and daring journeys made on portages. The country was explored. The dangers and restrictions imposed during the last twenty-five years appear in some localities to have checked this movement, and in others to have stopped it completely. But in most colonies it still goes on, though probably not usually enjoyed by mothers and children except to a limited extent.

By the first of September all have returned to the home, or joined another colony or assembled at the place where a new colony is to be founded. This annual vacation probably sustained the health of the colonists; they got away from the parasites and the bad air of their houses. The outing was taken for the sheer joy of it. Incidentally, it brought beaver into new territory and acquainted them with desirable colony-sites and the route thereto,—useful information in case the colonists were compelled suddenly to abandon the old home.

It is natural for the beaver to be silent. In silence he becomes intimate with the elements, and, while listening, hears and understands all moods and movements that concern him. He is a master in translating sound. It wakens or warns, threatens or gladdens, and woos him back to slumberland.

On the wild frontier in his fortress island home in safety he sits and sleeps in darkness. He cannot see outside, but the ever-changing conditions of the surrounding outer world are revealed to him by continuous and varying sounds that penetrate the thick windowless walls of his house. He hears the cries of the coyote and the cougar, the call of moose, the wild and fleeting laugh of the kingfisher, the elemental melody of the ouzel, and many an echo faintly from afar. He hears the soft vibrations from the muffled feet of enemies; and, above his head, the raking threat of claws upon the top of his house. Endlessly the water slides and gently pours over the dam, and softly ebbs around the pond’s primeval shores. The earthquake thunder warns of storm, the floods roar; then through day and night the cleared and calmed stream goes by. The wind booms among the baffling pines, and the broken and leafless tree falls with a crash! There is silence! Along the stream’s open way through the woods numberless breezes whisper and pause by the primitive house in the water.

The Beaver’s Engineering

Realizing that the supply of aspens near the waters of the Moraine Colony close to my home was almost exhausted, I wondered whether it would be possible for the beavers to procure a sufficient supply downstream, or whether they would deem it best to abandon this old colony and migrate.

Out on the plains, where cottonwoods were scarce, the beavers first cut those close to the colony, then harvested those upstream, sometimes going a mile for them, then those downstream; but rarely were the latter brought more than a quarter of a mile. If enemies did not keep down the population of a colony so situated, it was only a question of time until the scarcity of the food-supply compelled the colonists to move either up or down stream and start anew in a place where food trees could be obtained. But not a move until necessity drove them!

Not far from my home in the mountains the inhabitants of two old beaver colonies endured hardships in order to remain in the old place. One colony, in order to reach a grove of aspens, dug a canal three hundred and thirty-four feet long, which had an average depth of fifteen inches and a width of twenty-six inches. It ended in a grove of aspens, which were in due time cut down and floated through this canal into the pond, alongside the beaver house. The other colony endured dangers and greater hardships.

During the summer of 1900 an extensive forest fire on the northerly slope of Long’s Peak wrought great hardship among beaver colonies along the streams in the fire district. This fire destroyed all the aspens and some of the willows. In order to have food while a new growth of aspens was developing, the beavers at a colony on the Bierstadt Moraine were compelled to bring their winter supply of aspens the distance of a quarter of a mile from an isolated grove that had escaped the fire. This stood on a bench of the moraine at an altitude about fifty feet greater than that of the beaver pond. Aspens from the grove were dragged about two hundred feet, then floated across a small water-hole, and from this taken up the steep slope of a ridge, then down to a point about one hundred feet from the pond. Between this place and the pond was a deep wreckage of fire-killed and fallen spruces. To cut an avenue through these was too great a task for the beavers; so with much labor they dug a canal beneath the wide heap of wreckage, and through this, beneath the gigantic fallen trees, the harvested aspens were dragged and piled in the pond for winter food. The gathering of these harvests, even by beavers, must have been almost a hopeless task. In going thus far from water many of the harvesters were exposed to their enemies, and it is probable that many beavers lost their lives.

THE 334-FOOT CANAL

Beavers become strongly attached to localities and especially to their homes. It is difficult to drive them away from these, but the exhaustion of the food-supply sometimes compels an entire colony to abandon the old home-site, migrate, and found a new colony. Some of the beavers’ most audacious engineering works are undertaken for the purpose of maintaining the food-supply of the colony. It occasionally happens that the food trees near the water by an old colony become scarce through excessive cutting, fires, or tree diseases. In cases of this kind the colonists must go a long distance for their supplies, or move. They prefer to stay at the old place, and will work for weeks and brave dangers to be able to do this. They will build a dam, dig a new canal, clear a difficult right-of-way to a grove of food saplings, and then drag the harvest a long distance to the water; and now and then do all these for just one more harvest, one more year in the old home.

The Moraine Colony had lost its former greatness. Instead of the several ponds and the eight houses of which it had consisted twenty years before, only one house and a single pond remained. The house was in the deep water of the pond, about twenty feet above the dam. A vigorous brook from Chasm Lake, three thousand feet above, ran through the pond and poured over the dam near the house. The colony was on a delta tongue of a moraine. Here it had been established for generations. It was embowered in a young pine forest and had ragged areas of willows around it. A fire and excessive cutting by beavers had left but few aspens near the water. These could furnish food for no more than two autumn harvests, and perhaps for only one. Other colonies had met similar conditions. How would the Moraine Colony handle theirs?

The Moraine colonists mastered the situation in their place with the most audacious piece of work I have ever known beavers to plan and accomplish. About one hundred and thirty feet south of the old pond was a grove of aspens. Between these and the pond was a small bouldery flat that had a scattering of dead and standing spruces and young lodge-pole pines. A number of fallen spruces lay broken among the partly exposed boulders of the flat. One day I was astonished to find that a dam was being built across this flat, and still more astonished to discover that this dam was being made of heavy sections of fire-killed trees. Under necessity only will beavers gnaw dead wood, and then only to a limited extent. Such had been my observations for years; but here they were cutting dead, fire-hardened logs in a wholesale manner. Why were they cutting this dead wood, and why a dam across a rocky flat,—a place across which water never flowed? A dam of dead timber across a dry flat appeared to be a marked combination of animal stupidity,—but the beavers knew what they were doing. After watching their activities and the progress of the dam daily for a month, I realized that they were doing development work, with the intention of procuring a food-supply. They completed a dam of dead timber.

At least two accidents happened to the builders of this dead-wood dam. One of these occurred when a tree which the beavers had gnawed off pinned the beaver that had cut it between its end and another tree immediately behind the animal. The other accident was caused by a tree falling in an unexpected direction. This tree was leaning against a fallen one that was held several feet above the earth by a boulder. When cut off, instead of falling directly to the earth it slid alongside the log against which it had been leaning and was shunted off to one side, falling upon and instantly killing two of the logging beavers.

The dam, when completed, was eighty-five feet long. It was about fifty feet below the main pond and sixty feet distant from the south side of it. Fifty feet of the new dam ran north and south, parallel to the old one; then, forming a right angle, it extended thirty-five feet toward the east. It averaged three feet in height, being made almost entirely of large chunks, dead-tree cuttings from six to fifteen inches in diameter and from two to twelve feet long. It appeared a crude windrow of dead-timber wreckage.

Moraine Colony with Dead-Wood Dam
(Select to Enlarge)

The day it was completed the builders shifted the scene of activity to the brook, a short distance below the point where it emerged from the main pond. Here they placed a small dam across it and commenced work on a canal, through which they endeavored to lead a part of the waters of the brook into the reservoir which their dead-wood dam had formed.

There was a swell or slight rise in the earth of about eighteen inches between the reservoir and the head of the canal that was to carry water into it. The swell, I suppose, was not considered by the beavers. At any rate, they completed about half the length of the canal, then apparently discovered that water would not flow through it in the direction desired. Other canal-builders have made similar errors. The beavers were almost human. This part of the canal was abandoned and a new start made. The beavers now apparently tried to overcome the swell in the earth by an artificial work.

A pondlet was formed immediately below the old pond by building a sixty-foot bow-like dam, the ends of which were attached to the old dam. The brook pouring from the old pond quickly filled this new narrow, sixty-foot-long reservoir. The outlet of this was made over the bow dam at the point nearest to the waiting reservoir of the dead-wood dam. The water, where it poured over the outlet of the bow dam, failed to flow toward the waiting reservoir, but was shed off to one side by the earth-swell before it. Instead of flowing southward, it flowed eastward. The beavers remedied this and directed the flow by building a wing dam, which extended southward from the bow dam at the point where the water over-poured. This earthwork was about fifteen feet long, four feet wide, and two high. Along the upper side of this the water flowed, and from its end a canal was dug to the reservoir.

About half of the brook was diverted, and this amount of water covered the flat and formed a pond to the height of the dead-wood dam in less than three days. Most of the leaky openings in this dam early became clogged with leaves, trash, and sediment that were carried in by the water, but here and there were large openings which the beavers mudded themselves. The new pond was a little more than one hundred feet long and from forty to fifty feet wide. Its southerly shore flooded into the edge of the aspen grove which the beavers were planning to harvest.

The canal was from four to five feet wide and from eight to twenty inches deep. The actual distance that lay between the brook and the shore of the new pond was ninety feet. Though the diverting of the water was a task, it required less labor than the building of the dam.