Cold weather came one fall before my new beaver neighbours had laid in their winter’s food. They had harvested one food supply several miles down stream but a fierce forest fire had devastated the region while they were in the midst of their preparations for winter and left their home site unliveable. The beavers in a body started off to found a new colony, having the hardships and adventures that ever fall to pioneers. The place selected for their new home was on a tributary stream not far from my cabin. Here they built a typical house of sticks, sod, and mud. The stream ran through an old glacier meadow partly overgrown with forest. One side carried a belt of pines. Beyond the pines was a ragged and extensive growth of quaking aspen. Up stream the mountain rose steeply to the summit of Mt. Meeker. While the beavers were working on a dam which was to give them ample water in the pond to prevent its freezing to the bottom, a trapper These beavers had been industrious. They had planned well. But it was a case of one misfortune quickly following another. A severe cold wave still further and seriously handicapped the harvest gathering of the colonists. The quieter reaches of the stream were frozen over and a heavy plating of ice was left on the pond. They would have difficulty transporting their food-cut aspens under such conditions. Winter supplies for this colony—green aspen or birch trees—must be had. Ordinarily, beavers cut the trees most easily obtained: first those on the shore of the pond, then those up stream, and finally those on near-by, down-hill slopes. Rarely does a beaver go fifty feet from the water. But if necessary he will go down stream and float trees against the current, or drag trees up steep slopes. This pond did not have, as is common, a border of aspen trees. Late October I visited this new wilderness home. In the lower end of the frozen pond was a two-foot hole in the ice. This had been One crew of loggers had started to work in a grove about two hundred feet from the hole in the ice. They were cutting aspens that were about four inches in diameter and twelve feet high. But before dragging them to the pond an opening or trailway through the woods had been cleared. Every bush in the way was cut off, every obstructing log cut in two and the ends rolled aside. Dragging their tree cuttings to the pond was slow, hard work, and it was also dangerous work for a slow-moving beaver to go so far from the water. A beaver is heavy bodied and short-legged. With webbed hind feet he is a speedy swimmer, but on land he is a lubber and moves slowly and with effort. A few days later the purpose of the hole in the ice of the frozen pond was made plain. A freshly swept trail in the snow led to it out of the woods. The beavers were taking their green aspen cuttings through the hole into the pond for their winter’s food. They had begun storing winter food at last. I followed the trail back to where a number of aspens had been cut. Their stumps were about fifteen inches above the snow. Two trees still lay where they fell. These were about six The beavers had not nearly finished their harvesting when a heavy fall of snow came and they were compelled to abandon their carefully made dragway and the aspen grove where they had been cutting. The nearest aspens now available were only sixty feet from the edge of the pond. But a thick belt of pines and a confusion of large, fallen, fire-killed spruce logs lay between the pond and this aspen grove. Deep snow, thick pines, and fallen logs did not stop their harvest-gathering efforts. Tracks in the snow showed that they went to work beyond the belt of pines. During one night five beavers had wallowed out to the aspens, felled several and dragged them into the pond. But wolves appeared to realize the distress of the beavers. They lurked about for opportunities to seize these hunger-driven animals. While harvesting the aspen grove wolves had pounced upon one of the beavers at work and another on his way to the pond had been pursued, overtaken, and killed in the deep snow. During three days of good weather which followed, ever watchful for wolves, the beavers cut few aspens. Then came another snowstorm. But beavers never give up. To obtain aspens which were to supply them with winter food they finally dug a tunnel. They began this on the bottom of the pond near the shore and dug outward toward the aspen grove. The tunnel was about two feet under the surface for fifteen feet. From this point it inclined upward and came out under a pine tree, close to the aspens. In only the last few feet, where the digging was through frozen ground, was there difficult digging of this tunnel. Apparently the thick carpet of fallen leaves and the deep snow checked the frost and the earth had not frozen deeply. From the end of this tunnel the beavers cleared a dragway about eighteen inches wide to the aspen grove. In doing this they cut through three or four large logs and tunnelled under a number of others. Then aspens were felled, cut in short sections, dragged to the end of the tunnel, pushed through this out into the pond beneath the ice, and finally piled on the bottom of the pond close to the house. Solid snowdrifts formed in the grove while this slow work of transportation was going on. A few aspens were cut from the top of a five-foot snowdrift. The following summer these At last cold, ice, snow, and enemies completely stopped the beavers’ harvest gathering. The food provided for the colony’s winter supply was less than one half that needed. But the beavers had done their best, and come what may, they would alertly, stoically meet it. These colonists had a hard winter. I visited them a number of times. Now and then snow covered the frozen pond, but usually the wind in sweeping down the open-stream avenue through the woods left the ice clear. One day, looking through the clear ice of the pond, I counted six beavers, but on most occasions I was able to see only one or two. The population of this colony probably numbered twelve or fifteen. The upper part of the area flooded by their pond had been a semi-swampy tract bearing thick growths of water-loving plants. The roots of sedge, bulbs of lilies, tubers of many plants, and long juicy roots of willow and alder were made use of by these beavers facing a food-shortage. I supposed it was only a question of time before they would be shut off by the thick ice from this root supply. But they dug a deep waterway—a canal about two feet wide and nearly as deep—from the house in the centre of the Mutual aid is a factor in beaver life. I do not know how many days’ work this ditch required; but when one of the beavers in a colony work, all work. Since late summer these beavers had worked at one task after another; they had unitedly worked for the welfare of each member of the colony. With mutual aid beaver colonists achieve much in a short time. Their strong love for home, causing them to remain long in one place, and the peculiar work which this calls for, makes changes on earth sometimes enduring for centuries. But they had only commenced to dig out the roots on the bottom of the pond when the ever-thickening ice froze over this life-saving food supply. The water would have been deeper over this area but the beavers’ early hard luck had prevented their building the dam as high as it should have been. I do not know how they handled the food-shortage, whether or not they went on short rations. But no beaver had more than his portion, for beavers are coÖperators, they work in common, and so long as the food supply lasts each has his share. I had glimpses of the beavers’ eager digging through the clear spots in the ice. They tore the root-filled section to pieces and devoured all that it contained. But not until the following summer, when the broken dam released the water, did I realize how deeply and completely the bottom of the pond had been stirred and ploughed. I have seen gardens uprooted by hogs, and mountain meadows dug to pieces by grizzly bears, but neither of them equalled this. The supply of roots ran out and the bark of the green aspens was eaten off, and still this mountain region was white with winter and the pond locked and sealed with ice. Beavers are strict vegetarians. There were trout in the pond, but these were not caught; nor were the bodies of the starved ones eaten, as sometimes occurs among other animals. The beavers must escape from their now foodless prison or perish. Spring examinations which I made indicated that they had tried to escape through the long tunnel which had been made to obtain the aspens, but this had nearly filled with ice. They had then driven several feet of a new tunnel, but evidently found they could not accomplish it through the frozen, gravelly earth. Beavers are engineers—the handling of earth in building dams or in the making of canals is as much in their line as tree felling—but cutting and tunnelling They then attempted to cut a hole upward through the two feet of ice, as I found out later when the ice was breaking up. And they had almost succeeded. On the edge of their house they had raised a working foundation of mud and sticks and gnawed upward to within three or four inches of the surface. Beavers are expert gnawers and have been known with their powerful teeth and strong jaws to gnaw off and fell trees more than two feet in diameter. Perhaps they might have succeeded eventually, but they apparently found another and better way out of the pond. What they finally did was to tunnel out through the unfrozen earth beneath the bottom of the dam. They had commenced on the bottom of the pond and driven a fifteen-inch tunnel nearly level through the base of the dam, and a foot or two beneath the water and below frostline. This came out in the ice-covered stream channel, beneath the frozen earth. As this tunnel had to be dug under water, it must have been slow work and to have constantly called for relay efforts. When a working beaver had to breathe it was necessary for him to swim to the house and climb up to the floor, above water level, in order to obtain air. Tracks of six muddy-footed fellows on the snow at the outer end of the successful tunnel told the number who survived the winter’s food-shortage. Spring came, and warmth and flood water broke up the ice on the pond about a month after they escaped. No young beavers were seen. These surviving beavers lived in bank holes along the stream until summer. Then they wandered away. Late that August they, or six other beavers, came to the place. They completed the dam and repaired the house, and by mid-October had a huge pile of food stored in the pond for the winter. |