Upon studying the government map, we figured that if he followed a chain of lakes and ponds through the connecting streams, he must have traveled thirty-five miles. If he had come over the mountain and several foothills in a straight line, which seemed unlikely, he might have shortened his trip to about twenty miles.
We saw the white headed beaver many times during our visits to the pond that summer, sometimes on shore, or sitting on the trunk of a poplar or birch tree which he had felled near the water. His body was about thirty inches long, tail ten inches long and six inches wide, hind feet webbed, like those of a goose, fore feet resembled the hands of a child but with long, sharp toe nails. He might have weighed forty or fifty pounds. He was a slow and clumsy traveler on land but a very efficient citizen in the water. He could dive and remain under water from eight to ten minutes without apparent inconvenience. Swimming, he could tow a log twice his own weight and against the current when necessary.
Early in September, his wife arrived. Whether the "old man" went after her, whether he sent a wireless message or a telepathic command, or whether the date of her coming had been arranged between them before he left home, we never knew. It seems quite probable that she just naturally knew that it was high time for her husband to stop exploring and loafing and to get busy building a house and storing a supply of food for the winter, so she arrived.
She would have no difficulty in following his trail, which after the habit of his kind, he doubtless marked at more or less frequent intervals by scooping up from the bottom of the pond or stream a double handful of soft mud, which he would place on the shore, shape it up into a nice round mudpie and deposit in its center a few drops of "Castoreum." This material has a peculiar, pungent and individual odor easily recognized by members of a beaver family. The Indians also highly prized the castoreum of the beaver for its supposed medicinal properties.
Immediately on the arrival of the female beaver the two began work building a house. This was placed on a point of land between the mouth of the river and a shallow bay or slough. The base of the house was about a foot above the normal level of the pond. Straight sticks and crooked branches two to four inches in diameter and about five feet long were placed on the ground for a foundation and were arranged in a circle like the spokes of a wheel. On these were piled other sticks, brush, stones, sod and mud, which latter was used as cement or mortar to bind the other materials together. An open space was left in the center, which grew smaller in diameter as the walls were carried up and was finally arched over. The house when finished was fourteen feet in diameter at the base; it was cone shaped and six feet high. It had no door or entrance visible on the surface; but as the side walls were being carried up one of the beavers dug a round hole twelve inches in diameter, straight down from the center of the house about eighteen inches, when it was curved toward the river and opened out in the bottom. Then he dug a second entrance, close to the first one, but this curved toward the slough. The water there being shallow, a ditch or canal dug in the bottom carried the outer end of the burrow down about three feet below the surface and a hundred feet or more out to deep water. The mud procured in digging the entrance and exit was used in plastering the walls of the house. No mud was used on the ventilating flue, which was a space about a foot in diameter in the center of the cone. This was thoroughly protected from outside enemies by two feet in thickness of criss-crossed sticks, but air could freely pass through the interstices.
The house building proceeded rapidly, much of the work being done at night, but we were able to inspect the building daily, and several times we found the beavers working in the daytime. Always the white crowned beaver was the leader and seemed to be directing the work of the other. When the structure was completed it proved to be an excellent example of reinforced concrete work of a most substantial character. Nevertheless, six weeks later, just before freezing weather started, a final coating of mud three inches thick was plastered over the entire outside surface of the house. When frozen, this armor plate would furnish complete protection to the furry inhabitants against their most ferocious enemies during the long and hungry months of winter.
Some years later, a beaver house, the side of which had been cut away, afforded an opportunity for us to learn how our white-headed friend finished the inside of his castle. The rough projecting inner ends of sticks, branches and brush were gnawed off making a roomy, smooth-walled, dome ceilinged space divided into two parts. The first, or ground floor, contained the openings for entrance and exit. It also was used as a drying room; for no self-respecting beaver would ever permit himself, his family or guests to go to bed in wet clothes. Coming in from swimming in the pond or river he must sit in the vestibule until his wet fur is thoroughly dry before he climbs into the bunk.
The drying floor also serves the purpose of a dining room in winter, when the pond is covered with ice, as will later appear.
The sleeping apartment had its floor about six inches higher than the drying floor. The bed was made of thin shreds or splinters of dry poplar wood. A quantity of this material had been split out with an expenditure of much time and patience. A mattress three inches or more thick, made of this soft, elastic material would make a far better bed than many campers can boast of.
Mud for use in house building was procured, not only from the tunnel entrances and from the canal, but excavations were made in the river bottom near the house. A pocket was there dug out, about twenty feet in diameter, making the water six feet deep.
Into this hole the two beavers now proceeded to store their food for the winter. This consisted chiefly of the trunks of poplar saplings, two to six inches in diameter, cut into lengths of four to six feet, the sticks of larger diameter being the shorter. In the wood pile were also placed the branches of the same trees. Mixed in with the poplar were some alders and a few birch and soft maple sticks. The birch and alder apparently were used to add spice and tang to the otherwise sameness of their more staple food.
In the edge of the forest next the slough a few years before, a fire (doubtless started by some careless hunter), had burned over several acres, and this was now covered by a "second growth" of poplar. It was there that the beavers cut most of their lumber. The water in the slough was shallow and filled with pond lilies, so a canal three feet wide, two feet deep and two hundred and twenty feet long was dug across this mudhole. Through this canal the beavers floated their sticks and brush and placed them on their storage pile under water so that the bark, which they eat, might be kept soft and fresh for winter use. Also, so that it might be reached from their house under the ice, after pond and river were frozen.
Day after day Bige and I watched the progress of this harvest. Saw the beaver towing the floating logs through the canal into the pond and up the river to the lumber pile where the beaver would dive with his stick and presently come to the surface again, leaving the stick under the water; and we wondered how he did it. Also we discussed possible ways of making a floating stick sink. From our boat we could see the pile of wood below the surface of the water and we could see no stones on the pile.
Bige stoutly argued in support of the theory that the beaver sucked the air out of the pores in the wood, that the water flowed into the vacuum thus produced, making the stick heavy enough to sink. In order to demonstrate his theory, Bige took the axe from camp, cut a poplar sapling an inch and a half in diameter and the usual beaver length, put one end in the water and sucked on the other end of the stick. After repeated trials and failures to make the stick do anything but float, Bige decided that his "sucker was not powerful enough." The next day, looking down into the water from our boat, we saw one end of the axe-cut stick in the wood pile with other sticks cut by beaver teeth.
After my return to the city, Bige reported from time to time, making visits to the beaver house, seeing beaver swimming under the ice, carrying sticks from the wood pile into the tunnel leading to the house; also later, beaver bringing peeled sticks out of the house and placing them in a very orderly manner on another pile. Reports also reached me of beaver under the ice digging pond lily roots and carrying them into the house.