There is plenty of beaver sign to see around these days, some of it good and some of it bad. If beavers build a dam in a secluded region they are fawned upon as great engineers and conservationists. If they flood the fairway between the fifth and sixth holes of the local golf course they are denounced as destructive critters and a menace to civilization. There are deep struggles over the role of the beaver in modern America but I am glad to report that the pro-beaver forces are getting the upper hand.
America owes one of its greatest debts to the beaver. This doesn't mean that the beaver is going to be paid off. He never could be paid in full, for it was this ingenious animal that led the pioneers to most of the riches of this continent. But now our nature students are proving that the beaver has a far greater worth than the money to be derived from the sale of his hide. Furthermore, something is being done about it—hence all this beaver sign.
Most of the states are taking some sort of official action. In the West beavers in boxes have been parachuted into wilderness areas. When the parachute lands the box opens and the beaver is free to start engineering projects. (They'll build a $5,000 dam for nothing.) In New Jersey beavers are constructing dams within sight of Manhattan's tall buildings, some of which stand on land once purchased with beaver money. In many states conservation-department men are now moving beavers into forests where they have been missing for decades.
In all these areas the beaver tribe was once legion. When the Dutch colonists settled on Manhattan Island they found the country inland was populated by an astonishing rodent, the engineer of the animal world. Small streams flowed through countless ponds created by their dams, elaborate structures of mud, grass, twigs, limbs, logs and stones. But of greatest interest to the colonists was the rich, brown fur of the animal. It provided them with exportable merchandise from the start and they pounced upon it. By 1800 the search for fur had reached the West Coast. John Jacob Astor merged various companies into the American Fur Company and became by far the richest man in America.
Under such pressure the beavers dwindled. By as early as 1870 they had become scarce in many states east of the Rocky Mountains and in time the great fur trade was gone. The country had been opened up and Americans were harvesting other riches they had discovered in the search for beaver pelts.
For a long time nobody much missed the beaver, except naturalists who were fascinated by his engineering skills. Beaver dams may be several hundred feet long. One classic structure was 260 feet long, six feet, two inches high and 18 feet wide at the base. It backed up a lake of 60 acres.
It was when the ecologists became interested in the beaver that the present revival began. Ecology is the relationship of an organism to its environment and to other organisms. The ecologists found that when a group of beavers build a dam they help conserve water, raising the water table and providing more moisture for plant growth. As uncut trees in the flooded area die, woodpeckers, flying squirrels and other creatures are attracted to them for food or nesting places. The watery expanse behind the dam is shared by wild ducks, muskrats and a host of lesser forms of animal life. The beaver pond and its environs become a busy community.
Slowly the pond silts up and eventually the beavers abandon it to seek another site. The old dam disintegrates and the water drains away, leaving once more the small winding stream. But now it flows through a valley in which has been deposited several feet of rich topsoil. The former pond becomes a lush meadow. Shrubs appear and finally the large trees rise again under conditions more favorable to their growth. Another segment of the wilderness has been enriched and regenerated, thanks to the beaver. Multiply this by thousands and the importance of the beaver's role in the scheme of the American forest becomes obvious.
During these studies a few beavers were released in wooded sections where, just like their ancestors, they set right to work. Such a place was the 51,000-acre Palisades Interstate Park bordering the Hudson River at Bear Mountain. The last beaver in those parts had been seen in 1882 at Round Pond near West Point. In 1920 three pairs were released in the park. In 1938 a survey disclosed 42 colonies in the park totaling about 500 individuals.
Then mysterious events began to take place beyond the park boundaries. A pond would appear suddenly on the edge of a golf course. A road would become flooded where there had been no rain. The level of a pond would start to rise or trees would be found lying across highways. Lengthy struggles over riparian rights developed between beavers and landowners. One Connecticut estate owner broke down a beaver dam every night only to find it repaired the next morning. This went on for five weeks before the beavers finally gave up. Culverts proved ideal places to stop up and make ponds. At Bear Mountain beavers had built a dam which flooded a road. Park rangers broke a hole in the dam and set a forbidding scarecrow, or scarebeaver, in the break. The next morning the dam had been repaired neatly. The scarecrow was gone and the pole that had supported it had been used in rebuilding the dam.