Beavers Carve Out a Niche in the Greenbelt

by Don Recklies

After our 296th scheduled Restoration Workshop, where over 20 volunteers helped clear vines off trees on and around Moses' Mountain, several of us took a walk back into Buck’s Hollow to check out the beaver site close to Buttonbush Swamp. Beavers are crepuscular and nocturnal animals, denning up in their lodges during the day, so there was little chance we would spot one, but what I call “pencil” stumps gave indisputable evidence of their presence.

North American beaver of the kind most likely found in the Greenbelt.

(Source: Steve from Washington, D.C., USA, via Wikimedia Commons)

I say “their,” but there is no evidence that there is more than one beaver. I suspect that this beaver might be one of the family that in 2016 built a dam at Historic Richmond Town that the city tried hard to remove. That dam, which made it easy for us to cross the creek on the Red Trail, raised the water upstream and created a flooding issue for houses along Richmond Road, in back yards if not in basements and low garages. At least three times their dam was breached or removed, and the enterprising beavers built it back up within a matter of days until finally the dam and even the rocks in the stream which anchored it were removed and the beavers disappeared. Perhaps they were trapped and transported elsewhere - but I have no sure knowledge of that. In any case, in 2019 the New York City Department of Environmental Protection (DEP) applied to the New York State Department of Environmental Conservation (DEC) for a permit to remove the dam---a complicated issue because the beaver is a protected animal on NYS public lands. I can’t find later notices about that DEP action, or what was done, but the beavers seemed to have disappeared. There was a family, and I wonder now if one of the young males might have been old enough to have set out on his own and has now resurfaced at Buttonbush Swamp.

There was also some suggestion about building in a device that has been used elsewhere to control the water level behind the dam. Beavers respond quickly to the sound of running water, and it is this clue that leads them to start repairing. In some places a long pipe has been installed that takes water from upstream of the dam and discharges it downstream below the dam. The height of the intake of the pipe is what limits the height of water behind the dam. The intake is placed far enough upstream that the beavers don’t sense the sound of running water there as any threat. It’s said to work, but expensive to accomplish, and I don’t think that at Richmond Town any rise at all in the water level would have been tolerated.

The week before the restoration I walked around the site doing a rough count of pencil-point remnants of at least 66 chewed off saplings and shrubs. By the time we got to that site after the workshop this week it had become overcast, otherwise those bright white, newly chewed pencil stumps would have grabbed at our eyes. So far the wire cages the Greenbelt educators placed around the persimmon trees there have kept them safe. What will happen to them if the beaver tries to dam up the swamp this summer to make deep water for storing his winter twigs I don’t know.

Indisputable evidence of beaver activity in preparation for dam building.

(Source: B. Schoenmakers at waarneming.nl, via Wikimedia Commons)

Beavers were important in New York as early as the time of the Dutch settlement - then New Amsterdam - that’s why they figure on both the seals of New York and New Amsterdam. At their colony at the mouth of the Hudson the Dutch traded with native peoples for beaver pelts, and the English continued that trade after they compelled the Dutch to hand over control of that territory. The trade was mostly for the fur of the beaver; the rest of the animal was incidental. The skins were shipped to Europe where the fine fur was cut away from the pelts and hammered to make a dense, pliable and waterproof felt much desired for the production of hats. Interestingly, old worn pelts commanded a higher price than new fresh ones because old pelts, such as pelts the trappers had worn through the winter or had been slept on for several years, had the long, coarse winter hairs worn off the dense short hair layer below. Felters had to labor more to remove the long hairs from fresh pelts, so the old stuff was desirable. In the 1500s through 1700s felted beaver hats were a necessary part of most middle class men’s wardrobes and military headware. Beaver fur was so necessary for this purpose, that the European beaver had been almost exterminated, and the industry was desperate until the American animal provided equally suitable fur. Probably all our beaver would now have vanished but for that in the mid 19th century silk hats had become fashionable, and the beaver felt market collapsed. In New York State beaver populations did not recover in until just before WWII.

As a matter of curiosity I looked on the web for new beaver felt hats. Prices varied widely, but when I looked more closely I saw that in the itemized description of the cheaper hats only “felt” or “fur felt” was declared; and the fur the hat was made of was usually rabbit or some other animal. The ones that specified “beaver felt” were often over $1000.00. So, there still is a market, but it’s somewhat a luxury market not requiring “harvesting” of beavers by the tens of thousands.