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Saturday, July 18, 2020

A Beaver and a Conundrum

It is the nature of beavers to bring change. Where they go, new and improved ecosystems follow. What was once a slow, babbling brook becomes a pond or lake, resplendent with life. What was cropland becomes a marsh with minnows and amphibians, shorebirds, waterfowl, and aquatic insects. Beavers leave a wake of biological diversity. 

And so it was that when beavers moved into Spring Creek and laid claim to our property there was great celebration. By deed we controlled a reasonable length of stream so the consequences of a dam or two would affect us without influencing neighbors who relied on certain creek elevations for field drainage. We welcomed the beavers, looked forward to their impact, and prepared ourselves for the accommodations that might be necessary to support and encourage them. 

On a single night one early fall, the season when a beaver is actively building its winter food cache, we had a row of trees magically disappear from our plant nursery, which at the time was a primary source of income. The trees were about 2 inches in diameter on the stump. They had been cultivated for several years and were prime for conversion to currency. But on that fateful night they disappeared, not a twig or stem remained, only short, pointed stumps and a few chards of wood bearing tell tale impressions of beaver incisors. 

Rarely does a man’s land use objective coincide with a beaver’s intended purpose. Over the years we have had to abandon flooded irrigation pump pits, repair chewed power supply lines, relocate property access lanes due to standing water, stand by as nursery crops were inundated, lost valued yard trees, all due to beaver activities. But there have been extraordinary benefits: a gathering of nearly 100 migrating waterfowl in a flooded lowland, a deafening chorus of spring peepers and chorus frogs where there had been none, a pair of sandhill cranes staying through the nesting season, and endless opportunity to view changes to a landscape where habitat diversity and wildlife use increased on a logarithmic scale. 

In the years before beavers we had three ponds constructed. The two most valued covered three acres and put water within feet of the house, giving us a commanding view from our kitchen and patio. The largest of the ponds was built by pushing up a berm running parallel to Spring Creek over a distance of several hundred feet, so the pond and creek were separated by a sliver of land perhaps 30 feet wide. 

The current perceived problem is a new beaver dam which is backing water onto the berm, providing an open invitation for muskrats to burrow. The berm was designed wide enough that muskrats burrowing in from the pond side should never succeed in digging through to the back, thereby causing a breach. But now, with the stage set for muskrats to excavate from both sides, the risk of losing berm integrity becomes a clear and present danger, and I find myself rehearsing the day when I pour a cup of morning coffee and look out the window to what was the pond but is now a hole of putrid, dying algae resting in a black soup. 

I had read enough to understand the futility of removing beaver dams-- those blown out with dynamite or completely deconstructed via excavating equipment are typically rebuilt in record time-- but I had never had the experience of removing one by hand. I felt my time had come, so on a hot afternoon I waded in. I picked a point mid-dam, and standing in knee-deep ooze and water to my waist, began disassembling. In short order the details of a master engineer came into view. 

The dam was composed of primarily dead woody material which was sealed on the upstream side with large quantities of fresh green grasses, rushes, and sedges laid horizontally and packed with mud. As I scooped up handfuls of the topmost layer, a small torrent of water ensued, providing welcomed aid in loosening and carrying additional material downstream. In time the torrent grew to such force that even 6 inch diameter logs of 8 foot length were dislodged and easily launched downstream through the sluiceway. Occasionally, in the assorted construction materials, were lengths of wild rose and greenbrier, randomly placed so my bare feet and hands were soon embedded with thorns. I could have imagined these were located purposely, to discourage the very activity in which I was now engaged, but stopped short of giving the beaver such credit. 

With every log dislodged, with every bundle of sedge and mud swept downstream, I thought of the beaver and the effort and time it would take him to rebuild. I pictured him working methodically, steadfastly, employing ancient skills to transform a landscape for the benefit of many. I imagined him in a burrow somewhere upstream, perhaps sensing a drop in water level, perhaps hearing a rush of water where before there was none. I occasionally glance over my shoulder to see if he's come to assess the source and extent of damage, but he has not. I continue my work, and eventually create an opening near 10 feet wide with a newly established water level fully a foot lower than when I started, a level that no longer invited muskrats to the berm, a level I could live with. 

As expected, within three days the dam had been returned to its former magnificence and water covered the lower aspects of the berm. I let the situation ride for about a week before launching a second attack. I had learned from my first experience to wear a pair of lined gloves, but remained barefoot, and with the first step into the ooze landed squarely on a cluster of greenbrier thorns, embedding them nicely in the arch of my right foot. I again imagined the beaver, taking time out from his dam repair, hunched on the shore and contemplating my entry point, then carefully placing and concealing the prickly deterrent. I hobbled on and with an earnest effort opened up a section nearing 20 feet in width, again lowering the water level by about a foot. 

I now convinced myself the beaver was indeed fully aware, even from the confines of its burrow, that something was amiss. In my mind I saw him venturing out at dusk to document the damage, his long nights of labor intentionally and inexcusably destroyed once again. I see him reacting without rage or judgement or dread, but with calm acceptance of a task at hand, and gets to it. 

My first real experience with beavers came while doing research on moose and wolves in Isle Royale National Park. Beavers were incidental to our focus but their influence surrounded us. Their dams peppered the island and provided welcomed bridges across wetlands during field work, their ponds provided aquatic vegetation invaluable to browsing moose, their habits benefited a raft of life as they always do. It was on the island that I first heard the resounding flap of a beaver’s tail on water, signaling alarm. It was there I first breathed air rich with castor, marveled at a beaver’s ability to fell and maneuver trees, looked with appreciation on the massiveness of their winter food caches, heard them vocalize, watched them groom. 

Those memories only fuel my appreciation of having them on our property today, and not before now have I tried to enforce parameters on them. This is big ag country, where opportunity for beavers to work their ecological magic unrestricted is exceedingly rare. 

Within a week the dam is again rebuilt, the water resting against the berm. Once more I do the deed, begrudgingly, not because the task is difficult, it's actually invigorating, but because I'm not totally convinced it's necessary. Maybe I'm wrong about the muskrats. Maybe they won’t threaten the berm. I love the new wetland, it's waters filling the original serpentine course the stream held before it was straightened, the mounds of spoil dredged decades ago transformed to islands. It's all beautiful, and beautifully functional. 

It's been several days with no evidence of rebuilding. I won't pacify myself with the prospect of an accord being met. The beaver is likely demonstrating an exaggerated lack of urgency, has been picked off by a coyote, or has moved upstream with the hopes of finding a more welcoming site. If it's the latter, he will be backing water onto a neighbor who holds a loaded gun and no appreciation for beavers.  
I'm staring down a conundrum, digging greenbrier thorns from my feet, waiting. In a world of multiple crises, I'm hoping to find common ground and do right by a beaver, an animal slaughtered by settlers, once extirpated over most of its historic range, despised by row crop practitioners of today. An animal gifted like none other to bring life to a desperate and abused land, to offer a free environmental service that contributes to flood and sediment control, restores aquifers, and contributes mightily to wild diversity. I'm on its side, with no apology.

2 comments:

  1. We're engaged in a similar though more violent dance with raccoons, shotgun, and electrically charged barriers that was initiated by our introduction of bird feeders.

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