Leave It to Beavers

Building better ecosystems--one beaver at a time! 

I live in an expanding western Massachusetts town that’s short on available housing stock. As in all such towns, this has sprouted new developments on lands that for centuries have been meadows and forest, many of which are bounded by wetlands. New suburbanites generally like the idea of living in sylvan developments, but they often have trouble with the reality of deer munching their rhododendrons, foxes carrying off Fluffy the cat, or black bears taking down bird feeders and frightening little Joey. But nothing seems to inspire their ire quite like beavers, those buck-toothed, pancake-tailed varmints who build domed dams that  (very occasionally) cause water levels to rise to the point where suburbanites living nearby get wet basements. God forbid the trunk of a prized magnolia–a non-native invasive species–ends up on the dam. That leads to demands for poisoning the beavers. (Note to complainers: Install a sump pump or move to an in-town condo!)

I live on a street that was once woodlands, so I steadfastly refuse to sign all neighborhood petitions for any sort of wildlife control. That certainly extends to beavers. Hell’s bells, developers cut down thousands of trees to build the houses on my street and those that adjoin it, so it would the height of hypocrisy to get bent out of shape by a few rodents taking down some saplings. Courtesy of the Spokane-based Lands Council, I now have ammunition at my disposal other than principled crankiness the next time the Beaver Posse comes to my neck of the (radically thinned) woods.

These days we speak of the “environmental” movement. I’m fine with that, but back in the late 1960s the term of choice was “ecology.”  Ecology is a stronger word in that it sees the earth as a series of interconnected systems, not merely a mindset about nature. Ecological research shows that each species–plants and animals alike–live in interdependent relationships within specific natural environments. Those of you who are science fiction fans (or anthropologists) have no doubt encountered some variant of the “butterfly effect,” which derives from ecology. In simplest terms it says that you can’t change one thing within a system without inadvertently changing a whole lot of other things. To boil it down ecologically, you shouldn’t mess with Mother Nature, and Mom likes beavers.

The Lands Council has pretty convincing data–some of which goes back to the 1920s–that shows that removing beavers from an ecosystem increases the likelihood of erosion, drought, and floods. The latter was an eye-opener. To put it in suburban terms, all those wet basement homeowners who want to run Bucky the Beaver off the pond are actually increasing the odds of devastating floods. Beavers not only prefer wetlands, their dam-building activities build and preserve them. Those wetlands, in turn, retain rainwater and snow melt, and give them somewhere to go when they come in abnormal amounts. They also raise the water levels that sustain vegetation. Therein lies the irony; remove the beavers that are chewing your trees and you’ll eventually end up with fewer trees, not more. Your grass, bushes, and flowers won’t grow as well either, and your soil will deplete its nutrients. Shrink the watersheds and all that water once absorbed in them will find a new home. Ask Smith College, which responded to beaver damage by cutting down hundreds of trees along Paradise Pond, which is now silting at alarming rates due to bank erosion. Ask New Orleans, which drained wetlands decades ago that would have diverted much of the floodwater unleashed by Hurricane Katrina in 2005.

Idaho is embarked on a project that would cause some of my neighbors to see red: it’s parachuting beavers into ecosystems in an attempt to rebuild colonies. Washington has reestablished 50,000 beavers in the eastern part of the state. Mountainous areas of New Mexico hope to do the same. My town recently had the good sense to build a few water-diverting culverts that appeased the Beaver Posse at one of the new developments. Let’s hope that practice continues here and everywhere else; the fate of our ecosystems rests (in part) in the paws of Castor Canadensis.