Beavers are habitual explorers. They search the landscape for suitable habitats and mates. Being territorial, they also seek sites unoccupied by other families.
An important habitat variable is dam “economics.” For example, long dams require an enormous amount of effort to build and maintain. Narrow outlets, by contrast, are easy to dam and quickly form reservoirs and protection from predators. Because of the significant energetic savings and security value, a good dam site is enough to make the overall habitat “high-quality.” Favorable dam sites can be narrow breaches in old dams, constrictions in the bedrock, or road culverts.
Roads are basically large manmade dams with tiny holes in them for water passage. When culverts are located in beaver damming habitatlow-gradient areas on small streamsthey attract a certain wanderlust-imbued species like a magnet, and almost always become clogged.
When the beaver(s) is subsequently killed by trapping or shooting, as is often the case, a high-quality habitat becomes vacant. The magnet is thus made more powerful. A defense-by-killing policy ensures an expensive, never-ending cycle of beaver eradication, culvert cleaning (usually with heavy equipment), and road repairs. Einstein would tell us that repeating the same kill cycles and expecting a different clogged-culvert result is insane. On a related note, killing is often done in the spring and summer when beavers have kits that will slowly starve to death in the lodge. Add moral irrationality and impoverishment to the formula.
There’s also an ecological cost to this craziness. To effectively protect culverts without using high-quality flow devices like Beaver Deceivers™ requires the permanent extirpation of this invaluable, native species from the general vicinity. Nearby, non-threatening dams and wetlands will not survive in the absence of beavers, and the potential for new wetlands to develop will also die. Rich, open wetlands like those created, maintained, and improved by beavers are rare and very valuable to the natural world and humanity.
If society neglects to eliminate these magnets a lot of money and ecological potential will be lost. Conversely, a more creative and less violent approach can de-magnetize roads and communities and generate vast quantities of diverse wealth.