Problematizing Beaver Habitat Identification Models for Reintroduction Application in the Western United States
Jeff Baldwin Sonoma State University
Dr. Jeff Baldwin is assistant professor at Sonoma State and heads the Waters Collaborative there. He has been a long-time friend of Worth A Dam and is a student of Suzanne Fouty’s from way back in Oregon. He recently published an excellent paper in the Association of Pacific Coast Geologists on the inadequate way would-be beaver relocators currently assess where beavers could be transferred or HSI (Habitat Suitability Index). And guess what? It turns out that just because you get all scientific-sounding and apply acronyms to your ideas, they still might not be worth the paper they’re printed on!
Seems one of the problems isn’t that beavers chew trees or block roads, but that folks go through all the expense and trouble of moving them, even buildling them a little lodge they have to chew their way out of and when they come back to see how they’re doing they’re dead or gone. (And I’m looking at you Methow Project with a success rate of 50%!) Jeff concludes that factors like gradient slope and browse material might not be the most important considerations in where beavers can thrive.
Humans are not the only species that kill beaver. Bear, wolves, coyotes, and cougar/mountain lion are all natural predators of beaver, and in the Western U.S. the populations of each have been rebounding over the past few decades. These predators are particularly relevant to relocation efforts because beaver are most vulnerable to predation at times and in places when they do not have pooled water in which they can cover reasonably safely. In small streams this requires a natural pool, or a pool created by a beaver dam. Thus, the presence of human and nonhuman predators may have as much or more to do with beaver absence than any of the environmental attributes identified in HSIs.
As importantly, because the HSIs used for beaver relocation fail to include causes (human and other) of mortality and extirpation, their results are likely to continue to disappoint.
Yes because lots of things can’t wait to kill beavers. We know that in Martinez. Hey, I’ve got a great idea for deciding where beavers can live. Let them colonize the area on their own and move wherever the hell they want to! Teach every beaver relocator how to install a successful flow device instead and let the beavers settle where they chose and teach the people to adapt.
Am I Crazy?
