The not-quite-a-victory in the threat of lawsuit by the Center for Bioligical Diversity has been getting a great deal of press – I even saw it on the KQED science note. What’s getting less press of ourselves is the charming list of 101 exceptions to the agreement to spare their lives. I’m still reeling from the notion that beavers that don’t build dams are slackers that shouldn’t be spared, so of course I asked folks that are smarter than me what they might think.
I thought I’d share some of author Ben Goldfarb’s very smart reply.
- The fact that non-damming beavers aren’t protected defies common ecological sense. First, there’s good evidence from California that even bank-dwelling beavers create important habitat. Check out Marisa Parish’s PhD research, which showed that several salmon species relied on bank burrows as refuges during juvenile stages;
- Also, if we want beavers to disperse into the upper reaches of watersheds to build dams and do all the great stuff they do, we have to approach carrying capacity in the lower reaches. (Jakob Shockey made this point nicely in his State of the Beaver talk this year.) I don’t know this for sure, of course, but I strongly suspect that if we keep killing them in lakes and big rivers, we won’t achieve sufficient population densities to compel them up into the headwaters, where they’d be more motivated to build. They want to live where they can be lazy, whereas we want them to live where they have to work hard — but we have to reach saturation for that to happen. Reflexively killing them in the lower reaches of watersheds assures that we’ll never attain such saturation. At least, that’s my — and others’ — hypothesis.
Excellently put Ben, as usual. And of course it makes sense in every way possible that beavers would matter whether they’re in the ideal location or NOT, just like they did in the urban channel of Martinez, which was very far from idea. I hope when CBD comes to earth after their 3 day champagne celebration they will pay attention to what the experts are saying about this.
And now on to yesterdays discovery, from beaver friend Sarah Koenigsberg:
Beaver eating slo-mo from Tensegrity Productions on Vimeo.
