Tag: Beaver dams and trout

No wonder no one believes us. The annals of research trying to show that beavers benefit ecosystems is just too good to be true. It’s like a new issue of Goofus and Gallant, or one of those religious stories about a good child who suffers brightly with a terrible disease because of her very strong faith. A mistrustful world is never going to believe that any single animal can do that many good things for a crippled planet. They just won’t. Here’s an example:

Do Beaver Dams Impede the Movement of Trout?

Ryan L. Lokteffab, Brett B. Roperab & Joseph M. Wheaton

 Dams created by North American beavers Castor canadensis (hereafter, “beavers”) have numerous effects on stream habitat use by trout. Many of these changes to the stream are seen as positive, and many stream restoration projects seek either to reintroduce beavers or to mimic the habitat that they create. The extent to which beaver dams act as movement barriers to salmonids and whether successful dam passage differs among species are topics of frequent speculation and warrant further research. We investigated beaver dam passage by three trout species in two northern Utah streams.

So far, so good. An investigation is warranted. Let’s get to the bottom of this. Tell us the gory details. How do those rotten beaver dams ruin our streams?

Our results suggest that beaver dams are not acting as movement barriers for Bonneville Cutthroat Trout or Brook Trout but may be impeding the movements of invasive Brown Trout.

Did you get that? Not only are beaver dams NOT blocking passage of the good fish. They are also keeping out the bad ones. Who’s going to believe that, I ask you? Here’s another example.

These are the Ruby Mountains of Nevada, just outside Elko where beaver friend Brock Dolman just got back from a mountain trip and exploration. He found some fantastic beaver habitat, and a species of frog that is only doing well near beaver dams. This is the Columbia Spotted Frog that is listed as endangered everywhere else.

 Here’s a little something from Fish and Wildlife on the topic.

U.S. FISH AND WILDLIFE SERVICE SPECIES ASSESSMENT AND LISTING PRIORITY ASSIGNMENT FORM

Beaver Management

The reduction of beaver populations has been noted as an important feature in the reduction of suitable habitat for Columbia spotted frogs (Reaser 1997a, p. 39; NDOW 2006, p. 163; ODFW 2006, p. 288). Beaver are important in the creation of small pools with slow-moving water that function as habitat for frog reproduction and create wet meadows that provide foraging habitat and protective vegetation cover.

Honestly, it’s like beavers are the “Dudley Do-right” of the animal kingdom, another famous  Canadian who was a hero of unbelievable proportions that gets everything right and makes everything better without important flaws to endear them to us. Beavers are superman without kryptonite – Rooster Cogburn without the eye patch – or in the language of modern fiction, an annoying Mary Sue character without an absent parent. They do EVERYTHING right. Of course no one can believe in them.

Except us.

There were lots of fans and believers on the bridge last night, to catch the end of summer beaver show. Three kits and JR. VERY high tide. In fact, don’t ask how high it was. Ask how LOW the dam was in comparison.

The dam was so low  that both a kit and the yearling SWAM through it! Guess mom has some repairs to do this morning. Love the yearling’s little shake at the beginning.