A Look at a Beaver Wetland Being Built

I watched this beaver dam built over a period of about a month last fall. It’s fascinating to see how the beavers interlace the logs, branches and river rock. They picked a spot in the river where the dam ties into strong willows at both ends. They add branches by pushing the base of the branch over the top and wedge the bottom into the tangle on the downstream side of the dam. The branches stick up and hold the materials they add to the top.

They created a three-acre wetland that includes two other dams this size and dozens of little spillway dams. The wetland holds about 1,300,000 gallons held in place by the innate talents and work of about six beavers. They dug canals between the ponds, so they can navigate the entire wetlands by water. The rising water flooded an old lodge which they busily renovated for winter, adding new wood and lots of mud. There are no trees nearby, so I put my camera on a tripod of lashed aspen. It ended up being added to the lodge before I recovered it.

Now, in January, the wetland is snow and ice until next spring. The lodge is covered in frozen mud that creates an impenetrable barrier to predators. Snow covers the top and creates an insulating layer. Body heat will maintain the lodge at about 32 degrees – the water temp directly below the lodge. In winter the beavers will stagger their sleep/activity cycles so there are always beavers in the lodge to maintain the temperature. Fur gets thicker. They grow two kinds of hair - long fur and shorter hairs with tiny barbs that create air pockets for warmth. They cover the fur in waterproofing oil with frequent grooming. Tails get heavier with fat stored for extra winter calories.
The inside of the lodge probably has two or three ledges. One for eating/pantry/drying, one for sleeping, maybe one for a nursery. The lodge has two underwater tunnels. Food, aspen and willow branches shoved into the mud, are stored in water under the ice so they can swim out and fill the pantry as needed.

Wetlands visitors include moose, elk and deer. Muskrats and raccoons were hanging out at the lodge and mink seem to like the dams. Lots of birds - sparrows, juncos, chickadees, nuthatches, woodpeckers, dippers, kingfishers, hawks. And, before the ice closed in, trout rising in morning and evening. I’m looking forward to seeing how spring runoff affects this landscape.

Видео A Look at a Beaver Wetland Being Built канала Michael Horwith