The lazy, hazy days of summer are dwindling, and beavers’ internal clocks are telling them it’s time to batten down the hatches and prepare for several months of life below the ice. This entails adding a significant amount of mud to the outside of their lodge. The mud freezes and creates an impenetrable barrier between them and predators such as coyotes that, thanks to ponds being frozen, will have access to beaver lodges. This mud is anchored by the addition of debarked branches and logs that have provided the beavers with meals of cambium during the summer.
A beaver can transport its own weight in material (roughly 45-60 pounds). Retrieving debarked pieces of wood in many cases involves carrying them over both land and water, using only jaws and sometimes a shoulder for support. A beaver’s short, muscular neck and its powerful lower jaw muscles make this possible. Try lifting one of the larger logs on a lodge or beaver dam sometime. Then imagine carrying it any distance in your mouth with no assistance from your hands. (This feat rivals that of a moose carrying two 25 – 30 pound antlers around for several months.) While there are recorded cases of beavers felling trees 150 feet tall and 5 feet in diameter, logs of this size are not used as building material for dams and lodges, but rather the bark and upper branches provide them with food. (Thanks to Roger and Eleanor Shepard and Sara and Warren Demont for photo op.)