Recently I have had the pleasure of watching a couple of young beavers as they go about their version of the daily grind. Among the largest of rodents, the North American beaver ( Castor Canadensis ) is primarily nocturnal, but may be seen during daylight hours, especially in the late afternoon. My little tree fellers are out and about around 2:00 in the afternoon at this time of year, so there are a couple of hours of daylight in which to watch them.
While extremely robust in form and awkward in locomotion on land, they seem sleek and graceful in the water. After diving to the pond bottom for aquatic plants or tree branches cached upright it the mud underwater, beavers laboriously pull themselves out of the water to eat their food. Often they use a felled tree trunk that has fallen into the water from the pond bank as a platform for dining out. Beavers will lumber out of the water to cut off fresh waterspouts from nearby trees, or they cut down smaller trees to eat the bark. Leftovers with no useful cambium or bark left for food are often used as material for building or repairing dams and lodges.
Active all year, these hard-working lumberjacks must eat large quantities of leaves, innerbark and twigs of trees, aquatic plants, grasses and ferns to maintain their hefty bodyweight and fat level. If surface water is frozen, beavers relay on food caches they anchor to the bottom of the waterway and bring the items back to their lodge to eat them in a dry, protected chamber within.
They construct an underwater entryway that prevents most would- be predators from gaining access inside the lodge. Waiting until frosts arrive to ready a lodge for winter, beavers pack sticks and mud together in an architecturally sound manner without the benefit of years of MIT classes or civil engineering blueprints. The mud hardens to such a degree at this time of year, especially if freezing occurs, that the lodge is virtually impregnable from the outside. Beavers can easily access cattail and lily roots and stems beneath ice, or from banks throughout the winter. If enough food has been stored on the bottom of waterways, beavers can access it without being seen from above.
One beaver went underwater across the pond and had a difficult time breaking through the ice to surface. There was a loud noise each time it tried to ram itself through the thin ice on the other side. After several attempts, the beaver finally broke through with a loud crash and dragged its chubby self onto the end of a favorite tree trunk to eat a twig it picked off from the bottom of the pond of its way over. Beavers can swim underwater for a good fifteen minutes, so there was no need to become alarmed.
One time, one of the beavers wanted to come up the bank where I was discreetly watching. At the last minute it saw me and quickly did an about-face in the water, slapping its tail loudly before diving. It was startling- loud, abrupt and not expected, although I knew beavers did such things when frightened. It was hard to tell which of us was more startled, but we were both equally surprised.
Beavers can make short work out of cutting down trees. Where beavers are active it is obvious. Small trees with thin bark are often cut down andbecome a source of bark and cambium tissue that be nibbled on over time. Then the leftover parts can be used for building and repairing material.
Beavers may not build a dam, or bother repairing one they make, if an existing pond is deep enough to allow normal activities and to provide an easily accessible underwater entryway to the lodge. Some lodges are built along the banks of streams, ponds, or lakes, and some are constructed in the middle of quiet ponds. Ducks may build their nests on the tops of lodges, and Great Blue Herons often alight on them for a safe rest. Sometimes muskrats share the living chamber of the lodge with beavers, and often can be swimming alongside them.
Well, I know where I will be spending some time this winter, trying to shake off some winter blues. I will be sitting along the banks of the beaver pond waiting to catch a glimpse of these very busy beavers.
Pamm Cooper All photos © 2013 Pamm Cooper Use of photos restricted to permission only