Most folks know that stream-flow ponds impounded by
dams built of sticks, stones, and mud are created by beavers.
Conical or dome-shaped lodges surrounded by water are also
recognizable signs of Castor canadensis. As summer slips into
autumn, reminding us that winter is not that far away, how do
we know that beavers are actually in residence within a given
pond complex? Here are four signs of active beaver occupancy
that one can easily find:
Look for an abundance of freshly cut trees, saplings, and
woody shrub stems in the vicinity of the pond. During
autumn, beavers shift into overtime for food gathering.
A colony may need to store hundreds of woody stems
to have enough food for the winter. Fresh-looking sap
and wood chips will be obvious evidence on and around
recently cut stems.
Freshly peeled sticks and mud will have been added to the
dam. It is critical that the dam is strong enough to hold.
The pond and its associated canals allow these semi-aquatic
rodents an effective means of minimizing their exposure
to predators while collecting food. In addition, the pond’s
watery environment makes it easier for beavers to access
and transport their foods. A pond is perfect for the creation
of a safe, weatherproof lodge in which beavers can escape
from enemies, rest, keep warm, mate, raise families, and eat
Look for fresh mud plastered on the lodge. In all but the
most gravel-bottomed habitats, beavers will gather and
apply a seal of mud to the surface of the lodge, covering
all but the air vent. This serves both as weather shield and,
when frozen, a cement-hard fortification against predators.
In our region, coyotes, bobcats, occasionally bears, and
historically wolves and cougars all prey(ed) on beavers.
Seek to find evidence of food caches. In preparation for
winter, beavers collect branches and construct a raft of less
desirable species whose collective water-logged weight will
push down and hold the food branches they like, including
poplars, willows, maples, red osier dogwood, and yellow
birch stems. When the pond is frozen, the beavers benefit by
having underwater access to their preferred foods. The raft’s
branch tips can be seen protruding from the water or even
the frozen pond’s icy surface. Species that are not generally
eaten, such as eastern hemlock, red spruce, white pine, and
alder will be visible poking above the surface of the raft.
Susan C. Morse is founder and program director of Keeping Track in Huntington,
Story and photos by Susan C. Morse
Beavers at Home for the Winter
Above: Beaver; Orange
forester David Paganelli
admires a recently
Left: Forester Gaetan
a beaver dam in the
Sutton Mountains of
Quebec. Note that sticks
have been arranged
parallel to the direction
of the water flow, lending
strength to the dam.