It’s hard to find near-perfect examples of tracks from terrestrial mammals, let alone from semi-aquatic ones. That’s why I was thrilled to receive this wonderful photo of Beaver tracks here on PEI taken by Theresa Redmond (Photo 1, used with permission).
I’ve never been lucky enough to see really good Beaver tracks first-hand, though I do know of one otherwise level-headed Islander who did and was very much unnerved at the sight. It was winter and – just as we see in Photo 1 – only the imprints of the Beaver’s hind feet were visible. This person was convinced they were left by a person walking through the snow on his hands – clearly an unnatural occurrence!
The Beaver tracks I find are in soft mud around our rivers and ponds, and so the details are often hard to see (Photo 2). The small front feet have five toes, but their imprints are almost always obscured under the tracks of the large hind feet or drag of the tail. Hind feet have five webbed toes, but it’s rare to find tracks that show them all; the one beside the Human foot in Photo 1 is a great example.
While Beaver tracks can be easy to miss, their engineering feats are anything but. Dams (Photo 3) are usually the first things we notice and are used by the Beavers to flood an area large and deep enough to offer protection from predators and freezing. These ponds can be important features on the landscape, providing habitat not only for Beavers, but also waterfowl, Muskrats, fish, amphibians, invertebrates and the birds and mammals that prey on them. Unfortunately, when dams are built in the wrong places, they can also interfere with fish migration, as well as Human land use and roadways (Photo 4).
Contrary to what you might think, Beavers don’t live in the dam. They build houses (also called lodges) of sticks and mud in the pond itself or along the edge of the stream (Photo 5). The entrances – usually at least two – are under water, and tunnels connect the entrances to one or more cozy chambers inside.
Each house typically holds two to as many as eight Beavers, and their combined body heat keeps it well above freezing all winter. The top of the house has an opening to allow fresh air in and you can tell an active house by the lack of snow around this air vent, melted away by the body heat inside. On the coldest days you can see heat rising from the opening like a chimney.
A warm winter house isn’t much good without a well-stocked pantry, and that’s where the feed patch comes in. In Fall, Beavers start piling branches in the water near the house. Those branches in Photo 5 are the top of the patch, which extends far enough under water that it won’t freeze. The dam keeps the water deep enough for this, and those branches above the surface trap snow, further insulating the patch. All winter, the Beavers will swim under the ice from the house to the feed patch, grab a stick and take it back to the house to eat the outer layer.
Beavers have a long and interesting history on PEI, having been here originally and extirpated and re-introduced twice. You can read the whole story (https://www.pei-untamed.com/post/beaver-extirpation-and-reintroduction) to get a new appreciation for these members of PEI Untamed!
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