It wouldn’t take more that taking a nickel out of your pocket or biting into a “Beaver Tail” to remind you of this Canadian icon. Beavers are imbedded into Canadian culture and history. Whether you love them or think of them as a pest; beavers are pretty spectacular creatures which play an important role in their ecosystem. There are few animals anywhere in the world that can do anything as impressive as our beavers do, which is how they got their nickname “nature’s engineers”. To explain to you why they deserve this name, I’m going to take you on a journey through time.
Photo by Kelton Adderley Heron
Our story begins in a narrow, shallow stream. Cedar trees tower overhead, and sensitive ferns grow in their shade. Our beaver is attracted to this area by the sound of running water. To him, this looks like the perfect place to build a dam. You have probably seen a dam before, and because they are such a common sight in our waterways, you may not have stopped to think about its significance. Our beaver, along with the help of his colony will build a dam around 5 metres long and 1 metre thick. But other beavers have built dams much larger than this! In fact, the largest dam in Canada is found in Alberta’s Wood Buffalo National Park and measures 850 metres. It can be seen from space!
Once the dam is built, a beaver pond is created. What was once a narrow stream is now a much deeper pond. Beavers are the only animal other than humans to change the environment around them significantly to better themselves. The beaver has created the ideal habitat for himself. The pond provides safety from predators, and a perfect place to make a home. Beavers live in lodges with their family which consists of adults and their kits.
Beaver Lodge, photo by Grace Wiley
The pond also provides them with food. Of course, surrounding the pond is all the trees they need for building and eating, but in the summer months a beaver would prefer to eat aquatic vegetation. The beaver’s favourite summer treat is not an ice cream cone, but a White Water Lily! The pond can sustain many aquatic plants like lilies that would not have grown in the stream. This vegetation creates habitat for aquatic invertebrates and fish.
Water lilly, photo by Grace Wiley
These benefits to the beaver also extend to other wildlife. Waterfowl stop over here to rest. Green Frogs hop to and fro. Moose now visit our pond to cool off and eat the vegetation. Great Blue Herons fish near the shore. Soon enough there is enough food, water and cover to support a turtle population! A Common Snapping Turtle walks along the silty bottom, feeding on minnows and frogs. Midland Painted Turtles bask on a felled log that the beavers left behind. A Blanding’s Turtle swims through the aquatic grasses, grazing on vegetation and insects, stopping to basking on the edge of the beaver’s lodge. The depth of this pond provides overwintering habitat for the turtles as well. These creatures could not have survived in the stream that existed here before, and therefore would not survive here without the beaver.
Our beavers will not stay in their pond forever. Eventually, they will use up all of the surrounding trees. Once the journey to a tree becomes too far from the water and therefore too dangerous, the beavers will decide to move on. They will abandon their lodge in search of a new stream to dam up. Over time, the unattended dam will break, and the water will flow once again. What is left now is another new habitat that the beavers have created. We call this a beaver meadow. The exposed muddy area left behind by the beavers will be quickly colonized by grasses and sedges. The warm nutrient rich waters provide a new and different habitat for wildlife. Dragonfly larvae and other invertebrates flourish here and are in turn food for our turtles. A Blanding’s turtle buries itself in the mud on a warm summer day. A juvenile Snapping Turtle aquabasks in the shallow water. A meadow jumping mouse balances on a sedge. Her nest is hidden under the grasses on the edge of the wet meadow. In the middle of the meadow, the original stream runs cool. Brook Trout now use this stream to travel to deeper waters, and a crayfish rests on its rocky bottom.
Looking down on a beaver meadow in Algonquin Provincial Park, photo by Grace Wiley
More time passes, and trees such as the sun loving (and beaver favourite) Trembling Aspen begin to grow and fill in the meadow. The sound of the stream, and the new growth will soon attract a new beaver to this area. With his colony the new beaver will build a dam and start the cycle over again.
Beavers play an important role in the natural cycle of a wetland. These wetlands provide habitat for many kinds of wildlife, including turtles. According to the Nature Conservancy of Canada, studies show that 90 per cent of Blanding’s Turtle habitat is in ponds created, maintained or regulated by beavers. Beavers have truly earned their title as nature’s engineers.
Beaver Pond Trail Guide, Friends of Algonquin Park