The American Beaver (Castor canadensis) is an important species in Canada. It is a keystone species, meaning it has a substantial impact on this environment.
You can spot a beaver by either sight or signs. Firstly, note its size, as this is North America’s largest rodent. Next is the waterproof fur that is mostly brown, although it can also be more reddish or blackish. And lastly is the flat scaly tail - one sure way to distinguish a beaver from a Muskrat, which are significantly smaller in size and have narrow more “rat-like” tail.
Beavers also leave obvious signs on the landscape around them, especially in wooded areas near water bodies. As they create their dams and lodges, trees are cut down by chewing with their powerful 2 front teeth. The downed trees then look like sharpened pencils. Drag paths and slides are also normally seen nearby as they drag logs into the water or enter and exit to forage for food on land.
Beavers in Winter
Photo by Gerald Romanchuk
Beavers may become largely out of sight during our Canadian winters, but they shouldn’t be forgotten. Beneath the ice and within their lodges, they are wide awake and active all winter. This means that they do not hibernate like some other year round residents. They can do this due to adaptations for the wet and cold, such as their insulated and waterproof fur. They are also adapted to take full advantage of the spring when it comes. Mating is done during the winter, mainly January and February, which means that kits are born in April to June, just in time for melting ice and new plant growth.
Preparing well in advance for the winter season is another key to their survival. They do this by constructing and maintaining 3 critical structures and areas.
The Dam. This holds back water and creates a pond deep enough not to freeze completely through in the winter, thereby enlarging the underwater habitat for the duration of the winter. This then gives them access to food storage and the ability to enter and leave the lodge effectively.
The Lodge. This large dome shaped structure is the equivalent of the beaver’s home, with various chambers for different activities. The entrance is located underwater so they can more easily evade predators and have access to the non-frozen underwater habitat in the winter. Snow fallen onto of the lodge will also provide added insulation.
The Food Cache. During the non-winter months, beavers accumulate their favorite woody foods, such as trembling aspen and willow, and create a cache pile in the middle of the pond, normally near the lodge. Although some may breach the water’s surface and freeze, most remains in non-frozen area under the ice. In the winter, beavers will bring sticks from this cache to their feeding chamber.
Photo Credit: Hinterlands Who Who
Healthy Ecosystems
As nature’s engineers, beavers can significantly alter their environment for their own benefit, with other positive effects for the ecosystem.
Wetland Habitat Created. As dams are created, ponds or wetlands, benefit many other species such as mammals, waterfowl, songbirds, fish, amphibians and insects.
Increase Biodiversity and Rejuvenation. Trees removed and flooded lands can allow different plant species to emerge, especially in an increasing riparian habitat. Species diversity of not only plants, but also mammals, invertebrates and birds can also increase. Trees such as Trembling Aspen can also quickly produce new saplings after a large tree has fallen, which can provide forest rejuvenation and better browsing for species such as Moose.
Better Water Quality. As ponds are created and water flow is reduced, erosion is also reduced and sediments are held back. This allows for the absorption and filtration of water as it passes through. Heavy metals, fertilizers and pesticides are reduced downstream, where it may potentially become drinking water for humans
Lessening the Hardship of Water Extremes. The wetlands that are created from beaver activity act as sponges. In times of drought, water is better retained. And during floods, they hold back water and then slowly release it, which can drastically reduce flood damage downstream.
Sometimes these changes to the environment raises concerns for rural landowners, particularly if areas become flooded or wind break trees are downed. Cows and Fish offers several solutions for living with beavers.
Beaver Pelts & Canadian History
Photo Credit: ~Pyb at https://opentextbc.ca/preconfederation/chapter/6-8-the-fur-trade-in-global-perspective/
The beaver pelt, or fur, is well adapted piece of ingenuity, that enables beavers to live in Canadian waters year round. The 2 layers of fur work together to retain the maximum amount of heat. The top layer of guard hairs acts like a rain jacket. These sleek hairs shed water and keep the undercoat dry. The lower layer, closer to the skin, acts more like a sweater. These fluffy hairs provide insulation, but only as long as they stay dry.
During the late 1600’s to early 1700’s Europeans development a taste for fur hats. Having access to Canadian resources meant access to the over 6 million beavers that were present before the fur trade. Using beaver pelts to make fur hats proved to be very profitable for English and French fur traders, and this major commercial enterprise spread across Canada, lasting for about 300 years. But by the mid-19th century, beavers were facing the threat of extinction due to over trapping. Luckily, during this time Europeans began to take more of a liking to silk hats. While this new demand grew, the demand for beaver pelts drastically reduced and their populations were allowed to recover
Looking back on these events, we can thank our current stable populations of beaver to conservation efforts and the shifting fashion trend to silk hats. Many of the permanent European settlements that have become major cities in Canada were development to sustain the beaver pelt industry during the fur trade. This industry was so profitable and substantial in Canada’s history that is now seen as a symbol in Canada; seen everywhere from our 5 cent coin to the Canadian Pacific Railway crest.
Sources
An Overview of Beaver Management for Agricultural Producers. Retrieved from Cows and Fish: http://cowsandfish.org/pdfs/Beaver-Matrix-FINAL.pdf.
Beaver Fact Sheet. (2019). Retrieved from Hinterland Who's Who: http://www.hww.ca/assets/pdfs/factsheets/beaver-en.pdf
Beaver: Our Watershed Partner. Retrieved from https://cowsandfish.org/wp-content/uploads/BeaverOurWatershedPartnerWEB.pdf.
Beavers: 5 ways beavers keep our ecosystems healthy. Retrieved from Parks Canada: https://www.pc.gc.ca/en/pn-np/mb/riding/decouvrir-discover/nature/animals/mammals/castors-beavers.
Fur Trade: How and Why? Retrieved from Museum of Ontario Archaeology: http://archaeologymuseum.ca/fur-trade-how-and-why/
Official symbols of Canada. Retrieved from Government of Canda: https://www.canada.ca/en/canadian-heritage/services/official-symbols-canada.html#a11