North American Beaver (Castor canadensis)

In celebration of yesterday’s Canada Day, I’m going to write about the most Canadian animal around, the beaver. If you can think of something more Canadian, let me know and I’ll keep it in reserve for next year. But I don’t think you’ll think of something. Beavers are just too damned Canadian. It’s even in their scientific name, Castor canadensis.

Despite this clear allegiance to Canada, beavers do not just reside there. They live all across North America, except in desert areas of the US and Mexico, and the really cold northern parts of Canada. They have been introduced to the extreme southern tip of South America, and into Scandinavia. They are semi-aquatic rodents, that live in lakes, ponds, streams or river deltas.

A beaver lodge in a lake.  Source: http://www.toledo-bend.us/index.asp?beaver

A beaver lodge in a lake.
Source: http://www.toledo-bend.us/index.asp?beaver

The beaver, of course, is famous for its architectural exploits. There are two types of beaver constructions: lodges and dams. Lodges are the beaver’s home, and they are built with sticks, rocks and mud. Lodges are made with at least two entrances, at least one of which opens directly into the water. Platforms are put into the lodge to allow the beaver to dry off. The second and more famous type of building that beavers partake in is creating dams. They do this to maintain an adequate level of water in their lodges, so they have easy access to water and thus to an escape route. It has been shown that beavers react to the sound of running water, and quickly move to the sound and dam it up. Beaver dams can reach enormous sizes – the largest dam in the world is 850m long. It is in northern Alberta, is twice the width of the Hoover Dam, and can be seen from space.

A beaver dam - as seen from space, via Google Earth imaging. A very, very impressive structure.

A beaver dam – as seen from space, via Google Earth imaging. A very, very impressive structure.

As I mentioned, beavers are rodents, and are the second largest rodents in the world, losing out only to the capybara. They normally weigh between 11 and 32 kg, but can reach much larger sizes, up to 50 kg. Beavers are covered with a thick double coat, which help keep the beaver warm. Special glands near the animal’s anus produce castoreum, an oil that helps waterproof the beaver’s fur. Other adaptations help beavers survive in a watery environment: their webbed back feet and famous tail make beavers excellent swimmers. Their eyes have a nictitating membrane, allowing them to see underwater, and their ears and nostrils close up when the animal is swimming.

An adorable and chunky beaver.  Source: Wikipedia

An adorable and chunky beaver.
Source: Wikipedia

The beaver’s main food consists of the bark of trees, as well as the soft tissue under tree bark. They are usually active during nighttime, and prefer to forage in the water, as they are rather awkward on land. Beaver dams help with this part, as they tend to flood the surrounding woods, giving beavers underwater access to their food.

Beaver dams, as you can imagine, have large impacts on the environment. It is generally thought that beavers are very beneficial to the environments, as their ponds create open pools of water that fish, birds and other animals can utilize. Still, beaver flooding can damage forests and land, so they can be a major problem to people. Overall though, I think beavers deserve our respect, both for being kind of cute and for being some of the world’s greatest architects.

Cover image source: http://www.wild-life-rehab.com/Education-Beaver.htm

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2 thoughts on “North American Beaver (Castor canadensis)

  1. “I’m going to write about the most Canadian animal around” — I immediately thought of the Canada goose, from my south-of-the-border perspective.

    And what about penguins? (jk) 🙂

    • I also thought of the goose, but beavers to me are just more Canadian, not least because of the huge economic impact their fur had on our burgeoning country’s economy.

      But I will post about the Canada goose someday, I promise 🙂

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