Beavers Know Best

We humans are recognizing that trapping and killing Beavers is a bad practice. It is better for our environment and for biodiversity to allow beavers to do what they do best—build dams and lodges.

“Beavers, the animal that doubles as an ecosystem, are ecological and hydrological Swiss Army knives, capable, in the right circumstances, of tackling just about any landscape-scale problem you might confront. Trying to mitigate floods or improve water quality? There’s a beaver for that. Hoping to capture more water for agriculture in the face of climate change? Add a beaver. Concerned about sedimentation, salmon populations, wildfire? Take two families of beaver and check back in a year. If that all sounds hyperbolic to you, well, I’m going to spend this book trying to change your mind.”
—Ben Goldfarb, Eager: The Surprising, Secret Life of Beavers and Why They Matter (2018)

North American Beaver (Castor canadensis) Beavers can grow up to 1.2 metres (snout to tail) and weigh up to 35 kilograms. Photo by blickwinkel / Alamy Stock

The North American Beaver (Castor canadensis) is Canada’s best-known symbol, but the Beaver is much more than that, not only to Canadians, but wherever the Beaver finds a home. It will always be in and around water, because water is home. This is the place where the beaver meticulously and diligently builds his home, called a lodge, made up of trees that he has cut down and dragged to the site where he will live. Yes, beavers are busy; their reputation is well-earned.

The only time I have seen a beaver up close is at Montreal’s Biodome. True, it is not the same as seeing a beaver in their natural habitat, going about their business of ensuring that Nature is served well. I am posting this short piece about beavers because I think humans can learn something good and beneficial about Nature Conservation from these water engineers.

There are a number of noteworthy facts about these beavers: they are vegetarian; they are monogamous and mate for life; their teeth grow continuously and the lifespan is on average 10 to 12 years. When beavers are two years old, they leave the family home (lodge) and seek a mate elsewhere, building their own lodge and having their own children, called kits. Beavers are mammals but ones who are excellent swimmers, able to swim underwater for 15 minutes. Most humans can hold their breath underwater for, at most, two minutes; dolphins for a maximum of 10 minutes and elephant seals for two hours. The beaver is well-adapted for its particular role in Nature.¹

The beauty of beavers is that they can restore places that have dried up and once had water but no longer do; beavers are bringers of water; they dig deep channels in ponds and creeks, thus increasing its storage capacity. It is hard to imagine that at one time, beavers almost went extinct. This was a result of the fur trade in Canada and the United States, driven by European fashion. Here is some background from The Canadian Encyclopedia (2021):

As an emblem of Canada, the beaver goes back at least as far as the 17th century. The rich-pelted beaver was the staple of the fur trade that prompted Europe's commercial interest in North America. Beaver pelts were considered the most valuable, particularly while felt hats made from under-fur were symbols of prestige in the 17th century. The pursuit of beaver pelts from the Maritimes to the Mackenzie Valley led to the exploration of vast regions of North America. When the fur trade first started, it is estimated that there were 6 million beavers living in what is now Canada. By the time the fashion had changed in the mid-1800s, the beaver was almost extinct. Today, thanks to many protections, thriving populations of beaver exist across Canada once again.

There were early campaigns to raise awareness of the beaver. For example, the National Film Board, in Canada, made a 13-minute silent documentary, Beaver People, released in 1928.² (You can watch it by clicking on the link.) But it is only recently that scientists and even farmers have started to understand and appreciate the important and essential work beavers do.

Beavers are a keystone species that keep the aquatic ecosystem moving along.³ There are an estimated 15 million beavers residing in the United States and a high estimate of about 12 million in Canada, although some say it is only 6 million. At its peak, before European colonization and the fur trade. there were almost 200 million beavers living in North America; and some estimates place the numbers as high as 400 million.⁴

We are nowhere near that, but their numbers are growing, and thankfully so. This documentary, Leave It To Beavers (aired on PBS-TV on Nature; 5/13/2014) goes into much detail and explanation on the importance of beavers. It shows how beavers build dams and lodges for their homes, and in doing so, how they are helping to maintain the Earth’s wetlands and the biodiversity that is necessary for our Earth to have the ecological richness we desire, and, most essential, we require for our health and well-being. If you want to avoid drought, make sure that there are beavers working in your area. If this all sounds too good to be true, it’s not. Beavers are truly that amazing. Small wonder, then, that beavers are called Nature’s Engineers.

Merci et à bientôt
Born at 315 ppm
Now at 425 ppm

1. From The Canadian Encyclopedia: The beaver’s tail — which can be up to 30 cm long, 20 cm wide and 2.5 cm thick — has important uses both in the water and on land. Leathery and sparsely haired, it acts as both a propeller (in water) and prop (on land). Flexible and muscular, the beaver uses its tail as a rudder for swimming. On land, where the beaver is less nimble, the tail props up a sitting or standing beaver.

Large, webbed hind feet are powerful paddles for swimming. The eyes are small and have transparent membranes, which can be drawn across the eyeball, so the beaver can see while under water. In addition, the nostrils and ear openings have valves that can be closed at submersion.

2. Canadian Geographic: Meanwhile, hundreds of kilometres to the south, Archibald Belaney, an English immigrant who had adopted a First Nations persona and the alias Grey Owl, had taken up the beaver’s cause. In 1928, after years of making his living as a trapper in northern Ontario and Quebec, Belaney swore off trapping and set out to save the species he had come to see as a symbol of Canada’s vanishing wilderness. His passionate and eloquent writings, published under his pseudonym, soon drew international attention to the beaver’s plight.

In 1928, the Dominion Parks Branch made a 13-minute, black and white silent motion picture featuring Grey Owl — wearing his customary buckskin jacket and moccasins — and his two pet beavers, Rawhide and Jelly Roll. No professional filmmaker had ever filmed beavers in a natural setting, and Beaver People (which can be viewed on the National Film Board website) was a hit.

3. From Wikipedia: A keystone species is a species that has a disproportionately large effect on its natural environment relative to its abundance. The concept was introduced in 1969 by the zoologist Robert T. Paine. Keystone species play a critical role in maintaining the structure of an ecological community, affecting many other organisms in an ecosystem and helping to determine the types and numbers of various other species in the community. Without keystone species, the ecosystem would be dramatically different or cease to exist altogether. Some keystone species, such as the wolf and lion are also apex predators.

The role that a keystone species plays in its ecosystem is analogous to the role of a keystone in an arch. While the keystone is under the least pressure of any of the stones in an arch, the arch still collapses without it. Similarly, an ecosystem may experience a dramatic shift if a keystone species is removed, even though that species was a small part of the ecosystem by measures of biomass or productivity.

4. From Wikipedia: Historically, the North American beaver was trapped and nearly extirpated because its fur was highly sought after. Protections have allowed the beaver population on the continent to rebound to an estimated 6–12 million by the late 20th century; still far lower than the originally estimated 60–400 million North American beavers before the fur trade.^[43]