14 June 2024

Beaver Superheroes: Five Facts

“What swims like a fish, cuts like a chainsaw, logs like a lumberjack and transforms landscapes like a water engineer?” That riddle, from Nature Conservancy Canada, has an easy answer. It’s Canada’s national symbol, of course: the “true” beaver, Castor canadensis.

Centuries after their fur was in such high demand for European fashion that trappers and traders almost wiped them out, Canada’s beavers are having another moment. This time, they are valued “ecosystem engineers.” As CodeBlue reported last year, beavers are recruited to repair BC watersheds damaged by mismanagement, development, industrial destruction, and pollution.

It turns out that beavers’ superpower–their rare ability to transform the environment–was always far more important than putting their thick reddish fur to use in hats and coats. Beavers are a “keystone species” - a species on which all inhabitants of an ecosystem depend, such that if it were removed the ecosystem would change drastically. Beavers dam up flowing water to create ponds that retain sediment and store then slowly release water. Their ponds and dams help prevent wildfires and floods by stemming the flow of water. They enhance wetlands, sometimes called “beaver meadows,” in which other creatures and plants thrive, and which filter and clean water.

Removing beavers from ecosystems causes profound damage, notes Nature Trust BC. “Large areas of stored surface water are lost, and rivers begin to flow faster, becoming more erratic during floods.” Wetlands dry up and become vulnerable to fire, and species that cannot migrate die off.

Beaver youngsters. Photo credit Deborah Freeman via Flickr, Creative Commons

Not everyone appreciates beavers at all times. The rodents can cause conflict, notes the BC government, especially in agricultural or residential areas where they sometimes dam culverts, bridges or drainpipes. In those cases, provincial and federal permits can be obtained to remove them.

And in BC, beavers are still classified as furbearers under the Wildlife Act and may be trapped in-season by a registered trapper.

It was as furbearers that beavers transformed Canada economically and politically. That role was recognized by their depiction on Canada’s first postage stamp, a five-cent coin, and place names across the country. In the 17th Century their pelts were so highly prized in Europe that the valuable fur trade became a foundation of Canada’s resource economy. By the mid-1800s, the industry had killed so many beavers the species was almost extinct.

Beaver populations are now faring much better than during the fur trade boom, but their much smaller namesake the mountain beaver, Aplodontia rufa, is listed as a species of Special Concern. However, while the mountain beaver-which lives in burrows in the Cascade Mountains-has the same name, it is not closely related to “true beavers.”

The "ecosystem engineering" by beavers allows all other creatures to thrive, from ducks to caddisflies. Photo credit: Deborah Jones

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Five Facts About Beavers:

Beavers, North America’s biggest rodents, dwell in rural and urban rivers, lakes and streams. Adults can weigh as much as 32 kilograms (71 lbs), live for about 12 years, and mate for life. A typical family in a beaver lodge includes parents, yearlings and two to four babies called kits. At age two the youngsters leave the lodge and strike out on their own.
Beavers are vegetarians, munching on the bark and cambium of trees, as well as aquatic plants like water lilies, cattails, and watercress. In turn, beavers are eaten by coyotes, foxes, bears, river otters, eagles–and people.
Canada’s Indigenous cultures consider beaver a prized traditional food, historically made tools from beaver teeth, and captured beaver by either blocking them in their lodges with a pole fence, netting them, or spearing them. Many First Nations also regard beavers as influential animal spirits. Hunters and trappers use their meat as well as their fur. “It is delicate meat with a subtle yet desirable taste,” claims the website Outdoors Chef.
The popular Canadian treats known as “Beavertails” are not in fact made from parts of beavers. These sweet pastries are traditionally made of dough with wheat flour, stretched into the shape of a beaver tail, fried, and topped with sugar and cinnamon.
Beavers have many remarkable traits. Their powerful teeth never stop growing and are coloured orange from the iron in the enamel–which makes them strong enough to cut wood. Specialized lungs allow them to hold their breath underwater for more than 15 minutes. Two glands near their anuses secrete castor, which they groom into their fur to make it water resistant. Those distinctive leathery beaver tails serve as propellers as their large webbed hind feet paddle them along, and their small eyes have transparent membranes to allow them to see underwater. Their nostrils, ears and throat are able to block water from entering.