Beaver Dams Mean No Love Lost for Canada’s Emblematic Animal

ALGONQUIN PROVINCIAL PARK, Ontario — The beaver may be one of Canada’s official national symbols, as iconic as the maple leaf, but Canadians have a love-hate relationship with the creature, with the emphasis for many more on the second emotion.

Some communities in Alberta offer bounties on beavers’ tails. A mayor in Quebec has called for them to be “eradicated.” Fingers of blame frequently point their way, rightly or wrongly, for highway washouts, including some with fatal consequences. Farmers look on with despair as their land vanishes beneath a beaver pond.

For the second time in the past 15 years, Colleen Watson watched this summer as beavers flooded a 100-acre woodlot in the Atlantic province of New Brunswick that her grandfather, a blacksmith, took as payment from a customer during the Great Depression.

“I love to see the nature, right? You can watch it do its thing,” Mrs. Watson said in a tone more of exasperation than anger with the animal. “The hate is what it’s done to my property.”

The large rodent has played an outsize role in Canada’s history.

The push by Europeans to take control of what would become Canada from its Indigenous people was driven in large part by a mania for beaver-felt top hats, a craze that wiped out Europe’s population. For 200 years, one-third of Canada’s current territory was the exclusive trapping ground of the Hudson’s Bay Company.

After beavers almost went extinct by the mid-19th century, fashions shifted and Canada’s fecund beavers rebounded. They can now be found, more or less, in all of the country’s wooded areas, and in 1975, the beaver was declared an official symbol of Canada.

Beaver dams are the source of the most common complaints of beaver damage. When they are first built, the ponds flood formerly dry land. When a dam collapses — which typically happens only after beavers, excellent builders, abandon their pond — the rush of water can wreck rural roads and railways.

But some of the problems caused by beavers are more unusual, and those grab local headlines.

This year witnessed a number of notable episodes: Beavers chomped through a fiber optic cable, cutting off internet service to Tumbler Ridge, British Columbia, and a subway station in Toronto was shut down after a lost beaver took a tour.

A lot of likely beaver-linked offenses are blamed by the authorities on “weather events,” as when a beaver pond is overwhelmed by rain, but sometimes the police catch them red-handed (a beaver’s feet are webbed, its front paws are not). In May, the Royal Canadian Mounted Police got their beaver in a case involving stolen wooden fence posts. (The crime’s location was a reminder that beavers are not Canada’s only cute, but hardly cuddly wild animal: Porcupine Plain, Saskatchewan.)

Figuring out just how much damage beavers cause each year is difficult, said Glynnis Hood, a professor of environmental science at the University of Alberta and an unabashed champion of beavers. She was part of a research project that determined that beavers cost cities and towns in Alberta at least 3 million Canadian dollars a year, but she called that a “very, very low estimate” because many municipalities simply had no idea what they spent on beaver-related repairs.

Professor Hood herself is no stranger to unwelcome beaver behavior. This year, a beaver family hauled away several trees from in front of her house.

“But, you know, trees grow back,” she said. “That’s the consequences of living right up against a very natural area.”

While the professor said she held no grudge against these famously industrious animals,she did have some sympathy for people who believe that “any beaver, regardless of whether it’s causing flooding or cutting trees, is one beaver too many.”

Once beavers arrive in your life, it can be difficult to dislodge them.

“I’ve talked to different people, and they said that once they’re in your land, it’s very, very hard to get them out,” said Mrs. Watson, who is now trying to figure out a solution to remove them from her woodlot in New Brunswick.

Trappers are one option.

Darcy Alkerton has been a licensed trapper in Spencerville, Ontario, for 45 of his 61 years. That experience, he said, has taught him the value of taking action the instant beavers are spotted moving in.

“It’s just like ants: If you feed them and don’t manage them, they’ll overpopulate,” he said.

Until 1987, Mr. Alkerton’s beaver-management technique included dynamiting dams.

One reason he stopped: “You never see an old dynamite man,” he said another trapper told him.

Now, Mr. Alkerton, along with 21 employees, uses picks and shovels to dismantle parts of dams to lower water levels.

By law in Ontario, beavers can be moved no more than one kilometer after a live trapping. But Mr. Alkerton said that any beaver moved such a relatively short distance was unlikely to take the hint and would soon return.

That means Mr. Alkerton has to sometimes, with great reluctance, kill beavers.

“There is some people that say the only good beaver is a dead beaver, and I don’t believe that,” he said.

Beavers do have their ardent defenders, including those who denounce the default urge to destroy any beaver dam, even those that pose little real risk. And some evidence suggests that intact beaver dams might actually mitigate river flooding.

The dams — the world’s longest of which, in Alberta, measures 2,788 feet, according to Guinness — create ponds that offer both defense and food. The lodges where they live can be entered only from underwater, deterring most predators. In the fall, they gnaw down trees to create a winter food cache warehoused under the ice.

On a remote gravel road used by both canoeists and loggers in Algonquin Provincial Park in Ontario, Michael Runtz, the author of “Dam Builders: The Natural History of Beavers and their Ponds,” disapprovingly pointed out a dam that had been partly destroyed. He said logging companies come along the road each spring and take out any nearby dams.

“In most cases, it doesn’t threaten the road,” he said. “But they have this fear that it’s going to wash it out and they’ll need to spend money to repair it.”

After stopping to admire a large birch tree felled by beavers, Mr. Runtz confirmed their work ethic. But he hesitated when asked about their intelligence.

“They have great instinct,” he said. “But they are easily, easily trapped and easily caught by wolves, so, no, they’re not exactly the brightest animal on the street.”

Also, despite millions of years of experience, beavers, to their peril, still have not figured out how to direct where trees fall. “There’s been records of beavers being killed by fallen trees,” Mr. Runtz said. “I keep hoping someday to find a skeleton.”

Beavers’ reliance on instinct over intelligence has helped humans develop techniques that allow for at least a standoff between the two species, if not absolute peace.

A large pond in Gatineau Park, a federal wilderness area in Quebec, lies near a road that doubles as a cross-country ski trail in the winter. But it does not flood, thanks to something known as the Beaver Deceiver.

If a dam is demolished or damaged, the sound of spilling water swiftly puts beaver colonies into repair mode. The Beaver Deceiver — submerged piping that can control the flow of water — lowers and maintains the depth of a pond without the telltale trickling.

This deception has helped the park avoid damage to its roads and buildings without killing any of its 1,400 or so beavers, said Catherine Verreault, the park’s acting director.

In Ms. Verreault’s view, Canadians generally underestimate beavers — and their exotic appeal to non-Canadians.

During a visit to the park by wilderness-area officials from around the world, the unexpected highlight was a beaver spotting, which led to the guests spilling off the tour bus for a photo opportunity.

“These were people who have animals that are really impressive: tigers, lions and elephants,” she said. “But they were so excited when the beaver came along, slapping its tail. It was just perfect.”