Beavers have a Vancouver Problem
Updated: 43 minutes ago
Canada was built on dead beavers. The legacy of the Beaver in Canada is a well-known story. Beaver Fur was a fashion sensation in the early days of Canada, and it almost drove our beavers to extinction. However in the last 100 years, beaver populations have been on the rebound, and their human fanbase keeps growing.
We are entering a new age of the beaver. The only animal other than humans that can drastically reshape landscapes. As beavers expand back into old territories – or claim new ones – they are radically changing ecosystems in a way that raises complicated questions. Similar questions to those that humans face in the age of climate change and the Anthropocene. How do you stop a species with a seemingly uncontrollable urge to change landscapes? An urge that might be bringing about its own extinction?
Ocean saltwater is like poison to beavers. They can only swim in it for a few hours without it shutting down their body and turning them into a stiff carcass. For this reason, Vancouver has historically not been good beaver habitat. Before european settlers arrived there were a number of beaver lodges in the city, but all in the interior of the city, none existed along th ocean coastline. And it’s not just the ocean coastline that repelled beavers. Our steep mountain streams and dense coniferous forest made Vancouver a terrible beaver habitat. While we do have freshwater flowing streams like the Capilano River, these mountain streams are surrounded by steep cliff walls, which stop beavers from having easy access to trees for dam building.
Beavers also only eat deciduous trees, not the coniferous trees that dominate our mountain forests. Any beaver that arrived at one of these streams, looking to find a new home, would have been quickly trapped between steep rock and ocean saltwater, starved for food, and easy prey for a bear or cougar.
Not till European Settlers began remaking Vancouver Forests to better resemble European Parks - full of deciduous shade trees and ponds - did beavers begin to arrive here. When Jericho Beach Park was transformed from a military base to a public park in the late 70s, the city mass planted European shade trees and dug a new pond. This was a very different ecosystem from what the area had historically been – a salt marsh and dense coniferous forest – and immediately non-native species began to invade and take hold.
Today Jericho is dominated by non-native plants and animals like European rabbits, Himalayan blackberry, sycamore maple, red slider turtles, barred owls, and English Ivy. Creatures that constantly are on the verge of wiping out all our native species of the park and are only held back by active removal and planting by local naturalists (like the Jericho Stewardship Group and the recently deceased John Coope) and Vancouver’s Park Department.
Soon after the Jericho Pond was dug in the late 70s, the first beaver arrived in the early 80s. Likely a young adult who had aged out of its parents’ territory in interior B.C. and was looking to find its own home. This Beaver travelled down the Fraser River looking for a suitable habitat, but found them all taken by other beavers or uninhabitable due to conifers or carnivores. When they finally washed down into the Pacific Ocean, it must have been quite the shock for a beaver that had never encountered saltwater before.
Swimming for a couple of hours in saltwater dims the senses of a beaver. Massively dehydrating them and making them appear as if they are drunk. Our original Jericho Beaver probably ‘shore hopped’ along Wreck Beach, only entering the ocean for short time periods to swim and then recover on land. Or it might have got lucky and hitched a ride on a floating log or barge.
Jericho would have been an oasis. A pond close to the ocean, fed by freshwater streams and surrounded by young deciduous trees. Especially with one of beavers’ favourite ‘food’ trees - Willows! - a tree that has evolved with beavers to be able to resprout after beavers chew it down.
Our Jericho Beaver settled in and got busy. Beavers can’t help but block running water. Put them in a room with a tape recorder of the sound of running water, and they will cover it with whatever they can. Put them in a room with the sound of running water coming in via multiple speakers, with no clear sound source to the beavers, and it will drive them insane. They will run around frantically and attempt to cover the walls completely in sticks and mud.
A brief city report on Jericho from the 80s mentions how a newly arrived beaver caused chaos in the park. Newly planted shade trees were being chewed down rapidly.
Soon other half-dead beavers began to wash ashore in Jericho. There probably were some territorial battles, but with nowhere else to go, the Jericho beaver population began to grow rapidly. Things started getting bad. Not just for the trees that the beavers cut down, but for the beavers themselves. The Jericho Beaver Colony began to get too crowded, and young adults, after staying with their parents for a couple of years, had to set out on their own. The ocean of poison was still there, though.
In recent years I’ve seen the beavers attempt it. They often try it at night when few humans are around. They swim out for a little bit and then quickly turn around and come back to the shore. They look strangely winded and exhausted after such a short swim. Eventually they built up their tolerance to the salt so that they could survive a bit longer, and off they go. But where do they go? Even if they can make it to the freshwater areas of Stanley Park or Olympic Village, they are in another beaver’s territory and are in no shape to challenge those beavers for it.
Unfortunately, most of the beavers from Jericho end up like the two I have seen at Granville Island. Two stiff and dead beavers, trapped between the waves and the seawall. A shock to tourists who were not expecting this to be how they first encounter Canada’s most iconic animal. (But perhaps a good reminder, though, of whose deaths this country was built on!)
As the overpopulation of beavers in Jericho began to raise some concern about it becoming a treeless park, the city began to actively trap and remove beavers from the park. This happened continuously until about the mid-2000s. What happened to these trapped beavers? Likely some were killed, but even the ones that were relocated likely did not survive. Problematic beavers in Cities are often trapped and relocated to the country, but problematic country beavers are often just killed.
However, by the early 2000s, beavers had been studied - and loved! - enough that novel solutions to beaver problems had been discovered. The legacy of this can be seen in the metal cages that encircle tree trunks around the Jericho Pond. Beavers can’t chew through metal, so these cages ensured that Jericho Trees could keep growing. If you walk around the Jericho Pond today, you will notice that practically every tree within 10 meters of the pond is covered in this metal mesh.
The real conflict between humans and beavers isn’t their removal of trees, though. It is the flooding beavers cause by making dams. In modern times, flooding, not furs, has become the main reason why beavers are trapped and killed. Beaver dams, which they can build overnight, flood roads and farmlands. Removing the beavers is usually a short-term solution until another beaver arrives.
Enter the Beaver Baffler.
This brilliant piece of anti-beaver dam engineering is deceptively simple but has started a revolution of peaceful co-existence with beavers.
It is made up of a long tube that connects to the pipe or outlet that the beavers keep blocking. The tube has a metal cage on the exposed end. The steady flow of water through the pipe confuses the beavers about where to block it. They will attempt to dam the section near the outlet first and then slowly work their way back to the end of the tube. The metal cage at the end of the tube stop them from being able to completely block it. In some cases, beavers might be able to build a dam big enough to surround the metal cage and block it, but it is easy work to quickly disassemble this flimsy dam.
Beaver Bafflers have created a new status quo in Jericho. Two of them have been installed. One is at the northern tip of the pond, where an underground pipe connected to the ocean keeps the pond from overflowing in the winter. This ocean pipe has been a human-beaver battleground for decades until they installed the Beaver Baffler just last year.
Beavers dam flowing water to create standing, still water like ponds and lakes for many reasons, but the main two are for food and protection.
Standing water means more area for water-loving broadleaf trees and plants - beaver food! – to grow. Beavers make their lodges surrounded by this standing water. The water acts as a moat to protect them from predators.
Standing water is also how beavers store their food for the winter. They take trunks and branches and store them in the mud below the water. Usually, they do this right below their lodges. The mud and water preserve the wood so that it doesn’t decompose. It is often compared to the beavers having a ‘fridge’. A food source they quickly access by swimming below their lodge. They heavily rely on this food cache in the winter when there is a lack of plant growth to eat and the ice on the pond makes it much easier for predators to hunt them.
The Jericho Pond is not a naturally formed body of water, and since it is reliant on rainwater to fill the pond, the pond often dries out during our increasingly rain-free Vancouver summers. Beavers are actually the main reason the Jericho Pond has water in it at all during the summer. They have strategically dammed certain areas around their lodge so that the water doesn’t dry out. They have also dug deep canals through the pond so that some standing water still remains. These canals, another marvel of beaver engineering, allow them to transport branches and swim away from predators. On land, beavers are slow lumbering beasts, but in the water, they are powerful swimmers and almost impossible to catch.
For decades now the Beavers have blocked the ocean outlet pipe to keep the water in the pond and the city has come in with a mechanical digger – at least once a year – to remove the sticks and mud.
If the city did not remove this dam, the pond would quickly overflow in the winter, creating a much bigger pond, but a much smaller park for Jericho visitors to enjoy. Now that the Beaver Baffler is installed, ideally the city will not need to constantly clear the pipe from being blocked.
However, it is a bit shocking just how quickly the beavers have been able to cover this Beaver Baffler in mud and sticks. The real test will be to see how it does this winter. As someone once mentioned to me, the Beaver Bafflers will only work until Beavers “figure it out”.
The second Beaver Baffler the city has installed at Jericho gives some fascinating insight into how beaver minds work. This Baffler is located about the middle of the pond, where a pipe goes beneath a trail. On the west side of the pipe is a Fen. A marsh full of beaver-nibbled willow and Black Cottonwood. Fed by a seasonal stream that runs through the Park Forest. On the east side of the pipe is the beaver lodge.
It doesn’t make any sense for the beavers to block this pipe. Blocking the pipe means less water flows into the west side of the pond. Which means less water surrounds the dam. This exposes the beavers to predators like coyotes in the summer. Beavers block this pipe anyway, though! Damaging and threatening their own habitat! By installing a beaver baffle here, the city is actually saving the beavers from themselves.
One Beaver Baffler hurts the beavers, draining their precious water into the ocean. The other saves the beavers, allowing more water to flow and surround their lodge. It doesn’t matter to the beavers, though. Both Beaver Bafflers are where flowing water is and flowing water must be stopped.
This instinctive urge to do the same thing again and again, regardless of whether it hurts or helps you, can’t help but remind me of humans. Of our ceaseless march toward a future of climate change disasters. Winters of extreme storms and summers of forest fires. Beavers need to block running water, even if it means they run out of it. Humans need to burn energy and create plastics, even though we know that it will be the death of us.
I mentioned that when the Jericho was transformed into a park, it was immediately invaded and taken over by non-native species. The surrounding neighbourhoods have kept this status quo with a constant invasion of seeds from ornamental plants. Also, with escaped and released pets like rabbits and turtles.
The beavers, perhaps unsurprisingly, have also stopped Jericho from turning back into its native forest. On the Jericho Pond bridge, you can find a city sign saying that the pond is a ‘seasonal wetland’ and that it drying out every summer helps to control invasive species. The beavers' constant work (admittedly self-defeating sometimes) to keep water in the pond allows invasive species like Purple Loosestrife, Red Slider Turtles, and American Bullfrogs to survive. All three require standing water as habitat, and if the beavers keep the pond from drying out, they can continue their assault on our native species. Loosestrife outcompetes and steals habitat from our native plants. Slider Turtles will pull ducklings underwater and drown them. American Bullfrogs will eat our much smaller, native chorus frogs.
So what do we do about the Jericho beavers? In recent years, the Jericho Beavers have become a bit of a sensation, their lodge being so close to the pond bridge that you can get very close to observe them. They have made it onto Instagram and TikTok reels, and the number of visitors keeps increasing. The beavers seemingly have no fear of humans and are unbothered by dogs. Both are not good adaptations for their beaver offspring, who, if they manage to cross the deadly saltwater sea, will be easy prey for larger creatures that they have not learned to be afraid of. Familiarity with dogs is especially worrisome, because they look so similar to coyotes and wolves.
The Jericho Pond breaks all sorts of typical beaver habitat rules because there is such a lack of other habitat in Vancouver. Typically, the biggest you will ever see a beaver colony is about 10 beavers, but the Jericho beaver population has gone up to 20 some years. Also, usually a lodge that is overgrown with plants means it is no longer an active lodge. The Jericho lodges (there are two of them!) are both covered in growing green plants, showing just how long the beavers have been there.
Should we remove the Jericho beavers? Their dams allow invasive species to flourish, and beaver offspring are destined to die tragically because they can’t find habitat elsewhere.
Likely, removing the beavers would just result in more beavers, dehydrated and desperate, arriving in Jericho and restarting the beaver colony.
Perhaps the real way forward is one that looks to the past. Where we transform the Jericho Pond back into what it was: an active salmon stream. As stunning a wildlife habitat Jericho is, it has become a hotspot for invasive species to reproduce and invade other natural areas of Vancouver. Changing it back into a salmon stream would be a massive change, but it would help turn the habitat back into the native forest that it once was.
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To learn more about returning a Salmon Stream to Jericho I recommend reading this report 2018 report - Restoring a Salmon Spawning Stream to the Jericho Watershed
