Beavers: remarkable rodents and a crucial climate ally
Chris Jones, a Cornish farmer in his sixties, is leading me through a meadow, hobbit stick in hand. He stops by a large pool of water beside a dam filled with mud, rushes, sticks and stones. It’s a dam created purely by beavers: an animal I’m quickly learning could play a vital role in restoring UK ecosystems.
An active beaver wetland is thought to store around 35 times more carbon than an equivalently sized grassland. And beaver dams perform the vital task of trapping harmful pollutants like phosphates and nitrates, stopping them flowing downstream into coastal water.
This intercession is much-needed. According to a sobering 2021 report by the Natural History Museum, the UK is one of the most nature-depleted countries in the world. We have just 53 per cent of our native wildlife still intact, well below the global average of 75 per cent. And, owing to high levels of pollution, only 14 per cent of our rivers are in good ecological condition.
Jones sighs. “The way we look after our environment is shocking. If ever a species deserved extinction, it’s us!”
He isn’t just referring to our reckless treatment of rivers. It’s also a comment on how we foolishly drove a crucial climate ally to extinction.
The Eurasian beaver was once native to the UK. But it was hunted to extinction by humans around 400 years ago.
Soft beaver fur wasn’t the sole motivation. They were preyed on for some other, fairly unorthodox reasons too. In the 15th century, the Pope sent out an edict all around Europe giving catholics permission to eat beavers on Fridays. His reasoning: as aquatic animals, beavers counted as fish.
More niche still: beavers secrete a liquid from their bums known as castoreum. These glandular secretions were once prized as a medical remedy: a magic headache cure (owing to the large chunk of time beavers spend munching on willows, the key ingredient in aspirin). Beaver bum juice was also a sought-after liquid in the perfumery industry, used by the likes of Givenchy, to prevent perfume from losing its smell.
All of these desirable attributes made for a sad end to the Eurasian beaver. But now, the species is making a comeback, and being reintroduced in wetlands and rivers across the UK. Beavers are fast becoming a rewilding buzzword (as evidenced in Boris Johnson’s recent “Build Back Beaver” speech).
Admittedly, when I was invited on a press trip to visit the Cornwall Beaver Project, I hadn’t been keeping up to date. My prior knowledge of beavers was scant, and I struggled to distinguish them from otters. A trip to learn about the role of beavers in tackling the climate crisis sounded like a fun – albeit random – opportunity.
I soon discovered it was anything but random. These buck-toothed rodents are renowned “ecosystem engineers”. Not only do beaver dams capture carbon, they also reduce flooding, store water for times of drought, and attract a host of other wildlife.
Beavers have been re-introduced in parts of Scotland, Wales, Cornwall and Devon (on the river Otter, just to add to the aforementioned confusion).
“Clever little sods”, remarks my taxi driver, as he drops me at Woodland Valley Farm – Jones’ home and the site of the Cornwall Beaver Project.
Jones, who’s lived in the area for 61 years, is one of two local farmers I’m visiting with a beaver enclosure. Within minutes of meeting him, it’s clear he is evangelical about the vital role these aquatic rodents play in restoring healthy ecosystems.
“To use a crude analogy, if nature is a bonfire, then the effect of introducing beavers is like pouring a bottle of petrol on top,” he tells me.
Jones got two beavers in 2017 with the help of the Beaver Trust – a group of self-identifying “beaver believers” working to bring beavers back home to Britain. One came from Wales and the other from Devon (although the first beavers to be reintroduced in the UK were brought over in vans from Poland and Norway).
Within a week of their arrival, they had built a credible dam. Four years on, the farm contains eight dams, two lodges and complex wetland.
Beavers reset the way our rivers and streams work, as it quickly becomes apparent on the tour around Jones’ beaver wetlands. The first dam we stop at is a smaller one, in a leafy area with a slow flowing stream. The dams are living structures and the green rushes in the water are incredibly luscious – fertilised by materials beavers place in them. Beavers walk on their hind legs when carrying stones to build the dams – hence why the Scandis call them the “little people.”
James Wallace from the Beaver Trust believes beavers may have actually taught humans aspects of engineering: all of our water structures mimic beaver technology: not just dams but also locks, weirs and canals.
Beavers build dams to make the water deeper and give them a habitat they can swim through. It also allows them to build underwater entrances to their lodges, sheltering them from predators.
While this building mission isn’t altruistic, the knock-on benefits for humans and other creatures are endless.
Beaver dams slow down the flow of water in rivers, helping to prevent flooding – highly useful when we consider that flooding cost the UK economy £5 billion in 2015 alone. At the same time, the dams enable us to hold more water on the land, providing the possibility of pumping it out during a drought. Jones did just this to water his fields during the dry summer of 2018. Meanwhile, the neighbouring farm failed to set up irrigation for crops because it lacked the necessary reserve of water.
We walk from the enclosed woodland area into an open field with a beaver-made pond. These deep pools of water act as watering and feeding spots for an abundance of wildlife. Since beavers took up residence and started building, new species to appear on the site include nine new birds, four new mammals, numerous plants, insects and reptiles. Jones has taken particular delight in spotting water shrews, kingfishers and polecats.
Beavers won’t prey on any creature showing up – they are committed vegans, or to use a less anthropocentric term, strict herbivores.
What’s more, Jones tells me, further afield, we’re even witnessing beavers’ capacity to fight wildfires. Research in California shows green vegetation near beaver ponds is too wet to burn when a fire ignites.
With everything they’ve got going for them, it’s hardly surprising that Jones isn’t the only one in the area to cotton on to the benefits of beaver reintroduction.
Merlin Hanbury-Tension, a farmer in his late 30s living 20 minutes away on Cabilla farm, speaks with equal levels of passion about the beaver.
His is a younger project; he got his first beavers last year – “a female called Sigourney Beaver and a man named Jean-Claude Van Damme.” For six months, they lived in separate dams and refused to speak to each other. In early March came the first sign of interaction. Then, within weeks, they had shacked up together in the bottom dam. By late May, Merlin started to see mini footprints in the mud and in June this year, he spotted baby beavers for the first time (who’ve since been christened “Beavie Wonder and Beavie Nicks”.)
Why did he get beavers in the first place? Because “farming isn’t just about food production.” Merlin wanted to return the farm to a state of “true ecosystem equilibrium,” and, he hastens to add, “you can’t do that without beavers. That’s why people use terms like ‘keystone species’ to describe them.”
After a night in a tent with a bunch of other beaver enthusiasts, Merlin leads us at dawn through the green, closed canopy woodland, clutching his large hobbit stick (a prerequisite for beaver keepers, it seems.)
His beavers live in a five-acre enclosure. It’s a steeper valley than Jones’, and this different topography means the pools are smaller and the dams narrower.
While the project is still in infancy, he’s already seen “an incredible increase in wildlife and insect life.” Creatures to appear include herons, common newts, common toads, adders, dormice and dragonfly species he hadn’t seen before. Animals that were already there, such as trout, “have got bigger and healthier.”
“There’s no animal kingdom that beavers don’t benefit in some way,” he adds. “They bring so much energy back into the environment.”
As we trudge around the enclosure, Merlin suddenly stops and points his stick at a large, mauled branch lining the ground: “Breakfast snack bar!”
Beaver teeth oxidise, hence why they’re a startling orange colour. They need to wear down this rust, so they resort to scraping their teeth on trees.
Their tree-chewing antics don’t appear to phase Merlin- on the contrary, it’s all part of the “messy, mosaic woodland” beavers produce, he explains. And this type of woodland is good for habitat creation: “It provides more spaces for different species to slot in.”
But not everyone is so blasé. Here, we touch on a central tension when it comes to beaver reintroduction: some farmers are worried that beaver tree activity will destroy the woodland.
Every conservation project has trade-offs and beaver reintroduction is no exception. Even Jones admits, they are “a remarkable but sometimes troublesome species.”
Hence why the Beaver Trust has a restoration team fully trained in “beaver conflict resolution”. It’s very important to properly listen to people’s concerns, Sophie Pavelle from the Trust tells me. But she believes the benefits of beavers massively outweigh the costs. Beaver management is “cheap and easy.” And the Trust employs managers to assist farmers – helping them, for example, to wrap a protective tape around trees.
As for concerns that the physical structure of a dam poses a barrier to migratory fish: evidence from different countries suggests otherwise, Merlin argues. “Norway is one of the best places for salmon and they have tons of beavers.” Fish can get through the dams; after all, these two species “have tens of thousands of years of co-evolution.”
Ultimately though, beaver reintroduction will only succeed if its current advocates can build consensus across communities.
The team from the Beaver Trust wear red t-shirts containing the slogan: “Beavers without Borders”. What does this mean? “Beavers are sat in the river so they don’t abide by borders,” James explains. But there’s also a message here for humans: rewilding efforts must cut across borders too. It requires “people from both sides of the bank working together” and collaboration between conservation groups, landowners, farmers, gardeners and policymakers.
Before finishing, I perhaps should acknowledge, you may have noticed a glaring omission in this piece: a description of any actual beaver. Full disclosure: during my two-day trip, I only managed one brief sighting: a fleeting glimpse of a baby beaver on my 6am walk with Merlin while poking my head out from behind a tree. Seconds after I had confirmed it was definitely a beaver and not in fact a small log, it had retreated back into its lodge. (Beavers, as it turns out, are nocturnal…)
A fully fledged sighting of one of these sweet, furry creatures would have been a welcome addition to my trip. But, more importantly, I saw the impressive fruits of their labour.
Beavers are gifted environmental engineers. These remarkable rodents have the potential to breathe life back into our ecosystems – so back the beaver!