Devon beavers to stay
Find out how these industrious dambuilders have been affecting the landscape of their new home
Marching over the bridge in Otterton, Devon, I steal a glance to the river below. It’s midMarch, and this is my final excursion before national lockdown.
Brown and churning, the river scurries another two miles to Budleigh Salterton, where it spills into the sea. It’s chilly and overcast, but spring is well on its way. A preening mallard murmurs sweet nothings at the edge of the bank; a bumblebee loses itself in blackthorn blossom.
Mark Elliott, project lead for Devon Wildlife Trust’s River Otter Beaver Trial, strides ahead. Delighted, he suddenly crouches by coppiced aspen – the woody victim of an unmistakable assailant. A closer look reveals a repetition of linear grooves whittled into a now pencil-shaped stump. “Classic beaver signs,” says Mark. A host of gnawed branches, felled trees and stick piles are scattered around the riverbank, all signs that we’re in beaver territory. After four centuries bereft of these native wetland architects, hunted to extinction in Britain for their fur and castoreum (an anal secretion used in perfumes, flavouring and early medicines), wild beavers are back – hopefully for good.
Today, in this glorious valley, I am wandering through one of about 17
beaver ‘territories’, each of which is home to three or four individuals. In this year of global uncertainty, and during a time of unprecedented species loss across the planet, this remarkable conservation story in a quiet corner of Devon is also one of hope.
Following the surprise discovery of a group of wild beavers living on the Otter in 2013 – their origins uncertain – the species found itself catapulted into the epicentre of conservation chatter. After a passionate plea from East Devon communities to Defra, imploring that the beavers be allowed to stay, Devon Wildlife Trust was granted a license in 2015 to conduct a lengthy investigation: exactly what impact do beavers have on the local wildlife, economy and community?
After all, beavers are renowned for the benefits they can bring. Dam building retains soil nutrients, reducing peak water flow to slow the effects of flooding. Their industrious behaviour improves water quality, creating countless microhabitats for many species of plant and animal – all making for a more biodiverse landscape than before.
And thus the River Otter Beaver Trial was born. Devon Wildlife Trust, partnering with landowner Clinton Devon Estates and the University of Exeter, had five years to prove that beavers deserved their place in our wetlands across the country.
There is no doubt that beavers are a cost-effective ally in Britain’s response to flooding.
“The beaver is the first extinct native mammal to be brought back into the wild in England,” says Peter Burgess, director of conservation at Devon Wildlife Trust. “Its future is hanging in the balance – it’s the most exciting conservation project I’ve been involved with.”
Following in their footsteps
With the trial now complete, Defra has decided to give the beavers the permanent right to remain in their Devon river home. But what have Mark and his colleagues learned? And how did they do it?
As the afternoon wears on, I start to find out. As a zoologist, the prospect of large mammals not only returning to, but transforming my local river, is beyond thrilling. We veer off the main path, ducking our heads below the saplings guarding an offshoot of the mother river.
Prints are clearly visible in the loamy sand. “The back feet are much bigger than the front”, says Mark. “People often mistake one set of beaver prints for two separate animals.”
These prints are a hopeful sign for the River Otter trial. Following the success of a release in Knapdale, Scotland, the Scottish Government reclassified beavers as a native species and granted them legal protection in 2019. “But this is the first and only licensed release of beavers into the wild in
England,” Mark says. A rousing thought when much of the country’s wilder state has been abandoned.
I’ve never thought of beavers as particularly athletic, lacking the agility of an otter, for instance. But they redeem themselves with grit. Mark recollects a tagged one-year-old female embarking on a mammoth 50km dispersal from her release site. Whilst it’s common for two-year-old beavers to travel long distances between territories, such a feat of endurance was unheard of in one so young. Now settled with a partner and kits, it’s a relatable tale. When presented with a virtually ‘empty’ catchment, these mammals can afford to be choosy in where they make their homes.
So, in a valley that covers 250km², how do you follow wild beavers? The project took the lead from the Scottish Beaver Trial, in which annual field surveys during the beavers’ ‘peak work time’ (January to March) proved the game changer in gaining a window into their watery world.
Radio-tagging and tracking became costly and risky, due to the beavers’ semiaquatic lifestyle, so the teams in Devon instead worked with what was available to them: gnawed saplings, stripped bark, stick piles, ‘thatched’ lodges, exit slips into the river, castoreum-bound scent mounds
– a wealth of information pointing to a thriving population.
Such signs were noted, geotagged and inputted into revealing maps of the catchment, finding a consistent tendency for the beavers to be most active towards the south-west regions. Flood-risk properties there have measured noteworthy decreases in ‘peak flow rates’, due to the nearby dams. While it’s wise not to label beavers as a ‘super-solution’, there is no doubt that they are a cost-effective ally in Britain’s response to flooding.
Contrary to popular belief, not all territories contain a dam. In 2019, just under half of those known on the
We round a bend through a copse of poplar trees and I encounter another world.
Otter had a dam present, mainly on the tributaries. “The number of territories is a key measure of success,” says Mark. Though the current estimated 17 is a good number, the River Otter could, ecologically speaking, support up to 179. However, reaching the river’s carrying capacity of beavers is not realistic. “The way we intensively manage this landscape, and the harmony that’s required ‘mammal-tomammal’ places a natural social cap on the beaver population here.”
The benefit of beavers
During their five-year tenancy, the beavers have already had a profound impact in the Otter Valley, not least in bolstering otherwise dwindling numbers of a fellow riparian mammal. “We’ve got new areas that are being re-colonised by water voles as a result of the beavers,” says Mark, “and we’ve had some lovely responses from wetland birds – teal, snipe, even woodcock have all benefitted. We’ve seen kingfishers in new areas, herons feeding on a thriving population of amphibians – even otters are clearly benefitting.”
Such findings shouldn’t come as a surprise. Beavers have ‘British waterways’ etched into their DNA. Naturally, many other creatures would have evolved alongside them.
But it’s the impact on local fish populations that has been particularly interesting. Many anglers have been concerned that beaver dams will prevent salmon migration upstream, despite very few dams coinciding with known salmon runs. And nature continues to surprise. A 37 per cent increase in fish populations has been measured in the beaver pools, and footage shows sea trout defiantly leaping the dams during high flows. If dams are buffered by scrubby margins, Mark explains, the resulting overflow creates multiple channels – migrating salmonids can swim around the dams.
We round a bend through a copse of poplar trees and I encounter another world.
Mark laughs at my stunned expression. “This is why we love beavers!”
Spread out before me is a vast wetland, protectively held in the embrace of an enormous dam. Mini waterfalls tumble into semi-aquatic microhabitats, pools, eddies and flows. It’s chaotic and unruly – but in a good way. I have never seen anything like it. “Human engineers like concrete, straight lines, neat edges – things they can predict and design. With beavers,” Mark beams, “you get this.”
Pressing reset
A year ago, this was all but a patch of scrub ribboned with a tiny vein of water. Today, reclaimed by the beavers, it showcases the best of the mammals’ handiwork. “600 years ago, all of our wetland communities would have been created in these conditions,” says Mark. “This is why we call beavers a keystone species.” Complex, rich and diverse, the potential for supporting a robust foodchain is plain to see.
The clear, shallow currents beyond the main dam spill into navigable side channels rolling over a clean gravel system. “If you’re a trout,” nods Mark, “there’s your spawning ground.”
The beavers tend to their dams constantly – guided by instinct. If the wall is breached, they react to the sound of the new rush of water, sourcing wood, mud and vegetation to patch it up. The water level is raised and the wetland conserved.
Wetland habitat covers 3 per cent of the UK, yet houses 10 per cent of our species.
Wetlands are disproportionately important to our environment, but are declining three times faster than forests. This particular wetland is a staggering example of what beavers can do if a management system of the catchment area is in place.
Where the water approaches the road, Clinton Devon Estate officers intervene. Even removing the top few inches from the dam can lower the water level such that the flooding doesn’t reach farmland. After the February storms, field officers and volunteers removed one dam altogether, as the pools that had accumulated behind it had waterlogged a nearby field. Mitigating strategies such as these are crucial to preserve concord between industrious beavers and a lively farming community.
“Beavers are a brilliant part of the solution in tackling issues that arise with the way humans manage water,” says
Mark. “But, if you’re going to have beavers, you must allow space.”
A key concern within the agricultural sector is the future management of a landscape shared with beavers. The Beaver Management Strategy Framework accompanied the Science and Evidence Report presented to Defra. Not only does it extensively outline Devon Wildlife Trust’s response to conflicts on the Otter, but it offers a blueprint of how landowners on any river can accommodate beavers safely.
“There’s natural tension,” Mark admits, “between what humans want out of a landscape and what beavers want to do to it.”
Beavers can work with farmers, retaining soil in headwaters, filtering nitrates and pollution, sometimes threefold, from our watercourses. Tree guards in local orchards have prevented them from feeding on windfall fruit. Where waterlogging prevents tractors and harvesters accessing fields, dams have been actively removed or reduced, some installed with harmless ‘beaver deceivers’ – a fence paired with a pipe system – that sneak water away from beavers and deter further damming.
Back by popular demand
“The thing about beavers, is that people love them,” says Mark, referring to the trial’s latest public perception survey, where 90 per cent of respondents wanted the species to stay. Local pubs and the famous Otterton Mill regularly report a boost in trade from visitors eager to learn about the beaver project. “Those who aren’t so keen often have misunderstandings about what beavers actually do.”
Now that the Government has allowed the beavers on the River Otter to stay, what does the future hold for the species in Britain? The River Otter Beaver Trial has re-defined our approach to rewilding. Championing science, communication, trust and stakeholder collaboration at the heart of decision making, it clarifies the often murky relationship between nature and people – representing the very best of British conservation. Reintroducing beavers to a landscape is inescapably complex, but a return to the way things ought to be.