RETURN OF THE BEAVER
In Scotland and England, the beaver is the first native mammal to ever successfully be reintroduced. Now a legally protected species in both countries, the beaver has become a totem for change; will we place less faith in the artifice of man, and more trust in the wisdom of nature?
A constant, calming murmur of water follows us through the wood. All around, the white tendrils of old man’s beard lichen, thriving in the pure air, grip the branches of ancient sessile oaks. The sound of walking boots is muffled on the soft forest floor, where a thousand years of non-disturbance has allowed a mesh of mycelial connections to flourish beneath us. The shallow stream we’re following becomes blocked at intervals by felled trees. Merlin Hanbury-Tenison, who inherited the temperate rainforest of Cabilla, Cornwall – one of the UK’s last – puts a finger to his lips, and points up the stream. There, sitting atop a makeshift structure of broken branches is a revenant, not seen here since a time long forgotten. ‘To have them back, breeding again in an ancient woodland – the first time in maybe 300 years – is magical,’ he whispers, with not one, but two pairs of binoculars readied, as if willing himself more eyes to soak in the moment.
Beavers, Back Again
The campaign has been arduous, but the Eurasian beaver is back. In Scotland, following a trial phase and monitoring of a free-living population that had escaped onto the River Tay from a private collection, beavers were listed by Scottish Natural Heritage as a Protected Species in May 2019. In England, there are a number of enclosed beaver trials, and now free-living populations established on the rivers Otter, Tamar, Wye, Avon and Stour. Following the success of the River Otter Beaver Trial – which published results last year – the UK Government announced that the River Otter beavers could remain wild. As of October 2022, they officially became a Protected Species, making it illegal to deliberately capture, kill or injure them, or interfere with their dams and ‘lodges’. Scotland now has a population of around 1,000 beavers; England around 800.
With what he calls ‘The Thousand Year Project’ underway, Hanbury-Tenison has been captivated by the return of beavers to Britain’s riparian woodlands and waterways. His goal is to treble the 100 acres of this remaining temperate rainforest, and to reintroduce native species that were driven from it. Three years ago, he began exploring options with Natural England and The Wildlife Trust to undergo controlled releases of beavers into his woodland. After receiving a grant for the fencing from Tevi – an EU-funded environmental scheme – and receiving a non-native animal keepers licence, he released a male and female into a woodland enclosure in July last year.
Britain has been missing the Eurasian beaver since around the late 1700s. The last record of a beaver on our lands can be found at Bolton Percy, near York, where a church warden’s account in 1789 records ‘twopence’ being paid to a Mr John Swail for ‘a beaver head’. Castoreum, rich in salicylic acid and produced in the beaver’s scent glands, was then a coveted commodity. Combined with our predilection for their fur, it proved terminal for the UK’s population.
We sit a while in the dark wood, under a cerulean blanket of early morning’s first light. Birdsong breaks the silence; to me, the calls blend into one, but they are distinct to the ecologists around me, whose ears are attuned to their symphony. Hanbury-Tenison reorientates himself to a vantage point on the river bank. From his pocket, he produces a thermal imaging scope, and trains it on the dam ahead. ‘Two beaver kits, that’s fantastic,’ he says, handing me the scope. Down the lens, the dark woodland becomes a grey otherworld, as two tiny, glowing red faces emerge from the rubble of deadwood.
Up until the 1960s, the lands surrounding us at Cabilla were devoted to upland hill farming, producing dairy, beef, sheep, pigs, chickens and a wide variety of crops. ‘In the last 60 years,’ Hanbury-Tenison explains, ‘the farm has been channelled down a path toward monocultures. That degraded the health of the land and soil to the point where it was hard to even sustain the business.’ Now, Cabilla has diversified into ecosystem restoration, while education and hospitality form a new business model. ‘She doesn’t know it yet, but my nine-month-old daughter will inherit this project, and her children after her,’ says Hanbury-Tenison, as the beavers and their kits scurry into dens at the waters’ edge.
Ecosystem Engineers
The real motivation behind this project stems from the idea that forest habitats like this one in Cornwall are incomplete without beavers. These small, semi aquatic rodents are true ecosystem engineers. For shelter, they build lodges using foraged sticks, vegetation and mud and they burrow into soft banks and dig networks of canals to provide access to wooded areas for feeding. The dams they build raise and stabilise water levels, providing access to resources and safety from predators. Over time, their dams and the trees they fell extend river water out onto naturally created wetlands and floodplains.
‘The end result is a net increase in habitat heterogeneity – the bedrock of biodiversity,’ says James Wallace, CEO of the Beaver Trust. ‘They breathe life into waterways and woodlands.’
Hanbury-Tenison pauses at a stripped oak branch. New shoots burst from its wound. ‘A beaver breakfast bar,’ he says. ‘It was only by observing beavers that early foresters learned how to coppice. Beavers are better managers of the wood than we.’ Coppicing is the technique long used by foresters which sees trees repeatedly cut at the base to prolong their life and promote new growth. Around our feet, hundreds of oak saplings rise from the soil, springing forth in pools of sunlight. ‘This regrowth is all because just two beavers have helped to clear the canopy. For ecosystems to function, the pieces have to be back in place.’
Last year, Cabilla experienced an oak ‘masting year’ – an ancient mechanism of reproduction where communities of oaks simultaneously drop a horde of acorns to the forest floor. Botanists believe the phenomenon evolved to sporadically flood the forest with saplings, providing deer with more food than they could eat, thus increasing the number of saplings surviving into adulthood. Beavers would also have played a part in this. By clearing the canopy, they would have enabled sunlight to reach the forest floor, helping those saplings to grow at a faster rate. Meanwhile, their coppicing activity would have sprouted new forage for the deer, also giving the saplings a better chance.
Today however, beavers may not recognise the lands they are returning to. In the 19th century, technological innovations in agriculture transformed seasonally flooded marsh and pasture into the agronomically productive farmland we see today. After the Second World War, the Ministry of Agriculture, Fisheries and Food began issuing grants to farmers for draining wetlands. An estimated 300,000 hectares of lowland wet grasslands were converted between 1970 and 1985, and 1.5 million hectares of upland peatland was drained in the mid-century, mainly through the mechanical digging of channels designed to lower the water table. On official record, one million hectares was drained in the 1970s alone. The trend has continued, with land-cover maps showing that between 2006 and 2012, over 1,000 hectares of natural wetland was converted to artificial surfaces.
In the UK, the AMBER project has found that 99 per cent of our rivers are fragmented by artificial barriers, such as dams, weirs and culverts. Many have important functions, but on average, a barrier punctuates every 1.5 kilometre stretch of river. ‘Everywhere you look, there’s water management; the imposition of culverts and drains that transport water unnecessarily rapidly, and of course, more polluted than it would ordinarily be,’ says Richard Brazier, professor of earth surface processes at Exeter University, and chief scientist on the River Otter Beaver Trial. According to the Water Framework Directive, just 14 per cent of UK rivers are today in ‘Good’ ecological health; none of the UK’s rivers pass ‘Good’ chemical health standards. More than two-thirds of our groundwater bodies are in poor health due to over-abstraction, and agricultural run-offs now pollute more than 2,296 rivers, leading to nearly two thirds becoming what the Water Framework Directive dubs ‘ecological failures’.
All of this activity has decreased the availability of habitat for plants and animals. Since 1970, there has been a 14 per cent decline in species abundance in the UK on average. More species show strong or moderate decreases in abundance (41 per cent) than show increases (26 per cent) since 1970 – during which time annual agricultural productivity has increased by over 150 per cent. ‘Our obsession with order and control has been to the detriment of biodiversity,’ adds Wallace.
And yet, trials show that nature can bounce back. It is obvious to see in this undisturbed ancient wood, where the river is now managed by a pair of beavers; where lungwort and barnacle lichens flourish on every inch of the tree-trunks; and where, as dawn broke this morning, a green woodpecker flitted in gleeful acrobatics between hazel branches either side of the riverbank. Such rich fragments of habitat, teeming with new life, are a vision of what nature in Britain might be like. What’s more they could have positive impacts for each and every one of us.
Handing Over the Reins
‘I think you will find this habitat particularly fascinating,’ says restorative farmer Chris Jones, with the warm glow of a naturalist in nature, as he guides us through a boggy marsh near the village of Ladock in Cornwall. In 2012 and 2013, Ladock experienced severe flash flooding, but the Environment Agency had no budget to spend on flood defence. At the time, Jones suggested that he release beavers into an enclosure uphill, to redistribute water onto the land. In 2017, after receiving a non-native animal licence, Jones’s beavers had begun work on their first dam. Now, four years into what he calls ‘The Cornwall Beaver Project’, the same individuals have extended the system to eight dams.
As he leads us down to the beavers at Woodland Valley Farm, my eye traces the network of pools threading the wetland. The river’s surface fans outward, the weight of its flow easing as it passes a meshed system of dams. Grasses and reedbeds line the wetland’s edges. ‘You wouldn’t believe it, but these same dams that you’re looking at now provided huge flood defence when Storm Dennis came,’ says Jones. Wellington boots squelching through the water, he plunges his walking stick into a thick slop of sediment. ‘All of this is the nitrates, phosphates, and other agricultural runoff that is not able to get downstream because of the beavers’ work.’ Given that these substances can cause huge damage to waterways, contributing to deoxygenation and pesticide pollution, it’s significant work.
In 2019, a study was released examining the effect of Jones’s beavers, along with three other groups in the Forest of Dean, Budleigh Brook and Cropton Forest. By building dams, beavers attenuated average flood flows from extreme weather events by 60 per cent. An earlier study on the River Tamar showed that beavers reduced total discharge of water onto inhabited areas downstream, purifying the agricultural runoff. When water had passed through the system of 13 dams that the beavers created, there was three times less sediment, 0.7 times less nitrogen, and five times less phosphate.
Government bodies have described the results of such studies as ‘astonishing’, and are now calling for more ‘nature-based solutions’ to contemporary land management problems. But ecologists, long campaigning for beaver reintroduction, were less surprised. They already knew that beaver dams cause streams to cut into riverbanks, widening the incised channels. As dams trap sediment, the stream bed raises and forces water out onto the floodplain, recharging groundwater. All of this helps to purify the water system, control flooding, and help prevent agricultural runoff from reaching the coast. ‘Our problems on waterways, rivers and landscapes have been accelerated by the fact that we haven’t had natural functions to counterbalance them,’ says Brazier. ‘If you think of human jobs since the intensification of farming started as getting water off the land, the beavers’ job is to do the opposite.’
This is hugely important given that data from the Met Office, published in the State of Our Rivers 2021 report, shows that from the 1990s, as average temperature has risen above 9°C, average rainfall has increased dramatically. Now, across England, 5.2 million homes and businesses are at risk of flooding, and annual average damages caused by floods have risen to over £1 billion.
For years, conservation groups have pushed to allow more space for natural processes to shape our waterways. A critical hurdle has been unstitching the dependency of farmers on agricultural subsidies, which have historically favoured greater land-use, encouraging farmers to extend arable land right to the edge of rivers and incentivising the drainage of wetland to create more space for crops. Now, the government is developing a new Environmental Land Management scheme, billed to help deliver the goals in its ‘25 Year Environment Plan’. For rivers, there has been a significant breakthrough. Announced on 25 September 2021, the ‘Woodlands for Water’ project will aim to create 3,150 hectares of trees in six river catchments from Devon to Cumbria by March 2025, and will make direct payments to farmers for planting woodlands and conserving riparian ecosystems.
Beavers will become a critical aspect of the mission. DEFRA publicly stated in 2020 that beaver reintroductions contribute to the government’s 25 Year Environment Plan, and UK Prime Minister Boris Johnson recently announced that to help the UK reach net zero by 2050, his government will ‘build back beaver’. The UK has already committed to consecrating 30 per cent of the UK’s countryside to nature, and the carbon sequestration potential of naturally-functioning ecosystems has accelerated the move. A 2018 study found that beaver dams increase the amount of dissolved organic carbon in rivers and riparian woodland; another 2019 study showed that beaver ponds increase the amount of organic carbon in trapped sediments. ‘Where suitable habitat exists currently, it’s about getting beavers back into them. Elsewhere, it’s about encouraging farmers to step away from the river’s edge through payment schemes, allowing regeneration of riparian woodlands, and then we will see beavers’ range extend naturally,’ says Brazier.
The Flourish that Follows
The afternoon light creeps over Jones’s wetland, as more signs of the beaver’s influence on the ecosystem are unearthed. Grasses elbow their way up from the riverbed, water lilies jostle for position, and felled trees droop over the riverbanks. Older beaver dams harbour muddy pools behind them, from which dragonflies burst forth. Above them, the limbs of larger trees are cleared, and sunlight shines through the canopy, falling on the pale pinks of cuckoo flowers and the canary yellows of marsh marigolds at the water’s edge.
‘It’s obvious when you see it, but this is all about creating the messiness that our ecosystems are missing in our now tightly managed environment,’ says Wallace. ‘Nature like this has become sort of alien in the UK.’ He is right: according to WWF, the UK ranks 184th out of 219 countries for the status of its ecosystems.
The UK subscribes to the IUCN’s rules on species reintroduction, and according to Brazier is obliged to actively consider the reintroduction of lost native species. Yet, while celebrating the beaver’s return, conservationists are keen to point out that it is the first native mammal to ever be reintroduced. ‘We are clearly not sticking to the guidelines. We’re not acting on species reintroduction at a governmental level swiftly enough.’
In fact, the founding populations of beaver on the rivers Tamar and Otter came from clandestine releases – possibly a symptom of public impatience with the bureaucracy that accompanies proposed reintroductions. ‘People are taking the power back,’ says Brazier. ‘I can’t endorse that, because the better way would be a politically and environmentally progressive action plan. But in the absence of that, there’s been a huge groundswell of support for reintroduction of species like the beaver, and now pine marten, red squirrel, golden eagles and white-tailed eagles.’
In the years ahead, rowan, alder, hazel and willow saplings will keep springing from the banks of Jones’s wetland. Some 37 bird species will feed on the rowan berries, 90 animal species will be supported by alder, and the endangered kingfisher will nest in the willow’s branches. Through a single act of engineering, beavers ignite a cascade of resource distribution that ripples through the ecosystem. Through the creation of pools and wetlands during the River Otter Beaver Trial, beavers increased the biomass of trout by 37 per cent. Devon Wildlife Trust found that 55 species of bryophyte increased in abundance with beavers, along with 26 species of wetland beetle, and 41 species of aquatic invertebrates. ‘Since they arrived, we’ve had eight new species of birds at the farm: hobbies, green sandpiper, water rail, cormorants, fire crest, gadwall, spotted flycatcher. Even these grasses wouldn’t flourish without the canopy-clearing activity of the beavers,’ says Jones, plonking his hat on the bank and moving to the river’s edge. He points towards a glimmer in the shallows. ‘You see there? Brown trout. Juveniles. We’re seeing so many more: the water is cleaner, and the beavers have let sunlight reach the riverbed where the juveniles can spawn in the growing reeds.’
It is odd to think of the beaver’s long, bloody history at the hands of man. Odder still, to see them here again, when the health of our rivers has depleted, and when the case for their reintroduction has been hurried by the threat of man-made climate change. Perhaps at this juncture, the beaver – busy on our waterways again – is a symbol of humility, of transition, where we no longer rely on our own ingenuity, but place more trust in the methods of nature. By Jacob Dykes, The European Nature Trust. Courtesy of HFF Nature.