One May afternoon in East Devon, Alan Puttock, a scientist at the nearby University of Exeter, led me over sodden farm fields, past willow thickets, and through the gates of a fenced paddock. Within the enclosure, 13 dams, composed of tightly packed sticks and mud, had converted a narrow stream into a chain of turbid ponds, waters writhing with beetles and tadpoles. A web of canals snaked through the brush, and fragrant woodchips lay piled beneath half-toppled trees. The landscape was the unmistakable handiwork of England’s most vital wild imports: a family of four beavers, descended from a pair released in 2011 by the Devon Wildlife Trust.
In the US, my home nation, such beaver-influenced landscapes are commonplace with around 15 million beavers inhabiting North America’s waterways. In Britain, however, beavers remain a bewildering novelty. The Eurasian beaver, was once abundant in the British Isles, creating clearings in which early humans could hunt and fish, irrigating agricultural fields, and taught people how to coppice trees for firewood. Homo sapiens responded by slaughtering them for their fur, meat, and scent glands, which were thought to have medicinal value. They vanished during the 18th century, leaving behind naught but an atlas of place names such as Beverley or Beversbrook.
Lately, however, beavers have begun to return. In some cases, such as the Enclosed Beaver Project in Devon and the Scottish Beaver Trial in Argyll, they’ve been relocated from Germany and Norway with governmental permission. Elsewhere, such as Scotland’s River Tay and England’s River Otter, they’ve escaped or been released from private collections, establishing unauthorised populations in their historic haunts.
These covert releases have enraged many farmers, who have accused burrowing beavers of undermining flood defences. Fishermen, who fear that dams will block salmon and trout migrations, aren’t pleased either. Although the Scottish government is expected to grant beavers legal protection later this year, special licenses will still allow farmers to gun down the rodents.
You can’t blame British landowners for harbouring trepidation about the return of such a meddlesome creature. Yet scientific research from North America demonstrates that beavers offer us far more help than harm. Their dams and ponds improve water quality by filtering out pollutants, provide drought-stricken farmers with valuable water sources, contain the spread of wildfire, and turn dry pastures into lush meadows by raising water tables and sub-irrigating floodplains.
Most extraordinary, perhaps, is the beaver’s status as a keystone species. In North America, beaver ponds and wetlands provide prime habitat for just about everything that crawls, walks, flies and swims. Aquatic insects shelter in the crevices of dams and lodges. Ducks nest in the tall grasses that spring up around pond fringes. Songbirds perch in coppicing willows. Moose and swans feast on dripping weeds. According to one 2016 study, beaver dams even boosted the survival of threatened steelhead trout by more than 50 per cent.
Wildlife may be the most immediate beneficiaries of the British beaver renaissance, but humans, too, have much to gain. The UK loses £45million annually to soil erosion – a problem beavers might be able to address. Earlier this year, Alan Puttock and other Exeter scientists found that the 13 beaver ponds in Devon trapped more than 100 tonnes of sediment, most of it eroded soil from upstream farms. Much of that stored silt was rife in agricultural chemicals, namely excess nitrogen and phosphorus from fertiliser; by settling out sediment in their ponds, beavers thus prevented pollution from fouling downstream rivers.
To reap beavers’ benefits, of course, we have to let them live. Although we Yanks are hardly paragons of good beaver management – the US government killed more than 23,000 beavers in 2017 alone – North American researchers have developed plenty of techniques for non-lethally averting beaver damage. Wrapping trees in wire or coating them with abrasive paint can thwart beavers from gnawing down valuable timber, while pipe-and-fence systems called ‘flow devices’ prevent them from inundating fields. Indeed, these techniques are already helping humans coexist with beavers in the River Otter, where the rodents have become a charming tourist attraction.
Britain’s ecosystems, like the world’s, stand on the precipice: Birds, butterflies, and other organisms are plummeting, water quality is deteriorating, and climate change is fuelling both droughts and floods. Not even the mightiest rodent is capable of solving all those crises, but rejuvenated beaver populations could still make a significant dent in many ecological problems. Encouraging beavers’ spread will only benefit the environment – on both the North American and European sides of the pond.
This was published in the September 2018 edition of Geographical magazine
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