beavers
Beavers were once part of the British landscape. Place names echo their presence – from Beverley in Yorkshire to Beverston in Gloustershire and Beverley Brook running through Richmond Park down to the Thames.
They were hunted to the verge of extinction during the reign of King Henry VIII, prized for their silky fur and castoreum – the secretion from the scent sacs close to the tail, used for making perfume and medicines. The last known British beaver was killed in 1789 in Bolton Percy, Yorkshire.
Living without them for so long, ecologists argue, we’ve lost sight of how important they are to our ecosystem. Research in America, Canada and Europe has identified beavers as a ‘keystone species’ whose activities result in an exponential rise in biodiversity. Their coppicing of trees along the riverbanks – for food and to build dams and lodges – lets in sunlight which encourages green oxygen-producing aquatic plants. Woody debris dragged into the water by the beaver provides a jungle of substrate for micro-organisms to grow on – fuel for populations of invertebrates which, in turn, provide food for fish and aquatic birds.
As hydrological engineers, beavers are also hugely effective at creating water-systems that purify water, store it, and protect against devastating floods.
Much of the work we’ve done at Knepp to restore watercourses, including returning our stretch of the River Adur to its floodplain, could have been done more efficiently and at no expense, by a family of beavers.
We’ve been campaigning for greater appreciation of this keystone species for many years and hope it won’t be long before we see free-living beavers throughout the UK, with a reliable management plan to support their return and to swiftly address any problems they may cause farmers and land managers. For the moment, beavers have been allowed to re-establish themselves (from both illegal and licensed releases) in Scotland, where they are now protected by law. In England, which has been much more cautious, a free-living population of beavers has been granted permission to remain on the River Otter in Devon, and over a dozen licenses have been granted by DEFRA to establish beavers within enclosures at trial sites. Knepp is one of these.
In November 2020 we released a male and female beaver that had been caught on the River Tay in Scotland (where many farmers object to their presence) into the Southern Block. Our particular license was for a ‘semi-enclosure’ – the hope being that, if we fortified the deer fences and beaver-proofed the culverts and ditches leading downstream, the beavers would swiftly settle into the rewilding project and, with plenty of wetland and sallow to keep them busy, stay on site for many years.
Unfortunately, within weeks, both had escaped in different directions. The male, Bramber, crossed twenty weirs heading down the Adur towards Shoreham, eventually being captured on an organic farm. The female, Billie, escaped to an angling pond a mile away where she, too, was caught up. Sadly, Bramber died on the night of his capture. Pathology revealed he had succumbed to a virus – quite common in wild mammals – that had probably afflicted him for several weeks. Billie is now with a mate in an enclosure on National Trust land.
The positives from this rather disappointing failed first attempt at Knepp were the public response – overwhelmingly enthusiastic at seeing beavers once again in the wider landscape – and the ease with which Penny Green, our ecologist, was able to catch them up again.
Our next reintroduction attempt at Knepp (in 2022) will be into a temporary enclosure where we hope the beavers will invest in the creation of a lodge, dams and other infrastructure – an effort that will, effectively, ‘heft’ them to the site.
We look forward to seeing how this extraordinary ecosystem engineer makes its mark on our landscape with, we hope, a significant effect on biodiversity and water management
