Eurasian beavers released by the National Trust as part of a river restoration project have built what is believed to be the first beaver dam on Exmoor for over 400 years.
The construction appeared at the Holnicote Estate in October and has already created an ‘instant wetland’, according to rangers at the site.
Footage captured on wildlife cameras shows the animals gnawing nearby trees and collecting vegetation to create a dam across small channels that run through the Somerset estate.
It comes nine months after the animals were introduced to slow the flow of water through the landscape and improve river quality and biodiversity. The beavers were the first to be released into the wild by the National Trust in its 125-year history.
Beavers are often referred to as ‘ecosystem engineers’. Given the right conditions, they can build dams to create deep pools of water which offer shelter from predators and places to access and store food.
This evolutionary response enables them to move around their habitat more easily and, crucially, turns the surrounding land into a mosaic of nature-rich habitats.
Ben Eardley, Project Manager at the National Trust, said: “It might look modest, but this beaver dam is incredibly special – it’s the first to appear on Exmoor for almost half a millennium and marks a step change in how we manage the landscape.
“What’s amazing is that it’s only been here a few weeks but has created an instant wetland. We’ve already spotted kingfishers at the site, and over time, as the beavers extend their network of dams and pools, we should see increased opportunities for other wildlife, including amphibians, insects, bats and birds.”
Beaver dams, ponds and channels can also help prevent flooding by slowing, storing and filtering water as it flows downstream. The industrious animals create space for water and wildlife, leading to a more resilient river catchment.
Ben continued: “The recent rain we’ve had is a reminder of the significant role beavers can play in engineering the landscape. As we face into the effects of climate change and more frequent extreme weather events, natural interventions like this need to be part of the solution.”
Beavers became extinct in the 16th century due to hunting for their meat, fur and scent glands. Since the early 2000s, they have been reintroduced at a handful of sites in Britain.
Evidence is mounting that beavers could help improve the state of UK waterways. A five-year trial on the River Otter in Devon was recently hailed a success by the UK government who are now consulting on a national strategy for the reintroduction and management of beavers.
The beavers at Holnicote were relocated from wild populations on the River Tay catchment in Scotland, under licence from Scottish Natural Heritage, to England under licence from Natural England.
They took up residence in a specially built 2.7-acre enclosure on the estate in January and have remained under careful monitoring by National Trust staff and volunteers with help from Exeter University.
The project is part of the Trust’s Riverlands programme which aims to revive UK rivers by boosting wildlife, water quality, community engagement and tackling the effects of climate change. Donations to the programme can be made on the National Trust website: www.nationaltrust.org.uk/appeal/riverlands-appeal