British Wildlife of the Week (Special)

Reintroducing Beavers

In recent decades, Britain has seen the reintroductions and translocations of many animals, from red kites and great bustards to pine martens and natterjack toads. But the pioneering Scottish Beaver Trial has been, if anything, even more ambitious and significant than any of those. It was the first time a licensed, government-sanctioned project returned a nationally extinct mammal to the wild in the UK.

Britain has been bereft of beavers for over 400 years. Their disappearance in the mid-16th century coincided with a steady loss of their woodland habitat and a burgeoning human population. They were also hunted for their fur and meat, and to harvest their pungent anal secretion, castoreum (which you can read about in our previous beaver article here).

But now, finally, beavers are back – not only in Scotland, but in other parts of Britain as well. The proposed full reintroduction of these large, semi-aquatic rodents to our nation could help address flooding, climate change, and the loss of fragile, damaged ecosystems. Their manipulation of the landscape can turn species-poor woodlands into biodiverse, carbon-sequestering wetlands humming with life. But does everyone believe that bringing beavers back to Britain is a good idea?

Bringing Back the Beaver

The first wild beavers to return to the British Isles since their extinction were in Scotland, both by design in Knapdale on the west coast and less deliberately on the River Tay on the east. Between May 2009 and June 2010, 16 beavers were released into Knapdale Forest from Norway, as part of a trial project to see how they would fare and what impact they would have on the environment. They quickly established themselves and began breeding. Later, between 2017 and 2019, this population was reinforced with 21 other individuals to boost genetic variation. Armed with powerful jaws and huge, iron-coated, chisel-like incisors, these enthusiastic gnawers have since created new wetland habitats by coppicing trees, opening up ponds, and building dams.

No one is quite sure where the population at Tayside came from, although they are thought to be escapees from private collections. From presumably just a small number of animals, their numbers have roughly trebled since 2012 and there are now thought to be more than 400 beavers in the Tayside area. Between 2013 and 2015, they built 500 metres of canals, an acre of freshwater ponds, and 195 metres of dams.

In England, a few small, fenced and very closely monitored populations of beavers can be found in several counties, including Gloucestershire, Kent, Devon and Cornwall. For now, at least, they are kept contained so that their impact on the surrounding environment can be studied. This, it is hoped, will provide scientific evidence to strengthen the case for a more widespread reintroduction.

The Otter, in Devon, is the only river in England known to contain a free-living breeding population of beavers – although, once again, the origin of these animals, which were first noticed in 2013, is not known. Most likely, they came from unofficial, unlicensed releases. Whatever the case, they are making the most of their newfound freedom: they have raised kits and the number has risen from two breeding pairs in 2015 to perhaps 15 family groups today, which have expanded into nearby tributaries.

In January 2015, Natural England, the government’s conservation watchdog, declared that the beavers on the River Otter would be allowed to remain there on condition that they were free of disease and of European descent (they would be considered an invasive species if they were North American beavers). These conditions were passed (apparently, they come from Bavaria) and they were returned to the river as part of a five-year trial scheme, where the Devon Wildlife Trust conducted a lengthy investigation into what impact beavers have on the local wildlife, economy, and community. It was, in effect, five years to prove that beavers deserve their place in the British countryside once again. In 2020, that trial ended, and it was announced that these free-living beavers can officially remain there indefinitely.

This momentum, I’m happy to say, is showing no signs of slowing down. A record number of beavers will be released by the Wildlife Trusts into Britain this year. In February, Dorset Wildlife Trust released a pair of beavers into an enclosure on a wetland nature reserve, and within a few days they began to construct their first dam. Less than two weeks ago, on March 31, licensed beavers were released in Wales for the first time, at the Cors Dyfi nature reserve in Powys. And there are plans for more to be released in enclosed areas in Derbyshire, Nottinghamshire, and the Isle of Wight within the year. If all goes to plan, by the end of 2021, beavers will have been restored to five counties where they have been extinct for at least five hundred years.

The Benefits of Beavers

Reintroducing beavers to rivers in Britain has long been encouraged by environmentalists, who have argued that these industrious lumberjacks can play a hugely important role in restoring nature to our country. For a start, they are an excellent and cost-effective form of flood defence. A five-year study of fenced and wild beavers revealed how their dams can greatly reduce flash-flooding downstream by drastically slowing the flow of water. Dams can also hold water in dry periods and, by trapping silt, reduce erosion and improve water quality. In essence, they can be a great way of managing river systems in a more natural way.

Being a keystone species, beavers also bring many benefits in terms of enhancing biodiversity. After beavers were released into an enclosure in west Devon, frogspawn increased significantly, attracting predators such as herons and egrets. Aquatic plants, dragonflies, butterflies and trees thrived in and around new ponds created by the beavers. They essentially re-engineered small valleys with insect- and amphibian-friendly pools, creating a miniature wildlife paradise. And in Scotland, ecologists recently found that beavers increased the number of plant species by nearly 50% because they create such a rich variety of habitats.

The benefits of beavers, therefore, are clear: they help mitigate flooding, freshwater pollution, soil erosion, and habitat and species loss. They can be natural allies, and their presence, in the future, may also boost tourism in the countryside (as seen in many other European countries that have recently reintroduced these animals). So maybe it’s time to start introducing beavers fully into the wild, rather than into enclosed areas. They are, after all, a native species with every right to be here; they shouldn’t be kept in enclosures in the long term.

Beavers can certainly live in Britain. But can the British live with beavers? In truth, not everyone is convinced that the reintroduction of Europe’s largest rodent to our waters is a good idea. Some people object strongly to their presence, fearing that they will wreak havoc on our manmade landscape. There are concerns that they could cause problems for intensely farmed lowlands such as the Somerset Levels, with their dams flooding productive land.

Many anglers are also antagonistic to the idea of reintroducing beavers. Beavers don’t eat fish, but their activity can, or so the anglers claim, create still, static pools that are far less useful to fish that prefer to spawn in fast-flowing water, such as salmon and trout. But on the whole, although some anglers seem reluctant to accept it, beaver pools will be mostly good news for river fish; the clearer water and greater diversity will be a positive asset to them, and may even recreate the conditions necessary for species now extinct in the UK, such as the burbot, to thrive again.

It has also been argued that beaver dams may negatively affect the populations of some fish species by preventing them from migrating upstream to breed. However, we must remember that fish have been migrating up our rivers for hundreds of thousands of years – and for much of that time, beavers were also creating dams. The fish had little problem then and they’ll have little problem now. In many other European countries, which have much larger and more widespread beaver populations, beavers and salmon – surprise, surprise – co-exist without much issue.

Our rivers have, of course, changed significantly in the four or five centuries since beavers last lived in them. So maybe there is a valid argument to be made that their former presence here is no guarantee of their suitability for modern conditions. But mounting evidence tells us that beavers can assist with the many problems that currently plague our river systems, such as flooding, pollution and habitat loss. In fact, these large, charismatic rodents could well be the best tool we have to improve the ecological quality of our waterways and wetlands.

Perhaps the main issue at play here is that, by allowing beavers to roam and modify our landscape once again, we are conceding some control over the environment. We are allowing – even encouraging – beavers free reign to do with their surroundings as they will, and sometimes their idea of landscape manipulation may clash with our own. For some people, I suspect, relinquishing that control may be intolerable.

So will the beaver ever be permitted into the wider British countryside? There certainly seems to be public interest and appetite, and there are plenty of suitable rivers, so I think their proper return is inevitable. Obviously, reintroducing beavers to a landscape that has changed enormously since they last lived in it is extremely complex and should not be rushed, but I think we’ve reached a point in the history of our nature-depleted country that we can’t afford not to reintroduce beavers. Successful reintroductions, in my opinion, are a sign of hope that we can reverse the decades, if not centuries, of harm we have done to wildlife and nature. Hopefully, it won’t be long before these industrious rodents are an intrinsic part of our landscape once again.

In the next British Wildlife of the Week, we’ll be looking at a wading bird that, in the male’s case at least, undergoes one of the most spectacular avian transformations in the world as the breeding season approaches – the ruff.