The Beaver

This is the first of a new series of articles on the role of reintroductions and translocations as a tool in wildlife conservation. Sadly, many species have been lost from the UK and aiding the restoration of those that are part of the Caledonian Forest is a key part of our long-term vision.


Beavers are semi-aquatic mammals. They are the largest native European rodent and measure up to a metre in length. They have a long, flattened tail which they use as a rudder and webbed feet that are used for propulsion. Beavers generally inhabit lowland riparian woodland bordering slow-moving streams or ponds. They live in lodges which they construct from tree branches and sticks, and they build dams to control water movement. They are completely vegetarian and eat both the lush green parts and the woody stems and trunks of trees, as well as a variety of rushes and sedges. They live in family groups and produce kits (young) every year.

Why should beavers be reintroduced?

The European beaver (Castor fiber) was present in the UK until the 16th century, when it was hunted to extinction for its pelts, meat and musk oil. Since the early 1990s there has been a growing movement to see the species reintroduced, which has culminated in the Scottish Beaver Trial in Argyll, which has just come to an end.

We are legally obliged by various European directives to consider the reintroduction of the beaver and, at Trees for Life, we believe that we also have an ethical obligation to reintroduce the species, given that we caused its extinction. There are also likely to be significant benefits from tourism and estimates have shown that beavers could bring in £2 million a year in revenue.

However, the main reason that we believe beavers should be reintroduced is due to their role as ecosystem engineers. Beavers are a keystone species, meaning that they play a critical role in maintaining the ecological community of which they are a part. They coppice and fell trees, opening up the canopy and letting light into the forest, enabling other species to grow. By damming water courses they create new areas of wetland which attract other species and they also improve water quality and reduce siltation. Together, these factors lead to a huge increase in species diversity.

Dispelling the myths about beavers

A number of concerns have been expressed regarding beaver reintroduction, but many of these are inaccurate or unfounded.

  • Beavers will damage the salmon industry Beavers are entirely vegetarian and do not eat fish. Concern has been expressed that they will dam rivers and prevent salmon getting upstream to spawn; however, salmon are easily able to negotiate beaver dams and the two species have existed together for centuries in many European countries. In Norway, beavers have actually been shown to benefit the salmon industry. They oxygenate the water and, through damming, create additional pools that are ideal for spawning.
  • Beavers will damage forestry operations Beavers prefer broad-leafed trees and so should not have an adverse impact on commercial forestry. Concern has been expressed that they may damage native aspen stands (their favourite food), but most aspen stands are away from suitable beaver habitat and those that are near water courses can be easily protected by fencing or by placing sheaths around the trunks.
  • Beavers will eat crops and destroy farmland Beavers do sometimes feed on crops such as maize and sugar beet, but this is usually small-scale and localised. Crop damage is easily prevented by leaving a buffer strip alongside water courses, or by planting crops that they don’t like.

The history of beaver reintroduction

Beavers were extirpated from much of their former range but have been reintroduced to 25 European countries, with Sweden leading the way as long ago as 1922. The UK remains one of only seven countries that have not reintroduced the species.

However, a trial reintroduction is currently underway. From 2009-2010 16 beavers from five family groups were brought over from Norway and released at Knapdale in Argyll as part of the Scottish Beaver Trial. The trial will last five years and its aim is to determine the impact that beavers have on the natural and socio-economic environment and to gain knowledge to aid a full-scale reintroduction, should the trial be deemed to be successful.

There is also another population of beavers living wild in the UK. There are believed to be 120-150 beavers in the catchment of the River Tay, the result of five generations of breeding by beavers that escaped from captivity. The Scottish government wished to trap and remove the beavers but, due to pressure from a number of organisations, this has now been suspended until the official trial has been completed.

Trees for Life’s position on beavers

We strongly support full-scale reintroduction of beavers to Scotland, as we believe that they are integral to the health of our rivers and are a crucial part of the Caledonian Forest ecosystem. We have been targeting much of our Aspen Project towards expanding stands of aspen in riparian areas, particularly around Loch Beinn a'Mheadhoin in Glen Affric and at Dundreggan (where we planted 3,000 aspens in 2009), to create a better habitat for any beavers that may be re-introduced there in the future. We've been advocating the return of the beaver for many years, through, for example, the 'Wild , Free and Coming Back' conference we co-hosted in 2008, and by our participation in a Beaver Study Tour to Brittany in France in 1996.

Becky Priestley

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