Article Movement & Migration

The beaver heroes of Telemark

Russell Scott and Helena Greenlees investigate how the reintroduction of the beaver to Scotland has been an all-round success

The Eurasian beaver (Castor fiber) lived in Britain 1.5 million years before humans but was hunted to extinction in 16th century Britain and to near extinction throughout Europe. When we lost the beaver we lost yet another keystone species and true “ecosystem engineer” that created habitats for many other species through felling trees and creating ponds.

By the early 20th century, beavers were close to extinction in Europe, but fresh hope was on the horizon. With the help of changes in legislation and management practice as well as translocations, reintroductions and natural recolonisation, the population in Europe has bounced back, reaching one million.

The first ever formal reintroduction of this mammal to Britain began with their release into Scottish lochs in Knapdale in May 2009. It was a milestone in British conservation history and had taken years to come to fruition.

The release was part of a five-year trial to study the feasibility and benefit of beavers to nature conservation and deprived rural economies. The trial is now over and the results of the trial will determine the fate of the beaver in Scotland.

Why do we need the beaver?

The beaver is a keystone species for forest and riverbank environments; its modification of the environment and the new habitats brought about by its activity provide an overall positive effect on biodiversity. Although there may be occasional negative effects, these can realistically be managed by human intervention where necessary.

Disturbance of trees by beavers promotes vigorous new growth and improves biodiversity, allowing for open glades as well as more open forest stands. Beavers stabilise wetlands during dry periods, creating ponds and flooded forests that serve as breeding habitats for birds and stable deep-water habitats for fish. The stability of water levels in beaver ponds make them a haven in times of drought. The increase in invertebrates resulting from the creation of beaver ponds provides an important food source for fish and, in turn, the stable fish population provides a reliable source of food for otters and birds. Otters use abandoned lodges as holts and many species of birds are drawn to the ponds to nest. In studies, the number of dragonfly species has been found to double or triple following beaver activity.

The beaver is therefore widely regarded as having a particularly positive impact on biodiversity as well as ecosystems and socioeconomic resilience.

Beaver as disturbance agent

Headline events such as massive wildfires in North America or the destruction of crops by insects tend to suggest that disturbance of our ecosystems is an unwelcome influence that should be excluded wherever possible. This is understandable and quite correct where there is a risk to life, livelihood or precious ecosystems that are limited in extent. However, natural disturbance events are increasingly thought to play a vital role in maintaining biodiversity in areas that are set aside or managed to maintain that diversity.

With influence ranging from thousands of hectares to a single tree or even a branch, disturbance is thought to be the engine that creates opportunity for a diverse range of species where otherwise a smaller range of species would be supported. A simple example of the positive influence of disturbance is when large trees are uprooted by a storm to expose areas of bare soil with accompanying high levels of light, which is vital for seeds to sprout. Disturbance can create so much diversity in the space occupied by ecosystems that whole ecosystems can collapse when disturbance agents are excluded.

During the 20th century, beavers were absent from much of their former range, including the UK. At the beginning of the century only around 1,200 Eurasian beavers survived a period of unprecedented overhunting. As herbivores and dam-builders, beavers massively influence their natural habitat of water features and the woodland margins surrounding these aquatic habitats. It is for good reason that beavers have variously been described as disturbance agents, keystone species and ecosystem engineers.

What puts beavers in contrast to other local herbivores is their ability to fell large, mature trees. This creates vital deadwood habitats for insects that then serve as a food source for other species such as woodpeckers and swallows, while also creating perches and nesting opportunities. Through the creation of dams, beavers even transform terrestrial ecosystems into aquatic ones in the form of beaver ponds. Beaver ponds not only trap water but also sediment, and this sediment acts as a nursery for a high abundance of insect life, which in turn supports a plethora of species such as fish, birds, bats and otters. By engineering these very scarce habitats that otherwise wouldn’t exist in the landscape, beavers create biodiversity hotspots that go hand in hand with ecosystem resilience and health.

Why Knapdale?

Knapdale in Mid Argyll, Scotland, was chosen for the beaver trial because its ecology is suited to beavers with its variety of land and freshwater habitats, which in turn provided a variety of species to monitor. Steep ridges (knaps) and the sea create natural containment to minimise dispersal. The working Forestry Commission Scotland (FCS) forest in the area provided infrastructure for access as well as the opportunity to study the impacts of the beaver on forestry. Scottish Natural Heritage (SNH) and FCS both have offices near the trial area and there was considerable local support as well as existing visitor facilities.

Each of the initial three release lochs (Loch Coille-Bharr–Dubh, Loch Linne and Creag Mhor) provided suitable habitat and, since beavers are highly territorial, each was large enough for an average beaver territory. The lochs are connected by watercourses and are close enough to allow the beavers to meet and establish new families and territories. The watercourses provided a buffer zone, allowing beavers to explore without immediately meeting other families and risking attack. The trial area as a whole is capable of supporting 25 beaver territories and contains several smaller lochs into which some beavers moved or were later released.

How it happened

Following successful reintroductions across Europe, discussions began in the 1990s for Scotland to follow suit. However, although there was strong public support for beaver reintroduction (two-thirds of respondents supported it), public consultations showed that there were concerns, mostly from the agricultural, forestry, field sports and fishing sectors, about negative effects following beaver activity. As a result, a trial reintroduction in Knapdale Forest was proposed by SNH in 2000 to address these reservations.

Section 14 of the Wildlife and Countryside Act 1981 states that it is illegal to release any wild animal not normally resident in the UK, so a licence was required before the trial could proceed. The initial application was rejected mainly because of its potential damaging effect on the Special Area for Conservation (SAC) in Knapdale.

However, following a change of government in 2007 a “Species Action Framework” (SAF) was launched. The framework identified species in need of targeted management and action and included two reintroductions: the white-tailed eagle and the Eurasian beaver. An in-depth licence request was presented to the Scottish government detailing legal issues, public consultation results, management methods, impacts, exit strategy, research and monitoring methods, risk assessment. A licence was finally granted for a five-year, independently scientifically monitored trial in 2008. It was to be the first ever licensed release of a mammal species in the UK.

Concern over any damaging impact on outside interests was addressed specifically in the Scottish Government licence condition number 18:

Arrangements must be put in place by the licence applicants to ensure that local businesses and properties have a clear route to pursue compensation claims for damage caused by the beavers during the period of the trial.

The geographically restricted trial was limited to five years and ended in May 2014. The results of the trial, which will determine the future of the beaver in Scotland, were analysed and the resulting report presented to the Scottish government in June 2015.

The aims of the trial (as stated by the Scottish Beaver Trial) were:

“i. to study the ecology and biology of the Eurasian beaver in the Scottish environment;

ii. to assess the effects of beaver activities on the natural and socioeconomic environments;

iii. to generate information during the proposed trial release that will inform a potential further release of beavers at other sites with different habitat characteristics;

iv. to determine the extent and impact of any increased tourism generated through the presence of beavers; and

v. to explore the environmental education opportunities that may arise from the trial itself and the scope for a wider programme should the trial be successful.”

The beavers released in Knapdale were wild Eurasian beavers from Telemark, Norway. Following six months of quarantine, in May 2009, 11 beavers (three families) were released into three separate freshwater lochs.

The Telemark beavers

International Union for Conservation of Nature (IUCN) guidelines state that for any reintroduction the taxonomically closest animals to the original native ones should be used. An SNH commissioned study showed that the fossil skulls of British beavers were closest to the Scandinavian beavers. The study also recommended selecting animals from a similar environment and climate. The mild climate of Telemark meant that it should not be too great a leap for the beavers to adapt to life in Scotland.

The beavers that were trapped were complete families. Population density and landowners’ wishes were taken into account so that families were selected where landowners wanted them removed or where they represented a “surplus” and were likely to be shot or trapped by hunters.

The beavers were quarantined and examined especially to ensure that they did not carry, and therefore introduce, parasites and diseases such as the potentially pathogenic and zoonotic parasite Echinococcus multiloris.

Complete family groups were used on the basis that, being already bonded, they would be more likely to settle during captivity and stay together following release. During quarantine beaver families were kept together and provided with artificial lodges that they quickly adapted and modified. It also reduced the likelihood of the beavers moving beyond the trial area.


On the 28 May 2009 the first beavers were released, with radio transmitters mounted on their tails to keep track of them. A soft-release approach was taken so the beavers had the chance to gradually acclimatise to their new surroundings and they were provided with supplementary food for the first few days to reduce stress levels and to encourage them to stay in the area. Artificial release lodges were created at the edges of the three lochs. These had temporary barriers (which the beavers would eventually gnaw through) intended to retain them while they acclimatised. However, the beavers all broke out of the lodges within minutes so the intended soft release turned into a hard release. The beavers didn’t return to the artificial lodges. Some experts believe that the scent of humans in artificial lodges following transportation only adds to the stress levels anyway.

Later releases were done slowly and, although artificial lodges with food were provided, the beavers were released into the surrounding environment and allowed to acclimatise in their own time: a much calmer process. The artificial lodges were also supplied with bedding from their quarantine lodges to provide familiar scents. Reducing stress levels during captivity and transportation and release are important to reduce mortality levels, always an issue in the first year for translocated beavers.

A 10-day post-release tracking programme followed the release, after which visits were reduced to every other day, then every third day and finally once a month.

There was some initial dispersal, resulting in some beavers going missing with radio signals being lost and others relocating within the trial site. A SBT field officer reported having heard gunshots at a time when one adult female from Creag Mhor was lost and there were fears that she had been shot. An investigation by police followed but no evidence was found. Some kits were also predated, one by what appeared to have been by a domestic dog.

The female was never found but an adult male from from Creag Mhor was found living in in a coastal woodland not far from the trial site along a freshwater burn. The route this beaver was likely to have taken meant he almost certainly moved through seawater to reach his new site – an important discovery as it was thought beavers were unlikely to disperse via the sea. The beaver was caught and re-released in his original loch. The missing sub-adult from Loch Coille-Bharr–Dubh appeared to have travelled to another part of the trial site but was never found.

Beavers moving from their release site had been expected and planned for; however, it was more extensive than expected. The trial site was not as enclosed as had initially been believed.

Beaver activity in Knapdale

The first dam built was on a burn between Dubh Loch and Loch Coille-Bharr, resulting in Dubh Loch expanding and stabilising at four times its original size. Dams had to be monitored to make sure that if any were built in the oligomesotrophic loch feature of the SAC natural water levels were maintained, either by devices designed to manage water flow or by removing the dams. This did not apply to Dubh Loch. A walking detour route for visitors round the flooded area was constructed, with a viewing platform providing a clear view of the dam. One dam at Loch Linne was removed because it was close to a culvert by a much-used forestry track, to avoid rising water levels undermining the track.

All the trial beaver families built short canals less than 2m in length. However three 30m, 1m wide and 0.5 m deep canals were built at Dubh Loch, leading from the loch into the regenerating birch forest around it. This is a key new habitat that has been colonised by aquatic plants, sticklebacks, amphibians and aquatic invertebrates.

The released beavers have gone on to breed successfully and 14 kits were recorded to have been born over the four breeding seasons of the trial from three breeding families.

Public engagement

On top of the initial consultations in 1998 and 2000, the SBT ran two more public consultations: one in 2007 before submitting a licence application to the Scottish government and another in 2014 near the end of the trial.

The results of the 2007 survey showed that 72% of the responses from residents in Mid-Argyll were in favour of beavers returning to Scotland and 73% in favour of them returning to Knapdale. The strongest opposition came from those living in Knapdale, in part from landowners and stakeholders. Public attitudes from those in favour showed an awareness of the benefits to biodiversity, wildlife tourism and the return of a keystone species. Those against were worried about damage caused by beaver activity, insurance and compensation issues, containment, questions about historical evidence supporting the previous range of the beaver and best use of resources.

The 2014 consultation received a great deal more responses. Of the respondents living in Mid Argyll 84% were in favour of wild beavers living in the area (11% disagreed), 74% of the Scottish adults that were aware of the trial support beaver re-introduction, according to YouGov (6% disagree) and 80% of locals believe beavers will help the local economy (4% disagree).

A great deal of effort was put into PR, media and marketing, resulting in a great deal of media coverage, including BBC’s Springwatch and nearly 3 million people being engaged with the trial via TV, social media, website, education, events or visits. Twenty-six countries were included in the Knapdale visitors book. The story of the release was picked up by a wide range of media locally and internationally and the news reached an estimated 10 million or more people on Friday 29 May 2009.

The trial was awarded the Lonely Planet Wildlife Comeback Award in 2011, was highly commended in the Nature of Scotland Awards in 2013 and was voted Best Conservation Project in the UK by readers of the BBC’s Countryfile magazine.

The beaver trial has been very high profile: it is estimated that 2.9 million people engaged with the trial, whether via television, websites, social media or educational activities. The resulting tourist industry means beavers have a positive socioeconomic impact. For rural communities beavers can bring a revenue boost, as much as £2m a year, in the form of wildlife tourism.

The high profile nature of the trial has raised nature conservation awareness and increased awareness around returning native species to the wild, resulting in beavers being regarded as a “flagship” species.

Research and education

The beaver trial provided a unique research opportunity over and above the objectives of the project. Work placements, student projects and research papers were facilitated by it. Field trips were organised at the site and SBT staff gave more than 80 lectures. Students ranged from high school, adult night classes and universities.

The provision for local and national education programmes helped to promote understanding and awareness of Scotland’s natural heritage and encourage the restoration of wetland habitats. Education provision was both formal, engaging with the national curriculum (schools, nurseries, colleges and universities), and informal (activities with the public and special interest groups) enabling wider participation. Both promoted environmental awareness and responsibility.

There was a high level of demand for guided talks, walks and events (a total of 31,100 people attended) and a part-time education ranger was hired to meed this demand; 5,343 children and 2,092 adults engaged in the formal education programme. Over 200 schools were visited. More than 100 talks and presentations were given to over 4,000 people.

A curriculum-linked “Scottish Beaver Trial Education Pack” was sent to every primary and secondary school in Scotland. Educational resources were made available to download online and two live education events for primary schools using the online community portal for Scottish schools were provided. An international seminar was held at Edinburgh Zoo in 2009. Informal activities were created for public events such as feely boxes, a GPS beaver trail and geocaching.

Visitors and tourism

Objectives for visitors were established and leaflets and a visitor centre provided to facilitate these objectives. Learning objectives included why the trial was happening, the positive impact beavers can have on biodiversity, that Knapdale forest is a rich and valuable habitat for wildlife, who manages and resources the trial and that it is in an FCS forest. Emotional objectives were that visitors would feel the trial was exciting and well managed, worthy of support and that Knapdale is an enjoyable place to visit. Behaviourally it was hoped that visitors would interact with the provisions made and minimise disturbance to beavers and wildlife by keeping to the paths provided.

Steps were taken to facilitate the increase in visitors to the site that the beavers would attract, and also to protect wildlife from visitor impact. The existing car park and visitor centre were upgraded and interpretation panels and waymarkers provided.

The re-routed path round the Dubh Loch area provided the opportunity to add a floating pontoon on loch Coille-Bharr running parallel to the beaver dam and giving visitors a unique view of it.

The future of the beaver

A great deal of effort has been put into planning and implementing the Scottish Beaver Trial. More than 40 people from 10 organisations and three countries were involved in the 12 months that led up to the first release. The complicated five-year independent monitoring programme that followed the release allowed the opportunity for new animal-management techniques and study methods to be rigorously field tested. The work has advanced understanding of beavers, their role as a keystone species and how this reintroduction could be built and improved on should there be further releases in the future.

Over the five years of the trial, data was collected about the beaver ecology and the environmental and social impacts their activity brought about. The trial is now over, the results of the independent monitoring programme have been analysed and final reports produced. This package has been presented to the Scottish government by SNH and the future of the beaver in the UK hangs on the government’s decision.

In part two we aim to discuss some of the results of the trial and possible future scenarios for beavers in Scotland. One day this native animal could be back at home in lochs, rivers and burns throughout the country.

This article is a response to the topic idea; Where have all the hedgehogs gone?.

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