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REINTRODUCING BEAVERS TO ENGLAND Digest of a report The feasibility and acceptability of reintroducing the European beaver to England Commissioned by Natural England and the People’s Trust for Endangered Species Why commission a feasibility study? Why consider reintroducing beavers? Natural England and People’s Trust for Endangered Beavers were a natural part of the British countryside Species jointly commissioned this report. until driven to extinction by humans hunting them for their fur, food and the medicinal properties of their Natural England commissioned this report for two main scent glands. They mostly died out in the sixteenth purposes: century although there is some evidence that a few • to help Natural England, as the lead delivery body may have hung on until the eighteenth century in for the England Biodiversity Strategy, develop a northern England. By the 1900s, beavers had been lost view on the feasibility and desirability of beaver completely from large parts of their native range across reintroductions in England and what contribution Europe with numbers estimated as low as 1 200. beavers might make to national habitat restoration Since then numbers have recovered in many other targets. At the time of the publication of this report, European countries through regulation of hunting, Natural England’s Board has not yet considered its translocations, reintroductions as well as naturally. position on beaver reintroductions. In Britain, the Scottish Wildlife Trust and The Royal • to help Natural England, as the licensing authority, Zoological Society of Scotland have been granted prepare itself for making a decision when it receives permission by the Scottish Government for a trial a licence application to release beavers into the reintroduction of beavers in Knapdale from 2009. wild in England. In Wales, the North Wales Wildlife Trust, is assessing Beavers are strictly herbivorous; they suitable habitat for a potential reintroduction there. do not eat fish or any other animals. People’s Trust for Endangered Species is a UK In spring and summer they mainly So far, in England, beavers are only present in a semi- eat aquatic and riparian plants, at conservation charity concerned to ensure a future for other times of the year they depend captive state in a few wildlife parks and sanctuaries and endangered species throughout the world. It provides heavily on woody species for food, on private land. such as willow, alder, aspen and birch, practical conservation support through research, grant particularly those that are found in very There are several reasons why beavers deserve close proximity to the water’s edge. aid and educational programmes. People’s Trust for consideration for reintroduction to England: Endangered Species commissioned this report to inform • Beavers were a native species and were for centuries its own view on the feasibility and desirability of beaver a natural part of our countryside. Human activity reintroductions in England when assessing any future was entirely responsible for their disappearance. applications for funding any such reintroduction. • We have a legal obligation to at least consider reintroduction. As part of our commitment to conservation as an EU Member State, the UK is required to carry out studies on the desirability of reintroducing species that have become extinct. • Beavers are what is known as a ‘keystone A copy of the full report The feasibility and acceptability species’: their loss has a profound effect on their of reintroducing the European beaver to England can be found at www.naturalengland.org.uk or www.ptes.org. Our surroundings. Beavers are nature’s water engineers, thanks go to the authors of the full report as follows: naturally managing riverbank, wetland and forest habitats and the way those habitats behave. Cover image laurie campbell J. Gurnell, C.G. Faulkes and E.J. Hare (School of Biological and • Many people find beavers inherently interesting Chemical Sciences, Queen Mary University of London); A.M. such that they have the potential for raising Gurnell, D. Demeritt and S. Nobert (Department of Geography, awareness much more generally about nature Terry Whittaker King’s College London); P.W.W. Lurz, M.D.F. Shirley and S.P. Rushton (Centre for Life Sciences Modelling, University of Newcastle-upon- conservation. Tyne). What effects are beavers likely to have recolonisation under certain climatic conditions, or on their surroundings? cause unfavourable shifts in the structure of a fish community. Many of these problems could initially be Reintroductions of any species can pose benefits and avoided by siting reintroduced beaver populations in risks and both must be carefully assessed. areas where flow to adjacent water bodies is unlikely Laurie Campbell to significantly decrease, preventing the likelihood of PLANTS fish being unable to pass by. Furthermore, the positive Beaver dam construction can create extensive, mixed impacts of beaver on fish populations are likely to wetland habitats that substantially increase the variety increase with the maturity of beaver ponds. Monitoring of species of herbaceous plants around the water banks. of fish populations following beaver reintroduction Beavers like to feed on a small number of woody plant is essential and may prove useful in reassuring local species which encourages other woody species to fisheries and landowners if positive impacts on predominate. Beavers naturally coppice trees, a practice commercially important species can be demonstrated. still emulated today in woodland management. Where young trees are browsed and felled, shoots develop AMPHIBIANS from the stumps which rejuvenate the woodland by The reintroduction of beaver to England is likely to increasing the number of tree stems and helping to benefit native British amphibians by increasing suitable PTES stabilise the banks of water bodies. Overall, the impact breeding habitat, although in certain parts of the of beavers on plant diversity is very positive, particularly ABOVE TOP: the European beaver country this could also benefit non-native species such usually digs burrows in riverbanks in across a whole landscape. which to nest. However, they cut wood as the American bullfrog. to build dams if the water is not deep enough to cover the entrance to the INVERTEBRATES burrow. They will also build lodges from REPTILES wood if burrowing in banks is difficult. Beavers significantly alter the local invertebrate British reptiles are terrestrial and will not be particularly ABOVE BOTTOM: beavers are able to population in a predominantly beneficial way by fell quite large trees. This provides dead affected by the reintroduction of beavers, although grass increasing the number and variety of invertebrates. The wood habitat which is beneficial to many snakes favour damp areas and are good swimmers, so other species of wildlife. overall increase in aquatic habitats of all types provides they could benefit from beaver impoundments. additional foraging habitat for numerous species of birds, fish, mammals, reptiles and amphibians. Less BIRDS favourably, beavers do have the potential to harm Beaver ponds provide suitable nesting, foraging, RIGHT: Beavers are able to occupy endangered freshwater pearl mussels which are a and/or modify a wide range of water- breeding and roosting habitat for a multitude of protected species, so some areas might need to be marginal environments, but in general avian species. Bird abundance, prime beaver habitat would include easy protected against beavers for this reason. access to grasses, forbs and riparian production, diversity and tree species; low flow water depths, at least near their lodge and burrow sites, species richness is generally FISH of >0.6m; river channel gradients of less much greater at beaver-created than 0.15 and preferably as low as 0.06 Overall, beavers are likely to have a positive impact on and ‘soft’ or finer calibre bed and bank wetlands and very few species materials. fish populations creating foraging habitat and refuge decrease in abundance with for a wide variety of species including those that are the presence of beavers. Beaver considered commercially important. Increased growth reintroduction in England rates experienced by some fish in beaver pools, along is likely to benefit most bird with a tendency for larger species to replace smaller species and could provide ones in warm water streams, could provide excellent additional foraging habitat for Duncan Halley opportunities for anglers. Nevertheless, beaver dams conservation priority species, may restrict fish movement, migration, and prevent such as the osprey. MAMMALS Is there public support for Beaver habitats attract a large number of mammals and reintroducing beavers? could provide food and shelter for many native British species, including semi-aquatic mammals such as water There appears to be broad but shallow support from voles, otters, and water shrews. Any negative impacts the public at large for wildlife reintroductions. A few on mammals are most likely to be an indirect result of interest groups are strongly opposed, but the majority beaver activity, for example by creating habitat which is of organisations interviewed for this project, like the favoured by introduced pest species, such as American general public at large, are likely to be cautiously, mink. sometimes even enthusiastically, supportive of any proposals to reintroduce European beavers to England. As with all reintroductions, careful monitoring would The most commonly perceived benefits of be required in trial areas but the net result of the reintroducing beavers were the potential opportunities presence of beavers is likely to be positive with a for eco-tourism and various improvements to the Laurie Campbell substantially higher level of biodiversity. natural habitat. Where there were concerns, these centred on the system for regulating and managing introduced populations and on the potential for ABOVE European beavers consume flooding, for damage to woodlands and crops, and their woody vegetation, grasses, forbs, and aquatic vegetation. They depend largely effects on fish. on woody food sources in winter, but There was consensus among those consulted on four can spend up to 90% of feeding time consuming grasses, forbs and aquatic things: vegetation in summer. • any future reintroduction should be piloted in some small, controlled areas, where the impacts RIGHT TOP: trails and paths such as this one, made by a mature, resident of beavers could be assessed and, if necessary, beaver are apparently easy to follow and can be used to set traps along if the reversed by their removal animals need to be removed. • the legal status and management responsibility for What does the law say about beavers? any pilot introduction must be clear RIGHT BOTTOM: tree guards, and • there must be extensive public consultation Laurie Campbell The UK is obliged through the EU Habitats Directive to consider exclusion fences may be used where the desirability of reintroducing beavers as they are one of a necessary to protect specific trees early enough in the planning process to have a or whole areas from potential beaver number of species listed as requiring action to achieve favourable damage. substantive influence on the details of whether, conservation status across their former range. where, when, and how beavers are introduced and Possession of beavers in England has to be licensed by Natural England. managed Releasing beavers into the wild is an offence under the Wildlife & • there must be objective and trustworthy Countryside Act because the species is not ‘ordinarily resident in information widely available about European Great Britain’. beavers and their likely impacts on the landscape. If beavers are released into the wild in England, they would be considered by the law to be wild animals. But because they are not living here now, they are not protected by any UK legislation, There were contrasting views on where any pilot so reintroduced beavers could be disturbed or killed. However, reintroduction would best be located. One view was that the UK would be obliged to protect beavers if they became beavers should be placed in remote areas away from established in the wild. Once protected, the management of the beavers could be human populations to reduce the potential for conflict licensed by Natural England, under various provisions in the between beavers and people. The alternative view was existing Habitats Regulations. Beaver dams are probably not that beavers ought to be reintroduced to accessible Phoebe Carter always protected, as they are not breeding sites or resting places. areas (perhaps floodplains or brownfield landscapes), However, a licence would be needed to destroy one if it affected a nearby breeding site or resting place. so that the ecological benefits can be easily witnessed Duncan Halley and their economic potential harnessed. yearlings born the previous year and the young of the Certainly any future reintroduction plans would need current year. A 2km length of river with suitable habitat to involve extensive public consultation, backed by should be sufficient to support a colony, where habitat clear, objective and trustworthy information about is assessed within 20m of the water’s edge. the management and likely environmental impacts Densities of beaver populations at particular sites vary of reintroduced beaver. Local public acceptance is depending on how long the sites have been occupied. particularly important so that restoration plans and Population growth may continue for 25 years or more the licensing approvals on which they depend are not until all available sites have been occupied. Where data compromised. are available, over half of introductions of beavers in The ‘success’ of any reintroduction must be judged Europe have been successful. Failed introductions have not simply in scientific terms of how well the species been attributed to release into unsuitable habitat and is doing in its habitat, but also in terms of how those too few individuals being released with subsequent impacts are perceived and understood by the public poor population growth. and other stakeholders. Whatever their relationship to LEFT: beavers often excavate canals From work in other countries, much is known about to allow more extensive access to the received scientific opinion, public perceptions of the riparian zone. the habitat requirements of beavers including how potential impacts of a beaver reintroduction have to be much river habitat would be required to support a addressed by any future reintroduction plan. BELOW: water levels in beaver ponds beaver family, the most appropriate width, gradient, Some of the concerns expressed by the stakeholders consulted, such as worries about the reflect the balance between river flow, interviewed for this study requested more information about European beavers to help them precipitation and groundwater seepage velocity and depth of the river, the composition into the pond versus river flow and decide upon a formal policy position on the issue. and profile of the banks, the vegetation required for What habitat best suits beavers? groundwater seepage out of the pond and surface evaporation. food and construction, and appropriate floodplain characteristics. Beavers are able to live in a wide range of wetland environments, but in general there appear to be four broad characteristics of prime beaver habitat: • they like easy access to grasses, non-woody herbaceous plants and riparian tree species, especially poplars and willows • water at least 60cm deep when at its lowest near lodges and burrow sites • river channel gradients typical of lowland rivers • ‘soft’ or fine bed and bank materials Beavers normally live as a family unit or colony of four or five individuals, consisting of two parental adults, the Is it safe to reintroduce beavers? There is no evidence that reintroducing beavers into England poses any significant public health risk, providing appropriate quarantine procedures and health checks are followed. There is considerable experience of moving and managing captive beavers within England. Importantly, stress should be kept to a minimum Terry Whittaker during the capture, transportation, quarantine and release of beavers, to minimise disease risks that can be aggravated by a weakened immune system. Where would beavers best be Duncan Halley Potential candidate release sites should: • have sympathetic land managers and conservation introduced in England? designations if present • be good beaver habitat (low-moderate flows, Many, if not most, of England’s rivers could provide presence of aquatic, semi-aquatic vegetation, suitable habitats to support beavers. There are various bankside trees and bushes) within wetlands ways to identify the most advantageous habitats but and/or a river system with the potential for the deciding upon trial sites would require many factors beaver population to grow and expand across to be taken into account, the lie of the land being only neighbouring areas within at least a five-year one. period Using GIS (Geographical Information System) mapping • be a wetlands/river system with natural barriers to techniques, maps of woodlands and inland waters have unlimited expansion so that containment, control been created, taking account of appropriate river slopes, or removal is achievable if required to identify suitable beaver habitat. Urban and suburban • be located away from urban/suburban areas to avoid high levels of interaction with humans ABOVE: along with the potential for • be a river system with headwater catchments of eco-tourism, various improvements to ecosystem services were the moderate elevations to assess effectiveness of most commonly perceived benefit of beaver dams and managing flood risk should dams reintroducing beaver. fail • have the capacity to use fencing to prevent stock infiltrating the bankside habitats, or to prevent beavers moving onto agricultural land or woodland • have the capacity to study changes in animal and plant biodiversity before and after reintroduction, and to study the beavers • be degraded, partially degraded or flood-risk habitats to demonstrate potential restoration of natural habitat features and the water table, flood alleviation and water purification of beavers, beaver dams and beaver ponds • have the physical capacity to accommodate potential ecotourism. Stakeholder groups consulted: Anglers’ Conservation Association; Association of Drainage areas were omitted because of potential conflicts with Authorities; Association of River Trusts; British Association for humans or their activities, and areas that contained a Shooting and Conservation; British Waterways; Centre for Ecology & Hydrology; Confederation of Forest Industries; Country Land substantial amount of agriculture were omitted because & Business Association; Campaign to Protection Rural England; Figure 1a. Results of the GIS study of of potential damage to crops. The most suitable sites for beaver habitat suitability, allowing a 3% Environment Agency; Forestry Commission; Game and Wildlife topological slope. Green indicates at beaver colonisation were considered to have a total of Conservation Trust; Kent Wildlife Trust; National Farmers Union; least 2km of suitable river habitat; blue 4 or more kilometres of wooded river, and minimum National Gamekeepers Organisation; National Trust; Pond indicates 3km of suitable river habitat; Conservation; Royal Society for the Protection of Birds; Salmon and and purple indicates 4km of suitable suitability had between 2 and 3km of wooded river. river habitat in each 5km square. Trout Association; Water UK; Woodland Trust. A wide range of potential release sites emerges. The Figure 1b. Results of the GIS study of beaver habitat suitability, allowing a 6% designations). Also to consider is the likelihood of any topological slope. Green indicates at least 2km of suitable river habitat; blue chance of flooding due to the construction of a beaver indicates 3km of suitable river habitat; dam or, conversely, whether the presence of beavers and purple indicates 4km of suitable river habitat in each 5km square. could assist in river restoration and flood avoidance work; either could occur depending on the site chosen. It would also be helpful to know which candidate sites would naturally restrict the dispersal of beavers in the short term. In short, there are numerous factors to consider when considering possible reintroduction sites but there are likely to be suitable places in England. maps of beaver habitat preference are shown in Figures 1a & 1b. Squares coloured in purple contain the most habitat suitable for beaver colonisation, although those coloured blue or green may contain enough habitat to support small populations. The most suitable habitat for beavers according to this analysis, in the most general sense, is in the Weald of Kent, the New Forest, and Bodmin Moor in the south; the Peak District in the west; and the Lake District and the Forest of Bowland in the north west; along with a few other locations of less-concentrated suitable habitat. There are many options and finding appropriate river systems is not likely to be a limiting factor. One limiting factor, however, might be the proximity of heavily-populated areas. A glance at the maps indicates that, despite removing urban and suburban areas, some of the suitable habitat is still near heavily- populated areas which might count against some of them. Laurie Campbell The conservation status of an area is also important. Candidate release sites would need to be explored as to their special protection status (SAC or SSSI What actions would need to be taken local management group to oversee and monitor for a reintroduction to happen? the release • pre-emptive management at any candidate site Firstly, the IUCN has established a set of guidelines on (eg to protect vulnerable trees and crops) reintroductions (IUCN 1998), and any reintroduction • provision of sufficient funds to carry out the of beavers to England must comply with the key reintroduction programme recommendations made in those guidelines. • importation of the beavers and quarantining with In addition, the following actions need to be taken appropriate health checks into account in any plan to reintroduce beavers into • preparation of the site for a soft release: after six England: months of quarantine, releasing the beavers and monitoring for at least five years • production and dissemination of educational • widespread publicity locally and nationally of the material about beavers, their possible impacts presence and conservation importance of the and management to enable informed public return of beavers to England. consultation • reviewing and, if necessary, amending legislative mechanisms to protect and manage beaver populations in England So is it feasible? • clarification of who would be responsible for any release and management of It is clearly feasible to reintroduce beavers into beavers and grant-aid schemes established England with many consequent benefits, not least the to offset any financial costs of management and potential for beavers to assist with river and floodplain mitigation BELOW: the selection of a restoration. The success of reintroductions elsewhere • selection of candidate release sites for detailed canditate release site will depend in Europe has demonstrated the feasibility of putting on local consultation as well as the habitat analysis, population modelling and a risk environmental requirements of the in place measures to deal with any possible adverse beavers. analysis of human-beaver interaction consequences. However any further consideration of • thorough local consultation candidate sites needs to be made in the context of the PTES exercise of stakeholders to necessary actions described above. gain their approval, including landowners and the general For more detail on the issues explored in this digest public, at any candidate site to please refer to the full report referenced in the box on explore the costs and benefits the first page. of such a reintroduction • consideration of the costs, timing and source of beavers and their quarantine and the necessary licences and permits to carry out the importation, quarantine and release of beavers secured • properly costed research and monitoring proposals at any site and establishment of a Beavers belong to the rodent family Castoridae, of which there are two species, fact one American, one European. Both species had close brushes with extinction file in the early 19th century but are now out of danger, thanks to intensive conservation efforts on both continents. Laurie Campbell Common name european Beaver SCientifiC name Castor fiber HaBitat: semi-aquatic living in rivers, streams, ditches, lakes and wetland areas. SiZe: large for a rodent, 15 – 38 kg in weight, 122 – 137 cm long. DiStRiBUtion: presently extinct in UK; returning to much of its former range across Europe. ReaSon foR DeCLine: human activity – hunting for fur, food and medicinal properties. famiLY Life: live in small family groups of an adult male and female, and one to three young within a territory of 1-13km of river or lake bank. Diet: strictly herbivorous; do not eat fish or any other animals. In spring and summer they eat aquatic and riverbank plants, at other times of the year they depend heavily on bark for food, such as willow. Can fell trees leaving characteristic feeding signs. In autumn, they transport felled wood to store close to their riverbank burrows or lodges made of cut wood, to provide winter food. Sometimes build dams of tree trunks, branches, twigs, earth, mud and stones in order to raise and stabilise the local water level, providing deeper water to cover lodge entrances, support the transport of food, and extend the position of the water’s edge. May also dig canals to extend their waterside foraging area. eCoSYStem effeCtS: often called ‘ecosystem engineers’ because of their ability to build, dams and canals, create ponds and fell trees.
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