Natural England Commissioned Report NECR002 The feasibility and acceptability of reintroducing the European beaver to England First published 17 March 2009 www.naturalengland.org.uk Introduction Natural England commission a range of reports from external contractors to provide evidence and advice to assist it in delivering its duties. This report was commissioned jointly by Natural England and the People‟s Trust for Endangered Species. The views in the report are those of the authors and do not necessarily represent those of Natural England. Background The beaver Castor fiber is a native species that It is important for Natural England: was hunted to extinction in Britain, probably by the 16th Century. Recently, there has been to understand the benefits and drawbacks of considerable interest in reintroducing it, both to beaver reintroductions; restore lost biodiversity and because of the to consider to what extent the beaver may be contribution it could make to river and wetland able to help deliver wider river and wetland management. The European Habitats & Species restoration objectives; and Directive also requires Member States to to understand the challenges that the consider the reintroduction of extinct native presence of the beaver may bring. species. The purpose of this report is to help Natural The beaver has been widely reintroduced England: across Europe and there is a considerable body of evidence arising from these projects. As the lead delivery body for the England Biodiversity Strategy - develop a view on the In 2008 the Scottish Executive issued a licence feasibility and desirability of beaver for a trial reintroduction of beavers to Knapdale, reintroductions in England and what Argyll. These are expected to be released in contribution beavers might make to national 2009. In Wales a feasibility study is under way. habitat restoration targets. In England there are captive beavers in large As the licensing authority - prepare itself for enclosures in five places around the country. making a decision when it receives an It seems likely that Natural England will receive application to release beavers into the wild in an application for a licence to release beavers England. into the wild within the next few years. This At the time of publication, Natural England‟s would be considered in the context of the Board has not considered its position on beaver International Union for Conservation of Nature‟s reintroductions. This report will contribute to that Guidelines for Reintroductions and the debate. reintroductions policy adopted by the conservation agencies in the UK. Specific background information would also be required. Natural England Project Manager - Tony Mitchell-Jones, Northminster House, Peterborough, PE1 1UA Contractor - Professor John Gurnell (Consortium Leader), School of Biological and Chemical Sciences, Queen Mary, University of London, London E1 4NS Keywords - Beaver, Castor fiber, reintroduction, ecology, habitat, legal status, history, feasibility Further information This report can be downloaded from the Natural England website: www.naturalengland.org.uk. For information on Natural England publications contact the Natural England Enquiry Service on 0845 600 3078 or e-mail [email protected]. ISSN 2040-5545 The feasibility and acceptability of reintroducing the European beaver to England Report prepared for: Natural England and the People‟s Trust for Endangered Species By J. Gurnell1, A.M. Gurnell2, D. Demeritt2, P.W.W. Lurz3, M.D.F. Shirley3, S.P. Rushton3, C.G. Faulkes1, S. Nobert2 & E.J. Hare1 1 School of Biological and Chemical Sciences, Queen Mary University of London, London E1 4NS 2 Department of Geography, King‟s College London, The Strand, London WC2R 2LS 3 Centre for Life Sciences Modelling (CLSM), University of Newcastle upon Tyne, Newcastle upon Tyne NE1 7RU 2008 Project Details Project manager Dr A J Mitchell-Jones, Evidence Team, Natural England J Nelson, Chief Executive, People‟s Trust for Endangered Species Contractor Dr J Gurnell, School of Biological and Chemical Sciences, Queen Mary University of London, London E1 4NS Acknowledgments We warmly thank Derek Gow (Derek Gow Consultants, Devon), Peter Smith (Wildwood Trust, Kent), Ken West (Wildwood Trust, Kent), John McAllister (Kent Wildlife Trust) and Simon Pickering (Cotswold Water Park) for showing us their captive beavers and for discussing beavers and beaver management with us. We should like to thank Tony Sainsbury for commenting on Chapter 7, Peter Smith (Wildwood Trust, Kent) for information about import licensing and quarantine, and Wendy Finlay for proof reading large parts of the report. We are also grateful to Neal Armour Chelu, Bryony Coles, Peter Holmes, Mark Robinson, Jonathan Spencer, Jonathan Reynolds, and Charlie Wilson for their thoughts, and all those who contributed to the survey of stakeholders views reported in Chapter 9. Last we should like to thank the members of the England Beaver Steering Group: Jill Nelson (PTES), Nida Al-Fulaij (PTES), Tony Mitchell-Jones (NE), Chris Mainstone (NE) and Alastair Driver (EA). The project was funded by Natural England and the People‟s Trust for Endangered Species. i Contents 1. Introduction 1 Summary 1 Background 1 Why reintroduce beavers? 4 Literature 4 Aim and objectives 5 The report 6 2. Habitat requirements and population densities 8 Summary 8 Colonisation of new habitat 8 Habitat requirements 9 Water 9 Food and foraging 10 Grouping of habitat features 11 Density of established beaver populations 12 3. Beavers dams, hydrogeomorphological ecosystem effects and British rivers 18 Summary 18 Building dams and dens 19 Environmental conditions encouraging dam construction 21 Environmental effects 22 Hydrology, geomorphology and chemistry 23 Beavers and the river continuum 25 Beavers and British river types 26 4. The effects of beavers on plants and animals 30 Summary 30 Introduction 31 Plants 31 Animals 32 Invertebrates 32 Fish 35 Amphibians 38 Reptiles 38 Birds 39 Mammals 44 5. The identification of suitable regions for candidate reintroduction sites in England 47 Summary 47 Habitat requirements for reintroduced beavers 47 ii A preliminary GIS analysis of habitat suitability within England 49 Where next? 49 6. Beaver reintroductions to England: the legal position by Tony Mitchell-Jones, Natural England 54 Summary 54 Introduction 54 Legislation covering the possession of beavers and their release into the wild. 54 Possession 54 Release 55 Other legislative considerations 55 The legislative position of released beavers and beaver management 55 Current domestic legislation 55 The Habitats Directive 56 Beaver management 56 7. Parasites, mortality and quarantine and release of beavers 58 Summary 58 Parasites and disease 58 Post-release mortality in beavers 60 Quarantine and licenses 61 Release protocols 62 8. Phylogeographic history of European beaver populations and identification of suitable source populations for reintroduction 63 Summary 63 Introduction 63 Taxonomy 64 Genetic diversity and phylogenetic relationships 65 Summary and recommendations for source populations for UK introductions 68 9. Public perceptions and stakeholder responses 69 Summary 69 Introduction 69 Attitudes and perceptions of the general public 69 Views of key stakeholders and interest groups 70 Perceived benefits of beaver reintroductions 72 Stakeholder concerns 72 Conclusions and recommendations 75 10. The financial costs and benefits of reintroducing beavers 76 Summary 76 Introduction 76 Financial benefits 76 Cost-benefit analysis 79 11. Beaver management 82 iii Summary 82 Introduction 82 Flood control 82 Riparian zone management 83 Repellents and wire fencing 84 Traffic collisions 84 Animal control 84 Culling beavers 84 Live-trapping and netting 84 Fertility control 85 The effectiveness of control 85 Methods used to manage beavers in Europe 85 Management and the reintroduction programme 86 12. Beaver reintroductions to England 88 Summary 88 Mammal introductions and reintroductions 88 Key points concerning reintroducing beavers to Britain 89 Reintroducing beavers to England 89 Characteristics of candidate release sites 89 What next? 90 13. References 92 iv Executive Summary This review considers the technical feasibility, and ecological and social desirability of reintroducing European beavers Castor fiber to England and follows on from the recent decision by the Scottish Parliament to reintroduce beavers into Knapdale, Scotland in 2009. The particular objectives are: To review the ecology of beavers with respect to potential benefits of the ecosystem services they may provide and the possible ecological risks of their reintroduction. To define criteria for identifying candidate reintroduction sites. To identify the most appropriate source populations for potential reintroduction to England. To assess stakeholder concerns regarding reintroducing beavers. To identify actions and mechanisms that would maximise the benefits and eliminate or control any risks related to reintroductions. To make recommendations for further work that would be required to develop and implement a reintroduction programme, if this is considered desirable. Beavers are large (15 – 38 kg in weight), semi-aquatic rodents that live in rivers, streams, ditches, lakes and wetland areas. At one time they were widespread and common in Europe, but by 1900 they had been lost completely from large parts of their native ranges, including the United Kingdom, as a result of hunting and habitat loss. However, since