Feasibility Assessment for Reinforcing Pine Marten Numbers in England and Wales Jenny MacPherson The Vincent Wildlife Trust 3 & 4 Bronsil Courtyard, Eastnor, Ledbury, Herefordshire, HR8 1EP November 2014 Co-authors and contributors ELIZABETH CROOSE The Vincent Wildlife Trust, 3 & 4 Bronsil Courtyard, Eastnor, Ledbury, Herefordshire HR8 1EP DAVID BAVIN The Vincent Wildlife Trust, 3 & 4 Bronsil Courtyard, Eastnor, Ledbury, Herefordshire HR8 1EP DECLAN O’MAHONY Agri-Food and Bioscience Institute, Newforge Lane, Belfast, BT9 5PX, Northern Ireland JONATHAN P. SOMPER Greenaway, 44 Estcourt Road, Gloucester, GL1 3LG NATALIE BUTTRISS The Vincent Wildlife Trust, 3 & 4 Bronsil Courtyard, Eastnor, Ledbury, Herefordshire HR8 1EP Acknowledgements We would like to thank Johnny Birks, Robbie McDonald, Steven Tapper, Sean Christian and David Bullock for their input and helpful comments and discussion during the preparation of this report. We are also grateful to Paul Bright, Liz Halliwell, Huw Denman, Kenny Kortland, Colin Seddon, Roisin Campbell-Palmer, Peter Lack, Roger Powell, Pete Turner, Catherine O’Reilly, members and staff of the Dutch Mammal Society, Henry Schofield, Hilary Macmillan, Kate McAney, Orly Razgour and Matthieu Lundy for their help and advice. The questionnaire survey in chapter 5 was carried out as part of the People & Pine Martens in Wales project, funded by the Welsh Co-operative to whom we owe thanks. We are grateful to all organisations and individuals who publicised the online survey, including the People’s Trust for Endangered Species, the Federation of City Farms and Community Gardens, The Mammal Society, Denmark Farm, Gwent Wildlife Trust and Brecknock Wildlife Trust, and to all those who took time to complete the survey. Special thanks to Professor David Macdonald for reviewing and commenting on this report, and to members of the UK Pine Marten Strategy Group for their feedback. © A. Achterberg Page 2 Feasibility Assessment for Reinforcing Pine Marten Numbers in England and Wales Contents Co-authors and contributors 2 Acknowledgements 2 Contents 3 List of Figures 4 List of Tables 5 EXECUTIVE SUMMARY 6 CRYNODEB 8 1. INTRODUCTION 10 1.1. Objectives 11 1.2. Background 11 1.3. References 12 2. HABITAT ASSESSMENT: USING HABITAT MODELLING TO IDENTIFY PRIORITY AREAS IN ENGLAND AND WALES FOR PINE MARTEN TRANSLOCATIONS 14 2.1. Introduction 14 2.2. Methods 14 2.3. Results 15 2.4. Discussion 18 2.5. References 20 3. POTENTIAL PINE MARTEN REINFORCEMENT REGIONS IN ENGLAND AND WALES 23 3.1. Introduction 23 3.2. Methods 25 3.3. Results 26 3.4. Discussion 35 3.5. References 36 4. POTENTIAL IMPACTS OF RECOVERING PINE MARTEN POPULATIONS ON OTHER SPECIES 39 4.1. Introduction 39 4.2. Methods 40 4.3. Results 41 4.4. Discussion 43 4.5. References 47 5. ASSESSING PUBLIC ATTITUDES TOWARDS PINE MARTEN REINFORCEMENTS 51 5.1. Introduction 51 5.2. Methods 51 5.3. Results 52 5.4. Discussion 56 5.5. References 59 6. ASSESSMENT OF PROPOSED PINE MARTEN REINFORCEMENT AGAINST IUCN GUIDELINES 61 6.1. References 64 7. CONCLUSIONS AND RECOMMENDATIONS 66 7.1. Conclusions 66 7.2. Further Work & Recommendations 67 Feasibility Assessment for Reinforcing Pine Marten Numbers in England and Wales Page 3 List of Figures Figure 2.1 Response curves from a single, randomly selected MaxEnt replicate, showing the contribution of each variable to prediction of pine marten occurrence. Figure 2.2 Habitat suitability map for the pine marten in Britain based on MaxEnt model predictions. Darker shades of grey represent higher predicted habitat suitability Figure 3.1 Map of the UK showing the location of the six potential reinforcement regions (PRRs) evaluated here. Figure 3.2 The percentage of broadleaved, conifer, mixed and open IFTs within each PRR. Figure 3.3 Map of Afan PRR showing all motorway, A, B and minor class roads in relation to national forest estate and privately owned woodlands. Figure 3.4 Map of Dean PRR showing all motorway, A, B and minor class roads in relation to national forest estate and privately owned woodlands. Figure 3.5 Map of Gwydyr PRR showing all motorway, A, B and minor class roads in relation to national forest estate and privately owned woodlands. Figure 3.6 Map of Mawddach-Dyfi PRR showing all motorway, A, B and minor class roads in relation to national forest estate and privately owned woodlands. Figure 3.7 Map of North Ceredigion PRR showing all motorway, A, B and minor class roads in relation to national forest estate and privately owned woodlands. Figure 3.8 Map of Tywi PRR showing all motorway, A, B and minor class roads in relation to national forest estate and privately owned woodlands. Figure 5.1 The 8 hot-spot catchments in Wales, designated by the highest concentrations of recent pine marten sightings and records, collated by the Vincent Wildlife Trust since 1996. Figure 5.2 Frequency distribution of the amount mailing and weblink respondents were willing to pay to support a pine marten restocking. Figure 5.3 Frequency distribution of weblink (n=121) and mailing (n=99) respondents who gave information on organisation membership. Respondents were able to make more than one choice. Figure 5.4 Frequency distribution of mailing (n=135) and weblink (n=146) respondents who gave information on past and current employment. Respondents were able to make more than one choice. Page 4 Feasibility Assessment for Reinforcing Pine Marten Numbers in England and Wales List of Tables Table 2.1 Description of environmental variables and their contribution to the model. Table 3.1 Woodland characteristics and amount of each interpreted forest type within each PRR. Table 3.2 Road lengths, traffic flow and index of road mortality risk for each PRR. Table 3.3 Proximity of each PRR to commercial shoots Table 4.1 All red (n=28) and amber (n=51) listed birds recorded as breeding in PRRs (data from BTO breeding bird atlas 2007-2011) Table 4.2 Nest habitat of red and amber list breeding birds recorded in PRRs. Table 4.3 The number of potentially vulnerable red and amber listed bird species found in each PRR. Table 4.4 Percentage of the British breeding distribution of potentially vulnerable red and amber list bird species within PRRS (mean±SE). Table 5.1 Reasons respondents gave for supporting restocking, categorised and ranked based on number of responses (n=755). Table 5.2 Reasons respondents gave for being against restocking, categorised and ranked based on number of responses (n=57). © A. Achterberg Feasibility Assessment for Reinforcing Pine Marten Numbers in England and Wales Page 5 EXECUTIVE SUMMARY Successful translocations of pine marten to recently and historically occupied, suitable habitat could be a major proactive step towards improving the conservation status and genetic diversity of pine marten in England and Wales. This report provides an initial assessment of the feasibility of undertaking translocations to reinforce existing populations that have failed to recover naturally. The pine marten, Martes martes, was once widespread throughout Britain but during the 18th and 19th century pine martens declined dramatically due to habitat loss, compounded by increases in trapping and predator control associated with the rise in game shooting. By the beginning of the last century pine marten were only found in the far north west of Scotland, with small isolated pockets in some upland areas of northern England and Wales. Populations are now recovering well and expanding back into their former ranges in Scotland, but this is not the case elsewhere in the UK. Sightings reports and occasional unequivocal records suggest that some animals are still present in some parts of southern Britain but in such low numbers that population viability is highly vulnerable. A landscape modelling approach was used to predict habitat suitability for pine marten across England and Wales at the 10km square resolution. The model identified a number of areas with high suitability values, these were in the north of England (Northumberland, the Lake District and in the Pennines), with some clustered in the West Country and around the Forest of Dean. There was a proportionately greater predicted area of high suitability in Wales, from Snowdonia in the north down the Cambrian Mountains through central Wales and in the Vale of Neath in the south. Informed by the results of habitat modelling, and our database of reported pine marten sightings collected since 1996, six potential reinforcement regions (PRRs) were identified.These are areas of high predicted habitat suitability in regions where reports of recent sightings and other evidence suggest pine martens are still present in extremely low numbers. For each of these PRRs, initial desk-based analyses of variables that are likely to have an impact on establishment and spread were carried out. Roads are likely to be an important source of mortality affecting the viability of newly reinforced pine marten populations. The total length of roads in each PRR and the percentage of those within woodland, combined with annual volume of traffic were used to calculate the relative likelihood of marten mortality due to road traffic accidents. Even a low rate of additional mortality will increase extinction risk and jeopardise the establishment of a newly reinforced population. Therefore, translocations should first be to those PRRs identified here that have woodland blocks large enough to support relatively high marten numbers, and where likelihood of additional mortality is low. Page 6 Feasibility Assessment for Reinforcing Pine Marten Numbers in England and Wales © A. Achterberg The perception that the recovery of a native predator will have a negative effect on native prey species is a major concern for some stakeholders. A thorough risk assessment, evaluating the ecological roles of translocated animals in their new environment, and potential impacts on other species already present in release areas is an essential aspect of the feasibility study.