Strategies for species conservation in changing freshwater environments

1. Strategies for species conservation in changing freshwater environments Hollie Walker, Scottish Mink Initiative Coordinator John McAvoy

2. Introduced for fur farming Widespread in Europe AMERICAN MINK INVASION Escaped through intentional and non-intentional releases

3. BACKGROUND • Three independently funded sister projects (2007-2010): • Cairngorms Water Vole Conservation Project • North East of Scotland Water Vole Project • North West Highlands Mink Control Project • Cairngorms Project 10,000km2 by 2009 • Use of volunteers • Took an adaptive management approach: informed by and improved ecological understanding

4. Upland heather moorland Productive farmland Mink caught above 300m are predominantly dispersing males • There were no mink captures (out of 650) in 3500km2 of montane habitat Immigration can be reduced by creating vacancies in lowland Bryce et al (2011), Biological Conservation

5. 600 500 400 Rafts deployed 300 Number of rafts Rafts run by volunteers 200 100 0 2006 2007 2008 2009 RESEARCH 80% of rafts monitored by volunteers

6. The analysis of mink capture rate indicated that the level of mink activity within a focal sub-catchment was affected by the intensity of mink control and decline of mink numbers in the rest of the catchment RESEARCH 70% of mink were caught and dispatched by volunteers 400 350 Total mink captures Mink caught by volunteers 300 250 Number of mink 200 150 100 50 0 2006 2007 2008 2009 2010

7. - The resulting pattern of apparent competition threatened the upland refuge for native water voles + - 50 km Identified preferred settlement habitat by mink dispersing in prey poor uplands: rabbit populations in upland farms Defined potential “attractive sinks” if focus of trapping Oliver, Luque-Larena, Lambin (2009), Ecology Letters, 12

8. Characterised scale and frequency of mink dispersal • Genotyped culled mink at 15 microsatellite markers • Aged from tooth structure, • Identified family group, first order relatives • Identified dispersers … over 10,000 km2 Mean natal dispersal: 16 km (n= 365), max 102 km Daily displacement from natal site ~ 100 m Oliver, Piertney Lambin MS

9. PRACTICAL APPROACH TO LARGE SCALE INNS MANAGEMENT • Valuable lessons learnt from research • Mink disperse great distances. The Cairngorms project identified the need for multi catchment scale mink removal • Immigration can be reduced by creating vacancies in the lowlands= focus area for control • Mink are attracted to rabbits in prey poor uplands= focus area for control • Adaptive management delivers: research fully integrated with conservation delivery made unprecedented scale eradication feasible A large scale approach to mink control helps to effectively protect focal native species at both local and wider scales

10. BACKGROUND • Partnership between the Rivers And Fisheries Trusts of Scotland, Scottish Natural Heritage, Scottish Wildlife Trust, Cairngorms National Park Authority and University of Aberdeen • April 2011-August 2013 • Builds upon and expands three independently funded sister projects (2007-2010): • Cairngorms Water Vole Conservation Project • North East of Scotland Water Vole Project • North West Highlands Mink Control Project • Coverage: +20,000 km2

11. AIMS AND OBJECTIVES • To eradicate breeding mink from the north of Scotland • To ensure the long term sustainability of mink control in the project areas through the coordinated and resourced transfer of responsibility for ongoing mink management to local organisations • To raise awareness of the benefits of the community-based and adaptive management approach to invasive non-native species management

12. DESIGN CRITERIA Four mink control officers working with local organisations and volunteers are establishing a cohesive network of mink monitoring rafts across the project area. • A community based approach in establishing and maintaining mink monitoring and trapping networks • Utilisation of an adaptive management strategy • Link between applied research and elements of the management strategy

13. SUCCESSES AND CHALLENGES • Expanding raft coverage takes time • New sightings of mink in the north west Highlands • Volunteer recruitment and enthusiasm from organisations and community groups has been good • Raft coverage is expanding despite the challenges of recruiting volunteers and gaining access permissions • Media coverage has been good • Awareness is picking up • 105 mink have been dispatched

14. Greater understanding of volunteer demography DEPENSATION will use unique data from the initial eradication and ongoing consolidation and expansion stages of the project to rigorously evaluate the contributions of depensation, compensation, dispersal and multi-species interactions on patterns of recolonisation by mink FUTURE OF RESEARCH

15. www.scottishmink.org.uk www.invasivespeciesscotland.org.uk Hollie Walker Scottish Mink Initiative Coordinator hollie@rafts.org.uk Photos courtesy of SWT, University of Aberdeen and SNH Thanks to our Partners and funding organisations