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

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

Three independently funded sister projects ( ): Cairngorms Water Vole Conservation Project North East of Scotland Water Vole Project North West Highlands Mink Control Project Cairngorms Project 10,000km 2 by 2009 Use of volunteers Took an adaptive management approach: informed by and improved ecological understanding BACKGROUND

Upland heather moorland Productive farmland Immigration can be reduced by creating vacancies in lowland Bryce et al (2011), Biological Conservation Mink caught above 300m are predominantly dispersing males There were no mink captures (out of 650) in 3500km 2 of montane habitat

80% of rafts monitored by volunteers Rafts deployed Rafts run by volunteers Number of rafts RESEARCH

Number of mink Total mink captures Mink caught by volunteers % of mink were caught and dispatched by volunteers RESEARCH 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

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

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

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

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 ( ): Cairngorms Water Vole Conservation Project North East of Scotland Water Vole Project North West Highlands Mink Control Project Coverage: +20,000 km 2 BACKGROUND

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 AIMS AND OBJECTIVES

Four mink control officers working with local organisations and volunteers are establishing a cohesive network of mink monitoring rafts across the project area. DESIGN CRITERIA 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

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 SUCCESSES AND CHALLENGES

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

Thanks to our Partners and funding organisations Photos courtesy of SWT, University of Aberdeen and SNH