Achieving large scale, long term invasive American mink control in Northern-Scotland despite short term funding Xavier Lambin Chris Horrill Rob Raynor & loads more people

Bold or Foolish?? An invasive control project that … Tackled the American mink, one of the worlds most difficult invasive species after prevention failed On a ridiculously large (29,000 km2) “bit of an island” Without secured long-term funding With a fuzzy, ever shifting, endpoint Using mostly unpaid “citizen- conservationists volunteers

From Rio to Aberdeenshire: Biodiversity Action plans a bottom up process arising from UK Government’s response to Rio 1992 Water vole driven towards extinction by mink invasion. “At least 95 % of the sites occupied in the 1950ies were lost by 2000.”

Modest beginnings remove mink from 30 km2 Objective: to safeguard a remnant lowland water vole metapopulations surrounded by American mink

The Cairngorms Water Vole Conservation Project (2007–2009) A defensible stronghold for water voles? If anywhere, mink control can be achieved in the Cairngorms National Park The Cairngorms Water Vole Conservation Project (2007–2009)

1000 Mink rafts: a low tech breakthrough and key component of coverage and participation Bryce et al (2011), Biological Conservation 144, 575–583 6

Mink density decreased with increasing years of control despite density dependent fecundity and dispersal Oliver et al (2016) Biological Invasions 18, 3047-3061 Melero et al (2015) Biological Invasions 17, 2645-2657

Federation of local institutions: Embedding invasive management with users of salmon resources to ensure legacy (2011–2015) Transfer of management responsibility to river trusts to ensure mink control and monitoring is self-sustained with limited (but not zero!) input of additional resources.

Partnership and volunteers removed breeding mink from over a 29,000 km2 area bounded by seas and mountains

Mink density bounced back then decreased again 1 2 3 4 5 6 Oliver et al (2016) Biological Invasions 18, 3047-3061 Melero et al (2015) Biological Invasions 17, 2645-2657

After a long 2 year gap, arose the Scottish Invasive species Initiative (2018-2022) Vision: Transferring approach refined with mink to other invasive species Wider public engagement Self sustained volunteers is key deliverable

Ongoing control short of eradication: Lessons learned, challenges yet to overcome

Challenge (1): the funding roller coaster: short term funding of long term conservation is wasteful 300 300 250 200 Annual spend (x£1000) 150 100 50 1996 1997 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2019 2021 Lambin, et al 2019 in Island invasives: scaling up to meet the challenge, IUCN 651

Challenge (1): the funding roller coaster: short term funding of long term conservation risks loss of achievement Short term funding is a major obstacle and increases the cost of long term invasive control. Repeated gaps in funding, associated staff turnover, re-badging of project are all damaging to the trust relationship built with volunteers.

Challenge (1): the funding roller coaster: short term funding of long term conservation is wasteful We all know we will still be at in after 2022 Succession planning is required now (as with Towards an integrated invasive project (squirrels, mink plants)?

Mean natal dispersal 20 km 20 % movements > 80 km Scale! Mink are stupendous dispersers! 90 % of mink emigrate, and dispersal is large scale Mean natal dispersal 20 km 20 % movements > 80 km Oliver et al (2016), Biol Inv

Challenge (2): no refuges from control. East coast coastal burn and bird cliffs were long overlooked

Challenge (2b): no refuges from control. Some individuals managing protected areas resisted spatially exhaustive control, despite institution support

>> Challenge (2c): no refuges from control. Some river management organisations were small, poorly resourced, or archaic Government re-structuring of organisations reduced coordination >>

Challenge 3: Mobilising and sustaining citizen conservationists Utilizing and coordinating the existing skilled workforce, such as gamekeepers and fishing ghillies; facilitated their roles as volunteers within a coordinated partnership

Challenge 3: Mobilising citizen conservationists CAN deliver large-scale, long-term conservation BUT Retention is key and volunteers cannot be seen as merely cheap labour Volunteers must be creatively enthused (with success and science stories), replenished with ongoing recruitment Volunteer diverse motivations (place attachment, desire to take action, personal fulfilment) must be understood and respected Inclusive public engagement and volunteer motivations may clash with rationalised invasive management. Tension between optimisation of management vs motivations of volunteers and inclusive participation in governance Pagès et al (2018) J Env Mgmt

Challenge 4: No built in resilience to extreme events

Summing up: Long term management despite short term funding American mink can technically be controlled Short term funding is a major obstacle and increases the cost of long term invasive control. Repeated gaps in funding, associated staff turnover, re-badging of project are all damaging to the trust relationship built with volunteers. Succession planning is required now. INNS projects United! Mink control is socially acceptable but ensuring comprehensive management is a constant battle. Tepid buy-in by some critical land managing organisations could destroy the covenant with volunteers asked to kill for conservation

Tasty water voles recovered well before the last mink was removed, … Golden eagles believe the project is a success!

Acknowledgements: 2,652 volunteer-years and a multidisciplinary team effort Project officers: Jamie Urquhart, Laura Taylor, Ros Bryce, Hollie Sutherland, Helen Gray, Llinos Davies, Anne Marie MacMaster, Gunnar Scholts, Jim Mann Conservation partners: Chris Horrill, Rob Raynor Ecology Researchers: Matthew Oliver, Yolanda Melero, Elaine Fraser Social Sciences researchers: Anna Evely, Marie Pagès, René van der Wal, Koen Arts Computer science Researchers: René van der Wal, Koen Arts, Nava Tintarev, Nirwan Sharma, Gemma Webster, Chris Mellish, Yaji Sripada :