Above picture: The sheer western cliffs of Auckland Island; photograph by Finlay Cox
The Mouse-Free Marion (MFM) Project does not stand alone. It benefits from over 50 years of experience accumulated from increasingly ambitious projects worldwide. These eradications of invasive pests have established a broad approach that comprehensively restores vulnerable island ecosystems. Since the 1960s, invasive mammals have been eradicated from more than 1200 islands globally. The body of knowledge that has been built up over this period has resulted in an increasingly high success rate, while generating a well-defined set of practical principles that maximise the likelihood of success of each eradication that follows. Rat species are prevalent on islands worldwide and have thus been a common target for eradication, but in the past two decades House Mice have increasingly been targeted, with a high success rate. Where projects have been unsuccessful, their managers often engage with international colleagues in reviews to identify and integrate key lessons into future operational planning.
The record for mammal eradication projects for the sub-Antarctic islands is also a good one. Australia’s Macquarie Island is free of its feral cats, European Rabbits, Black Rats and House Mice; New Zealand’s Campbell Island of its cattle, sheep, cats and Norway Rats, New Zealand’s Auckland Island of feral goats and more recently New Zealand’s Antipodes Island of its mice. Over in the South Atlantic South Georgia is now free of Reindeer, Norway Rats and House Mice. France’s Saint-Paul Island is free of European Rabbits and Black Rats, and Amsterdam Island has recently been the subject of an eradication project to rid it of feral cats, Norway Rats and mice, So far the results seem promising; feral cattle had been removed previously. However, not every eradication project in the sub-Antarctic has been wholly successful: House Mice remain on France’s Saint-Paul and House Mice have survived the eradication attempt on the United Kingdom’s Gough Island in 2021. And there still remain some important seabird islands in the Southern Ocean with introduced mammals awaiting eradication attempts (although on some of them research on their pests has been undertaken). These include France’s Crozet Islands and Kerguelen (both multiple species), and Steeple Jason (House Mice) in the Falkland Islands.
Some islands in the Southern Ocean have fortunately remained free or largely free of invasive mammals. These include the UK’s Inaccessible (feral pigs died out) and Nightingale (both part of the Tristan da Cunha group), South Africa’s Prince Edward Island, Australia’s Heard and McDonald Islands, and New Zealand’s Bounty and Snares Islands.
I reached out to the managers and scientists involved with planned eradication efforts on two sub-Antarctic islands, Auckland Island south of New Zealand and New Island in the Falkland Islands, to ascertain the “state of play”. Their stories will be of interest to supporters and should help inform the MFM Project team that aims to eradicate House Mice from the island.
Auckland Island, New Zealand
The information below comes from Veronika Frank and Stephen Horn (National Eradication Team Manager), New Zealand Department of Conservation.
A technical feasibility study for the eradication of feral pigs, cats and mice from the main 46 000-ha Auckland Island in the New Zealand sub-Antarctic was undertaken between 2017 and 2021, leading to a detailed report. Research findings from the study were published in individual papers in a special issue of the New Zealand Journal of Ecology the following year.
White-Capped Albatross Thalassarche steadi on Auckland Island; photograph by Jake Osbourne
Following a pause in progress due to the COVID-19 pandemic, eradication of the three mammalian invaders is now another step closer thanks to recent government funding of NZD 3.65 million over two years. These funds will enable foundational work to ready the eradication project for initiation. Progress on research and development objectives include:
- development of a meat-based cat bait for use in New Zealand: two successful hand-laid trials and an aerial trial completed to support registration of this bait;
- development of efficient cat-trapping techniques and detectability with camera networks;
- successful testing of a feral pig bait and in-field GPS-tagging techniques; and
- development of an effective image classifier using artificial intelligence for managing trail cameras.
A feral cat feeds on the body of a White-capped Albatross chick close to fledging, Auckland Island; photograph by Stephen Bradley
The objectives of the current “Readiness Phase” include:
- securing the remaining funding required to implement the eradication project (NZD 78 million total over eight years) through donations, partnerships and government investment;
- establishment of project management, governance, and project delivery structure(s) and recruitment of core team members to progress planning and produce a suite of planning documents such as a Project Plan and Procurement Strategy; and
- complete research and development for required tools, which include:
- registration of the new feral cat bait;
- improved helicopter bucket for reliable distribution of rodent bait at low sow rates; and
- remotely reporting camera setup and communications system using artificial intelligence with high accuracy to report on target species detections as they occur.
A “storymap” with the title “Preventing extinctions and saving entire ecosystems Subantarctic Auckland Island, New Zealand” dated March 2024 sets out the project in visual terms.
New Island, Falkland Islands
Landsend Bluff on New Island; photograph by Ian Strange
Information below comes from Ross James of the NGO Falklands Conservation.
The New Island National Nature Reserve is considered one of the most globally significant wildlife sites in the Falkland Islands and is in major need of restoration. Four invasive mammal species; feral cats, European Rabbits, Black Rats and House Mice, threaten the site’s fauna and are degrading the island’s fragile habitats. Their removal is required for recovery and long-term climate resilience. The New Island Restoration project aims to complete the preparatory technical steps necessary for an ambitious four-species eradication programme and engage the Falkland Islands Government and community to secure support for New Island’s long-term restoration.
https://www.youtube.com/watch?v=5gLq9wqiRs0.
Video by Falkland Conservation
“The feasibility report is currently in the process of being externally reviewed and so isn’t ready to make public yet, but as with the 2013 report by Derek Brown the findings were that the removal of all four invasive mammal species remains feasible. Phase 1, which concluded in March, enabled us to collate all the technical data required, develop mitigation strategies, identify partners and secure permissions, and we’re currently in the fundraising stage to enable Phase 2 (the actual restoration work) to begin. We’ve recently updated the website to reflect this transition, which includes a stronger message – not if we should do it, but that we are fundraising in order to do it. We’re in a better position than ever before to deliver the restoration of New Island, and the island needs it now more than ever.”
At risk to feral cats and rodents: a White-chinned Petrel Procellaria aequinoctialis in its burrow on New Island, Falkland Islands; photograph from the New Island Restoration Project
Read more under the heading “New Island: completing preparatory steps for restoration against invasive mammals” and download progress reports on the Darwin Plus grants scheme website here.
A Black-browed Albatross Thalassarche melanophris pair on New Island; photograph by Ian Strange
References:
Brown, D. 2013. New Island Feasibility Study Report for the Potential Eradication of Ship Rats, Mice, Rabbits and Feral Cats from New Island, Falkland Islands. Unpublished report for New Island Conservation Trust. 87 pp.
Department of Conservation 2021. Technical Feasibility Study Report for Eradication of Pigs, Mice and Cats from Auckland Island. Invercargill: Department of Conservation Te Papa Atawhai. 123 pp.
Russell, J.C., Horn, S.R. & Broome, K.G. (Eds) 2022. Restoration of New Zealand subantarctic islands. New Zealand Journal of Ecology 46(3).
With thanks to Veronika Frank, Stephen Horn, Ross James, Mark Tasker and Megan Tierney for information.
John Cooper, News Correspondent, Mouse-Free Marion Project, 24 October 2024
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Attacked by Marion Island’s introduced House Mice, this Wandering Albatross chick soon died of its injuries; photograph by Vanessa Stephen, 06 July 2024
The Mouse-Free Marion Project is a registered non-profit company (No. 2020/922433/08) in South Africa, established to eradicate the invasive albatross-killing mice on Marion Island in the Southern Ocean. The project was initiated by BirdLife South Africa and the South African Department of Forestry, Fisheries and the Environment. Upon successful completion, the project will restore the critical breeding habitat of over two million seabirds, many globally threatened, and improve the island’s resilience to a warming climate. For more information or to support the project please visit mousefreemarion.org.
