As I sit back in Cape Town waiting for my flight home to New Zealand, it’s a great thought to consider that we’ve actually done it – we’ve spread two applications of rodenticide bait over the whole of Gough Island with a third application in some of the areas at greater risk of still harbouring mice.
This has come after nearly 15 years of preparation with numerous on-island trials, and more than three years of comprehensive planning to bring together the complex logistics as well as the legal and social requirements for the project. In the end, fewer than 50 people got to have the unique and satisfying opportunity of watching or assisting with the helicopters being loaded with the bait and flying off over the hill to spread it across every part of the island. But it is important to recognize all the other people who have been involved with the project over the years including the members of the planning team and RSPB management who worked tirelessly leading up to the implementation and continued to provide support while we were on the island, the field teams who undertook the various trials and monitoring work, the project partners who supported the project in various ways and the thousands of people, most of whom are RSPB supporters, who generously donated to the project both big and small amounts, without which it simply wouldn’t have been possible. The amount raised by the funding appeals is truly incredible.
It has not been a smooth trip to get to where we are. There have been plenty of bumps along the way, but most of these will be forgotten over time and we’ll just remember the good parts. Hopefully though, the lessons learnt – of which there were many – will be captured and passed on to future projects.
When I first joined the Gough team I said that every project I have been involved in has had at least one major thing go wrong in the lead up to implementation and, while it wasn’t possible to predict what it would be on this occasion, we had to make sure we had the capacity to deal with it. What neither I nor anyone else could see coming was a global pandemic that would hit just after we had started implementation. We had to recall the bait that was already in transit and scramble to get the initial setup team off the island and back into a world where few countries would let you enter. We then had to regroup and plan how to implement a complex multi-country project in the new Covid world. Sometimes it looked like we wouldn’t be able to do it but, thanks to the hard work and tenacity of a small dedicated team, we managed.
The conditions on the island meant that while I had a comprehensive Operations Plan prepared this had to be reviewed and modified nearly daily to fit the conditions at the time. This meant working closely with the pilots to confirm that what I wanted to do e.g. where I wanted to apply bait, was operationally possible e.g. the winds were flyable in that part of the island. From the start one of my biggest concerns with the operation was that we wouldn’t get suitable weather to allow even one full bait application to be completed – meaning we would have definitely failed. As such, once on Gough and seeing what 2021’s southern winter was bringing, I reversed the standard approach of making sure the first bait application is delivered to the highest standard possible (so allowing the second one to be more of a ‘top up’), and simply tried to make sure we got the first application completed. This meant we would still have a chance of success should the weather have closed in for the winter. Once the first application was complete, I then tightened the baiting criteria to ensure we delivered the best possible application the conditions allowed on the second drop.
As it happened, we got off to a great start with nearly half the bait spread in our first two weeks. Not surprisingly, some people extrapolated from this and thought we would be finished by mid-July, but experience had taught me not to be so optimistic and, as it turned out, we only had two days in the whole of July that were suitable for spreading bait. “Suitable” required that: 1) it not be raining (because that causes the bait to stick together); 2) the wind not to be blowing too strongly (that blows the bait off course as it is falling out of the spreader bucket and can also push the helicopter off course); 3) the area to be treated to be free of cloud – a major issue with the uplands of the island; and 4) there to be a clear forecast without heavy rainfall in the following few days (heavy rain can dissolve the bait before mice have a chance to access it). We knew that meeting all these criteria would be very challenging on Gough during the winter so it was with huge relief when the weather improved at the start of August and we could finish the job before the albatrosses returned – with their associated risks to the safe flying of the helicopters.
And it wasn’t just the weather that caused headaches. Eradication projects have a habit of throwing curve balls at all the preoperational planning – hence the adage to plan for everything that can go wrong to go wrong. One thing that came as a surprise to us on Gough was the amount of bait that the non-native slugs ate. This hadn’t been anticipated but as soon as we became aware of it, we adjusted the plans (again!). We had taken sufficient bait to treat some higher risk areas for a third time – but we knew we wouldn’t know precisely where those areas would be until late in the operation. As it happens, our highest risk areas were where the slugs hang out. (In case you are wondering, slugs won’t be impacted by the bait.)
When I say “we’ve done it” I am not saying we have definitely killed all the mice (although I think we have), just that we have spread the bait. The real result will only come in a few years’ time when it’s hopefully confirmed that all the mice are gone. What I am confident of is that the team did the job as well as anybody could have under the conditions we encountered, and if any mice have survived it’s not for lack of planning or hard work on behalf of the team.
When we sailed away from Gough Island, we left an eight-person team of aviculturists to continue looking after the captive safeguard populations of Gough moorhens and Gough buntings. Some of this team have been on the island since February and they are unlikely to get home much before the end of the year. Their role in ensuring the land birds have a bright future on a mouse-free Gough is vital and, with some of them having also been on Gough in 2020 when the project was suspended (and so spending several months away from home last year too), their dedication to the birds is awesome.
For me it will be with great relief that (once I’ve finished the reporting tasks) I can move on from this project knowing I’ve done the best I could have. I have great optimism that there are no longer mice on Gough and the island can once again belong to the albatrosses and other seabirds who can now breed without fear of being attacked by hordes of hungry mice. I’m also confident that the lessons learnt from Gough can be put to use on future projects such as the removal of invasive rodents from Tristan da Cunha itself, Marion Island or the Pitcairn Islands – along with many others around the world.
Now that the baiting is completed, we've either succeeded or we've failed – and there is nothing more we can do about it. If there are any mice left, we need to wait until they have built up in numbers to level that they can be reliably detected. Given the size and rugged nature of Gough this is likely to be 3 years at which time a team will go to the island to check for mice – in the meantime we wait! My thanks again to all of you who have supported the project in such a vast array of ways including financially and in spirit. Hopefully your support will be reflected in the project’s outcome, with Gough returning to a safe breeding ground for millions and millions of birds.
This year the RSPB and its partners have attempted to eradicate the house mice on Gough and make it a seabird paradise once again. The project was originally scheduled to go ahead in 2020, but the coronavirus pandemic meant the RSPB and the Tristan da Cunha government had to abandon these plans and airlift the team home. With the delays the project now has a significant funding deficit. If you would like to help close this funding gap, you can donate directly to the restoration project at
Acknowledgement The Gough Island Restoration Programme is being carried out by the RSPB in partnership with Tristan da Cunha, BirdLife South Africa, the Department of Forestry, Fisheries and the Environment (South Africa), the Royal Zoological Society of Scotland, Island Conservation, Conservación de Islas, Manaaki Whenua - Landcare Research and BirdLife International. The programme is part-funded by the RSPB, the UK Government, the National Fish and Wildlife Foundation and other generous individuals and organisations.