The project
G Rosin
Background
Gough Island is a remote, uninhabited island in the Tristan da Cunha archipelago, in the South Atlantic Ocean, more than 1,500 miles from Cape Town. Naturally free of land predators Gough has been an idyllic nesting ground relied upon by millions of seabirds including many who breed almost nowhere else. Its importance for threatened species and sites of outstanding universal value earned Gough World Heritage Site status in 1995 and Important Bird Area status in 2013.
Mice were accidentally introduced to the island, most probably by sailors during the 19th Century. After arriving on Gough they learnt to exploit all available food sources on the island, including seabirds. Video cameras revealed how the mice ate the flesh of seabird chicks. Tristan albatross chicks weigh up to 10kg, but open wounds inflicted over successive nights frequently lead to their deaths. Mice started to attack and kill adult seabirds too. The loss of adult birds added even greater urgency to this extinction prevention project.
Since the suspicion at the turn of the century that mice might be predating Gough's seabirds, we have been researching the impact and feasibility of a mouse eradication. Gough was the first island to record such astonishing mouse behaviour - and even now it is highly unusual. The project was the most challenging ever undertaken by the RSPB and took many years to plan.
Programme objectives
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To prevent the extinction of the Critically Endangered Tristan albatross, the Endangered MacGillivray’s prion, and several other small seabird species that are affected by invasive non-native mice.
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To restore the fortunes of Gough Island's seabirds and ensure the island remains one of the world's most important seabird nesting sites, worthy of its World Heritage Site status.
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To support Tristan da Cunha in ensuring the long-term future of this special island and its unique wildlife.
Eradication operation
The solution was relatively straightforward - eradicate the mice - though the operation to do this was logistically complex, mainly because of the island's remoteness, tough terrain, and harsh weather conditions. Using helicopters, highly experienced pilots spread cereal bait pellets containing a rodenticide across the island during the austral summer of 2021. At the same time we took safeguard populations of landbirds into our care so that they could stay safely out of the way until the operation was complete.
The RSPB and our partners have years of island eradication experience to draw on, but the operation was one of the most challenging mouse eradications undertaken to date anywhere in the world.
The programme involved some of the world’s leading experts in the field of island restoration who were instrumental in the success of the Macquarie Island Pest Eradication Project and the South Georgia Habitat Restoration Project, amongst many others. These two projects in particular give us confidence that, whilst hugely challenging, our efforts to restore Gough Island will have been successful. However, there will need to be no sign of mice between now and 2024 for us to be confident we have succeeded.
The future of Gough
Our commitment to Gough Island doesn't end now we have completed the eradication attempt. We will continue to work with the Tristan da Cunha Government, Island Council and community, as well as key stakeholders in South Africa to support the development and implementation of effective long-term biosecurity procedures to ensure that neither mice nor other non-native species are able to recolonise the island in the future.