World’s largest rodent eradication project a success: South Georgia declared rodent-free!

Published on 10 May 2018 in News and comment

– The UK Overseas Territory of South Georgia is officially declared free of rodents for the first time since humans arrived on the island over 200 years ago

– Scottish-based charity the South Georgia Heritage Trust and its USA counterpart the Friends of South Georgia Island raised £10 million to finance the Habitat Restoration Project to eradicate invasive rodents

– Covering 108,723 hectares (1,087 km2), the Habitat Restoration Project is more than eight times larger than any other rodent eradication area ever tackled anywhere in the world

– Three rodent detection dogs covered a total of 2,420 km, with their two female dog handlers walking 1608 km, searching for signs of rats and mice as part of a comprehensive monitoring survey

After nearly a decade of planning and four sub-Antarctic seasons of work by an exceptional international team, the South Georgia Heritage Trust (SGHT) has now declared South Georgia free of rodents for the first time since humans arrived on the island more than two centuries ago.

Professor Mike Richardson, Chairman of the SGHT Habitat Restoration Project Steering Committee said: “South Georgia Heritage Trust is delighted to declare that its Habitat Restoration Project is complete and that invasive rodents have been successfully eradicated from the island.  It has been a privilege to work on this conservation project, the largest of its kind anywhere in the world, and I am immensely proud of what the small charity has achieved – it has been a huge team effort.

“The popular TV series ‘Blue Planet’ highlighted our shared environmental challenges and raised awareness of South Georgia’s importance to seabirds and nature more widely.  We hope the results from this project will continue to inspire others to help protect our natural world.” Hear more from Mike Richardson here

Invasive mice and rats arrived on South Georgia as stowaways on sealing and whaling vessels from the late 18th century onwards and preyed on ground-nesting and burrowing birds.  The introduced rodents have had a devastating effect on these birds, which evolved in the absence of natural predators and were becoming increasingly confined to rodent-free small offshore islands.  In particular, the rodents have threatened the existence of two endemic species found nowhere else on Earth: the South Georgia pipit and South Georgia pintail.

Scottish-based charity SGHT started planning its ambitious Habitat Restoration Project in 2008, with the aim of reversing two centuries of human-induced damage to the island’s wildlife, so that millions of birds could reclaim their ancestral home.  The Trust launched the pilot phase of baiting in 2011, followed by a second phase in 2013/14 and a third phase in 2015/16.  This first phase of baiting alone – completed in just 28 days despite the harsh sub-Antarctic conditions – made this project the largest island rodent eradication operation ever undertaken in the world.  Since the last baiting phase in 2015/16, no sign of rodents have been detected with some bird species already showing very dramatic signs of recovery, but a comprehensive survey was essential before the island could officially be declared free of rodents.

The King Penguin colony at St Andrews Bay, South Georgia Tony Martin

Following international best practice, more than two years after the last baiting work, an expedition team – dubbed ‘Team Rat’- spent six months on South Georgia this past winter in the final phase of the project, assisted by representatives of the Government of South Georgia & the South Sandwich Islands, searching for any signs of surviving rats using a combination of detection methods.  Over 4,600 inert devices, including chewsticks and tracking tunnels, were deployed and checked as part of the survey.  The very best rodent detection experts were also brought in especially: three highly trained ‘sniffer’ dogs and their two skilled female handlers.  In an incredible feat of endurance and teamwork reminiscent of Sir Ernest Shackleton’s epic crossing of the island just over a hundred years ago, the handlers walked a total of 1608km, with the dogs covering a total of 2420km, searching for signs of rats.  This distance, roughly the equivalent of a return trip from London to Dundee, is all the more impressive given the rugged and challenging terrain of South Georgia.  Together, the handlers climbed the equivalent ascent of Mount Everest 8 times over, and the dogs climbed Mount Everest 12.9 times over.

Richardson commented: “Thanks to the outstanding work of the passionate and committed members of Team Rat and the Board of Trustees, the birds of South Georgia are free from the threat of rodents.  The Trust can now turn its attention and efforts to working with the Government of South Georgia & the South Sandwich Islands on conservation of a different kind: the conservation and reinterpretation of the island’s historic cultural heritage to educate and enlighten future generations about our environment.”

The Trust, along with its US-based counterpart the Friends of South Georgia Island (FOSGI), raised £10million to finance the entire Habitat Restoration Project, securing financial and in-kind support from numerous individuals, foundations, businesses, and government, including £885K from the UK Government through DEFRA and the Darwin Initiative.

Lord Gardiner, Parliamentary Under-Secretary, DEFRA said: “The UK is proud to be custodian of the precious and unique biodiversity of 14 Overseas Territories, most of which are island environments, like South Georgia, that are highly vulnerable to environmental change.  The last ten years has seen a step-change in how the UK responds to invasive non-native species and the rodent eradication work completed by the South Georgia Heritage Trust is undoubtedly among the most remarkable of recent island conservation efforts.  This successful project gives confidence and offers hope for invasive alien species management around the globe.”