Conservationists are undertaking a final push to wipe out millions of rats from South Georgia once and for all, in a bid to protect the island’s wildlife.

Described as the world’s largest rodent eradication project, the UK-led effort will see three helicopters dropping 95 tonnes of the poison Brodifacoum on the British overseas territory next year.

South Georgia is a crucial breeding ground for over 100 million seabirds including penguins, albatrosses and pintails, which feed on the food-rich waters of the Southern Ocean.

But rats introduced two centuries ago by sailors and whalers have devastated the island’s seabirds, causing their populations to drop by more than 90%. The brown rats have been filmed eating seabird chicks alive, and feeding on their brains to disable them, which is an “appalling thing to see” according to the team behind the eradication project.

The South Georgia Heritage Trust, a Scottish charity, will begin the £2.5m bait-dropping effort in February next year and is aiming to have covered a 364 sq km (140 sq mile) area by the end of March. It follows two earlier phases of rat poisoning in 2011 and 2013, which the trust hailed as successful, though it could not say precisely how many rats had been killed due to the difficulty and cost of measuring it.

Three helicopters will drop 95 tonnes of poison on the island next year to get rid of the rats. Photograph: Roland Gockel/South Georgia Heritage Trust

Tony Martin, the project’s director, said the island was of huge international importance for seabirds, but was now “a shadow of its former self in terms of the wealth of its wildlife”.

“Before humans came along and brought the rats and mice, South Georgia was quite possibly the most important seabird island in the world. It may well have held a greater concentration and diversity of seabirds than any other island,” Martin said.



The trust said the bait posed a minimal threat to the seabirds, and although some would be accidentally killed by the poison, the losses would be “sustainable” and their populations would bounce back – unlike those of the rats.

Martin said the team would be dropping the poison among a large colony of king penguins, the second largest species of penguin, despite his concerns about disturbing the penguins with the helicopters. “Absolutely [we will], because the place is stiff with rats, they feed on penguin excrement and will eat young chicks,” he said.

The final phase of the project next year takes place on the south-eastern end of the island, and the baiting team will head out two weeks earlier than in previous years because of the cold weather there. The project’s phased nature has been made possible by the island’s topography, with mountain ranges and glaciers divvying it up and blocking the rats travelling from infested areas to clear ones.

King penguin colony on South Georgia. The rats feed on the bird’s excrement and young chicks. Photograph: South Georgia Heritage Trust

It was too early to say if the first two phases had been successful but it was “looking remarkably good,” said Martin. “At the very western end of the island lots of [South Georgia] pipets [Anthus antarcticus] were sighted recently, which simply would not have happened before.”

The poisoning next year will be followed by months of camera traps and devices with food to attract rats, to monitor for rodent survivors.

“We don’t need to retreat areas unless there is evidence there have been survivors. The beauty of the poison is that it kills rodents with one consumption, they don’t need to have repeated meals of this stuff. Those pellets uneaten will just break down and return to the soil,” Martin said.



If the rats are eliminated entirely, it is quite possible that future human visitors will accidentally trigger a new invasion.

The only prevention is stopping the rats getting ashore, Martin said. If they do, there will be up to three tonnes of poison stored on the island as a contingency plan. “There should be an ability to snuff out any future risks,” he said.