Nature
PUBLISHED
In what is the largest rat eradication project ever undertaken, researchers have confirmed that the remote sub-Antarctic island of South Georgia is officially rodent free.
As with many remote islands, the rats and mice are thought to have arrived on South Georgia around 250 years ago as stowaways on seal and whaling ships. Having lived in splendid isolation this entire time, the seabirds already there were completely unprepared for the rodent invasion. With many species of birds nesting on the ground or in burrows, the eggs and chicks were fodder to the rats.
This has threatened many of the 30 million birds nesting, with some 81 species found on South Georgia, including four species of threatened penguin. Of most concern, however, are the futures of two endemic birds – meaning they are found nowhere else on Earth. Both the island's only native songbird, the South Georgia pipit, and the South Georgia pintail have been forced off the mainland and are hanging on by surviving on tiny offshore islands.
The island is around 160 kilometers (100 miles) long, with an area of 865,000 acres (350,000 hectares), and is frequently frosted over with ice and snow. Two main mountain ranges run down the island, with over a hundred glaciers filling their valleys.
Along the fringes a tussock grassland clings on, making the perfect home for many different seabirds, including huge albatrosses, burrowing petrels, and gentoo and macaroni penguins.
On the beaches, king penguins run the gauntlet of over half the world’s population of elephant seals, while roughly 97 percent of all fur seals choose South Georgia as a nursery for their young.
To try and protect this vitally important breeding ground for the South Atlantic’s wildlife, the UK-based South Georgia Heritage Trust teamed up with the US-based Friends of South Georgia Island to raise £10 million to try and rid the island of the pesky rodents.
After starting the project in 2008, with phase one starting in 2011, the team has finally been able to announce that they have succeeded in eradicating all rats and mice from the island, in the biggest project of its kind.
The incredible achievement has taken years of researchers working in the remote and incredibly challenging sub-Antarctic environment. Helicopters traversed the island dropping poison baits in three separate phases, with the last being carried out in 2016. Since then, no rats have been spotted, and to make certain, a team of two humans and three dogs were sent into double check.
After walking 1,608 kilometers (1,000 miles) across the rugged and difficult terrain, climbing the equivalent ascent of Mount Everest eight times over, they can confirm that there is not a single rodent is left on South Georgia.
Already, the birds are rebounding, and there is great optimism that the wildlife will rapidly recover and recolonize the island.
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