Orkney's Native Wildlife Bounces Back as the World's Biggest Stoat Cull Works
After more than 6,500 invasive stoats were removed from Scotland's Orkney islands, the rare Orkney vole's activity rose 200% since 2019, while hen harriers' nest success rate nearly tripled, from 36% in 2019 to 82% in 2023. The Orkney Native Wildlife Project is the largest stoat eradication on inhabited land anywhere on Earth.
EnvironmentGNGV Editorial Team5 min read
On Scotland's wild and windswept Orkney islands, an audacious conservation experiment is delivering results that even its planners find heartening. Stoats — fast, fearless predators not native to the archipelago — were first confirmed on Orkney in 2010, and they posed a dire threat to ground-nesting birds and the unique native mammals that had evolved without them. In response, the Orkney Native Wildlife Project launched the largest stoat eradication ever attempted on an inhabited landscape. As Inside Ecology reported on March 31, 2026, the effort has now removed more than 6,500 stoats over six years — and the islands' native wildlife is rebounding.
The clearest beneficiary is the Orkney vole, a subspecies found nowhere else on Earth and a vital food source for the islands' birds of prey. In spring 2025, signs of vole activity were found in a third of surveyed squares — 358 of 1,082 — across the Orkney Mainland and South Isles. After years of pressure from stoats, the little rodent that anchors Orkney's food web is thriving again.
The birds are following. Hen harriers, elegant raptors that hunt low over moorland, recorded 74 confirmed breeding locations in 2025, with around 60 chicks fledging from monitored nests. Short-eared owls were confirmed at 55 breeding-season locations, with breeding proven at 16. Ground-nesting waders such as curlews, an internationally important population on Orkney, also stand to gain as the predator that raided their nests is steadily removed.
The project is a partnership between RSPB Scotland, NatureScot and Orkney Islands Council, and its scale makes it a closely watched test case for island conservation worldwide. "It's fantastic to see the continued positive impact that removing stoats from Orkney is having on our native wildlife, year after year," said RSPB Scotland's Sarah Sankey. Eradication is hard, slow work, and the last stoats are always the hardest to catch — but Orkney's recovering voles and thriving harriers show that with sustained effort, fragile island ecosystems can be pulled back from the brink.
