Conservationists are celebrating the success of a large-scale stoat removal project in Orkney. The non-native mammals have wreaked havoc on indigenous birds and voles since their arrival on the Scottish islands 15 years ago. Since 2019, nearly 6,500 stoats have been eliminated, in what Anne McCall, director of the Royal Society for the Protection of Birds (RSPB) Scotland, described in a recent report as “the biggest project of its kind ever attempted”.
The Orkney Native Wildlife Project (ONWP), led by the RSPB, has been working to protect the populations of ground-nesting hen harriers and the Orkney vole, a species listed as vulnerable in Scotland. The report called 2023 a “great year” for the native vole, also reporting tangible impacts on several other species. In August, the project was awarded an additional £4 million to help finish the stoat-removal job, but leaders are still on the hunt for more funding to ensure Orkney is “stoat-free by 2030”.
Stoat invasion
Stoats (part of the same taxonomic family as badgers, weasels and otters) were first reported on Orkney in 2010, according to the ONWP, and soon began to threaten the island’s ecosystem. Fast breeders, with large appetites and advanced predatory skills, they have quickly put native species in vulnerable positions. The Orkney vole, found only on the archipelago, is particularly at risk. “Stoats also tend to kill more than they need and hide – or ‘cache’ – the rest to eat later,” said the Daily Record. “In Orkney, caches containing as many as 100 Orkney voles have been found.”
As omnivorous eaters, an unchecked population of stoats also poses a threat to mice, rabbits, hedgehogs and birds, including Orkney’s population of curlews and hen harriers.
Eradication efforts
The ONWP has developed a network of “intense ‘response trapping'”, overseen by a dedicated “eradication team”. “This means identifying stoat hotspots through public sightings, dog searches, and monitoring equipment,” said the organisation on its website. “Using this information, we’re creating a smarter network of traps that put more pressure on the shrinking stoat population.” Orcadians can plot stoat sightings on a map on the ONWP website. Once identified, the stoats are caught in “humane lethal traps”, said The Times.
“There will continue to be native predators, disease, bad weather and many other factors that influence the survival of our wildlife,” said McCall in the project’s most recent progress report. But “removing the invasive stoats from the island is our best chance at maintaining this balance and giving our special wildlife the best chance to build the resilience it needs to meet these threats”.
“This is a success story for conservation against the backdrop of a nature crisis that is pushing more of Scotland’s wildlife to the brink.”