- Orkney’s wildlife, including several threatened bird species and the endemic vole are showing signs of recovery with population numbers and nesting successes increasing since work began to remove stoats in 2019.
- Vulnerable ground nesting birds are also seeing increases with more successful nesting attempts and more young having the chance to fledge and rebuild the populations of Red-listed birds such as the Hen Harrier, Curlew and Lapwing.
- Signs of droppings and activity indicate that there has been a 200% increase in the numbers of the endemic Orkney Vole.
- The largest project of its kind ever attempted; the Orkney Native Wildlife Project is now at a critical stage as preparations are made that would see the final phase of work to completely remove stoats from the islands.
Conservation scientists monitoring the wildlife on Orkney are reporting that there are significant increases in successful nesting attempts of ground nesting birds such as the Hen Harrier and rare waders is a positive indicator that the work to remove an invasive predator from the islands is making a positive difference. And the team has observed more evidence of Orkney Vole activity.
The first time this work has been attempted in the Northern Hemisphere, the Orkney Native Wildlife Project was created after a stoat was recorded on the islands for the first time in 2010. An invasive predator that the wildlife of the islands was unaccustomed to, the arrival of fast breeding stoats presented a major new threat to many of Orkney’s native species and to the local economy. Work began in 2019 and a team of international experts have been working with the local community, RSPB Scotland and the Scottish Government to remove stoats from the islands.
The biggest project of its kind in the world, over 6,000 stoats have been removed, and using 2019 as a baseline scientists have been monitoring the difference this is making to native wildlife.
The islands are also home to nationally important populations of wading birds including Curlew and Lapwing, which are both Red-listed on the UK’s list of Birds of Conservation Concern, as well as the Amber-listed Oystercatcher. Despite a slight drop in 2023, nest success rates were still higher than in 2019 when the Orkney Native Wildlife Project began, and more than three times higher for Curlew and Oystercatcher.
And the ground nesting Hen Harrier, which also appears on the Red-list, has also seen increased nest success rates. Orkney is an important stronghold for this amazing bird of prey. Since 2019 the proportion of successful nesting attempts on islands where stoats are being removed has improved from 36% to 82% in 2023.
The elusive Orkney Vole is an endemic species found nowhere else, and signs of their presence are detected by looking for droppings and small food piles of grass ‘clippings’ along vole tunnels within the vegetation. Every year since the project began has seen an increase in signs of voles during spring, recording an increase of approximately 200% between 2019 and 2023.
The report notes that while there are several factors that play into nest success rates for all species, one constant over the past five years has been the removal of invasive non-native stoats.
Anne McCall, director of RSPB Scotland said: “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. Working in partnership on the biggest project of its kind ever attempted we are restoring the natural balance to Orkney. The accidental introduction of stoats to the islands has had a devastating effect on our wildlife, especially smaller mammals and ground nesting birds. Today’s report is a strong indication that our work is making a difference.
“There will continue to be native predators, disease, bad weather and many other factors that influence the survival of our wildlife, but these are largely things that our wildlife has adapted to. 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.
NatureScot’s Head of Biodiversity Dr Katherine Leys said: “It’s thanks to the Orkney Native Wildlife Project’s sustained efforts to remove stoats from the island that we are now seeing promising signs of recovery among ground nesting birds and the Orkney vole population, and we hope that these trends will continue.
“We are proud to be supporting this vital work through the Scottish Government’s Nature Restoration Fund, and we wish the project further success in achieving the goal to restore balance to the island with the complete removal of invasive non-native stoats.”