The Shiant Isles have been officially declared rat-free, thanks to a four-year partnership project to restore them as a secure haven for nesting seabirds.
A month-long intensive monitoring check in February found no sign of rats.
This means that none has been recorded there for two years, the internationally agreed criterion for rat-free status.
The EU LIFE+ funded Shiants seabird recovery project started in 2014 and is a partnership between the Nicolson family, custodians of the islands for three generations, Scottish Natural Heritage and RSPB Scotland.
It has benefited from the help of many volunteers, and significant private donations.
Over the last four years the project has focused on making the islands a safe place for seabirds to raise their chicks by removing the invasive, non-native black rats that were found there.
It has been a huge success and played an important role in developing future island restoration and biosecurity work in the UK.
Another key part of the project is a programme of research monitoring the response of the ecosystem to the removal of rats.
It is anticipated that seabirds such as puffins, razorbills, and guillemots will see improved breeding successes which could eventually support population increases in these long lived seabirds breeding on the Shiants.
It is hoped that Manx shearwaters and storm petrels will begin to nest on the islands as well.
The Shiants, a remote cluster of islands five miles east of the Isle of Lewis and Harris in the Outer Hebrides, is one of the most important seabird breeding colonies in Europe, hosting around 100,000 pairs of nesting seabirds each year.
However, there was evidence that the rats fed on the seabirds’ eggs and chicks, having a detrimental impact on their breeding success.
With many seabird populations facing a multitude of threats and severe declines in Scotland and around the globe, it was vital that action was taken to safeguard those nesting on the Shiants.
Dr Charlie Main, Senior Project Manager for the Shiant Isles Recovery Project said: “This is an absolutely fantastic moment for the Shiant Isles and everyone involved in the project is delighted that they are now officially rat free.
“With so many of Scotland’s seabird populations in decline it’s vital that we do all we can to help them.
“Making these islands a secure place for them to breed is really important.
“Over the next few years we’re really looking forward to seeing the full impact of the islands’ restoration flourish with the seabirds enjoying improved breeding successes, and other species beginning to breed there as well.
“We’ll also continue to work with the local community to ensure this special place remains free of rats.”