Predatory feral ferrets have been removed from Rathlin Island for the first time, in a boost for Northern Ireland’s largest seabird colony.
Rathlin Island is ferret-free after a £4.5m (€5.2m) five-year partnership led by RSPB NI (Royal Society for the Protection of Birds Northern Ireland) involving islanders, charities, volunteers and a red labrador called Woody.
The invasive, non-native ferrets were believed to have been let loose on to the picturesque island off the Antrim coast in the 1980s in a bid to reduce its wild rabbit population.
It was claimed only male ferrets were introduced, but females were among them and the rapacious mustelids bred, feasting on rare and declining burrow and ground-nesting birds.
Rathlin is home to endangered ground-nesting birds such as corncrakes, cliff-nesting birds including peregrine falcons and choughs and more than 250,000 seabirds, including puffins, razorbills, guillemots and Manx shearwaters.
The ferret population grew to more than 100, and were predators to Irish hares as well as eviscerating islanders’ chickens. In 2017, a single ferret got into Rathlin’s puffin colony and killed 26 birds over two days.
RSPB and Life Raft project staff mark the successful eradication of feral ferrets on Rathlin Island. Photograph: Tom McDonnell/RSPB/PA Wire
The Life Raft (Rathlin Acting for Tomorrow) project established a network of 110 cameras across the island to monitor the ferrets.
Thermal drones were deployed to detect animals alongside Woody the labrador, who was trained to sniff out ferret latrines and scent.
Live traps were set that alerted trained staff and volunteers as soon as an animal was caught, minimising the suffering of an animal in a trap. The trapped animals were swiftly shot, which is considered the most humane way to kill them.
Invasive predators are one of the biggest threats to biodiversity around the world and their removal from small islands has been repeatedly shown to boost rare and declining species, particularly seabird colonies.
The island of South Georgia successfully removed rats and mice in 2018 in the largest invasive species eradication project in the world.
Rathlin was ferret-free by last summer and immediately saw promising signs: it recorded six calling male corncrakes, which are not found breeding anywhere else in Northern Ireland. Burrow-dwelling Manx shearwaters also bred on the island for the first time in 40 years.
“It’s brilliant to be ferret-free,” said Erin McKeown, Life Raft programme manager for RSPB NI. “These islands are the last real safeguarded site for seabirds. Being able to create an environment where they can breed and raise their young safely is going to be a lifeline for many species. But going forward, we need to work with the community to keep ferrets off Rathlin.”
There is a regular ferry bringing visitors and supplies to the island, which has a human population of about 150. Cameras using AI monitoring alongside biosecurity checks by volunteers will watch for signs of ferrets and rats at Rathlin’s harbour and the port of Ballycastle on the Antrim coast.
A programme to remove invasive and predatory brown rats that found their way on to the island via ships in the 1800s and also threaten seabirds and ground-nesting birds is ongoing on Rathlin, with no rats spotted since last summer.
Michael Rafferty, Life Raft eradication manager, said: “This is a brilliant red letter day for Rathlin Island, and for the community who have been amazing to work with on the eradication programme with a field of dedicated experts since 2021.
“Collectively, they have created a safe haven so that the puffins and other seabirds can now nest safely on Rathlin without any threat from ferrets. The success of the project is the essence of teamwork and conservation excellence at its very best.”
“Lots of people like ferrets but they are a non-native species here and the situation was getting worse,” said Tom McDonnell of the Rathlin Development & Community Association, one of the partners in the island-wide effort.
“It’s going to make a massive difference, especially to the wildlife – the seabird colony will hopefully come back to what it was like 20 years ago and the people who keep chickens on the island will be able to keep their chickens. It’s a win-win for everybody.”
Elsewhere, seabirds trebled on Lundy in the Bristol Channel after black and brown rats were removed, and breeding birds received a similar boost on the Shiant Islands in the Hebrides, Scotland, after the black rat was eradicated.
The Orkney Islands are now seeking to eradicate non-native stoats, which threaten ground-nesting birds and the Orkney vole, a unique subspecies that in turn feeds crucial populations of rare hen harriers and short-eared owls. − Guardian