‘There were stoats in kitchen cupboards’: AI deployed to help save Orkney’s birds | Conservation

AAt first, the ermine looks like a faint speck in the distance. But as it gets closer, its sleek body is identified by a heat-sensing camera and, through it, an alert is sent to Orkney’s ermine hunters.

Aided by an artificial intelligence program trained to detect the shape and sinuous movements of an ermine, trapping teams are dispatched with the explicit goal of finding and killing it. It is the most sophisticated technology deployed in one of the world’s largest mammal eradication projects, which aims to detect the few remaining stoats in Orkney.

Conservationists on the islands, located in the far north of Scotland, have already used an array of 9,000 death traps and eight specially trained tracking and detection dogs to eliminate almost 8,000 stoats over the past six years. At least 30 of these digital cameras will soon be installed across the moors and coasts of the Orkney mainland, creating a network that will link images from the cameras to computers and mobile apps used by trapping teams.

The stoat is an existential threat to the native ground-nesting birds that Orkney is famous for: it is home to 11% of all the UK’s breeding seabirds and around 25% of its hen harriers, as well as its most valuable native rodent, the Orkney vole.

The Royal Society for the Protection of Birds Scotland, which runs the Orkney Native Wildlife Project, estimates that stoats arrived from the Scottish mainland around 2011. Since then, the population has exploded, colonizing the Orkney mainland and the neighboring islands of Burray and South Ronaldsay and the Deerness Peninsula (stoats can swim several kilometers) with devastating effects.

Sarah Sankey, regional operations manager for RSPB Scotland, says the biggest advantage of stoats is that they have no predators in Orkney. “They have nothing to control them: we have no foxes and very few buzzards. We’ve seen this all over the world. This stoat population would have continued until it wiped everything out,” she said, holding a laminated map of Orkney with thousands of red dots marking the network of traps.

“We saw it before we started eradicating them. There were stoats running between people’s legs, stoats in people’s kitchen cupboards, there were stoats in people’s lofts.”

In less than a decade, they had expanded to 58,000 hectares (143,260 acres). A feasibility study indicates that if they spread across all of the Orkney islands it would be financially and logistically impossible to control them. Thus, the project, which will last at least 10 years, has a budget of 16 million pounds sterling and 46 collaborators.

Stoats enter vole burrows, search for eggs and chicks in thousands of curlew, lapwing and hen harrier nests, and also hunt along Orkney’s vast coastline for seafood, feeding on starfish and sea urchins.

“Here we’re dealing with a perfect disaster, where we have tons and tons of food all year round,” Sankey says. “Nothing to control stoats and lots of native wildlife to lose, and a tourist economy that somehow depends on it.

“Why did we start all this? Orkney is less than 1% of the UK’s land area, but we are home to around a quarter of all Arctic terns and hen harriers, around a third of Arctic skuas, and we are the only place where Orkney voles live. So there was a lot to lose, basically.”

The latest survey data suggests the project was successful. Since it began in 2019, there has been a 1,267% increase in the chance of curlew hatching, a 218% increase in vole activity and a 64% increase in hen harrier numbers. Heavily persecuted by gamekeepers on the British mainland, Orkney is now home to 160 hen harriers.

“Against a backdrop of massive population declines, particularly of the curlew and lapwing, we are managing to stabilize the Orkney population,” Sankey said.

Sourced from New Zealand, where conservationists face an uphill battle to eliminate millions of non-native predatory mammals, the AI ​​system is complemented by thermal binoculars and drones, says James Geluk, the project’s lead technologist and a New Zealander who worked on an eradication project near Wellington.

Thermal detectors are much more sensitive to movement than surveillance cameras normally used by conservationists, he says. They work great in the dark and send live alerts in real time after video footage is uploaded to a cloud server. The AI ​​has learned to distinguish stoats from otters and voles.

“It’s a much more precise monitoring tool than a typical trail camera,” says Geluk.

After six years of concerted trapping efforts, including the disruption of lockdowns during the Covid crisis when stoat numbers exploded again, the RSPB hopes to begin the ‘mop-up’ phase in December – a threshold which will be reached after 95% of stoats have been eradicated.

They estimate that there are only around 100 pregnant stoats left in Orkney. “We’re all conservationists working here,” Sankey says. “None of us are here because we want to kill an animal. We are here because we want to protect the nature of Orkney.”