ISLAND HUNT FOR GREY TO SAVE REDS
APESKY grey squirrel sparked a frantic six-week hunt on Anglesey after it crossed the Menai Strait from the North Wales mainland. Its presence had custodians worried as a single grey squirrel could potentially wipe out the island’s resident red squirrels.
Anglesey’s reds are a conservation success story following the eradication of greys through culling. But a quarter of a century of work could be undone by a lone intruder and the only safeguard is round-the-clock monitoring.
The menace is constant. Not only are greys clambering across the two Menai Strait bridges, or hitching a lift on vehicles, in September 2022 one was pictured swimming across one of the UK’s most hazardous stretches of water to reach Anglesey.
In February a grey squirrel was reported by a member of the public in the island’s southeast corner. Red Squirrel Trust Wales sprang into action, installing a series of wildlife camera traps within 100 metres of where the woodland sighting was made. The exact location is not being disclosed to safeguard local colonies of reds.
The Squirrel Trust’s leading expert, Dr Craig Shuttleworth, said it then became a waiting game.
“Most of the images we captured were of reds,” he said.
“You never know if the grey squirrel was just passing through – it might never have been seen again in the same location.”
Eventually, two cameras yielded photos of the grey, enabling cage traps to be set up nearby.
“They were baited with food which also attracts reds,” said Dr Shuttleworth.
“These are protected by law and so must be released as soon as possible, which means the traps must be checked every few hours.”
Over a month-and-a-half, dozens of reds were caught and released – until the grey was finally snared on Thursday.
Posting on social media, a relieved Dr Shuttleworth said: “After weeks of searching, we caught up with it!”
The grey was euthanised – as a nonnative invasive species, it’s illegal to release them back into the wild. But questions remain. Was it infected with the squirrel pox virus that’s devastated populations of reds across Britain? Blood samples have been sent for testing: if these reveal the virus, the grey will have had weeks to spread it before being snared. Visual checks suggest it lacked telltale lesions associated with the disease.
As it was a young male, born in late 2023, it begs another question – was it born on Anglesey? If so, there must be others. But more likely it was a lone individual.
Since Anglesey was finally declared free of grey squirrels in 2016, there have been 10 immigrant greys reported on the island. One was elusive for longer than the recent capture, staying on the run for months before being trapped and euthanised. Another was found dead with suspected squirrel pox.
Dr Shuttleworth is worried by the declaration of the island’s grey-free status.
“It might foster a dangerous mindset – that there’s nothing to worry about,” he said.
“It’s something we’re trying to discourage. People who love the island’s reds must stay vigilant and report any squirrel they think might be a grey, even if they’re not sure.
“One grey was reported on the Isle of Skye (off Scotland’s northwest coast) and we’ve seen they can swim across the Menai Strait. One was apparently seen on Crib Goch (the infamous knifeedge ridge on Yr Wyddfa, also known as Snowdon).
“These guys are unstoppable. They’re amazing pioneers who will cross mountains, rivers and seas. That’s what we’re up against and we can’t afford to drop our guard.”
Another grey was found at the summit of Tryfan, Eryri.
Still, constant monitoring is tedious, laborious and imperfect, which is why red squirrel guardians continue to press for alternative solutions. Possibilities include vaccines, oral contraceptives and selective gene editing so that greys breed only males, leading to eradication within five to seven generations.
Another is the reintroduction of pine martens, a grey squirrel predator. Some exist in north Gwynedd and in July 2022 one was captured on a camera trap on Anglesey. But scientific and legislative hurdles mean all potential solutions will take years to have an impact, leaving monitoring as the sole line of defence for now.
For Dr Shuttleworth, it means the island’s eradication project was a doubled-edged sword, condemning squirrel guardians to years of relentless monitoring. But they have no choice.
“If the virus gets onto the island, it will be like a runaway train,” he said.
“The dominoes will fall very quickly, as happened in Swansea and to the reds around Bangor a few years ago.
“Anglesey has the biggest and most genetically diverse population of reds in Wales. They generate £1m-a-year for the island’s tourism economy, and they give a lot of pleasure and enjoyment to residents, so we have to keep going.”
To inform the squirrel trust of greys on the island, even if you’re not 100% sure, report sightings at www. redsquirrels.info/report-sightings