Robert Benson, chairman of the Penrith & District Red Squirrel Group, recalls growing up in Hampshire in the 1950s, and finding a red squirrel that had drowned in a water butt in his garden. He and his mother reared one of her kits.
By then, of course, the spectre of the grey squirrel – the species brought to this country from North America in the 1870s – was already present, with reds and greys mixing as far north as Lancashire.
But it’s surprising how recently red squirrels were still relatively common. In the early 1970s, greys were absent from almost everywhere north of the Yorkshire Dales, with no foothold in Scotland. The upper half of Britain belonged to the reds.
At that point – a little more than half a century ago, according to the organisation Save Our Reds, there were roughly 1.5 million of each species. Today, those figures have grown – and shrunk – to an estimated 2.7 million greys and 120,000–160,000 reds, with campaigners warning that our native squirrel is heading for extinction in England and Wales.
Not only are reds largely outcompeted by greys, they are also highly vulnerable to squirrelpox, a virus harboured by their American cousins that is almost always fatal to them.
“With the ferocity of the problem we face in Cumbria, I am worried we will lose our red population completely in the next 5–10 years,” says Benson.
He estimates the current population in the county to be around 17,000, but greys stream out of urban areas such as Carlisle and Kendal along what he calls “squirrel highways” into reds’ territory, knocking them for six.
Until recently, Benson says, you could visit the Shap Wells Hotel just south of Penrith and see 20–30 reds within half an hour, yet all but two pairs have disappeared in the past year. This crash isn’t down to the deadly pox virus, but it shows how vulnerable small, local populations can be.
Saving the red squirrel
Everyone agrees that time is running out. Earlier this year, Natural England published a report assessing all conservation options for our native squirrel.
“Ultimately, red squirrel recovery looks possible – but it requires clear priorities, national coordination and long-term commitment to balancing ecological needs with economic constraints and societal values,” the report concluded.
It will also need new tools. Right now, protecting reds is mainly reliant on trapping and shooting greys in areas where the two species overlap, and it’s a battle that can never be won. Nonetheless, two new, potential game-changers could give conservationists a crucial edge.
The first is an oral immuno-contraceptive for grey squirrels. This has been in development by the Government’s Animal and Plant Health Agency (APHA) since 2017, and is nearly ready for field trials.
The contraceptive targets a hormone specific to mammals and would affect both males and females, says project lead Bex Pinkham.
“We’ve had some good results with rats using this vaccine,” she says. “We’ve achieved infertility from oral delivery through a syringe, and also from free-feeding bait, which we think is a world first.”
In other words, an effective, non-lethal method to control grey squirrels could be achieved simply by putting a hazelnut-flavoured paste laced with the contraceptive into special feeding hoppers. At present, it’s about 50–60 per cent effective, Pinkham adds, but they are hoping to boost this figure to 70 or 80 per cent.
The hopper is designed to deny entry to larger mammals, and also to smaller ones by use of a weighted door.
“Grey squirrels can push it open with their heads, but the weight keeps out smaller rodents,” says Sarah Beatham, also of APHA.
In areas where red squirrels are present, an extra design step is required, because reds are nearly as strong as greys, and can open the door. Sarah and her team have developed a weighing system that denies access to any animal less than 450g.
“That excludes all reds while allowing access to more than 90 per cent of adult greys,” she explains.
Pinkham says they should be in a position to apply for a licence with the Veterinary Medicines Directorate (VMD) in 2028, and that the whole process would take three to five years – which takes us to 2031 at the earliest.
A field trial would also be permitted by the Home Office testing licence they currently possess, so that could happen within 2–3 years.
Squirrel contraceptive: a silver bullet?
No one is saying a contraceptive is the grey squirrels’ silver bullet. It might help keep them at bay where they overlap with reds, such as Cumbria, but it will rely on the dedication of volunteer networks.
That said, Pinkham says even their most pessimistic projections suggest it will involve at most two fieldwork efforts a year, which is vastly less than currently required, and without killing a single squirrel.
It’s hoped there will be grants available to help fund the contraceptive’s use once it becomes available – in forestry, for example. It’s estimated that grey squirrels are responsible for £37 million of tree damage every year, with oaks suffering disproportionate impacts.
Kay Haw of the Red Squirrel Accord – a UK-wide partnership of different groups dedicated to maintaining and enhancing red squirrel populations – says the contraceptive could be used, for example, to clear greys from somewhere like Cornwall, moving inland from the tip, and then reintroducing reds.
That way, you could always maintain a buffer zone. But she also warns that, for many people, grey squirrels are a gateway to wildlife. Removing them completely may not be an option in some areas.
Along with the oral contraceptive, conservationists have another advance up their sleeves – a vaccine that protects reds against the squirrelpox virus. Developing a vaccine has been tried before, but ran out of funding, and the details of the current project are being kept largely under wraps for now.
Benson will only say that it will be an injectable vaccine, that he expects the process of getting it registered with the VMD to be “long and expensive”, and that they are looking for statutory bodies such as Natural England, NatureScot and Natural Resources Wales to provide support and funding.
“If we have a vaccine, we could work on reintroducing reds into areas where greys have been cleared out,” he says. In that scenario, even if greys moved back in, the reds would at least be safe from the virus.
Natural born predators
If you also consider the growth of pine marten reintroductions in England and Wales (pine martens prey disproportionately on grey squirrels, which, having evolved without these predators, have little innate fear of them), then it is possible to be more upbeat about the reds’ medium to long-term future.
But, says Marie Carter-Robb, who set up Save Our Reds last year, all these ideas need to be put into effect.
“The Natural England report has produced some recommendations, but it doesn’t have an implementation timetable or a national delivery body and there is no clear accountability,” she says.
Craig Shuttleworth, who has been working to protect red squirrels on Anglesey for the best part of three decades, says the technological developments are welcome, but he doesn’t see them as a panacea.
He’d like to see more studies on what difference pine martens can make, but his view is that grey squirrels will be “very, very hard to eradicate in any part of the country.”
Another strand to the issue is that greys are unwittingly moved around by people. One stowed away in a campervan and made it to Glasgow.
“There’s evidence of them swimming across the Menai Straits [to Anglesey],” Shuttleworth adds. “I would be staggered if we weren’t still trapping and shooting grey squirrels in 10 years time.”
