England’s last refuges for red squirrels are under growing threat from invading grey squirrels, according to a new survey by Red Squirrels Northern England (RSNE).

Volunteers surveyed 246 sites in the annual squirrel check and found that while red squirrel numbers remain stable, grey squirrels now outnumber them in both Cumbria and Northumberland.

Grey squirrels, an invasive species from North America, pose a significant threat to reds. They carry squirrelpox, a disease lethal to red squirrels but harmless to greys, causing slow and painful deaths in red populations.

The survey revealed red squirrels at 52% of sites, a slight increase from 50% in 2023. However, grey squirrels were detected at 69% of sites, marking a 6.8% rise from the previous year. In Northumberland, grey sightings were 25% higher than reds, and in Cumbria, 17.3% higher.

Ian Glendinning, chair of Northern Red Squirrels, which represents volunteer conservation groups, said: “There is hope for reds with things like gene editing, contraception, but they are years away.

“By the time we come to that stage, I think it’s highly unlikely we’ll have any red squirrels left in England.”

Despite this, there was positive news: more sites in Northumberland’s Kielder Forest reported red squirrels than ever before, and Kyloe Red Squirrel Reserve near Berwick remained free of greys, highlighting areas of resilience for red populations.

RSNE said the survey showed “conservation intervention is paying off” but would welcome “more funding”.

Ms McQueen added: “We are not disheartened and we are so grateful to all those who work tirelessly to protect our red squirrels.”

But Mr Glendinning said: “The reality is all we’re doing is slowing down the inevitable.

“But I’ll keep going because I don’t want the last red squirrel where I live to die on my watch.”