A COUNTY’S snakes, already threatened by environmental destruction, are facing a second, equally dangerous, menace – rampant inbreeding.

That is the fear of experts at Durham County Council, Durham Wildlife Trust and Sunderland University, who have teamed up to launch a genetic survey of the adder population in rural west Durham.

They will be looking for genetic diversity across upper Derwentside, Weardale and Teesdale as the venomous snakes emerge from hibernation and start shedding their skins over the next few weeks.

Dead adders will also be analysed, to check for deformities suggestive of inbreeding – potentially brought about by declining numbers – such as missing eyes and deformed spines.

The survey is the first of its kind in the region and comes amid growing concerns adders are at risk as their populations dwindle through loss of natural habitat and breeding grounds.

Dr Noel Carter, a senior lecturer in molecular biology at Sunderland University, said: “The adder project highlights a growing concern for wildlife in the UK – maintaining genetic diversity in isolated populations.

“We hope to generate some preliminary data for substantial research, with a view to protecting this species for generations to come before they become dangerously inbred.

While genetic surveys of adder populations have taken place in other areas of the UK, this is the first in the North- East, looking initially at the Durham area, amid fears that dwindling populations will lead to inbreeding depression, a condition that could cause problems such as mutations from missing eyes to deformed spines to adders being born dead.”

University staff will undertake analysis in the lab, while Wildlife Trust experts will conduct tests outdoors.

Sarah Edwards, from the trust, said: “These dwindling numbers are very worrying.

“This project is essential to establish best practice methodology for future monitoring.”

If successful, the research could be extended to other atrisk species such as the water vole.

The adder research will feature on BBC One’s Countryfile programme at 7pm on Sunday.