Adder tunnels created at Greenham and Crookham Commons as BBOWT tried to save the vulnerable snake species

In a first-of-its-kind project for the UK, two snake tunnels have been created at Greenham Common to help save endangered native adders.

Adder Connections aims to link two isolated populations of the snakes to secure the species’ survival in one of their last remaining strongholds in West Berkshire.

new adder tunnels along the Old Thornford Road connecting the commons

The project has received a £113,000 grant from Natural England’s Species Recovery Programme Capital Grant Scheme and will form a best-practice case study.

Greenham and Crookham Commons, which is managed by Berkshire, Buckinghamshire & Oxfordshire Wildlife Trust (BBOWT) on behalf of West Berkshire Council, are home to two distinct populations of adders.

But the land management team discovered that the groups were not mixing after attaching radio tags to some of the adders to track their movements.

new adder tunnels along the Old Thornford Road connecting the commons

Results showed that the snakes were unable to cross Old Thornford Road, which divides the commons, and so two tunnels were created underneath the road to encourage movement.

With adders listed as a vulnerable species, recent scientific studies suggest that only a few of the larger populations could be left in England in 10 years’ time.

And as small groups are at greater risk, the Adder Connections project aims to form a larger local population with a wider mix of genetics to make them more resistant to potential threats such as disease.

BBOWT’s Tom Hayward, senior land manager for Berkshire, said: “The adders are at some points only a matter of metres apart, but they may as well be five hundred miles away.

The adder tunnels at Greenham and Crookham Commons. Pic by Logan Walker (BBOWT)

“We’re seeing adders disappearing from central England at alarming rates, but we know the importance of genetics to their survival and we’re hoping these tunnels will make our populations sustainable into the future.

“I’m looking forward to the first moment of seeing an adder using the tunnel on camera so that we know they stand a chance.”

The snake tunnels are the first of their kind in this country, but are used successfully elsewhere in Europe and America.

Inside the adder tunnels at Greenham and Crookham Commons. Pic by Logan Walker (BBOWT)

They have been designed in accordance with expert advice, using pebbles at the bottom to aid movement, with metal fencing to guide the snakes and other small creatures through the tunnels and away from the dangers of the road.

Radio tracking and camera traps will be used to monitor whether the plan is working and the populations are now mixing.

Debbie Lewis, head of ecology at BBOWT, added: “Adders are amazing creatures. They are the UK’s only venomous snakes and can live up to 30 years, but because they are naturally cautious of humans they are rarely spotted.

“We know that loss and fragmentation of their habitats – and even climate change – is having a huge impact on adder numbers, and it's sad to say that this incredible creature could be extinct from our counties in the next few decades if something isn't done to help them.

“Most have already disappeared from Buckinghamshire and Oxfordshire, with this area of Berkshire being a vital stronghold for them.

new adder tunnels along the Old Thornford Road connecting the commons
new adder tunnels along the Old Thornford Road connecting the commons

“New and innovative thinking is needed to combat the current crisis. We hope to contribute to the wider understanding of how we can better encourage mixing among adder communities, and a successful outcome of this project could lead to it being replicated across other sites, other wildlife trusts and for this scheme to be used as a showcase for landowners.

“Whatever the result, we will have gained vital insight into the behaviour of these fascinating reptiles.”

A major threat to adders is human interference and BBOWT said it would urge any visitors to the commons to not seek out adders and if you do see them, enjoy them from a distance as this is safer for the visitors, adders and pets.