Adders tracked with GPS in bid to protect species

Adders are being monitored using GPS trackers to identify what habitat they need to thrive to help support the long-term recovery of the protected species.

A project at Haldon Forest in Devon began in the spring of 2025 and research is expected to continue for another three years. Micro radio tags have been taped to the tails of the snakes - coming off as their skins are naturally shed two months later.

Another project in Cornwall is exploring how both natural and human-made barriers can isolate adder populations.

Aaron Boughtflower, ecologist for west Devon and Cornwall at Forestry England, designed the Haldon Forest project and said: "We've got more adders than we thought."

Forestry England said 10 snakes were measured, weighed and photographed before being fitted with trackers and released where they had been found.

Researchers tracked the snakes every two to three days using a radio receiver and each location was recorded with GPS.

The radio tags allowed the snakes to be located while they were hidden from view or underground.

Nigel Hand, herpetologist on the study, said: "I've got up to 90, even over 100 days of data of these animals moving around - and that's the important thing – trying to work out where they are going and what they are doing."

He said the site was important: "It is significant now we are starting to get a better picture of where snakes are and where we can focus habitat work.

"We've lost 40% of adders across the UK and where we know they occur, we've got to do the best we can to manage them."

Boughtflower said: "Adders at Haldon Forest are a fundamental part of the ecology.

"They sit right in the middle of the food chain... so they are a really good indicator species."

He said they wanted to discover how scattered the adders' distribution was and how robust the populations are in terms of genetic mix.

Boughtflower said: "We don't know when we are going to instruct works, if we are going to be damaging or killing adders."

He said they would use the evidence to inform habitat restoration.

The adder is the UK's only venomous snake.

According to charity The Amphibian and Reptile Conservation Trust, there are around 50-100 adder bites on people per year in Great Britain and the last human fatality was in 1975.

Hand said: "The adder is not an aggressive snake that's waiting to bite people as they walk around.

"They're hidden away and the first thing they'll do on an encounter even with a person though, is try to get away. It will only bite defensively."

The NHS said anyone bitten by a snake should seek emergency treatment.

The first year of the study has provided "valuable insights" according to Forestry England.

Hand said the trackers have not impacted the adders behaviour: "We've had them mating, breeding, combatting where the males do this ritualistic wrestling and also feeding."

Forestry England said the insights would help shape future habitat management at Haldon Forest.

It said the long-term aim was to expand the adder population and establish the forest as a regional stronghold for the species.

In Cornwall, Froglife, a reptile and amphibian conservation charity, is working with partners to explore how the fragmentation of natural habitats affects adder populations.

The project will explore how natural barriers, such as rivers and farmland, and human-made barriers, such as roads, can isolate adder populations.

Froglife said Cornwall had a 7km (4.3 mile) land connection between the River Tamar and the sea, while a second river barrier isolated adder populations on West Penwith. The A30 road also separates the north and south of the county.

A gourp spokesperson said: "This project will look at how Cornwall's rivers and roads have shaped and separated adder populations.

"Researchers will then compare this with other populations to understand how much this affects adders across Cornwall.

"The findings could also help us understand the impact on adder populations across England. The project will evaluate the genetics of Cornish adders relative to English populations."

Follow BBC Devon on X, Facebook and Instagram. Send your story ideas to spotlight@bbc.co.uk.