UK’s rarest reptile takes firmer hold in Devon

The Smooth Snake is largely confined to locations in Dorset, Hampshire and Surrey, thanks to the massive decline in its lowland heathland habitat since the 19^th century.

However, efforts to reintroduce the reptile to Pebblebed Heaths National Nature Reserve (NNR) in East Devon over 16 years have resulted in the emergence of a self-sustaining population.

The project’s collaborators, the RSPB, Amphibian and Reptile Conservation (ARC), Pebblebed Heaths Conservation Trust and Clinton Devon Estate, reported that their most recent survey last year had identified 39 snakes.

This represents a rise of 25.8% over the previous year (2023), when 31 individual Smooth Snakes were recorded, and a more than doubling of the population since the original 17 snakes were relocated from Dorset in 2009.

ARC reptile conservation officer Nick Moulton commented: “The Smooth Snake is an RSPB and ARC Priority Species. We aim to reintroduce it to counties where it became lost, to restore its status towards favourable.”

Smooth Snakes are unusually elusive; only identified as present in Britain in the mid-19^th century, unlike many other reptiles, they rarely bask on open ground and normally prefer to hide in thick vegetation.

At a maximum length of 70cm and slender in build, they are notably shorter than the much more common Grass Snake and less robust than the Adder – the other two native British species.

While the UK Smooth Snake population is recognised to be small and endangered, exact numbers are unknown. However, ARC UK monitoring programmes between 2019 and 2024 counted around 1,600 individuals.

Toby Taylor, manager of RSPB Aylesbeare nature reserve in Devon, said the rapid decline of UK heathland had been a crucial factor in the historical fall in Smooth Snake populations.

“Once common across the UK, heathland is now a rare habitat. Over the last 200 years it has been converted into farmland, destroyed for housing, used for forestry or mineral extraction and today tragically less than 15% of this landscape remains,” he stated.

“That’s why it’s vital that we work together to look after our heathlands and the wildlife that relies upon them.” 

Key to the growth of the new Devon population has been heathland management, says the RSPB. This has included restoration at scale using machinery, coupled with specific interventions to create micro-environments for threatened species, restricting some plants such as bracken and brambles to ensure the right vegetation can thrive. 

Also significant has been the activity of a small group of committed volunteers who have contributed 3,250 hours across a five year period.

“Crucial to this reintroduction is the dedication of RSPB’s trained and licensed volunteer surveyers,” said the ARC’s Nick Moulton.

“From their ongoing surveys we can confirm that the reintroduction has been a success (against IUCN guidelines); the animals are present, breeding and slowly colonising onto new areas of heath”.   

The Devon initiative has been complemented by success in more established Smooth Snake areas, notably RSPB Arne in Dorset, adds the organisation.

Numbers there were last reported at 35-40 individuals, making Smooth Snakes the most common snake species within the site. The area also hosts Adders, plus three species of native lizard: Sand Lizard, Common Lizard and Slow Worms.

For further information on volunteering with the RSPB click here. 

Pic: Clockwise from left: Smooth Snake, East Devon (Roger Hamling); Smooth Snake, Arne (Brian Attwood); juvenile Slow Worm, Arne (BA)