EXPERTS are warning dog walkers not to disturb the UK’s only venomous snake after sightings across the region.

Adders are sometimes spotted in Ynyslas sand dunes and in hills surrounding Aberystwyth - but they are not thought to be very common in Ceredigion or Gwynedd.

The Wildlife Trust of South and West Wales says populations are suffering declines across the UK – and they are a conservation priority in Wales in particular.

The shy creatures are often found in open habitats like heathland, moorland, open woodland, sea cliffs, and sand dunes. And the trust has urged walkers to keep their dogs on a lead when passing through such areas.

Digital Fundraising and Communications Officer Grace Hunt told the Cambrian News that, with Spring upon us, it is a great time of year for spotting the elusive reptiles.

She said: “As temperatures rise in spring, these snakes will venture out of their hibernacula, where they’ve been dormant over winter.

“You’re most likely to spot Adders on a sunny spring morning, when they are basking in the sunlight. Unfortunately, Adders are becoming a less common sight. Adders are a conservation priority in Wales and we’re working to ensure our reserves are a haven for these threatened reptiles.           

“Due to their venomous nature, there are some negative misconceptions about these beautiful snakes. Adders are shy creatures and are far more likely to slither away if they are disturbed.

“Adder bites are rare but can happen when they feel threatened, for example if they are trodden on or picked up. One of the easiest ways to help adders is to avoid disturbing them. If you do visit one of our reserves, please be mindful of these creatures. “By sticking to paths, and ensuring dogs are kept on short leads, it reduces the risk of disturbance and snake bites.”

The Woodland Trust says: “Male adders usually have silvery-grey colouration, while females can be copper or brown. Both have a distinctive, black zig-zag pattern along their backs. Fully black adders can be seen in some areas too. Once fully grown, adders usually measure between 60 and 80cm in length. Young are almost perfect replicas of adults and measure around 17cm in length at birth.”

The NHS advises anyone who is bitten by an Adder to seek medical attention immediately - though stresses the bites are rarely serious.

Adders pose the greatest threat to dogs, with about 100 reported cases per year of pets being bitten.