ADDER population numbers in Worcestershire are low due to walkers killing them out of fear.

Dogs not on leads have also led to the disturbance of adder dens.

Current estimated population numbers in the Malvern Hills are just 100 adults and half that number for the Wyre Forest.

Habitat fragmentation has also been noted as a contributing factor in the small numbers, as adders do not travel more than 1km during the mating season.

Wendy Carter, spokeswoman for Worcestershire Wildlife Trust said: “They’re being deliberately killed by people who fear them, which has reduced their numbers, and by dogs disturbing them so they hide away and don’t look for mates.

“They’re secretive creatures and are very sensitive to disturbance so people should leave them alone. Although they are venomous, they will only bite as last defence; they’d rather slither away from danger and save their venom to immobilise their prey.”

Adder expert, Nigel Hand from Central Ecology, said: “These areas in the county are the last remaining haunts for a species that has been around long before us.

“If here was a catastrophic event in the area I don’t think the snake population would stand a chance at re-population due to the low numbers.

If the numbers at, say, the Malverns drops as low as ten, then his would be a serious problem and drastic steps would need to be taken.”

The adder is protected under the Wildlife and Countryside Act, 1981 and the species is classified as a Priority Specie in the UK Biodiversity Action Plan.