Herpetology keeper Ruth Smith said: “Sand lizards are the UK’s rarest lizard and populations in some areas are so low that we can’t just rely on protecting the site, we have to help breed them to boost their numbers.

“Surveys have shown that sand lizard numbers have significantly improved in the locations where they have been released before and it’s proven that those bred in the likes of zoos have a higher chance of survival than those that hatch in the wild.

“That’s because we’re able to give them plenty of food and intensive care in their vital early days and build them up for around four to six weeks, giving them a great head start.