Tiny radio tags are being used to track the movements of a group of Britain’s rarest reptiles as they are reintroduced into the wild.

Marwell Wildlife in Hampshire has fitted transmitters to 24 out of 86 sand lizards being released at the site of special scientific interest at Eelmoor Marsh in Farnborough.

The aim is to use the trackers, which weigh just 0.29 grams – less than 5% of the lizard’s body weight – to help understand their behaviour.

Rachel Gardner, PhD student at the University of Southampton, said: “Because they blend into the environment and spend time foraging and hiding in dense undergrowth, sand lizards can be incredibly difficult to see.

“Being able to track them in this way is really exciting, I can’t wait to see how far they go, how quickly, and exactly how they use the habitat.”

She added: “Having spent the last year rearing the lizards in captivity, it’s wonderful to finally release them into their natural habitat and apply this novel technology to see how they do.”

Sand lizardOne of the sand lizards (Paul N Drane)

The sand lizard, Lacerta agilis, is found across Europe and Asia but the species disappeared from most of its habitat in England and Wales. Its numbers are now increasing following conservation efforts.

It will be the first time that radio tags, which fall off after a short period of time or when the lizard sheds its skin, have been used to monitor the sand lizard in the UK.

Marwell Wildlife is reintroducing 250 sand lizards to Eelmoor Marsh with a total of 2,000 across the south of England during the past 25 years.