In mainland Britain the common wall lizard (Podarcis muralis) is considered an alien species, and concerns have been raised that competition from this robust and agile continental reptile may be hastening the decline of our rare native sand lizard (Lacerta agilis).
The Isle of Wight colony is the longest established population of wall lizards in Britain and a celebrated part of the island’s fauna, though its origin is hotly debated. It is believed that in the 1920s there were deliberate releases of the reptile, though local legend has it that they are descendants of survivors from a shipwreck off Bonchurch.
Since the species is considered native just across the Channel in Jersey and northern France, there is also speculation that this may in fact be a relict native population.
Whether introduced or indigenous, it is easy to see why the lizards feel at home in the balmy Mediterranean-like microclimate of the Ventor Botanic Garden.
A swath of densely growing, leathery-leaved, evergreen shrubs punctuated by towering blue spires of giant echium typifies their preferred maquis scrubland habitat, and a south-facing terrace backed by a rocky bank provides the perfect combination of basking and hiding places.
As I lean over to inhale the intoxicating orange blossom scent of a flowering Pittosporum tobira, I hear the scuffle of clawed feet through the leaf litter and glance down just in time to see a lithe, greyish-brown, female streak down a dry gully.
Looking up, I immediately spot a larger, green-tinged, female on a sun-bathed rock. Her bulging body suggests she is gravid, distended with eggs. Spooked by a passing child, her tail whips round and she bolts into a deep fissure at the base of an olive tree trunk.
Males are known to be aggressively territorial, so I am unsurprised that after 20 minutes of wall watching all 11 of my sightings have been females.
Finally, I catch a glimpse of jewel-bright scales beneath a prostrate rosemary. Crouching down, I find myself face to face with a magnificent male, more than 20 cm in length. He is mottled onyx and emerald, with turquoise spots on his throat and lower flank.
Unlike the skittish females, he holds his ground, tilting his angular head and subjecting me to a steady stare as I raise my camera.
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