Altitude correlates with dorsal -but not ventral- scale number and dimension in a lacertid lizard

The primary function of the keratinised skin of squamates is modulating heat load, reducing water loss rates and protecting from abrasion. Furthermore, reptilian scale size and shape variation have also been observed depending on the habitat and associated environmental conditions. However, how climate can modulate intraspecific scale characteristics of reptile species in temperate regions is still a subject of debate. Here, we investigate the potential correlation between climate and lizard scalation for a European lacertid lizard. From 221 museum collection specimens of Podarcis muralis, we recorded body measurements and sex information and counted the number and size of dorsal scales and the number of ventral scales per individual. We obtained each specimens' capture location information from which we extracted environmental data like temperature, precipitation, humidity, wind speed, solar radiation and altitude. We found that individuals that inhabited higher elevations tended to have fewer and larger dorsal scales than those from lowlands, as a potential adaptation to decrease water loss in arid and windy environments. We did not find a correlation between the number of ventral scales and environmental conditions, except for wind speed. This study uncovers an intraspecific adaptive mechanism in an environment gradient that is key to understanding species' potential adaptation to future climatic conditions.