Genetic diversity of Horvath’s Rock Lizard meets current environmental restrictions

The Horvath’s rock lizard Iberolacerta horvathi (Méhely, 1904) is an understudied lacertid species, which is geographically isolated from its congeners and currently classified as Near Threatened under IUCN red listing criteria. Due to its limited distribution and narrow environmental preferences, we expect that the species had been affected by past climatic oscillations. By combining all available data on species occurrences and our own records, we produced an updated distribution map. We used ecological niche models to identify the current environmental factors underlying the species range and developed a habitat suitability map. We sequenced one mitochondrial and one nuclear marker to characterize the distribution of the genetic variability and infer the historical demography of the species. The habitat suitability map identified areas where targeted field searches should be prioritized, as well as unsuitable habitats coinciding with likely barriers to gene flow. We found considerable genetic variability suggesting that the species probably survived the Pleistocene glaciations in at least two main refugia, one in the South and the other in the central/northern portion of its distribution. While southern populations show a moderate demographic decrease starting at the onset of the Eemian interglacial, the northern populations underwent an expansion during Late Pleistocene. We provide a revised species distribution and a first characterization of its genetic variability across its distribution to guide conservation priorities for this endemic and spatially restricted species.