Genotypic structuring of Natrix natrix in the study region. Symbol colors indicate structure cluster membership; admixed ancestries are depicted as pie chart sectors according to Q values. In the bar plots below the maps, samples are represented by two bars, indicating their mitochondrial lineage (top) and their inferred cluster membership (bottom). Mitochondrial lineages are color-coded as in Figure 1; white bars indicate missing mtDNA data. Samples are arranged from west to east. The black arrows highlight samples from Cyprus; dark red arrows, samples identified as N. megalocephala; and the pink arrow indicates the only grass snake with mitochondrial lineage 6 of N. natrix. A most likely translocated grass snake from Borçka (Artvin, Turkey) representing the western cluster is not shown in the map (see footnote 1).