Shape PCA of distance measurements (a), standard PCA of scale counts (b) and standard PCA of colour marking measurements (c) for grass snakes assigned to the microsatellite clusters of Natrix helvetica (C-TI, C-VS, E) and N. natrix (N. n. vulgaris, mtDNA lineage 3, from northeastern Switzerland). Only individuals with a genotypic cluster assignment ≥ 80% are included.