Fig. 1
Top left: Distribution of Ch. montanus (red), Ch. parallelus (yellow) and the overlapping distribution of both species (orange) (distributional data from Kleukers [43]). Geographic map of each sample location in the Hunsrueck mountains and hybridization rate at each sample location (for geographic coordinates see Table 2). Triangle: allotopic population of Ch. montanus; square: allotopic population of Ch. parallelus; circle: syntopic populations