Conservation genetics of Bombina v. variegata (Anura: Bombinatoridae) in northern Hesse, Germany

We report the genetic diversity and population structure of the Yellow-bellied Toad (Bombina variegata) at the northern edge of its distribution range in northern Hesse, Germany. A total of 281 samples from 20 populations were analysed, using six polymorphic nuclear microsatellite markers (ncSSRs). Moderate genetic diversity (H-e = 0.37-0.59) was detected within these B. variegata populations. We found evidence of a distinctive population structure, with populations at the edge of the study area showing lower degrees of diversity and higher degrees of isolation than more central populations. No genetic differentiation was found between populations from the middle Fulda and Werra river valleys, suggesting that fragmentation, e.g., by the A(4) highway that separates the two river valleys, has not yet had genetic consequences. Furthermore, indications of an isolation-by-distance pattern was found, suggestive of restricted gene flow between the studied populations. To ensure the long-term survival of the Yellow-bellied Toad in northern Hesse, we recommend continuous management efforts that focus on the reconnection of isolated populations and continuation of demographic population monitoring supplemented by population genetic analyses.