Population genetics for conservation of spadefoot toads, , in Western and Central Europe.

European amphibians such as the common spadefoot toad ( (Laurenti, 1768)) exhibit alarming declines across large parts of their range, despite extensive legislation aimed at conservation. As knowledge about the genetic background of a species has become crucial for conservation assessment, we investigated nuclear genetic diversity and structure of , based on microsatellite loci. Clustering revealed major groups corresponding to postglacial colonization patterns. Additionally, we found contrasting patterns of genetic diversity across the 66 studied populations, reflecting the conservation status of the species in Europe and with marked genetic impoverishment across most populations in the northwestern part of the species' distribution range. Our findings provide genetic information on the conservation status of the common spadefoot toad across Europe, emphasizing the need for urgent conservation efforts. We recommend further genetic monitoring, habitat restoration and potential translocations to safeguard the species in the face of ongoing challenges.