Distribution and conservation status of endangered amphibians within the Aspromonte mountain region, a hotspot of Mediterranean biodiversity

Amphibian biodiversity loss in recent years has exceeded that of all other groups of vertebrates. In this context, biodiversity hotspots represent priority targets for conservation in amphibian populations. However, little information is available on the distribution and conservation status of amphibian species within most biodiversity hotspots. Here, we characterized the distribution and conservation status of four endangered amphibians ( Bombina pachypus , Salamandra salamandra gigliolii , Salamandrina terdigitata , and Rana italica ) in the Aspromonte Mountain region, a biodiversity hotspot in southern Italy where the conservation status of amphibians is almost unexplored. We conducted an intensive field survey of 507 potential breeding sites spanning over 2.326 km 2 . We found that all four species were widespread in the study area. We observed 337 species occurrences: 63 for S. s. gigliolii , 29 for S. terdigitata , 84 for B. pachypus , and 161 for R. italica . Species distribution analysis revealed that S. s. gigliolii and R. italica populations had an extended and homogenous distribution. Conversely, S. terdigitata showed a dispersed pattern, with long distances between breeding sites, and B. pachypus an aggregated pattern, associated with the availability of suitable artificial habitats. On the other hand, we reported a decrease in B. pachypus occupancy in its natural habitats, which was related to a negative trend of populations. Overall, our results provide an encouraging framework for the conservation of amphibian populations in this area, but highlight the low coverage of endangered amphibian populations in protected areas, claiming for a reassessment of conservation policies and spatial conservation planning for the Aspromonte region.