Melanesia holds the world's most diverse and intact insular amphibian fauna

Identifying hotspots of biological diversity is a key step in conservation prioritisation. Melanesia-centred on the vast island of New Guinea-is increasingly recognised for its exceptionally species-rich and endemic biota. Here we show that Melanesia has the world's most diverse insular amphibian fauna, with over 7% of recognised global frog species in less than 0.7% of the world's land area, and over 97% of species endemic. We further estimate that nearly 200 additional candidate species have been discovered but remain unnamed, pointing to a total fauna in excess of 700 species. Nearly 60% of the Melanesian frog fauna is in a lineage of direct-developing microhylids characterised by smaller distributions than co-occurring frog families, suggesting lineage-specific high beta diversity is a key driver of Melanesian anuran megadiversity. A comprehensive conservation status assessment further highlights geographic concentrations of recently described range-restricted threatened taxa that warrant urgent conservation actions. Nonetheless, by world standards, the Melanesian frog fauna is relatively intact, with 6% of assessed species listed as threatened and no documented extinctions; and thus it provides an unparalleled opportunity to understand and conserve a megadiverse and relatively intact insular biota. Melanesia, centred on the vast tropical island of New Guinea, is shown to have the most diverse and intact insular frog fauna in the world.

Automated summary

Melanesia in the Pacific, centered around the island of New Guinea, is home to the world's most diverse and intact insular frog fauna. It has over 97% of globally recognized frog species, with nearly 7% of them found in less than 0.7% of the world's land area. This exceptional biodiverse region offers valuable insights and opportunities for conservation efforts.