From threatened to widespread: a non-genuine conservation status update for a now widespread Asian Hylid - and the need for additional basic field research

Abstract Context. Non-genuine conservation status updates threaten the trust in Red Listing, but they are necessary building blocks in science. In addition, they often highlight the critical need for basic field research. The Suweon treefrog, Dryophytes suweonensis, is a hylid species long thought to be range-restricted and assessed as Endangered by the IUCN Red List of Threatened Species. Aims. This study aimed at determining the species of individuals encountered during call surveys in 2024 in China, and determine the areas of suitable habitat for the species. Methods. We sequenced the Cytb gene fragment to identify the species and compared the acoustic properties to identify the species. We also built ecological models with MaxEnt to predict suitable habitats for the species and guide future surveys. Key results. We confirmed the identity of the population found more than 985 km north of the northernmost known locality of D. suweonensis as the same species. The call properties also matched with those of D. suweonensis. The ecological niche models identified a very large area with suitable habitat spanning across the northern Chinese plains. Conclusions. The species is not endemic to the Korean Peninsula, occurring in a significantly broader range, and thus, the population size is higher than previously assumed. Implications. The species is unlikely to be threatened, and this huge range extension highlights the need for additional field surveys for all species in the area. Long term, the use of conservation prioritisation tools will highlight conservation needs in the region.