Spawning site selection and segregation at the landscape, habitat and microhabitat scales for five syntopic Asian amphibians

Species diversity, abundance and distribution relate to habitat preferences at multiple geographic and ecological scales. In this study, we aimed to understand the breeding ecology of five sympatric amphibians in the Republic of Korea – four anurans (Bufo sachalinensis, Rana uenoi, Rana coreana, Rana huanrenensis) and one caudata (Hynobius sp.) – by characterising their spawning habitat and to determine whether spawning site preference was influenced by species co-occurrence. We surveyed 120 water bodies focusing on the egg clutches to define the environmental properties associated with each taxa (water quality, depth, vegetation cover, topography and landscape), and we measured the distance between egg clutches and the bank of the water bodies (microhabitat). Habitats were partitioned among anurans along a gradient based on water depth. While the habitat used for spawning did not depend on species communities, the oviposition sites of R. uenoi and R. coreana varied in respect to their co-occurrence and the presence of the putative predator Hynobius sp. This suggests a plastic response in anurans’ reproductive behaviour potentially triggered by competitive interactions, and therefore subtle differences in microhabitats are significant yet overlooked drivers of breeding site selection.