Old World tree frogs from the family Rhacophoridae, one of the most species-rich groups of amphibians worldwide, are becoming a model in ecological and evolutionary research, notably for their tremendous diversity of breeding systems. In this study, we provide the most comprehensive temporally and spatially explicit phylogeographical framework for the tropical neo-genus Zhangixalus, with a specific focus on the evolution of inter- and intraspecific polymorphism in their egg-laying strategies. We combined ~500 sequences spanning ~4 kb of mitochondrial genes, representative of nearly all known Zhangixalus species from 373 localities. We recovered a robust timetree featuring ~60 phylogeographical lineages assigned to 36 taxa, illustrating a vast under-appreciation of the diversity of the genus. Patterns of diversification were intimately linked to climatic trends since the Mid-Miocene, leading to a remarkable biogeographical scenario for the onset of Taiwanese diversity. Finally, in contrast to the macro-evolution of conserved breeding strategies in rhacophorids, the striking variation of nesting behaviour documented across Zhangixalus species, whereby foamy egg nests are alternatively fossorial, deposited on the edge of the water or suspended on the overhanging vegetation, seems to have evolved rapidly from arboreal ancestors in all major clades, implying micro-evolutionary processes and/or phenotypic plasticity.

Conservation genetics must find the balance between the technical challenges of DNA sampling while promoting animal welfare. In amphibians, buccal swabs offer a least intrusive source of DNA, but most herpetologists still refrain to use them, partly due to doubts regarding their effectiveness to provide enough material now that next-generation sequencing (NGS) analyses have become routine. In this article, we hope to change their minds through an empirical demonstration that buccal swabs offer DNA amounts and success rates for a widely used NGS approach (RAD-sequencing) that are equivalent to those of more intrusive yet commonly used samples in frogs and toads. We thus call for a shift of DNA sampling practices, and stress the fact that beyond their proven reliability, buccal swabs facilitate the issue of collection permits by increasingly restrictive ethical committees, especially when it comes to endangered species. With this purpose in mind, we share our long-term experience with amphibian buccal swabs through visual and textual pointers.

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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.