Sessions

Amphibians are the most threatened class among vertebrates; therefore, their scientific investigation is of primary importance for developing effective conservation strategies. Previous comparative studies have identified several factors that may contribute to amphibian vulnerability, such as body size, microhabitat preference, geographic range size, and human encroachment. However, in multiple instances, these studies failed to account for the phylogenetic dependence among species or did not include key explanatory variables, thereby overlooking many important key drivers. Thus, in this study, using phylogenetic comparative methods, I investigated how reproductive strategies and ecological requirements influence the extinction risk status of frogs (Anura) and salamanders (Caudata). I hypothesized that niche width, habitat type, and mode of reproduction and development play a decisive role in species extinction risk. I compiled information on extinction risk status, population trends, habitat use, distribution, and reproductive traits (e.g., fecundity, egg size, developmental mode, and the form and duration of parental care) from the IUCN Red List and AmphibiaWeb databases, as well as primary literature sources. My results indicate that generalist species are less threatened than habitat specialists in both orders. Furthermore, amphibians that lay eggs or reproduce on land are less vulnerable than species dependent on aquatic reproduction. However, the effects of other factors differed between the two orders. In Caudata, species favouring forested habitats are less vulnerable than those that avoid forests. Additionally, biological invasions impacting their habitats increase the extinction risk of the affected species. In Anura, species associated with torrents and fast-flowing waters are more threatened than those occupying other microhabitats. Moreover, anuran species providing prolonged, complex parental care (such as feeding the offspring) are also exposed to higher risk. The discrepancies between the two orders are likely attributable to differences in reproduction, dispersal, and lifestyle. The high proportion of data deficient (DD) species gives further cause for concern, as it highlights a substantial knowledge gap. My findings contribute to identifying the developmental and ecological factors that primarily determine extinction risk, thereby may facilitate the establishment of conservation priorities and the targeted preservation of threatened species.