The unprecedented rate of global amphibian decline is attributed to The Anthropocene, with human actions triggering the Sixth Mass Extinction Event. Amphibians have suffered some of the most extreme declines, and their lack of response to conservation actions may reflect challenges faced by taxa that exhibit biphasic life histories. There is an urgent need to ensure that conservation measures are cost-effective and yield positive outcomes. Many conservation actions have failed to meet their intended goals of bolstering populations to ensure the persistence of species into the future. We suggest that past conservation efforts have not considered how different threats influence multiple life stages of amphibians, potentially leading to suboptimal outcomes for their conservation. Our review highlights the multitude of threats amphibians face at each life stage and the conservation actions used to mitigate these threats. We also draw attention to the paucity of studies that have employed multiple actions across more than one life stage. Conservation programs for biphasic amphibians, and the research that guides them, lack a multi-pronged approach to deal with multiple threats across the lifecycle. Conservation management programs must recognise the changing threat landscape for biphasic amphibians to reduce their notoriety as the most threatened vertebrate taxa globally.

Amphibians are among the most threatened vertebrate taxa globally. Their global decline necessitates effective conservation actions to bolster populations across both the larval and adult stages. Constructing man‐made ponds is one action proven to enhance reproduction in pond‐breeding amphibians. However, to achieve successful conservation outcomes, extensive knowledge about the ecology and behavior of the target species is required. In this study, we investigated how different hydroperiod regimes impacted the growth and development of Litoria littlejohni tadpoles. Over a 28‐week period, tadpoles were exposed to three hydroperiod treatments: constant high, declining, and constant low water levels. Weekly measurements of snout‐vent length, body mass, and Gosner stage were taken to assess treatment‐related changes. To determine whether different treatments affected locomotor performance, jump tests were conducted 3 weeks post‐metamorphosis. Individuals exhibited limited developmental plasticity in response to declining water, with a mean time to metamorphosis of 85.1 days ± 12.1. Comparatively, when L. littlejohni tadpoles were exposed to low water volumes, they were able to speed up development and reduce time to metamorphosis, with a mean time of 63.7 days ± 10.3. The speeding up of development had an apparent consequence for L. littlejohni. We found support for trade‐offs between rapid development and reduced morphometric measurements postmetamorphosis which resulted in reduced locomotive ability. Individuals from constant low water treatments exhibited an average total jumping distance of 171 cm ± 13.6 over 10 consecutive jumps, compared with 236 cm ± 17.3 in constant high and 210 cm ± 14.8 in declining treatments. Rapid larval development aids tadpoles in escaping suboptimal aquatic conditions, but its effects on locomotion may impact foraging efficiency and predator escape ability. Understanding developmental plasticity in threatened amphibians, especially in response to hydroperiod variations, is crucial for conservation programs, particularly under future climate change scenarios predicting increased drought and reduced hydroperiods in aquatic environments.

Environmental change is reshaping wildlife reproduction through increasing temperatures and often leading to the spread of emerging infectious diseases, yet the physiological consequences of managing these stressors remain poorly understood. Amphibians are particularly vulnerable due to their ectothermy and high susceptibility to chytridiomycosis, caused by Batrachochytrium dendrobatidis (Bd). Here, we examine how Bd infection and thermal treatment interact to influence sperm quality and reproductive investment in male green and golden bell frogs (Ranoidea aurea), a species that has suffered severe population declines. Moderate Bd infection was associated with elevated sperm concentration relative to uninfected and heavily infected males, consistent with increased short-term reproductive investment under elevated mortality risk. However, severe infection led to pronounced reductions in sperm concentration and motility. Thermal treatment successfully eliminated Bd infection but imposed reproductive costs: sperm concentration declined following treatment and remained significantly reduced six months later, despite partial recovery of sperm motility and membrane integrity. Our findings reveal that disease and thermal stress jointly shape amphibian reproductive outcomes through context-dependent trade-offs between immune defence and gamete production. While mild infection may trigger short-lived increases in reproductive output, both severe infection and pathogen clearance via thermal exposure impose lasting constraints on fertility. These results highlight an underappreciated cost of disease mitigation and suggest that increasing thermal extremes associated with climate change may further limit amphibian reproductive resilience, with important implications for conservation management and population persistence.

The application of population genetic metrics to evaluate the health of a population after undergoing anthropogenic management and experiencing environmental stochasticity remains underexplored in amphibians. Several metrics can be used to measure loss of genetic diversity and decreased gene flow to determine population health, including heterozygosity, inbreeding, and structure. This study assessed the genetic health of the endangered frog, Litoria littlejohni using genetic metrics in a population exposed to human modifications (dam creation) and extreme climatic events (droughts followed by heavy rainfall). We found strong population structuring, with two distinct subpopulations, one in the northern and another in the southern area of occupancy. Despite being only 2.5 kilometres apart, there was limited gene flow between the sub-populations. Genetic differentiation between these sub-populations, determined by PCA analysis, decreased after high rainfall in 2021. However, strong genetic structuring returned in 2023 during drought conditions. In the northern sub-population, where breeding habitats included both constructed ponds and natural creek pools, heterozygosity was significantly higher and mean kinship significantly lower compared to the southern sub-population where there are fewer natural creek lines nearby. Furthermore, in the southern sub-population, inbreeding metrics increased significantly from 0.003 in 2020 to 0.162 in 2023. As the southern sub-population predominantly relies on constructed ponds for breeding, the absence of natural creek pools may be limiting dispersal and affecting the genetic health of this sub-population. To improve heterozygosity and connectivity, additional ponds could be constructed between the two sub-populations, acting as stepping-stones to enhance gene flow and reduce inbreeding.

Amphibians are among the most threatened taxonomic groups, with many species experiencing rapid declines that have resulted in small, isolated populations vulnerable to inbreeding depression and reduced fertility. One major outcome of inbreeding is lowered fecundity, often linked to morphological changes in gametes. Littlejohn's tree frog ( Rawlinsonia littlejohni ; previously Litoria ) is a threatened species requiring targeted conservation management. To increase population numbers and restore genetic diversity, a captive breeding program has been established. This study aimed to optimize the timing of hormonally‐induced sperm collection to improve outcomes for captive breeding, cryopreservation, and in vitro fertilization. Three experiments were conducted with ten captive males. Experiment one examined the effects of different human Chorionic Gonadotropin (hCG) and Gonadotropin‐releasing hormone antagonist (GnRH‐a) concentrations on spermiation response over 6 h. Both 5 and 10 IU hCG/g bwt yielded high sperm concentrations with similar motility and membrane viability, whereas GnRH‐a (1 and 2 µg/g bwt) produced no response. Experiment two assessed seasonal effects on sperm traits over a year, showing high variability between individuals but no consistent seasonal pattern. Sperm motility and membrane viability remained high, with slight declines in January, April, and June. Experiment three compared captive and wild males during the breeding season. Sperm concentration was higher in June for wild frogs but variable across all months in both groups. Our findings demonstrate that sperm production and quality in R. littlejohni are shaped more by its breeding system than by seasonal cycles, informing strategies to enhance reproductive success and genetic recovery in captivity.

Amphibians are among the most threatened vertebrate taxa globally. Their global decline necessitates effective conservation actions to bolster populations across both the larval and adult life stages. Constructing man-made ponds is one such action proven to enhance reproduction in pond-breeding amphibians. However, to achieve successful conservation outcomes, extensive prior knowledge about the ecology and behaviour of the target species is required. In this study, we investigated how different hydroperiod regimes impact the growth and development of Litoria littlejohni tadpoles. Over a 28-week period, tadpoles were exposed to three hydroperiod treatments: Constant High, Declining, and Constant Low water levels. Weekly measurements of snout-to-vent length, body mass, and Gosner stage were taken to assess any treatment-related changes. To determine whether different treatments affected locomotor performance, a jump test was conducted three weeks post metamorphosis. Individuals did not exhibit developmental plasticity in response to declining water, with a mean time to metamorphosis of 93.3 days. Comparatively, when L. littlejohni tadpoles were exposed to low water volumes, they were able to speed up development and reduce time to metamorphosis, with a mean time of 56.5 days. The speeding up of development had an apparent consequence for L. littlejohni. We found support for trade-offs between rapid development and reduced morphometric measurements post-metamorphosis which resulted in reduced locomotive ability. Individuals from Constant Low water treatments exhibited an average total jumping distance of 170.5 cm over 10 consecutive jumps, compared to 235.8 cm in Constant High and 209.5 cm in Declining treatments. Rapid larval development aids tadpoles in escaping suboptimal aquatic conditions, but its effects on locomotion may impact foraging efficiency and predator escape ability. Understanding developmental plasticity in threatened amphibians, especially in response to hydroperiod variations, is crucial for conservation programs, particularly under future climate change scenarios predicting increased drought and reduced hydroperiods in aquatic environments.