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Conservation breeding programs (CBPs) are often the lifeline between extinction and survival for many imperilled amphibian species. With the goal of recovering wild populations, CBP success is reliant on their ability to successfully manage ex situ populations over time, breed viable offspring, and maintain genetic diversity and adaptive potential. Reproductive technologies have emerged as an important tool in the conservation toolkit to allow managers to improve reproductive output and genetic management, and their use in amphibian conservation is expanding. To date, studies investigating the efficacy of hormone therapies in amphibians typically only report spawning and fertility rates and do not monitor offspring to later stages of development. For the first time, here we assess the effect of hormone therapies on captive breeding outcomes beyond oviposition, to the point of metamorphosis, in the critically endangered Baw Baw frog, Philoria frosti. To determine the effect of hormone therapy on spawning success and offspring viability, male-female pairs were administered either 0 µg/g gonadotropin-releasing hormone agonist (GnRHa), 0.5 µg/g GnRHa, or 0.5 µg/g GnRHa + 10 µg/g metoclopramide (MET) (n = 12 pairs/treatment), and the number of pairs ovipositing, time to oviposition, clutch size, metamorph mass, and the proportion and number (mean and total) of offspring to metamorphosis were quantified. Overall, the percentage of pairs that oviposited was high across all treatment groups (92-100%). The percentage of fertile clutches was highest in the GnRHa group (92%) and lowest in the GnRHa + MET group (82%), though differences were not statistically significant. Both hormone treatment groups took significantly less time to oviposit than the control pairs. Notably, the proportion of eggs developing to metamorphosis was significantly higher in the GnRHa group, resulting in 74% (total eggs=539) metamorphosing compared to approximately 50% in the control and GnRHa+MET treatments (total eggs= 273 and 264, respectively). Interestingly, weight at metamorphosis was statistically similar across all groups, and results are consistent with previous studies in this species that show a narrow range in size at metamorphosis. The continued application of GnRHa is recommended to improve conservation outcomes for the critically endangered Baw Baw frog. The outcomes of this research advance our understanding of the impact of hormone therapies on reproductive outcomes and will inform amphibian conservation breeding programs globally.

Abstract In recent years, the potential to locate endangered animals using scent trained detection dogs (conservation detection dogs) has gained attention. Among vertebrates, conservation detection dogs have demonstrated a remarkable capacity to detect the scent of endangered mammals, reptiles, and birds, but their use in detecting amphibians is only beginning to be explored. A lack of work in this area is surprising given that amphibians are declining faster than any other vertebrate taxa. Moreover, amphibians are generally small, highly cryptic and breed in complex habitats, making them difficult to locate for the purpose of monitoring or establishing conservation breeding programs. This study aimed to provide a preliminary investigation into whether conservation detection dogs can be imprinted on the scent of the critically endangered Baw Baw frog (Philoria frosti) under captive conditions, and then effectively trained to locate wild frogs in their complex natural habitat. Two conservation detection dogs were trained to identify and locate P. frosti scent under controlled conditions before assessing their ability to locate wild P. frosti. Both conservation detection dogs were effective at locating P. frosti scent under controlled conditions, and also demonstrated an ability to detect live frogs under natural conditions. From an applied perspective, our findings provide new evidence that conservation detection dogs are capable of learning to detect the scent of small, cryptic anuran species. They also indicate that detection dogs are capable of locating frogs in highly complex forest habitat, confirming their untapped potential to aid in the management of imperiled species that have previously proven difficult to detect, monitor, and protect. We discuss the limitations of our approach and provide recommendations to help direct future amphibian conservation detection dog research.

Reproductive technologies (RTs) can assist integrated conservation breeding programs to attain propagation targets and manage genetic diversity more effectively. While the application of RTs to enhance the conservation management of threatened amphibians has lagged behind that of other taxonomic groups, a recent surge in research is narrowing the divide. The present study reports on the first application of RTs (hormone-induced spawning, hormone-induced sperm-release, and sperm cryopreservation) to the critically endangered Baw Baw frog, Philoria frosti. To determine the effect of hormone therapy on spawning success, male–female pairs were administered either 0 μg/g gonadotropin-releasing hormone agonist (GnRHa), 0.5 μg/g GnRHa, or 0.5 μg/g GnRHa + 10 μg/g metoclopramide (MET) (n = 6–7 pairs/treatment), and the number of pairs ovipositing, total eggs, and percent fertilisation success were quantified. To determine the effect of hormone therapy on sperm-release and to establish the peak time to collect sperm post-hormone administration, males were administered 0 IU/g (n = 4), or 20 IU/g hCG (n = 16). Total sperm, sperm concentration, and percent viability were quantified at 0, 2, 4, 6, 8, 10, and 12 h post-hormone administration. Overall, the percentage of pairs ovipositing was highest in the GnRHa + MET treatment, with 71% of pairs ovipositing, compared to 57% and 33% of pairs in the GnRHa and control treatments, respectively. The quantity of sperm released from males in response to hCG peaked at 4 h post-hormone administration, though it remained high up to 12 h. The percent sperm viability also peaked at 4 h post-administration (94.5%), exhibiting a steady decline thereafter, though viability remained above 77% throughout the 12 h collection period. The remaining sperm samples (n = 22) were cryopreserved using established protocols and biobanked for long-term storage and future conservation applications. The mean post-thaw sperm viability was 59%, and the percent total motility was 17%. The results from this preliminary study will direct further applications of RTs to the critically endangered Baw Baw frog to assist with species recovery.

Abstract Emerging infectious diseases are an increasingly prominent threat to biodiversity. However, traditional methods in conservation generally have limited efficacy in the face of disease threats. Ironically, although unintentional human movement of species has facilitated the spread of pathogens, intentional conservation translocations are a promising approach to combatting disease threats under certain circumstances. Here, we summarize two decades of published literature on translocations of Australian frogs threatened by chytridiomycosis—a fungal disease that has caused amphibian declines and extinctions globally. We identify key motivations, considerations, and factors associated with outcomes, including the role of chytridiomycosis in failures. In an effort to improve success, we then propose a conceptual framework for determining when conservation translocations may be both feasible and beneficial, with a focus on understanding mechanisms favoring host persistence. Lastly, we build on our findings from the review and the conceptual framework to develop a set of recommendations to guide practitioners aiming to translocate amphibians as a conservation strategy in the face of chytridiomycosis. Although diseases pose a unique set of challenges for managing declining species in the wild, we argue that progress is likely with careful and well‐informed adaptive management experiments to refine reintroduction and translocation efforts.