Environmental change is reshaping wildlife reproduction through increasing temperatures and often leads to the spread of emerging infectious diseases, yet the physiological consequences of managing these stressors remain poorly understood. Amphibians are particularly vulnerable owing to their ectothermy and high susceptibility to chytridiomycosis, caused by Batrachochytrium dendrobatidis (Bd). Here, we examined 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 6 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. Although 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.

ABSTRACT Governments globally have committed to Nature Positive, measurable gains in ecosystem health, and Net Zero, a balance where greenhouse gas emissions are equal to the emissions removed from the atmosphere, thereby addressing the interconnected crises of biodiversity loss and climate change. However, the pathways through which governments are choosing to achieve these goals are increasingly placing climate objectives and biodiversity conservation at odds. While the renewable energy transition is necessary for mitigating climate change and benefits biodiversity indirectly by doing so, these benefits have the potential to be in part offset by the direct impact of renewable energy's infrastructure itself. Here, we use Australia's recent environmental law reforms, which may allow renewable energy projects to be prioritized over biodiversity conservation, as a “lesson learned” for nations grappling with how to reconcile rapid renewable energy deployment with biodiversity integrity. We explore case studies where Net Zero does not compromise Nature Positive initiatives, and propose five key principles that must be adhered to truly achieve Net Zero: (i) plan early and strategically; (ii) adhere to the mitigation hierarchy; (iii) design for biodiversity and monitor adaptively; (iv) engage communities and custodians; and (v) align finance and policy with ecological performance.

Cryopreservation of intact fish and amphibian eggs and embryos is challenging due to the sheer size and yolk content, which prevents proper dehydration and causes lethal intracellular ice formation during cooling. Alternatively, cryopreservation of dissociated embryonic cells allows to biobank diploid genomes. However, amphibian and fish embryos have cells of varying sizes throughout the developing embryo and cell size distribution remains understudied in cryopreservation. This study examined cell size effects during cryopreservation of dissociated embryonic cells from two amphibian species. Most work used Limnodynatses peronii blastula, gastrula, and neurula cells cryopreserved with 10% dimethyl sulfoxide (DMSO) and sucrose at 0%, 1%, or 10%. Increasing sucrose concentration improved post-thaw recovery of membrane intact cells and cell concentrations, with gastrula and neurula cells having better recovery than blastula cells. An interaction amongst cryoprotectant concentration, cell size, and embryonic stage was observed. Higher sucrose improved recovery of larger cells, but reduced recovery of smaller cells. These results supported a “Goldilocks” model of cryoinjury, in which larger cells require more time to dehydrate adequately, while smaller cells are damaged by excessive dehydration and solute effects, implying that optimal cryoprotectant conditions differ by cell size. Based on post-thaw recovery, 10% DMSO + 10% sucrose was optimal and successfully applied to the cryopreservation of neurula cells from the threatened Rawlinsonia littlejohni , marking the first report of embryonic cell cryopreservation in a threatened amphibian. Our results demonstrated the importance of cell size effects on cryoinjury and their consideration in the application of cryopreservation for amphibian conservation. In brief: Since intact amphibian eggs and embryos cannot be cryopreserved, dissociated embryonic cell cryopreservation provides an alternative avenue for biobanking embryonic diploid genomes; however, cell size effects on cryoinjury is poorly understood and the developing amphibian embryo consists of different sized cells. We demonstrated that cell size influences cryopreservation outcomes by cryopreserving embryonic cells from three developmental stages under varying cryoprotectant concentrations. ### Competing Interest Statement The authors have declared no competing interest.

As amphibian populations continue to decline, there is a need to establish procedures to store and recover genetic diversity. Nuclear transplantation (NT) is a potentially useful reproductive technology with applications to conservation in specific circumstances. Although sperm have been successfully cryopreserved and used in in vitro fertilization to produce sexually mature offspring, there are many endangered and even extinct amphibian species that only exist as stored frozen adult or larval tissues. The only way to recover that genetic diversity is through NT. Nuclear transplantation can introduce new genes into captive breeding programs from individuals where no viable gametes from that individual have been cryopreserved. Amphibian NT research was common during the middle to late 20th century; however, it was never conducted for amphibian conservation. Early amphibian NT experiments were conducted for the purpose of determining whether differentiation was a terminal process that involved the loss of reprogramming genes. However, following the success of mammalian NT, amphibian NT research declined, and the field has been at a standstill for decades. This study developed the first nuclear transplantation protocol for a native Australia frog using Limnodynastes peronii , as a model. Specifically, this paper aimed to test: 1) nuclear transplantation with fresh embryonic cells in Limnodynastes peronii and trial the implementation of different egg enucleation methods (pricked eggs only, UV only, and pricked + UV), 2) use of cryopreserved cells in nuclear transplantation and 3) use single nucleotide polymorphisms to determine if the nuclear genomes of nuclear transplant embryos were derived from the injected donor cell nuclei. With both fresh and cryopreserved embryonic cells as donor cell nuclei, development of the nuclear transplant embryos was low compared to the fertilized controls. Only one nuclear transplant embryo derived from a fresh embryonic cell (injected into a UV only enucleated egg) developed into a tadpole. This attained stage 36 of the Gosner Staging System for Anurans (hind limbs) before dying. As an egg activation technique, pricking the eggs resulted in higher cleavage rates and development to blastula than UV only and pricked + UV nuclear transplants (in trials with cryopreserved cells), but none of the nuclear transplants from the pricked only group developed beyond blastula. None of the nuclear transplants derived from cryopreserved embryonic cells developed to tadpoles. The most advanced stage attained from cryopreserved embryonic cells was stage 13 (neurula) from UV only eggs. Single nucleotide polymorphism (SNP) analysis testing for genotype mismatches was used to determine if the genomes of developing nuclear transplant embryos were derived from the injected donor cell nucleus. SNP analysis confirmed that two true clones were generated in this study. This is the first confirmed nuclear transplantation in any Australian native frog. ### Competing Interest Statement The authors have declared no competing interest.

Estimating the abundance of wildlife populations at a landscape-scale is vital for conservation, but is often hampered by survey costs, data processing and imperfect detection. In this study, we developed a framework that combines a protocol for validating nocturnal thermal drone detections in real-time with N-mixture modelling to estimate the landscape-scale abundance of arboreal folivores. As a case study, we estimated the abundance of koalas (Phascolarctos cinereus) across seven reserves (673 km2) in New South Wales, Australia. We conducted thermal drone surveys of 208, 25-ha sites stratified across vegetation type and fire history, on average, three times over consecutive nights (range 1-12 repeats), between 18:00-04:00 h (May to September). All koala detections were validated by field personnel or in real-time with drones equipped with a thermal camera and searchlight. Koalas were detected on 245 occasions. We fitted N-mixture models to validated repeat count data to quantify the effect of site and observation variables on abundance and detectability. Using our top set of competing models, we estimated that 4357 koalas (95 % CI = 2319-8307) occupy the seven reserves, with a mean detection probability of 0.22 (95 % CI = 0.15-0.31) over all survey occasions. We found detection probability decreased with increases in relative humidity and temperature. Koala abundance was negatively associated with fire severity, elevation, tree height and soil clay content, and positively associated with available water content, forest cover and soil organic carbon. Our framework, which combines real-time field validated drone data while accounting for imperfect detection, improves the accuracy of abundance estimates for arboreal folivores across large-scales.

As sperm cryopreservation and other assisted reproductive technologies (ARTs) advance in common amphibian species, focus on applying non-lethal sperm collection methods to the conservation and genetic management of threatened species is imperative. The goal of this study was to examine the application of logistically practical ART protocols in a threatened frog (Litoria aurea). First, we tested the efficacy of various concentrations of human chorionic gonadotropin (hCG) (20, 40 IU/g bodyweight) and Gonadotropin releasing hormone antagonist (0.25 µg/g and 0.5 µg/g body weight GnRH-a) on the induction of spermatozoa. Using the samples obtained from the previous trials, we tested the effect of cold storage and cryopreservation protocols on long-term refrigerated storage and post-thaw sperm recovery. Our major findings include: (1) high quality sperm were induced with 20 and 40 IU/g bodyweight of (hCG); (2) proportions of live, motile sperm post-thaw, were recovered at higher levels than previously reported for L. aurea (>50%) when preserved with 15% v/v DMSO and 1% w/v sucrose; and (3) spermic urine stored at 5 °C retained motility for up to 14 days. Our findings demonstrate that the protocols developed in this study allowed for successful induction and recovery of high-quality spermatozoa from a threatened Australian anuran, L. aurea, providing a prime example of how ARTs can contribute to the conservation of rare and threatened species.

ABSTRACT The climate crisis adds multiple threats to the already long list of stressors on global biodiversity. The result is a paucity of resources and a growing list of species in need of conservation programs to secure their future. Conservation actions that deal with persistent and pervasive threats must focus on trying to understand the biology of the organism, its ecology and response to such threats without being paralysed by inaction due to gaps in knowledge. Following the devastating 2019/20 mega-fires across the east coast of Australia, a major effort to combine complementary conservation approaches to monitor and recover populations of threatened amphibians was mobilised. For one species, the cryptic Littlejohn's tree frog (Litoria littlejohni), this integrated conservation framework combined traditional ecological approaches including population monitoring, habitat creation, captive breeding and translocation, with established and emerging biotechnologies such as genetic analysis, biobanking, assisted reproduction and biomarkers of individual health. Littlejohn's tree frog was recently uplisted to Endangered, due to increased threat of extinction resulting from the fires, whilst already suffering from disease and reduced genetic diversity. Our integrated conservation approach attempts to accelerate recovery of a species threatened with multiple landscape persistent stressors that are not mitigated by singular conservation actions. Presented here as a case study, we argue this integrated approach used for Littlejohn's tree frog could be adopted for other species facing perilous population declines.

The sandpaper frog, Lechriodus fletcheri, is a temperate anuran that has previously been shown to be virtually semelparous, with adults overwhelmingly reproducing in a single year of life. Yet, this species almost exclusively oviposits in highly ephemeral pools where there is a high chance of total reproductive failure due to hydroperiods often being unpredictable and too short for their offspring to reach metamorphosis. We sought to understand how L. fletcheri copes reproductively in such a risky breeding environment in the absence of a classical iteroparous life history. We investigated aspects of reproduction in wild and laboratory-reared individuals to determine whether females are capable of intra-seasonal multi-clutching and/or clutch partitioning, and males of fertilizing multiple clutches. Direct field evidence was obtained that males participated in multiple mating events within season, while indirect evidence of this ability in females was obtained based on laboratory-held individuals that produced an additional batch of mature oocytes weeks after an initial release of eggs. Our findings suggest that both males and females likely have the capacity to participate in multiple reproductive events within season and, while most adults may not reproduce more than once, that they are abbreviate iteroparous rather than truly semelparous. Our findings provide evidence that short-lived anurans may exploit alternative bet-hedging strategies that mimic the fitness benefits of multi-year iteroparity.

Managed breeding programs are an important tool in marsupial conservation efforts but may be costly and have adverse genetic effects in unavoidably small captive colonies. Biobanking and assisted reproductive technologies (ARTs) could help overcome these challenges, but further demonstration of their potential is required to improve uptake. We used genetic and economic models to examine whether supplementing hypothetical captive populations of dibblers (Parantechinus apicalis) and numbats (Myrmecobius fasciatus) with biobanked founder sperm through ARTs could reduce inbreeding, lower required colony sizes, and reduce program costs. We also asked practitioners of the black-footed ferret (Mustela nigripes) captive recovery program to complete a questionnaire to examine the resources and model species research pathways required to develop an optimized biobanking protocol in the black-footed ferret. We used data from this questionnaire to devise similar costed research pathways for Australian marsupials. With biobanking and assisted reproduction, inbreeding was reduced on average by between 80% and 98%, colony sizes were on average 99% smaller, and program costs were 69- to 83-fold lower. Integrating biobanking made long-standing captive genetic retention targets possible in marsupials (90% source population heterozygosity for a minimum of 100 years) within realistic cost frameworks. Lessons from the use of biobanking technology that contributed to the recovery of the black-footed ferret include the importance of adequate research funding (US$4.2 million), extensive partnerships that provide access to facilities and equipment, colony animals, appropriate research model species, and professional and technical staff required to address knowledge gaps to deliver an optimized biobanking protocol. Applied research investment of A$133 million across marsupial research pathways could deliver biobanking protocols for 15 of Australia's most at-risk marsupial species and 7 model species. The technical expertise and ex situ facilities exist to emulate the success of the black-footed ferret recovery program in threatened marsupials using these research pathways. All that is needed now for significant and cost-effective conservation gains is greater investment by policy makers in marsupial ARTs.

EcologyAccepted Articles e4108 THE SCIENTIFIC NATURALIST Life stage dependent predator–prey reversal between a frog (Litoria aurea) and a dragonfly (Anax papuensis) Chad T. Beranek, Corresponding Author Chad T. Beranek [email protected] orcid.org/0000-0001-9747-2917 Conservation Science Research Group, School of Environmental and life Sciences, Biology Building, University of Newcastle, Callaghan, NSW, Australia FAUNA Research Alliance, Kahibah, NSW, Australia Correspondence Email: [email protected]Search for more papers by this authorJohn Clulow, John Clulow Conservation Science Research Group, School of Environmental and life Sciences, Biology Building, University of Newcastle, Callaghan, NSW, Australia FAUNA Research Alliance, Kahibah, NSW, AustraliaSearch for more papers by this authorMichael Mahony, Michael Mahony Conservation Science Research Group, School of Environmental and life Sciences, Biology Building, University of Newcastle, Callaghan, NSW, AustraliaSearch for more papers by this author Chad T. Beranek, Corresponding Author Chad T. Beranek [email protected] orcid.org/0000-0001-9747-2917 Conservation Science Research Group, School of Environmental and life Sciences, Biology Building, University of Newcastle, Callaghan, NSW, Australia FAUNA Research Alliance, Kahibah, NSW, Australia Correspondence Email: [email protected]Search for more papers by this authorJohn Clulow, John Clulow Conservation Science Research Group, School of Environmental and life Sciences, Biology Building, University of Newcastle, Callaghan, NSW, Australia FAUNA Research Alliance, Kahibah, NSW, AustraliaSearch for more papers by this authorMichael Mahony, Michael Mahony Conservation Science Research Group, School of Environmental and life Sciences, Biology Building, University of Newcastle, Callaghan, NSW, AustraliaSearch for more papers by this author First published: 22 May 2023 https://doi.org/10.1002/ecy.4108 Handling Editor: John J Pastor This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi: 10.1002/ecy.4108. AboutPDF ToolsExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Accepted ArticlesAccepted, unedited articles published online and citable. The final edited and typeset version of record will appear in the future.e4108 RelatedInformation

The novel fungal pathogen Batrachochytrium dendrobatidis (chytrid) is one of the greatest threats to amphibians worldwide. Small increases in water salinity (up to ca. 4 ppt) have been shown to limit chytrid transmission between frogs, potentially providing a way to create environmental refugia to reduce its impact at a landscape scale. However, the effect of increasing water salinity on tadpoles, a life stage confined to water, is highly variable. Increased water salinity can lead to reduced size and altered growth patterns in some species, with flow-on effects to vital rates such as survival and reproduction. It is thus important to assess potential trade-offs caused by increasing salinity as a tool to mitigate chytrid in susceptible frogs. We conducted laboratory experiments to examine the effects of salinity on the survival and development of tadpoles of a threatened frog (Litoria aurea), previously demonstrated as a suitable candidate for trialling landscape manipulations to mitigate chytrid. We exposed tadpoles to salinity ranging from 1 to 6 ppt and measured survival, time to metamorphosis, body mass and locomotor performance of post-metamorphic frogs as a measure of fitness. Survival and time to metamorphosis did not differ between salinity treatments or controls reared in rainwater. Body mass was positively associated with increasing salinity in the first 14 days. Juvenile frogs from three salinity treatments also showed the same or better locomotor performance compared to rainwater controls, confirming that environmental salinity may influence life history traits in the larval stage, potentially as a hormetic response. Our research suggests that salt concentrations in the range previously shown to improve survival of frogs in the presence of chytrid are unlikely to impact larval development of our candidate threatened species. Our study lends support to the idea of manipulating salinity to create environmental refugia from chytrid for at least some salt-tolerant species.

Summary Biodiversity monitoring is crucial for effective conservation efforts. Effective monitoring allows managers to determine the status and trends of biodiversity, as well as the success of conservation actions. The population of the Broad‐toothed Rats ( Mastacomys fuscus ) in the Barrington Tops National Park New South Wales, Australia has been monitored since 1999 via scat and live‐trapping surveys. We reviewed the methods used and analysed the data produced with the aim of describing patterns of population change over time using a range of outcome variables and identifying different climate correlates. A secondary aim was to explore the use of population statistics that account for imperfect detection by comparing naïve occupancy, with an index of relative abundance based on trap effort, the latency to find scats during scat surveys and an occupancy model based on trapping surveys. Neither of these three methods accounts for detectability variation. Naïve occupancy decreased slightly over time, while the relative abundance based on trap effort revealed no evidence of change. Additionally, naïve occupancy decreased with increasing temperature while temperature had no clear impact on relative abundance. Finally, precipitation had no impact on either naïve occupancy or relative abundance. We found no evidence of a relationship between the latency to find scats and the index of relative abundance, suggesting that one or neither is related to actual abundance. Finally, a multi‐season occupancy model found occupancy probability to be 0.78 ± 0.23 (standard error); detection probability as 0.51 ± 0.06; seasonal colonisation rate as 0.36 ± 0.13 and seasonal extinction rate at 0.44 ± 0.13. We conclude that despite significant investment in monitoring, this historical data set does not allow managers to ascertain whether population change has occurred and to identify potential drivers of change. Careful consideration of future methods, in particular, whether there is imperfect detection in scat surveys, will help to inform future monitoring.

In brief:Sperm cryopreservation has been recognised as a tool for preventing loss of genetic diversity in amphibians; however, the combined effect of penetrative and non-penetrative cryoprotectants in cryodiluents is poorly understood. We demonstrate a clear benefit of using low concentrations of non-penetrative cryoprotectants when cryopreserving sperm of Australian tree frogs.Abstract:Sperm cryopreservation protocols have been developed for an increasing number of amphibian species since the recognition of a global amphibian decline. Yet, the development of these protocols has neglected to elucidate the combined effect of the penetrative(PCP) and non-penetrative cryoprotectant (NPCP) on the recovery of live, motile sperm. The two-factor hypothesis of cryoinjury recognises a trade-off between cooling cells slowly enough to allow osmotic dehydration and therefore avoid intracellular ice formation, but fast enough to minimise effects from increasing extracellular osmolality as the frozen fraction of the media increases during freezing. We tested the effect of two concentrations of a PCP (10 and 15% v/v dimethyl sulfoxide (Me2SO)) and two concentrations of an NPCP (1 and 10% w/v sucrose) in various combinations on the sperm of six pelodryadid frogs. In all species, 15% v/v Me2SO with 1% w/v sucrose provided superior post-thaw recovery with high proportions of forward progressive motility, live cells and intact acrosomes (typically >50% for each). Theoretically, it has been suggested that increased NPCP concentration should improve cell survival by increasing the rate and extent of cell dehydration. We suggest, however, that the elevated osmolality in the unfrozen water fraction when 10% sucrose is used may be causing damage to cells via excessive cell shrinkage and solute effects as proposed in the two-factor hypothesis of cryoinjury. We showed this response in sperm across a range of frog species, providing compelling evidence for this hypothesis. We suggest protocol development using the PCP/NPCP ratios demonstrated in our study will be broadly applicable to many amphibian species.

In the application of reproductive science to conservation breeding, it has long been assumed that artificial insemination using frozen thawed sperm would be the default technology. This has always been problematic considering the wide range of tolerance to freeze thawing among vertebrate sperm. Furthermore, those providing leadership for genome banking should be proactive to preserve maximum genetic diversity, however, for many species there is little or no sperm motility after thawing of cryopreserved sperm. In this review article, there is the contention that a much wider range of tissues should be banked, and the range of evolving advanced reproductive and developmental technologies should be considered for conservation breeding programs, to realize the maximum opportunities of genome banking to contribute to conservation of animal species.

Abstract Context. Knowledge on the drivers of breeding behaviour is vital to understand amphibian ecology and conservation. Proposed drivers of amphibian reproductive behaviour include selection of optimum water quality, and avoidance of tadpole predators and competition. These hypotheses are underpinned by the logic that amphibians will choose breeding habitat that will result in enhanced metamorph output. Aims. We aimed to infer key drivers that influence metamorph output in the threatened green and golden bell frog (Litoria aurea). We hypothesised that (1) metamorph output would be higher in recently refilled wetlands than in wetlands with a longer hydroperiod, (2) metamorph output would be negatively correlated with tadpole predator abundance, and (3) waterbodies with long hydroperiods would have higher abundances of aquatic predators and lower abundances of L. aurea tadpoles. Methods. We tested these hypotheses by monitoring breeding, tadpole and predator abundances in a wild population of L. aurea. We coupled this with metamorph counts that were adjusted to represent per capita numbers via genetic means. We also ruled out the influence of detection probability in explaining the results with a manipulative experiment. Key results. We found support for all three hypotheses and hence provide evidence that the adaptive behaviour of L. aurea to preference recently refilled wetlands is governed by the abundance of tadpole predators. We found metamorph counts per clutch to be 8.2-fold greater in short-hydroperiod wetlands (26 ± 15–44 95% CI) than in long-hydroperiod wetlands (3 ± 2–5 95% CI). Four predator taxa were associated with low metamorph output and two of these occurred in higher abundances in longer-hydroperiod wetlands. Conclusions and implications. These results have provided evidence that the behavioural adaptation of L. aurea to select recently refilled wetlands has evolved in response to tadpole predation pressure. We recommend practitioners to conduct tadpole releases in newly refilled wetlands to enhance survival to metamorphosis in future reintroductions.

Communal nesting is a behaviour exhibited by some oviparous species, the adults of which deposit their eggs over the same time period in a common area and possibly in direct physical contact. While this may occur inadvertently, it is proposed to be an adaptive trait in some species. Herein, we describe both solitary and communal nesting behaviours in the sandpaper frog (Lechriodus fletcheri). Field observations over two consecutive breeding seasons revealed that adults of this species frequently deposit their eggs in frothed nests alongside those of other mating pairs to form floating communal rafts or "masses" on the surface of the water. The presence of communal masses despite; (i) the relatively small number of nests deposited within each breeding episode and (ii) the space available for nests to be deposited separately within a pool, both indicate that some adults are deliberately choosing to lay their nests together. We propose that adults are thus engaging in a form of social behaviour and that communal nesting may be highly advantageous for improving offspring survival by complimenting the anti-predator properties of the froth nest. This is because the communal mass further isolates embryos from the external environment during development prior to hatching, given a reduction in the surface area relative to volume of each nest that composes the mass. While future research is required to determine why both solitary and communal nesting behaviours are exhibited in this species, it could suggest that there are certain costs associated with communality that occasionally outweigh the benefits.

The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) causes the disease chytridiomycosis, which is a primary driver for amphibian population declines and extinctions worldwide. For highly susceptible species, such as the green and golden bell frog Litoria aurea, large numbers of Bd-related mortalities are thought to occur during the colder season (winter), when low temperatures favour the growth of the pathogen. However, extant L. aurea populations are persisting with Bd. We measured Bd prevalence and infection levels of wild L. aurea using capture-mark-recapture and radio-tracking methods. Using this information, we sought to determine host and environmental correlates of Bd prevalence and infection load. Mean ± SE infection load was higher in frogs sampled in autumn (431.5 ± 310.4 genomic equivalents; GE) and winter (1147.5 ± 735.8 GE), compared to spring (21.8 ± 19.3 GE) and summer (0.9 ± 0.8 GE). Furthermore, prevalence of Bd infection in L. aurea was highest in winter (43.6%; 95% CI 33.1-54.7%) and lowest in summer (11.2%; 95% CI 6.8-17.9%). Both prevalence and infection load decreased with increasing temperature. Seven frogs cleared their fungal infection during the coolest months when Bd prevalence was highest; however, these clearances were not permanent, as 5 frogs became infected again. Understanding the factors that allow amphibians to clear their Bd infections when temperatures are optimal for Bd growth presents the potential for manipulating such factors and provides an important step in future research.

Animals that reproduce in temporary aquatic systems expose their offspring to a heightened risk of desiccation, as they must race to complete development and escape before water levels recede. Adults must therefore synchronise reproduction with the changing availability of water, yet the conditions they experience to trigger such an event may not relate to those offspring face throughout development, potentially leading to clutch failure. The sandpaper frog (Lechriodus fletcheri) breeds in ephemeral pools that dry within days to weeks after rainfall has ceased. We examined whether spawning frequency and offspring survival differed across two consecutive breeding seasons based on (1) rainfall at the moment of oviposition and throughout offspring development, and (2) pool volume, given their combined effect on hydroperiod. Reproduction was triggered by rainfall, with more spawn laid during periods of greater rainfall and in larger pools. While pool size was a predictor of offspring survival, rainfall during oviposition was not. Rather, follow-up rain events were required to prevent pools drying prior to metamorphosis, with rainfall evenness during development the strongest predictor of reproductive success. High clutch failure rates recorded in both seasons suggest that adults do not have the capability to predict rainfall frequency post-oviposition. We thus conclude that unpredictable rainfall leading to premature desiccation of spawning sites is the primary source of pre-metamorphic mortality for this species. Understanding the influence of rainfall predictability on offspring survival could be critical in predicting the effects of altered hydroperiod regimes due to climate change for species that exploit temporary waters.

The parma wallaby (Notomacropus parma Waterhouse, 1846) is a small macropodid marsupial found in the temperate wet forests of south-eastern Australia. It is one of the most understudied critical weight range mammals in Australia, with the only detailed published ecological research being conducted in the 1970s. This chapter reports on the inadequacy of monitoring that has occurred on the parma wallaby (and other threatened macropods) in Australia, and how this lack of baseline information makes responding to the Black Summer bushfires of 2019–2020 exceedingly difficult.

Australian arboreal mammals are experiencing significant population declines, particularly due to land clearing and resulting habitat fragmentation. The squirrel glider, Petaurus norfolcensis, is a threatened species in New South Wales, with a stronghold population in the Lake Macquarie Local Government Area (LGA) where fragmentation due to urbanization is an ongoing problem for the species conservation. Here we report on the use of squirrel glider mitochondrial (385 bp cytochrome b gene, 70 individuals) and nuclear DNA (6,834 SNPs, 87 individuals) markers to assess their population genetic structure and connectivity across 14 locations sampled in the Lake Macquarie LGA. The mitochondrial DNA sequences detected evidence of a historical genetic bottleneck, while the genome-wide SNPs detected significant population structure in the Lake Macquarie squirrel glider populations at scales as fine as one kilometer. There was no evidence of inbreeding within patches, however there were clear effects of habitat fragmentation and biogeographical barriers on gene flow. A least cost path analysis identified thin linear corridors that have high priority for conservation. These areas should be protected to avoid further isolation of squirrel glider populations and the loss of genetic diversity through genetic drift.