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Nest microclimates influence embryonic development and survival in many lineages, including reptiles with temperature-dependent sex determination. These microclimates are dependent on physi...

Aim: The incidence of major fires is increasing globally, creating extraordinary challenges for governments, managers and conservation scientists. In 2019–2020, Australia experienced precedent-setting fires that burned over several months, affecting seven states and territories and causing massive biodiversity loss. Whilst the fires were still burning, the Australian Government convened a biodiversity Expert Panel to guide its bushfire response. A pressing need was to target emergency investment and management to reduce the chance of extinctions and maximise the chances of longer-term recovery. We describe the approach taken to rapidly prioritise fire-affected animal species. We use the experience to consider the organisational and data requirements for evidence-based responses to future ecological disasters. Location: Forested biomes of subtropical and temperate Australia, with lessons for other regions. Methods: We developed assessment frameworks to screen fire-affected species based on their pre-fire conservation status, the proportion of their distribution overlapping with fires, and their behavioural/ecological traits relating to fire vulnerability. Using formal and informal networks of scientists, government and non-government staff and managers, we collated expert input and data from multiple sources, undertook the analyses, and completed the assessments in 3 weeks for vertebrates and 8 weeks for invertebrates. Results: The assessments prioritised 92 vertebrate and 213 invertebrate species for urgent management response; another 147 invertebrate species were placed on a watchlist requiring further information. Conclusions: The priority species lists helped focus government and non-government investment, management and research effort, and communication to the public. Using multiple expert networks allowed the assessments to be completed rapidly using the best information available. However, the assessments highlighted substantial gaps in data availability and access, deficiencies in statutory threatened species listings, and the need for capacity-building across the conservation science and management sectors. We outline a flexible template for using evidence effectively in emergency responses for future ecological disasters.

Targeted gene flow (TGF) could bolster the adaptive potential of isolated populations threatened by climate change, but could also lead to outbreeding depression. Here, we explore these possibilities by creating mixed- and within-population crosses in a terrestrial-breeding frog species threatened by a drying climate. We reared embryos of the crawling frog (Pseudophryne guentheri) on wet and dry soils and quantified fitness-related traits upon hatching. TGF produced mixed outcomes in hybrids, which depended on crossing direction (origin of gametes from each sex). North-south crosses led to low embryonic survival if eggs were of a southern origin, and high malformation rates when eggs were from a northern population. Conversely, east-west crosses led to one instance of hybrid vigour, evident by increased fitness and desiccation tolerance of hybrid offspring relative to offspring produced from within-population crosses. These contrasting results highlight the need to experimentally evaluate the outcomes of TGF for focal species across generations prior to implementing management actions., Rudin-Bitterli et al. created pure and reciprocal crosses of the Australian crawling frog Pseudophryne guentheri among geographically distant populations to investigate fitness impacts of targeted gene flow in counteracting a drying environment. When reared on wet and dry soils, embryonic survival depended on the origin of gametes from each sex, highlighting the need to experimentally evaluate the outcomes of TGF prior to implementing management actions.

More than a third of the world’s amphibian species are listed as Threatened or Extinct, with a recent assessment identifying 45 Australian frogs (18.4% of the currently recognised species) as ‘Threatened’ based on IUCN criteria. We applied structured expert elicitation to 26 frogs assessed as Critically Endangered and Endangered to estimate their probability of extinction by 2040. We also investigated whether participant experience (measured as a self-assigned categorical score, i.e. ‘expert’ or ‘non-expert’) influenced the estimates. Collation and analysis of participant opinion indicated that eight species are at high risk (>50% chance) of becoming extinct by 2040, with the disease chytridiomycosis identified as the primary threat. A further five species are at moderate–high risk (30–50% chance), primarily due to climate change. Fourteen of the 26 frog species are endemic to Queensland, with many species restricted to small geographic ranges that are susceptible to stochastic events (e.g. a severe heatwave or a large bushfire). Experts were more likely to rate extinction probability higher for poorly known species (those with

Defining species habitat requirements is essential for effective conservation management through revealing agents of population decline and identifying critical habitat for conservation actions, such as translocations. Here we studied the habitat-associations of two threatened terrestrial-breeding frog species from southwestern Australia, Geocrinia alba and Geocrinia vitellina, to investigate if fine-scale habitat variables explain why populations occur in discrete patches, why G. alba is declining, and why translocation attempts have had mixed outcomes. We compared habitat variables at sites where the species are present, to variables at immediately adjacent sites where frogs are absent, and at sites where G. alba is locally extinct. Dry season soil moisture was the most important predictor of frog abundance for both species, and explained why G. alba had become extinct from some areas. Sites where G. alba were present were also positively associated with moss cover, and negatively with bare ground and soil conductivity. Modelling frog abundance based exclusively on dry season soil moisture predicted recent translocation successes with high accuracy. Hence, considering dry season soil moisture when selecting future translocation sites should increase the probability of population establishment. We propose that a regional drying trend is the most likely cause for G. alba declines and that both species are at risk of further habitat and range contraction due to further projected regional declines in rainfall and groundwater levels. More broadly, our study highlights that conservation areas in drying climates may not provide adequate protection and may require interventions to preserve critical habitat.

The blue-tailed skink (Cryptoblepharus egeriae) is endemic to Christmas Island but underwent rapid population declines in the 1990s and 2000s and was listed as Extinct in the Wild in 2017. As invasive giant centipedes (Scolependra subspinipes) were implicated as a cause of a failed reintroduction of captive bred skinks into a fenced enclosure, we undertook a mesocosm experiment to investigate if skink survival and body condition was negatively affected by the presence and density of S. subspinipes. In addition, we used DNA barcoding to determine if wild centipedes consume other reptile species on Christmas Island. In the mesocosm experiments, survival of skinks was reduced by 30% and 44% at low and high centipede densities respectively over 12 weeks, and skink body condition also declined significantly over this period. DNA barcoding confirmed that skinks that were lost during the mesocosm experiment had been consumed by centipedes. Further, we detected DNA of two invasive reptiles (the common wolf snake Lycodon capucinus and the Asian House gecko Hemidactylus frenatus) in the stomachs of wild-caught centipedes, suggesting that centipedes are a generalist predator of reptiles in this island ecosystem. Based on these results, we recommend that attempts to reintroduce C. egeriae to Christmas Island should include the control of centipedes to increase the likelihood of success.

Species with restricted ranges and long generation times are vulnerable to climate change due to limited opportunity to disperse or adapt. Australia’s rarest reptile, the western swamp turtle Pseudemydura umbrina, persists naturally in only one seasonal swamp that holds water in the Austral winter and spring. A marked reduction in winter rainfall in recent decades has shortened the swamp hydroperiod, restricting when turtles are able to feed, grow and reproduce. To mitigate possible future loss of reproductive capacity in the native habitat, assisted colonisation was trialled in 2016 using 35 captive-bred juveniles. Here, we report the outcomes of this 6 mo trial, which compared the growth of turtles released approximately 300 km south of the species’ indigenous range with growth of turtles released at an existing northern translocation site. We showed that growth rates comparable to those at warmer northern translocation sites can be achieved in the south, even in an atypically cool spring as occurred in 2016. Microclimates available to P. umbrina at 2 southern sites were suitable for foraging and growth in late spring and early summer, but juvenile growth at one southern site was significantly better than at the other, likely due to higher prey biomass when water temperatures were suitable for foraging. These early results suggest that introduction of P. umbrina to seasonal wetlands near the south coast of Western Australia could be considered in the immediate future, but further trials are recommended to assess growth and survivorship over longer periods.

Comprehensive assessments of species’ extinction risks have documented the extinction crisis1 and underpinned strategies for reducing those risks2. Global assessments reveal that, among tetrapods, 40.7% of amphibians, 25.4% of mammals and 13.6% of birds are threatened with extinction3. Because global assessments have been lacking, reptiles have been omitted from conservation-prioritization analyses that encompass other tetrapods4–7. Reptiles are unusually diverse in arid regions, suggesting that they may have different conservation needs6. Here we provide a comprehensive extinction-risk assessment of reptiles and show that at least 1,829 out of 10,196 species (21.1%) are threatened—confirming a previous extrapolation8 and representing 15.6 billion years of phylogenetic diversity. Reptiles are threatened by the same major factors that threaten other tetrapods—agriculture, logging, urban development and invasive species—although the threat posed by climate change remains uncertain. Reptiles inhabiting forests, where these threats are strongest, are more threatened than those in arid habitats, contrary to our prediction. Birds, mammals and amphibians are unexpectedly good surrogates for the conservation of reptiles, although threatened reptiles with the smallest ranges tend to be isolated from other threatened tetrapods. Although some reptiles—including most species of crocodiles and turtles—require urgent, targeted action to prevent extinctions, efforts to protect other tetrapods, such as habitat preservation and control of trade and invasive species, will probably also benefit many reptiles.

Our knowledge of the conservation status of reptiles, the most diverse class of terrestrial vertebrates, has improved dramatically over the past decade, but still lags behind that of the other tetrapod groups. Here, we conduct the first comprehensive evaluation (~92% of the world’s ~1,714 described species) of the conservation status of skinks (Scincidae), a speciose reptile family with a worldwide distribution. Using International Union for Conservation of Nature (IUCN) criteria, we report that ~20% of species are threatened with extinction, and nine species are Extinct or Extinct in the Wild. The highest levels of threat are evident in Madagascar and the Neotropics, and in the subfamilies Mabuyinae, Eugongylinae and Scincinae. The vast majority of threatened skink species were listed based primarily on their small geographic ranges (Criterion B, 83%; Criterion D2, 13%). Although the population trend of 42% of species was stable, 14% have declining populations. The key threats to skinks are habitat loss due to agriculture, invasive species, and biological resource use (e.g., hunting, timber harvesting). The distributions of 61% of species do not overlap with protected areas. Despite our improved knowledge of the conservation status of the world’s skinks, 8% of species remain to be assessed, and 14% are listed as Data Deficient. The conservation status of almost a quarter of the world’s skink species thus remains unknown. We use our updated knowledge of the conservation status of the group to develop and outline the priorities for the conservation assessment and management of the world’s skink species.

Terrestrial-breeding amphibians are likely to be vulnerable to warming and drying climates, as their embryos require consistent moisture for successful development. Adaptation to environmental change will depend on sufficient genetic variation existing within or between connected populations. Here, we use Single Nucleotide Polymorphism (SNP) data to investigate genome-wide patterns in genetic diversity, gene flow and local adaptation in a terrestrial-breeding frog (Pseudophryne guentheri) subject to a rapidly drying climate and recent habitat fragmentation. The species was sampled across 12 central and range-edge populations (192 samples), and strong genetic structure was apparent, as were high inbreeding coefficients. Populations showed differences in genetic diversity, and one population lost significant genetic diversity in a decade. More than 500 SNP loci were putatively under directional selection, and 413 of these loci were correlated with environmental variables such as temperature, rainfall, evaporation and soil moisture. One locus showed homology to a gene involved in the activation of maturation in Xenopus oocytes, which may facilitate rapid development of embryos in drier climates. The low genetic diversity, strong population structuring and presence of local adaptation revealed in this study shows why management strategies such as targeted gene flow may be necessary to assist isolated populations to adapt to future climates.

Dynamic energy budget (DEB) theory provides a generalised way to quantify how an organism assimilates and utilizes energy throughout its life cycle. Over 800 DEB models have been created to date, typically under the assumption of constant food supply. The Critically Endangered, semi-aquatic western swamp turtle occupies an ephemeral wetland environment in which food resources fluctuate from abundant to absent with the seasonal filling and drying of swamps. Approximately six months of each year are spent in aestivation underground when the swamps are dry and conditions are warm. We estimated DEB parameters for the western swamp turtle with the explicit incorporation of these seasonal fluctuations in food and temperature. A metabolic depression factor was applied during the aestivation stage, without which turtles lost both mass and length, and reserves were insufficient to reach puberty. The swamp turtle had a very high Arrhenius temperature, being almost 2.5-fold greater than that of the other Testudine species for which there are DEB models (typical Arrhenius temperatures are around 8000 K; western swamp turtle is 19,371 K). It also had the second highest somatic maintenance costs of the reptiles in the DEB ‘Add My Pet’ collection, and the highest for Testudines. We explore these results in context of the “waste to hurry” hypothesis, which we suggest may apply for this species. We also consider how a DEB model for this species might be applied in its future conservation and management.

Until recently, the reptile fauna of Christmas Island in the Indian Ocean comprised five endemic species (two skinks, two geckos, and one snake) and one native, non‐endemic skink. Four of these species were common and widespread until at least 1979, but by 2012 had disappeared from the wild. During the years of decline, little research was undertaken to examine why the species were disappearing. Here, we use a retrospective expert elicitation to rank potential factors that contributed to the loss of Christmas Island's reptiles and to assess the likelihood of re‐establishing populations of two species now listed as Extinct in the Wild. We additionally considered why one endemic lizard, the Christmas Island giant gecko (Cyrtodactylus sadleiri), and three introduced lizards remain common. Experts considered that the introduced common wolf snake (Lycodon capucinus) was the most likely cause of decline, as its temporal and spatial spread across the island closely matched patterns of lizard disappearances. An Asian co‐occurrence in recent evolutionary timeframes of the common wolf snake with the Christmas Island giant gecko and three introduced reptiles was the most marked point of difference between the extant and lost lizard species. The demise in less than 20 years of 80% of Christmas Island's native lizard assemblage highlights the vulnerability of island fauna to invading species.

Drier and hotter conditions caused by climate change threaten species that exist close to their physiological limits, as well as those with limited ability to move. Habitat specialists may also be particularly vulnerable if they have specific abiotic requirements. Here we assess whether thermal and hydric constraints can explain the highly restricted and declining distributions of the critically endangered terrestrial-breeding frog, Geocrinia alba. We also evaluate the species’ vulnerability to climate change based on the similarity of current microclimatic conditions to their physiological limits. We found that G. alba had low thresholds of thermal and desiccation tolerance relative to other anuran species. The estimated thermal optimum (Topt) and critical thermal maxima (CTmax) were 23.3°C and 29.6°C, respectively, and adult frogs had an absorption threshold (AT, the lowest water potential at which water can be absorbed from a substrate) of −50 kPa, the lowest recorded for an amphibian. Comparing environmental conditions and water loss in the field using agar models showed that riparian habitats where frogs occur provide a unique microclimate in the landscape, offering significantly lower desiccation risk during extreme summer conditions compared to immediately adjacent riparian and terrestrial habitats. Monitoring of microclimate conditions within occupied frog habitats over 2 years showed that in extreme dry and hot years the AT was exceeded at six of eight sites, and Topt was exceeded at two of eight sites. Given their specific physiological limits, the apparent rarity of suitable microclimates and a regional drying–warming trend, we suggest that G. alba occupies a potentially disappearing niche and may be indicative of other habitat specialists that rely on ephemeral drainages. More broadly, this study highlights that desiccation thresholds may tightly constrain amphibian distributions and need to be considered along with thermal tolerance thresholds when predicting the impacts of climate change.

Many Australian mammal species now only occur on islands and fenced mainland havens free from invasive predators. The range of one species, the banded hare-wallaby (Lagostrophus fasciatus), had contracted to two offshore islands in Western Australia. To improve survival, four conservation translocations have been attempted with mixed success, and all occurred in the absence of genetic information. Here, we genotyped seven polymorphic microsatellite markers in two source (Bernier Island and Dorre Island), two historic captive, and two translocated L. fasciatus populations to determine the impact of multiple translocations on genetic diversity. Subsequently, we used population viability analysis (PVA) and gene retention modelling to determine scenarios that will maximise demographic resilience and genetic richness of two new populations that are currently being established. One translocated population (Wadderin) has undergone a genetic bottleneck and lost 8.1% of its source population&rsquo, s allelic diversity, while the other (Faure Island) may be inbred. We show that founder number is a key parameter when establishing new L. fasciatus populations and 100 founders should lead to high survival probabilities. Our modelling predicts that during periodic droughts, the recovery of source populations will be slower post-harvest, while 75% more animals&mdash, about 60 individuals&mdash, are required to retain adequate allelic diversity in the translocated population. Our approach demonstrates how genetic data coupled with simulations of stochastic environmental events can address central questions in translocation programmes.

Ejaculate traits vary extensively among individuals and species, but little is known about their variation among populations of the same species. Here, we investigated patterns of intraspecific variation in male reproductive investment in the terrestrial-breeding frog Pseudophryne guentheri . Like most anurans, breeding activity in P. guentheri is cued by precipitation, and therefore the timing and duration of breeding seasons differ among geographically separated populations, potentially leading to differences in the level of sperm competition. We, therefore, anticipated local adaptation in sperm traits that reflect these phenological differences among populations. Our analysis of six natural populations across a rainfall gradient revealed significant divergence in testes and ejaculate traits that correspond with annual rainfall and rainfall seasonality; males from the northern and drier edge of the species range had significantly smaller testes containing fewer, smaller and less motile sperm compared with those from mesic central populations. These findings may reflect spatial variation in the strength of postcopulatory sexual selection, likely driven by local patterns of precipitation.

Tropical montane forests (TMFs) are major centres of evolutionary change and harbour many endemic species with small geographic ranges. In this systematic map, we focus on the impacts of anthropogenic habitat degradation on TMFs globally. We first determine how TMF research is distributed across geographic regions, degradation type (i.e. deforestation, land-use conversion, habitat fragmentation, ecological level (i.e. ecosystem, community, population, genetic) and taxonomic group. Secondly, we summarize the impacts of habitat degradation on biodiversity and ecosystem services, and identify deficiencies in current knowledge. We show that habitat degradation in TMFs impacts biodiversity at all ecological levels and will be compounded by climate change. However, despite montane species being perceived as more extinction-prone due to their restricted geographic ranges, there are some indications of biotic resilience if the impacts to TMFs are less severe. Species richness and key species interactions can be maintained in mildly degraded sites, and gene flow can persist between TMF fragments. As such, minimally degraded areas such as secondary forests and restored areas could play a crucial role in maintaining the meta-community and ecosystem services of TMFs - either via resource provision or by linking patches of pristine forest. Research deficiencies highlighted include poor research representation in Asian and African TMFs, few assessments of population and genetic-level responses to fragmentation, and little assessment of the impacts of habitat fragmentation at all ecological levels. To address these concerns, we present a list of the top research priorities to urgently address the growing threat of habitat degradation in TMF.

Intraspecific variation in the ability of individuals to tolerate environmental perturbations is often neglected when considering the impacts of climate change. Yet this information is potentially crucial for mitigating deleterious effects of climate change on threatened species. Here we assessed patterns of intraspecific variation in desiccation tolerance in the frog Pseudophryne guentheri, a terrestrial-breeding species experiencing a drying climate. Adult frogs were collected from six populations across a rainfall gradient and their dehydration and rehydration rates were assessed. We also compared desiccation tolerance of embryos and hatchlings originating from within-population parental crosses from four of the populations. Embryos were reared on soil at three soil-water potentials and their desiccation tolerance was assessed across a range of traits. We found significant and strong patterns of intraspecific variation in almost all traits, both in adults and first-generation offspring. Adult frogs exhibited clinal variation in their water balance responses, with populations from drier sites both dehydrating and rehydrating more slowly compared to frogs from more mesic sites. Similarly, desiccation tolerance of first-generation offspring was significantly greater in populations from xeric sites. Our findings suggest that populations within this species will respond differently to the regional reduction in rainfall predicted by climate change models.

In the original publication of the article, Figure 1 was published incorrectly. The correct figure is given below. The original article has been corrected.

The conservation of highly mobile species presents challenges to managers for assessment of threats to survival, given the difficulties in locating and observing such species. Here we evaluate satellite telemetry, DNA faecal metabarcoding and traditional field observations as three complementary techniques to acquire critical management information for an endangered species, Carnaby's Cockatoo Calyptorhynchus latirostris. Satellite telemetry of 23 birds resulted in 6026 location fixes accurate to within 500 m, and combined with extensive field observations and DNA faecal metabarcoding resulted in a more detailed understanding of how this species survives in an urbanised landscape. We identified 168 night roosts, 75% of which were previously unknown, which will contribute towards a more accurate population size estimate based on annual counts of roosting birds. We also determined the scale of daily movements (morning 5.4 ± 3.4 km from roost, afternoon 5.5 ± 3.3 km to roost; maximum distance between consecutive roosts 69.7 km) and the size of foraging areas around roosts (range 17 to 276 km2), and identified dependence on a variety of native and exotic food sources. Field observations identified 11 food-plant families, but combined with DNA faecal metabarcoding this was extended to 21 food-plant families. The three techniques were compared to assess their individual and collective values. By combining spatial ecology information from satellite telemetry with ecological knowledge from field observation and DNA faecal analysis, we gained deeper insights into the ecology of the species than would have been possible from any one technique alone. This information will lead to more strategic conservation planning to allow this species to persist within a rapidly expanding urban environment. This article is protected by copyright. All rights reserved.

The embryos of many egg-laying species develop under the environmental conditions selected by one or both parents, and these conditions may cease to be optimal under a changed climate. Assisted colonization is an emerging option to relocate species that are threatened by unfavourable changes in the local climate, but the incubation requirements of embryos are rarely considered in conservation translocations despite suggestions that relocation of early life stages could be more effective than relocating older animals. Here we review examples and outcomes of relocations of reptile eggs, and the decision tools currently available for guiding translocation decisions from an embryonic perspective. We then demonstrate a mechanistic approach, using the modelling framework NicheMapR, for assessing the optimal translocation range for the Western Swamp Turtle ( Pseudemydura umbrina ), a Critically Endangered reptile with an extremely restricted natural distribution. We determine thermal reaction norms and critical thermal limits for embryonic development based on laboratory and field data, and model soil temperatures at typical nest depths, simulate embryonic development at these depths, and map the probability of survival of P. umbrina embryos within the major bioregions of south-western Australia. The same model forced by future climates for 2050–70 demonstrates a southerly shift in the regions where embryos would be viable. However, if P. umbrina is to be translocated in the near future to regions 300–400 km south of its natural range, females will need to nest in relatively unshaded sites to achieve temperatures that are high enough to promote hatchling success.

In the last 30 years, islands and fenced exclosures free of introduced predators (collectively, havens) have become an increasingly used option for protecting Australian mammals imperiled by predation by introduced cats (Felis catus) and foxes (Vulpes vulpes). However, Australia's network of havens is not expanding in a manner that maximizes representation of all predator-susceptible taxa, because of continued emphasis on already-represented taxa. Future additions to the haven network will improve representation of mammals most efficiently if they fill gaps in under-represented predator-susceptible taxa, particularly rodents. A systematic approach to expansion could protect at least one population of every Australian predator-susceptible threatened mammal taxon by the addition of 12 new havens to the current network. Were the current haven network to be doubled in number in a systematic manner, it could protect three populations of every Australian predator-susceptible threatened mammal taxon.

Lizards and snakes (squamate reptiles) are the most diverse vertebrate group in Australia, with approximately 1000 described species, representing about 10% of the global squamate diversity. Squamates are a vital part of the Australian ecosystem, but their conservation has been hindered by a lack of knowledge of their diversity, distribution, biology and key threats. The Action Plan for Australian Lizards and Snakes 2017 provides the first comprehensive assessment of the conservation status of Australian squamates in 25 years. Conservation assessments are provided for 986 species of Australian lizards and snakes (including sea snakes). Over the past 25 years there has been a substantial increase in the number of species and families recognised within Australia. There has also been an increase in the range and magnitude of threatening processes with the potential to impact squamates. This has resulted in an increase in the proportion of the Australian squamate fauna that is considered Threatened. Notably over this period, the first known extinction (post-European settlement) of an Australian reptile species occurred – an indication of the increasingly urgent need for better knowledge and management of this fauna. Six key recommendations are presented to improve the conservation management and plight of Australian squamates. This Action Plan represents an essential resource for research scientists, conservation biologists, conservation managers, environmental consultants, policy makers from Commonwealth and State/Territory governments, and the herpetological community.

The complex life history of sea turtles presents challenges for researchers. These slow-growing, long-lived reptiles occupy several habitats throughout their life cycle, including oceanic environments where they are difficult to study. Consequently, much research on sea turtle biology has focussed on the nesting environment. Yet, to effectively manage sea turtle populations, the documentation of processes such as growth, maturation and reproductive output is critical to understanding their population dynamics. Dynamic Energy Budget (DEB) theory provides a mechanistic framework for investigating such processes. Here we developed a full life cycle DEB model for a green turtle (Chelonia mydas) population from Western Australia, where the model was based primarily on data collected on the embryonic life stage. The model provided a good fit to empirical data, including the limited data on juvenile and adult growth, and suggested that it is practical to investigate full life cycle energetics based on embryonic data that are comparatively easy to collect. Maternal effects on embryonic development and patterns of energy allocation throughout the life cycle were inferred from the DEB model. This is the first DEB model developed for C. mydas, and its potential applications include demonstrating how maturation, maintenance and reproduction of wild individuals depend on food availability and temperature. Such applications are especially valuable for understanding future impacts of climate change, and how best to manage this iconic species that plays a key role in marine ecosystems across the globe.

Environmental conditions experienced by animals constrain their energy acquisition and its subsequent allocation to growth and reproduction, which ultimately contributes to population dynamics. Understanding how environmental conditions affect these physiological processes is therefore important for predicting how threatened species will respond to altered food and temperature conditions. Here we use a mechanistic modelling approach based on Dynamic Energy Budget (DEB) theory to demonstrate that changing food availability has a strong impact on growth and reproduction for a Western Australian population of green sea turtles (Chelonia mydas), particularly in scenarios with simulated marine heatwaves. Models predicted increasing time between nesting years in scenarios of decreasing food availability. Furthermore, increased frequency of marine heatwaves reduced reproductive output with the number of eggs a female produced in its lifetime predicted to be approximately 20% lower when heatwaves occurred every five years compared to every 20 years. Our predictions suggest that frequent marine heatwaves could have similar adverse effects to long-term decreases in food availability. In all scenarios, direct impacts of changes in temperature were less pronounced and suggest that the strongest impacts of the increasing temperatures of climate change will be mediated through food availability. The approach demonstrated here provides a strong foundation for understanding how the Ningaloo C. mydas population will respond to climate change, and can be refined as new physiological, behavioural, and environmental data become available.

The thermal environment of sea turtle embryos has marked effects on many aspects of their development and energetics and has consequences for posthatching stages. Here we incubated Chelonia mydas embryos from Ningaloo Reef in Western Australia at a range of temperatures (27°, 29°, 30°, 31°, 32°, and 30° ± 5°C) to determine development rates and the pivotal temperature for sex determination. We also measured embryonic growth, oxygen consumption, and carbon dioxide production throughout development at 27° and 31°C. Metabolic rates were higher at 31°C than at 27°C, but total energy expenditure was greater at 27°C, with 2,281 mL of oxygen consumed compared with 1,992 mL at 31°C. Respiration at both temperatures showed a pattern typical of sea turtle embryos, with peak rates occurring at approximately 85% of development and then declining toward hatching. Hatchlings produced at higher incubation temperatures developed faster, were smaller, and had larger residual yolk masses than hatchlings produced at lower temperatures. The pivotal temperature that produced an equal sex ratio was 29.2°C, with mixed sexes produced between 27.9° and 30.4°C. Our results showed that the Ningaloo population of C. mydas has somewhat different thermal sensitivities than other C. mydas populations and justified why is it necessary to collect population-specific data to accurately project the impacts of global warming on focal populations.

When organisms encounter heterogeneous environments, selection may favor the ability of individuals to tailor their phenotypes to suit the prevailing conditions. Understanding the genetic basis of plastic responses is therefore vital for predicting whether susceptible populations can adapt and persist under new selection pressures. Here, we investigated whether there is potential for adaptive plasticity in development time in the quacking frog Crinia georgiana, a species experiencing a drying climate. Using a North Carolina II breeding design, we exposed 90 family groups to two water depth treatments (baseline and low water) late in larval development. We then estimated the contribution of additive and nonadditive sources of genetic variation to early offspring fitness under both environments. Our results revealed a marked decline in larval fitness under the stressful (low water) rearing environment but also that additive genetic variation was negligible for all traits. However, in most cases, we found significant sire-by-dam interactions, indicating the importance of nonadditive genetic variation for offspring fitness. Moreover, sire-by-dam interactions were modified by the treatment, indicating that patterns of nonadditive genetic variance depend on environmental context. For all traits, we found higher levels of nonadditive genetic variation (relative to total phenotypic variation) when larvae were reared under stressful conditions, suggesting that the fitness costs associated with incompatible parental crosses (e.g., homozygous deleterious recessive alleles) will only be expressed when water availability is low. Taken together, our results highlight the need to consider patterns of nonadditive genetic variation under contrasting selective regimes when considering the resilience of species to environmental change.

© 2017 Cambridge Philosophical Society Climate change is driving a pervasive global redistribution of the planet's species. Species redistribution poses new questions for the study of ecosystems, conservation science and human societies that require a coordinated and integrated approach. Here we review recent progress, key gaps and strategic directions in this nascent research area, emphasising emerging themes in species redistribution biology, the importance of understanding underlying drivers and the need to anticipate novel outcomes of changes in species ranges. We highlight that species redistribution has manifest implications across multiple temporal and spatial scales and from genes to ecosystems. Understanding range shifts from ecological, physiological, genetic and biogeographical perspectives is essential for informing changing paradigms in conservation science and for designing conservation strategies that incorporate changing population connectivity and advance adaptation to climate change. Species redistributions present challenges for human well-being, environmental management and sustainable development. By synthesising recent approaches, theories and tools, our review establishes an interdisciplinary foundation for the development of future research on species redistribution. Specifically, we demonstrate how ecological, conservation and social research on species redistribution can best be achieved by working across disciplinary boundaries to develop and implement solutions to climate change challenges. Future studies should therefore integrate existing and complementary scientific frameworks while incorporating social science and human-centred approaches. Finally, we emphasise that the best science will not be useful unless more scientists engage with managers, policy makers and the public to develop responsible and socially acceptable options for the global challenges arising from species redistributions.

A common feature of many citizen science projects is the collection of data by unpaid contributors with the expectation that the data will be used in research. Here we report a teaching strategy that combined citizen science with inquiry-based learning to offer first year university students an authentic research experience. A six-year partnership with the Australian phenology citizen science program ClimateWatch has enabled biology students from the University of Western Australia to contribute phenological data on plants and animals, and to conduct the first research on unvalidated species datasets contributed by public and university participants. Students wrote scientific articles on their findings, peer-reviewed each other’s work and the best articles were published online in a student journal. Surveys of more than 1500 students showed that their environmental engagement increased significantly after participating in data collection and data analysis. However, only 31% of students agreed with the statement that “data collected by citizen scientists are reliable” at the end of the project, whereas the rate of agreement was initially 79%. This change in perception was likely due to students discovering erroneous records when they mapped data points and analysed submitted photographs. A positive consequence was that students subsequently reported being more careful to avoid errors in their own data collection, and making greater efforts to contribute records that were useful for future scientific research. Evaluation of our project has shown that by embedding a research process within citizen science participation, university students are given cause to improve their contributions to environmental datasets. If true for citizen scientists in general, enabling participants as well as scientists to analyse data could enhance data quality, and so address a key constraint of broad-scale citizen science programs.

Southwest Australia (SWA) is a global biodiversity hotspot and a centre of diversity and endemism for the Australo-Papuan myobatrachid frogs. Myobatrachus gouldii (the turtle frog) has a highly derived morphology associated with its forward burrowing behaviour, largely subterranean habit, and unusual mode of reproduction. Its sister genera Metacrinia and Arenophryne have restricted distributions in Western Australia with significant phylogeographic structure, leading to the recent description of a new species in the latter. In contrast, Myobatrachus is distributed widely throughout SWA over multiple climatic zones, but little is known of its population structure, geographic variation in morphology, or reproduction. We generated molecular and morphological data to test for genetic and morphological variation, and to assess whether substrate specialisation in this species may have led to phylogeographic structuring similar to that of other plant and animal taxa in SWA. We assembled sequence data for one mitochondrial and four nuclear DNA loci (3628 base pairs) for 42 turtle frogs sampled throughout their range. Likelihood phylogenetic analyses revealed shallow phylogeographic structure in the mtDNA locus (up to 3.3% genetic distance) and little variation in three of the four nDNA loci. The mtDNA haplotype network suggests five geographically allopatric groups, with no shared haplotypes between regions. These geographic patterns are congruent with several other SWA species, with genetic groups restricted to major hydrological divisions, the Swan Coastal Plain, and the Darling Scarp. The geographically structured genetic groups showed no evidence of significant morphological differentiation (242 individuals), and there was little sexual size dimorphism, but subtle differences in reproductive traits suggest more opportunistic breeding in lower rainfall zones. Call data were compared to sister genera Metacrinia and Arenophryne and found to be highly conservative across the three genera. Like many taxa in SWA, topographic variation and Plio-Pleistocene arid fluctuations likely were historic drivers of diversification in M. gouldii.

Distributions of Earth's species are changing at accelerating rates, increasingly driven by humanmediated climate change. Such changes are already altering the composition of ecological communities, but beyond conservation of natural systems, how and why does this matter? We review evidence that climate-driven species redistribution at regional to global scales affects ecosystem functioning, human well-being, and the dynamics of climate change itself. Production of natural resources required for food security, patterns of disease transmission, and processes of carbon sequestration are all altered by changes in species distribution. Consideration of these effects of biodiversity redistribution is critical yet lacking in most mitigation and adaptation strategies, including the United Nation's Sustainable Development Goals.

Anthropogenic climate change is a key threat to global biodiversity. To inform strategic actions aimed at conserving biodiversity as climate changes, conservation planners need early warning of the risks faced by different species. The IUCN Red List criteria for threatened species are widely acknowledged as useful risk assessment tools for informing conservation under constraints imposed by limited data. However, doubts have been expressed about the ability of the criteria to detect risks imposed by potentially slow-acting threats such as climate change, particularly because criteria addressing rates of population decline are assessed over time scales as short as 10 years. We used spatially explicit stochastic population models and dynamic species distribution models projected to future climates to determine how long before extinction a species would become eligible for listing as threatened based on the IUCN Red List criteria. We focused on a short-lived frog species (Assa darlingtoni) chosen specifically to represent potential weaknesses in the criteria to allow detailed consideration of the analytical issues and to develop an approach for wider application. The criteria were more sensitive to climate change than previously anticipated; lead times between initial listing in a threatened category and predicted extinction varied from 40 to 80 years, depending on data availability. We attributed this sensitivity primarily to the ensemble properties of the criteria that assess contrasting symptoms of extinction risk. Nevertheless, we recommend the robustness of the criteria warrants further investigation across species with contrasting life histories and patterns of decline. The adequacy of these lead times for early warning depends on practicalities of environmental policy and management, bureaucratic or political inertia, and the anticipated species response times to management actions.

Australia is a global hotspot of reptile diversity, hosting similar to 10% of the world's squamate (snake and lizard) species. Yet the conservation status of the Australian squamate fauna has not been assessed for >25 years; a period during which the described fauna has risen by similar to 40%. Here we provide the first comprehensive conservation assessment of Australian terrestrial squamates using IUCN Red List Categories and Criteria. Most (86.4%; n = 819/948) Australian squamates were categorised as Least Concern, 4.5% were Data Deficient, and 7.1% (range 6.8%-11.3%, depending on the treatment of Data Deficient species) were threatened (3.0% Vulnerable, 2.7% Endangered, 1.1% Critically Endangered). This level of threat is low relative to the global average (similar to 18%). One species (Emoia nativitatis) was assessed as Extinct, and two species (Lepidodactylus listeri and Cryptoblepharus egeriae) are considered Extinct in the Wild: all three were endemic to Christmas Island. Most (75.1%) threat assessments were based on geographic range attributes, due to limited data on population trends or relevant proxies. Agriculture, fire, and invasive species were the threats that affected the most species, and there was substantial geographic variation in the number of species affected by each threat. Threatened species richness peaked on islands, in the Southern Alps, and across northern Australia. Data deficiency was greatest in northern Australia and in coastal Queensland. Approximately one-in-five threatened species were not represented in a single protected area. Our analyses shed light on the species, regions, and threats in most urgent need of conservation intervention.

All marine turtles have temperature-dependent sex determination (TSD), and there is mounting evidence that climate change has increased sand temperatures at some rookeries, leading to pronounced biases in hatchling sex ratios. Quantification of the variation in the key parameters that describe TSD will be essential to our ability to predict the adaptive capacity of marine turtles, and for implementing conservation programs where necessary. Here we integrate field and laboratory data on the embryonic development of a little-studied population of loggerhead turtles ( Caretta caretta, Linnaeus 1758) from Western Australia, which is home to a large rookery at the southernmost limit of the species' global range. We determined that the pivotal temperature that produces an equal sex ratio was 29.0. °C, centred within a transitional range of temperatures of 0.67. °C where both sexes are produced. For the first time for a marine turtle, embryonic development rates were modelled with a non-linear function, and were used to define the start and end of the thermosensitive period, where bipotential gonads differentiate into testes or ovaries. The period where gonads were sensitive to a masculinizing trigger occurred between 33 and 64% of development. In general, the TSD parameters for this southernmost population of C. caretta were similar to those estimated for other loggerhead populations, reinforcing previous findings that sex determination thresholds and processes are highly conserved.

Summary In cases where assisted colonisation is the appropriate conservation tool, the selection of recipient sites is a major challenge. Here, we propose a framework for site selection that can be applied to the Australian biota, where planning for assisted colonisation is in its infancy. Characteristics that will be important drivers in the decision-making process include the size of a recipient site, the potential to augment corridors and respond to niche gaps, the maximisation of climatic buffering, bioregional similarity, tenure security, and the minimisation of opportunities for hybridisation and invasiveness. Sites we suggest be precluded from assisted colonisation include sites of high species endemism, IUCN category 1 reference reserves and fully-functioning threatened ecological communities.