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Using genetic information to develop and implement conservation programs is vital for maintaining biodiversity and ecosystem resilience. Evaluation of the genetic variability within and among remnant populations can inform management of both natural and translocated populations to maximise species’ adaptive potential, mitigate negative impacts of inbreeding, and subsequently minimise risk of extinction. Here we use reduced representation sequencing to undertake a genetic assessment of the golden bandicoot (Isoodon auratus), a threatened marsupial endemic to Australia. The currently recognised taxon consists of three subspecies distributed among multiple natural and translocated populations. After confirming the genetic distinctiveness of I. auratusfrom two closely related taxa, I. fusciventerand I. macrourus, we identified four genetic clusters within I. auratus. These clusters exhibited substantial genetic differentiation (pairwise FSTvalues ranging from 0.18 to 0.65, pairwise DXYranging from 0.1 to 0.168), reflecting long-term isolation of some populations on offshore islands and the influence of genetic drift. Mainland natural populations in the Kimberley region had the highest genetic diversity and the largest contribution to overall allelic and gene diversity compared to both natural and translocated island populations. A population translocated to Guluwuru Island in the Northern Territory had the lowest genetic diversity. Our data suggest that island populations can appear genetically unique due to genetic drift and this needs to be taken into account when considering genetic diversity in conservation efforts to maintain overall genetic diversity of the species. We effectively demonstrate how genomic information can guide practical conservation planning, especially when declining species are represented by multiple isolated populations.

Comprehensive assessments of species’ extinction risks have documented the extinction crisis1and 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 extrapolation8and 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.

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 in-situ population refuges to alleviate the impacts of disease and climate change.

Australia hosts approximately 10% of the world’s reptile species, the largest number of any country. Despite this and evidence of widespread decline, the first comprehensive assessment of the conservation status of Australian terrestrial squamates (snakes and lizards) was undertaken only recently. Here we apply structured expert elicitation to the 60 species assessed to be in the highest IUCN threat categories to estimate their probability of extinction by 2040. We also assessed the probability of successful reintroduction for two Extinct in the Wild (EW) Christmas Island species with trial reintroductions underway. Collation and analysis of expert opinion indicated that six species are at high risk (>50%) of becoming extinct within the next 20 years, and up to 11 species could be lost within this timeframe unless management improves. The consensus among experts was that neither of the EW species were likely to persist outside of small fenced areas without a significant increase in resources for intense threat management. The 20 most imperilled species are all restricted in range, with three occurring only on islands. The others are endemic to a single state, with 55% occurring in Queensland. Invasive species (notably weeds and introduced predators) were the most prevalent threats, followed by agriculture, natural system modifications (primarily fire) and climate change. Increased resourcing and management intervention are urgently needed to avert the impending extinction of Australia’s imperilled terrestrial reptiles.

The article discusses populations of tuatara reptiles from the Order Rhynchocephalia on New Zealand's North Brother Island. Topics include the tuatara's physiological and behavioral adaptations to New Zealand's cool climate, the authors' study of tuatara ecology and population viability as part of Victoria University of Wellington's Tuatara Research Program, the link between offspring sex and temperature, and the tuatara's cultural significance to the indigenous Maori people.

Assisted Colonization (AC) has been proposed as one method of aiding species to adapt to the impacts of climate change. AC is a form of translocation and translocation protocols for threatened species, mostly for reintroduction, are well established in Australia. We evaluate the information available from implementation of translocations to understand how existing policies and guidelines should be varied to plan, review and regulate AC. While the risks associated with AC are potentially greater than those of reintroductions, AC is likely to be the only available method, other than germplasm storage and establishment of captive populations, of conserving many taxa under future climate change. AC may also be necessary to maintain ecosystem services, particularly where keystone species are affected. Current policies and procedures for the preparation of Translocation Proposals will require modification and expansion to deal with Assisted Colonization, particularly in relation to risk management, genetic management, success criteria, moving associated species and community consultation. Further development of risk assessment processes, particularly for invasiveness, and guidelines for genetic management to maintain evolutionary potential are particularly important in the context of changing climate. Success criteria will need to respond to population establishment in the context of new and evolving ecosystems, and to reflect requirements for any co-establishment of interdependent species. Translocation Proposals should always be subjected to independent peer review before being considered by regulators. We conclude that consistent approaches by regulators and multilateral agreements between jurisdictions are required to minimize duplication, to ensure the risk of AC is adequately assessed and to ensure the potential benefits of AC are realized.

Metamorphosis of larvae of the Australian moss frog (Bryobatrachus nimbus) occurs in a terrestrial nest approximately one year after oviposition. Neither parent attends the eggs, thus selection of an appropriate nest site is critical to egg viability. This study examined the dynamics of nest-site utilisation over six years and the characteristics of nests chosen as oviposition sites. Nest cavities were located at ground level amongst heath within one of 10 species of bryophyte, lichen and lycopod. On average, 2.6% of nests contained a male B. nimbus during daytime monitoring during the breeding season, and 7.3% of nests contained an egg mass. Despite an abundance of potentially suitable nests from previous years, males constructed a small proportion (<10%) of new nests each year and new nests were more likely to be used as oviposition sites than older nests. Discriminant function analysis showed that moss nests used as oviposition sites were distinguishable from empty nests by their greater horizontal dimensions. Eggs deposited in wider nests are restricted to fewer layers, and a preference for wider nests may be adaptive because embryonic oxygenation is enhanced under such conditions. However, rather than demonstrating nest-site selection, the use of relatively large nests as oviposition sites may be an artifact of their occupancy by a breeding pair.

Laboratory studies of terrestrial–breeding frogs have demonstrated that wetter substrates produce fitter offspring but the relevance of substrate wetness to adult reproductive strategies is unknown. I hypothesized that male toadlets (Pseudophryne bibronii) would select wetter areas for nesting and would advertise wet nests strongly, and tested these predictions by manipulating water potentials at a breeding site. Males preferred to nest in the wettest areas, and called at greater rates on almost twice as many nights as males occupying drier nests. Overall, males that mated called on significantly more nights than unmated males. Hence, because males occupying wet nests called more, they also mated more and in 19 out of 20 cases, oviposition occurred in wet nests that were suitable for embryonic development. Males occupying drier nests may have risked dehydration by calling, and so were less able to signal to females. Hydration states therefore have the potential to influence the reproductive success of terrestrial male frogs.

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. guentheriis 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.