ORCID Profile
0000-0003-0744-984X
Current Organisation
University of Western Australia
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Environmental Science and Management | Conservation and Biodiversity | Animal Physiology—Systems | Ecosystem Function | Physiology | Comparative Physiology | Sociobiology And Behavioural Ecology | Conservation And Biodiversity | Community Ecology | Population, Ecological and Evolutionary Genetics | Surfacewater Hydrology
ANZSRC Socio-Economic Objective (SEO)
Ecosystem Adaptation to Climate Change | Ecosystem Assessment and Management not elsewhere classified | Living resources (flora and fauna) | Expanding Knowledge in the Environmental Sciences | Expanding Knowledge in the Biological Sciences | Biological sciences | Global climate change adaptation measures | Flora, Fauna and Biodiversity at Regional or Larger Scales |
Related Links
Publications
Demographic effects of temperature‐dependent sex determination: will tuatara survive global warming?
Publisher: Wiley
Date: 02-12-2009
Low desiccation and thermal tolerance constrains a terrestrial amphibian to a rare and disappearing microclimate niche
Publisher: Oxford University Press (OUP)
Date: 2021
Abstract: 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 hibian. 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 hibian distributions and need to be considered along with thermal tolerance thresholds when predicting the impacts of climate change.
Environmental Stress Increases the Magnitude of Nonadditive Genetic Variation in Offspring Fitness in the FrogCrinia georgiana
Publisher: University of Chicago Press
Date: 10-2018
DOI: 10.1086/699231
Abstract: When organisms encounter heterogeneous environments, selection may favor the ability of in iduals 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.
Extensive geographical variation in testes size and ejaculate traits in a terrestrial-breeding frog
Publisher: The Royal Society
Date: 09-2020
Abstract: Ejaculate traits vary extensively among in iduals 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 ergence 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.
The recent decline of a New Zealand endemic: How and why did populations of Archey's frog Leiopelma archeyi crash over 1996-2001?
Publisher: Elsevier BV
Date: 11-2004
Simulated growth and reproduction of green turtles (Chelonia mydas) under climate change and marine heatwave scenarios
Publisher: Elsevier BV
Date: 09-2020
Assessing the benefits and risks of translocations in changing environments: A genetic perspective
Publisher: Wiley
Date: 18-06-2011
Securing the Demographic and Genetic Future of Tuatara through Assisted Colonization
Publisher: Wiley
Date: 24-07-2012
DOI: 10.1111/J.1523-1739.2012.01902.X
Abstract: Climate change poses a particular threat to species with fragmented distributions and little or no capacity to migrate. Assisted colonization, moving species into regions where they have not previously occurred, aims to establish populations where they are expected to survive as climatic envelopes shift. However, adaptation to the source environment may affect whether species successfully establish in new regions. Assisted colonization has spurred debate among conservation biologists and ecologists over whether the potential benefits to the threatened species outweigh the potential disruption to recipient communities. In our opinion, the debate has been distracted by controversial ex les, rather than cases where assisted colonization may be a viable strategy. We present a strategic plan for the assisted migration of tuatara (Sphenodon punctatus), an endemic New Zealand reptile. The plan includes use of extant populations as reference points for comparisons with assisted-colonization populations with respect to demography, phenotypic plasticity, and phenology optimization of genetic variation research to fill knowledge gaps consideration of host and recipient communities and inclusion of stakeholders in the planning stage. When strategically planned and monitored, assisted colonization could meet conservation and research goals and ultimately result in the establishment of long-term sustainable populations capable of persisting during rapid changes in climate.
The lost lizards of Christmas Island: A retrospective assessment of factors driving the collapse of a native reptile community
Publisher: Wiley
Date: 13-01-2021
DOI: 10.1111/CSP2.358
Identifying the most effective behavioural assays and predator cues for quantifying anti-predator responses in mammals: a systematic review
Publisher: Springer Science and Business Media LLC
Date: 04-2023
DOI: 10.1186/S13750-023-00299-X
Abstract: Mammals, globally, are facing population declines. Protecting and breeding threatened populations inside predator-free havens and translocating them back to the wild is commonly viewed as a solution. These approaches can expose predator-naïve animals to predators they have never encountered and as a result, many conservation projects have failed due to the predation of in iduals that lacked appropriate anti-predator responses. Hence, robust ways to measure anti-predator responses are urgently needed to help identify naïve populations at risk, to select appropriate animals for translocation, and to monitor managed populations for changes in anti-predator traits. Here, we undertake a systematic review that collates existing behavioural assays of anti-predator responses and identifies assay types and predator cues that provoke the greatest behavioural responses. We retrieved articles from academic bibliographic databases and grey literature sources (such as government and conservation management reports), using a Boolean search string. Each article was screened against eligibility criteria determined using the PICO (Population–Intervention–Comparator–Outcome) framework. Using data extracted from each article, we mapped all known behavioural assays for quantifying anti-predator responses in mammals and examined the context in which each assay has been implemented (e.g., species tested, predator cue characteristics). Finally, with mixed effects modelling, we determined which of these assays and predator cue types elicit the greatest behavioural responses based on standardised difference in response between treatment and control groups. We reviewed 5168 articles, 211 of which were eligible, constituting 1016 studies on 126 mammal species, a quarter of which are threatened by invasive species. We identified six major types of behavioural assays: behavioural focals, capture probability, feeding station, flight initiation distance, giving-up density, and stimulus presentations. Across studies, there were five primary behaviours measured: activity, escape, exploration, foraging, and vigilance. These behaviours yielded similar effect sizes across studies. With regard to study design, however, studies that used natural olfactory cues tended to report larger effect sizes than those that used artificial cues. Effect sizes were larger in studies that analysed sexes in idually, rather than combining males and females. Studies that used ‘blank’ control treatments (the absence of a stimulus) rather than a treatment with a control stimulus had higher effect sizes. Although many studies involved repeat measures of known in iduals, only 15.4% of these used their data to calculate measures of in idual repeatability. Our review highlights important aspects of experimental design and reporting that should be considered. Where possible, studies of anti-predator behaviour should use appropriate control treatments, analyse males and females separately, and choose organic predator cues. Studies should also look to report the in idual repeatability of behavioural traits, and to correctly identify measures of uncertainty (error bars). The review highlights robust methodology, reveals promising techniques on which to focus future assay development, and collates relevant information for conservation managers.
Benefits and challenges of incorporating citizen science into university education
Publisher: Public Library of Science (PLoS)
Date: 11-2017
The effect of incubation temperatures on nest success of flatback sea turtles (Natator depressus)
Publisher: Springer Science and Business Media LLC
Date: 14-06-2016
Managing consequences of climate-driven species redistribution requires integration of ecology, conservation and social science
Publisher: Wiley
Date: 06-2018
DOI: 10.1111/BRV.12344
Abstract: 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.
Perverse outcomes from fencing fauna: Loss of antipredator traits in a havened mammal population
Publisher: Elsevier BV
Date: 05-2023
Survival of an Extinct in the Wild skink from Christmas Island is reduced by an invasive centipede: implications for future reintroductions
Publisher: Springer Science and Business Media LLC
Date: 23-10-2020
How to Decide Whether to Move Species Threatened by Climate Change
Publisher: Public Library of Science (PLoS)
Date: 16-10-2013
The impact of high temperatures on foraging behaviour and body condition in the Western Australian Magpie Cracticus tibicen dorsalis
Publisher: National Inquiry Services Center (NISC)
Date: 04-05-2015
Metabolic Rates and Thermal Thresholds of Embryonic Flatback Turtles (Natator depressus) from the North West Shelf of Australia
Publisher: University of Chicago Press
Date: 11-2021
DOI: 10.1086/716848
Conservation implications of a long‐term decline in body condition of the Brothers Island tuatara (Sphenodon guntheri)
Publisher: Wiley
Date: 04-08-2006
Increased expression of Hsp70 and Hsp90 mRNA as biomarkers of thermal stress in loggerhead turtle embryos (Caretta Caretta)
Publisher: Elsevier BV
Date: 2015
DOI: 10.1016/J.JTHERBIO.2014.11.006
Abstract: The survival and viability of sea turtle embryos is dependent upon favourable nest temperatures throughout the incubation period. Consequently, future generations of sea turtles may be at risk from increasing nest temperatures due to climate change, but little is known about how embryos respond to heat stress. Heat shock genes are likely to be important in this process because they code for proteins that prevent cellular damage in response to environmental stressors. This study provides the first evidence of an expression response in the heat shock genes of embryos of loggerhead sea turtles (Caretta caretta) exposed to realistic and near-lethal temperatures (34°C and 36°C) for 1 or 3 hours. We investigated changes in Heat shock protein 60 (Hsp60), Hsp70, and Hsp90 mRNA in heart (n=24) and brain tissue (n=29) in response to heat stress. Under the most extreme treatment (36°C, 3h), Hsp70 increased mRNA expression by a factor of 38.8 in heart tissue and 15.7 in brain tissue, while Hsp90 mRNA expression increased by a factor of 98.3 in heart tissue and 14.7 in brain tissue. Hence, both Hsp70 and Hsp90 are useful biomarkers for assessing heat stress in the late-stage embryos of sea turtles. The method we developed can be used as a platform for future studies on variation in the thermotolerance response from the clutch to population scale, and can help us anticipate the resilience of reptile embryos to extreme heating events.
Models of primary sex ratios at a major flatback turtle rookery show an anomalous masculinising trend
Publisher: Springer Science and Business Media LLC
Date: 22-10-2014
Activity of a freshwater turtle varies across a latitudinal gradient: Implications for the success of assisted colonisation
Publisher: Wiley
Date: 14-05-2023
Abstract: The value of assisted colonisation as a response to climate change can only be realised if focal species are well suited to their new habitats. For ectotherms, new habitats must offer microclimates that promote crucial behaviours such as thermoregulation and foraging. The Western sw turtle Pseudemydura umbrina , a Critically Endangered species from south‐western Australia, serves as a global case‐study of assisted colonisation in action. Initial trials where juvenile P. umbrina were released into wetter and cooler climates found that in iduals spent considerable time at body temperatures that apparently limited their growth. Using high‐resolution biologging data (temperature and depth), here we tested if turtle activity is thermally constrained in cooler latitudes by releasing 48 juveniles into seasonal sw s at three sites. One site was core natural habitat, and the other sites were wetlands 380 km apart that offered either warmer or cooler microclimates. Generalised additive mixed models were used to evaluate behaviours and time spent at optimal temperatures for approximately 1 month following release, and growth rates were measured and analysed after release until the end of the hydroperiod 4–5 months later. We found that turtles released into the most poleward (southern) wetland spent significantly less time active and basking and grew significantly less compared to turtles released further north. When analysed together, behavioural and growth datasets showed that activity was positively correlated with growth rates. We conclude that poor growth of turtles in the southern wetland was likely a result of lower body temperatures, stemming from a reduced ability to thermoregulate in water. Consequently, for assisted colonisation of juvenile P. umbrina to be successful, recipient wetlands must offer aquatic microclimates that are sufficiently warm to promote foraging activity that leads to growth, and ultimately to maturation. Read the free Plain Language Summary for this article on the Journal blog.
Variation in thermal traits describing sex determination and development in Western Australian sea turtle populations
Publisher: Wiley
Date: 13-08-2020
Nest-site selection in a terrestrially breeding frog with protracted development
Publisher: CSIRO Publishing
Date: 2002
DOI: 10.1071/ZO01086
Abstract: 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 ( %) 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.
Systematic planning can rapidly close the protection gap in Australian mammal havens
Publisher: Wiley
Date: 2019
DOI: 10.1111/CONL.12611
Identifying the most effective behavioural assays and predator cues for quantifying anti-predator responses in mammals: a systematic review protocol
Publisher: Springer Science and Business Media LLC
Date: 18-12-2021
DOI: 10.1186/S13750-021-00253-9
Abstract: Mammals, globally, are facing population declines. Strategies increasingly employed to recover threatened mammal populations include protecting populations inside predator-free havens, and translocating animals from one site to another, or from a captive breeding program. These approaches can expose predator-naïve animals to predators they have never encountered and as a result, many conservation projects have failed due to the predation of in iduals that lacked appropriate anti-predator responses. Hence robust ways to measure anti-predator responses are urgently needed to help identify naïve populations at risk, to select appropriate animals for translocation, and to monitor managed populations for trait change. Here, we outline a protocol for a systematic review that collates existing behavioural assays developed for the purpose of quantifying anti-predator responses, and identifies assay types and predator cues that provoke the greatest behavioural responses. We will retrieve articles from academic bibliographic databases and grey literature sources (such as government and conservation management reports), using a Boolean search string. Each article will be screened for the satisfaction of eligibility criteria determined using the PICO (Population—Intervention—Comparator—Outcome) framework, to yield the final article pool. Using metadata extracted from each article, we will map all known behavioural assays for quantifying anti-predator responses in mammals and will then examine the context in which each assay has been implemented (e.g. species tested, predator cue characteristics). Finally, with mixed effects modelling, we will determine which of these assays and predator cue types elicit the greatest behavioural responses (standardised difference in response between treatment and control groups). The final review will highlight the most robust methodology, will reveal promising techniques on which to focus future assay development, and will collate relevant information for conservation managers.
Heat dissipation behaviour of birds in seasonally hot arid‐zones: are there global patterns?
Publisher: Wiley
Date: 02-2020
DOI: 10.1111/JAV.02350
Drying microclimates threaten persistence of natural and translocated populations of threatened frogs
Publisher: Springer Science and Business Media LLC
Date: 27-10-2021
DOI: 10.1007/S10531-020-02064-9
Abstract: 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.
Phenotypic differences in terrestrial frog embryos: effect of water potential and phase
Publisher: The Company of Biologists
Date: 15-12-2008
DOI: 10.1242/JEB.017913
Abstract: The terrestrial embryos of many hibians obtain water in two ways in a liquid phase from the substrate on which eggs are deposited, and in a vapour phase from the surrounding atmosphere. We tested whether the mode of water flux (liquid or vapour) affected the morphology and metabolic traits of the terrestrial Victorian smooth froglet (Geocrinia victoriana) embryos by incubating eggs both with a liquid water source and at a range of vapour water potentials. We found that embryos incubated with a liquid water source(ψπ=0 kPa) were better hydrated than embryos incubated with a vapour water source (ψv=0 kPa), and grew to a larger size. Eggs incubated in atmospheres with lower ψv values showed significant declines in mass and in the thickness of the jelly capsule, while embryos primarily showed reductions in dry mass, total length, tail length and fin height. The most significant deviations from control (ψv=0 kPa) values were observed when the ψv of the incubation media was less than the osmotic water potential (ψπ) of the embryonic interstitial fluid (approximately –425 kPa). Despite the caveat that a ψv of 0 kPa is probably difficult to achieve under our experimental conditions, the findings indicate the importance for eggs under natural conditions of contacting liquid water in the nesting substrate to allow swelling of the capsule.
Life in the slow lane? A dynamic energy budget model for the western swamp turtle, Pseudemydura umbrina
Publisher: Elsevier BV
Date: 2019
A genome-wide search for local adaptation in a terrestrial-breeding frog reveals vulnerability to climate change
Publisher: Wiley
Date: 04-07-2019
DOI: 10.1111/GCB.14703
Abstract: Terrestrial‐breeding hibians 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 ersity, 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 s led across 12 central and range‐edge populations (192 s les), and strong genetic structure was apparent, as were high inbreeding coefficients. Populations showed differences in genetic ersity, and one population lost significant genetic ersity 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 ersity, 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.
The Influence of Temperature on Embryonic Respiration, Growth, and Sex Determination in a Western Australian Population of Green Turtles (Chelonia mydas)
Publisher: University of Chicago Press
Date: 11-2018
DOI: 10.1086/700433
Abstract: 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.
Havens for threatened Australian mammals: the contributions of fenced areas and offshore islands to the protection of mammal species susceptible to introduced predators
Publisher: CSIRO Publishing
Date: 2018
DOI: 10.1071/WR17172
Abstract: Context Many Australian mammal species are highly susceptible to predation by introduced domestic cats (Felis catus) and European red foxes (Vulpes vulpes). These predators have caused many extinctions and have driven large distributional and population declines for many more species. The serendipitous occurrence of, and deliberate translocations of mammals to, ‘havens’ (cat- and fox-free offshore islands, and mainland fenced exclosures capable of excluding cats and foxes) has helped avoid further extinction. Aims The aim of this study was to conduct a stocktake of current island and fenced havens in Australia and assess the extent of their protection for threatened mammal taxa that are most susceptible to cat and fox predation. Methods Information was collated from erse sources to document (1) the locations of havens and (2) the occurrence of populations of predator-susceptible threatened mammals (naturally occurring or translocated) in those havens. The list of predator-susceptible taxa (67 taxa, 52 species) was based on consensus opinion from mammal experts. Key results Seventeen fenced and 101 island havens contain 188 populations of 38 predator-susceptible threatened mammal taxa (32 species). Island havens cover a larger cumulative area than fenced havens (2152km2 versus 346km2), and reach larger sizes (largest island 325km2, with another island of 628km2 becoming available from 2018 largest fence: 123km2). Islands and fenced havens contain similar numbers of taxa (27 each), because fenced havens usually contain more taxa per haven. Populations within fences are mostly translocated (43 of 49 88%). Islands contain translocated populations (30 of 139 22%) but also protect in situ (109) threatened mammal populations. Conclusions Havens are used increasingly to safeguard threatened predator-susceptible mammals. However, 15 such taxa occur in only one or two havens, and 29 such taxa (43%) are not represented in any havens. The taxon at greatest risk of extinction from predation, and in greatest need of a haven, is the central rock-rat (Zyzomys pedunculatus). Implications Future investment in havens should focus on locations that favour taxa with no (or low) existing haven representation. Although havens can be critical for avoiding extinctions in the short term, they cover a minute proportion of species’ former ranges. Improved options for controlling the impacts of cats and foxes at landscape scales must be developed and implemented.
A Threat to New Zealand's Tuatara Heats Up
Publisher: Sigma Xi
Date: 2014
DOI: 10.1511/2014.110.350
A review of applications of environmental DNA for reptile conservation and management
Publisher: Wiley
Date: 06-2022
DOI: 10.1002/ECE3.8995
Abstract: Reptile populations are in decline globally, with total reptile abundance halving in the past half century, and approximately a fifth of species currently threatened with extinction. Research on reptile distributions, population trends, and trophic interactions can greatly improve the accuracy of conservation listings and planning for species recovery, but data deficiency is an impediment for many species. Environmental DNA (eDNA) can detect species and measure community ersity at erse spatio‐temporal scales, and is especially useful for detection of elusive, cryptic, or rare species, making it potentially very valuable in herpetology. We aim to summarize the utility of eDNA as a tool for informing reptile conservation and management and discuss the benefits and limitations of this approach. A literature review was conducted to collect all studies that used eDNA and focus on reptile ecology, conservation, or management. Results of the literature search are summarized into key discussion points, and the review also draws on eDNA studies from other taxa to highlight methodological challenges and to identify future research directions. eDNA has had limited application to reptiles, relative to other vertebrate groups, and little use in regions with high species richness. eDNA techniques have been more successfully applied to aquatic reptiles than to terrestrial reptiles, and most (64%) of studies focused on aquatic habitats. Two of the four reptilian orders dominate the existing eDNA studies (56% Testudines, 49% Squamata, 5% Crocodilia, 0% Rhynchocephalia). Our review provides direction for the application of eDNA as an emerging tool in reptile ecology and conservation, especially when it can be paired with traditional monitoring approaches. Technologies associated with eDNA are rapidly advancing, and as techniques become more sensitive and accessible, we expect eDNA will be increasingly valuable for addressing key knowledge gaps for reptiles.
Reptiles on the brink: identifying the Australian terrestrial snake and lizard species most at risk of extinction
Publisher: CSIRO Publishing
Date: 2021
DOI: 10.1071/PC20033
Abstract: 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 (& %) 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.
Does incubation temperature fluctuation influence hatchling phenotypes in reptiles? A test using parthenogenetic geckos
Publisher: University of Chicago Press
Date: 07-2010
DOI: 10.1086/652245
Abstract: Many lineages of parthenogenetic organisms have persisted through significant environmental change despite the constraints imposed by their fixed genotype and limited evolutionary potential. The ability of parthenogens to occur sympatrically with sexual relatives may in part be due to phenotypic plasticity in their responses to their environment, especially with respect to incubation temperature--a maternally selected trait. Here we measured the incubation temperatures selected by two lineages of triploid parthenogenic geckos in the Heteronotia binoei complex by allowing them to deposit clutches along a thermal gradient. The average nest temperature selected was 28.4 degrees C, with no significant differences between parthenogenic races or in idual clones. To investigate the effect of nest-temperature variability on physiological and morphological traits, we incubated eggs from different races at one of four incubation regimes (32 degrees +/- 0 degrees, +/- 3 degrees , +/- 5 degrees , or +/- 9 degrees C). Embryos incubated at constant 32 degrees C developed faster than embryos reared under increasing extremes of diel temperature fluctuation (+/- 3 degrees , +/- 5 degrees C), and incubation at 32 degrees +/- 9 degrees C was unsuccessful. Incubation regime had no effect on the body size, preferred substrate temperature, or mass-specific .V(O2) of hatchlings. However, parthenogenic race had a significant effect on egg mass, tail length, snout-to-vent length, total length, and .V(O2) . We conclude that developmental traits are strongly influenced by clonal genotypes in this parthenogenic complex but are well buffered against fluctuations in incubation temperature.
Biodiversity redistribution under climate change: Impacts on ecosystems and human well-being.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 31-03-2017
Abstract: Distributions of Earth's species are changing at accelerating rates, increasingly driven by human-mediated 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 bio ersity redistribution is critical yet lacking in most mitigation and adaptation strategies, including the United Nation's Sustainable Development Goals.
Simulated climate change increases juvenile growth in a Critically Endangered tortoise
Publisher: Inter-Research Science Center
Date: 12-04-2012
DOI: 10.3354/ESR00410
Influence of Environmental Oxygen on Development and Hatching of Aquatic Eggs of the Australian Frog, Crinia georgiana
Publisher: University of Chicago Press
Date: 07-2000
DOI: 10.1086/317739
Abstract: The effect of oxygen partial pressure (Po(2)) on development and hatching was investigated in aquatic embryos of the myobatrachid frog, Crinia georgiana, in the field and in the laboratory. Eggs from 29 field nests experienced widely variable Po(2) but similar temperatures. Mean Po(2) in different nests ranged between 2.9 and 19.3 kPa (grand mean 12.9 kPa), and mean temperature ranged between 11.9 degrees and 16.8 degrees C (grand mean 13.7 degrees C). There was no detectable effect of Po(2) or temperature on development rate or hatching time in the field, except in one nest at 2.9 kPa where the embryos died, presumably in association with hypoxia. Laboratory eggs were incubated at 15 degrees C at a range of Po(2) between 2 and 25 kPa. Between 5 and 25 kPa, there was almost no effect of Po(2) on development rate to stage 26, but the embryos hatched progressively earlier-at earlier stages and lower gut-free body mass-at lower Po(2). At 2 kPa, development was severely delayed, growth of the embryo slowed, and morphological anomalies appeared. A high tolerance to low Po(2) may be an adaptation to embryonic development in the potentially hypoxic, aquatic environment.
Microclimate modelling of beach sand temperatures reveals high spatial and temporal variation at sea turtle rookeries
Publisher: Elsevier BV
Date: 02-2020
Heritable variation in heat shock gene expression: A potential mechanism for adaptation to thermal stress in embryos of sea turtles
Publisher: The Royal Society
Date: 13-01-2016
Abstract: The capacity of species to respond adaptively to warming temperatures will be key to their survival in the Anthropocene. The embryos of egg-laying species such as sea turtles have limited behavioural means for avoiding high nest temperatures, and responses at the physiological level may be critical to coping with predicted global temperature increases. Using the loggerhead sea turtle ( Caretta caretta ) as a model, we used quantitative PCR to characterise variation in the expression response of heat-shock genes ( hsp60, hsp70 and hsp90 molecular chaperones involved in cellular stress response) to an acute non-lethal heat shock. We show significant variation in gene expression at the clutch and population levels for some, but not all hsp genes. Using pedigree information, we estimated heritabilities of the expression response of hsp genes to heat shock and demonstrated both maternal and additive genetic effects. This is the first evidence that the heat-shock response is heritable in sea turtles and operates at the embryonic stage in any reptile. The presence of heritable variation in the expression of key thermotolerance genes is necessary for sea turtles to adapt at a molecular level to warming incubation environments.
Putting plasticity into practice for effective conservation actions under climate change
Publisher: Springer Science and Business Media LLC
Date: 07-2023
Temperature-Dependent Sex Determination and Contemporary Climate Change
Publisher: S. Karger AG
Date: 2010
DOI: 10.1159/000282494
Abstract: Whether species that have persisted throughout historic climatic upheavals will survive contemporary climate change will depend on their ecological and physiological traits, their evolutionary potential, and potentially upon the resources that humans commit to prevent their extinction. For those species where temperatures influence sex determination, rapid global warming poses a unique risk of skewed sex ratios and demographic collapse. Here we review the specific mechanisms by which reptiles with temperature-dependent sex determination (TSD) may be imperilled at current rates of warming, and discuss the evidence for and against adaptation via behavioural or physiological means. We propose a scheme for ranking reptiles with TSD according to their vulnerability to rapid global warming, but note that critical data on the lability of the sex determining mechanism and on the heritability of behavioural and threshold traits are unavailable for most species. Nevertheless, we recommend a precautionary approach to management of reptiles identified as being at relatively high risk. In such cases, management should aim to neutralise directional sex ratio biases (e.g. by manipulating incubation temperatures or assisted migration) and promote adaptive processes, possibly by genetic supplementation of populations. These practices should aid species’ persistence and buy time for research directed at more accurate prediction of species’ vulnerability.
Predicting the fate of a living fossil: how will global warming affect sex determination and hatching phenology in tuatara?
Publisher: The Royal Society
Date: 07-2008
Abstract: How will climate change affect species' reproduction and subsequent survival? In many egg-laying reptiles, the sex of offspring is determined by the temperature experienced during a critical period of embryonic development (temperature-dependent sex determination, TSD). Increasing air temperatures are likely to skew offspring sex ratios in the absence of evolutionary or plastic adaptation, hence we urgently require means for predicting the future distributions of species with TSD. Here we develop a mechanistic model that demonstrates how climate, soil and topography interact with physiology and nesting behaviour to determine sex ratios of tuatara, cold-climate reptiles from New Zealand with an unusual developmental biology. Under extreme regional climate change, all-male clutches would hatch at 100% of current nest sites of the rarest species, Sphenodon guntheri , by the mid-2080s. We show that tuatara could behaviourally compensate for the male-biasing effects of warmer air temperatures by nesting later in the season or selecting shaded nest sites. Later nesting is, however, an unlikely response to global warming, as many oviparous species are nesting earlier as the climate warms. Our approach allows the assessment of the thermal suitability of current reserves and future translocation sites for tuatara, and can be readily modified to predict climatic impacts on any species with TSD.
Support for a rare pattern of temperature-dependent sex determination in archaic reptiles: evidence from two species of tuatara (Sphenodon)
Publisher: Springer Science and Business Media LLC
Date: 29-06-2006
Breeding phenology of a terrestrial‐breeding frog is associated with soil water potential: Implications for conservation in a changing climate
Publisher: Wiley
Date: 23-10-2022
DOI: 10.1111/AEC.13122
Abstract: Amphibian breeding is often linked to environmental cues. Given accelerating global climate change and habitat alteration, it is important to understand how environmental changes may affect male calling activity, the necessary precursor to mating. Here, we investigate the calling phenology and activity of Geocrinia alba , a critically endangered terrestrial‐breeding frog with a highly restricted distribution in southwestern Australia – a region undergoing significant warming and drying. We investigated whether calling periods differed across eight sites during a single breeding season, and the environmental conditions associated with calling activity at the start, peak and end of the calling period. We found consistent and prolonged calling activity over several months of the austral spring, but the length of the calling period varied two‐fold across sites, ranging from 3 to 6 months. Initiation of calling by G . alba was relatively similar across sites and was associated with warmer temperatures and higher soil water potential. However, the end of the calling period varied from October to January and was significantly associated with decreasing soil water potential. Calling only occurred when soils were close to saturation point, between −8 to −11 kPa, and therefore, breeding opportunities were likely also constrained by the length of time that soils were close to saturation. Changes in the regional climate, such as declining winter rainfall, could result in shorter breeding periods and consequently reduced breeding opportunities. More broadly, our study highlights the sensitivity of hibians, particularly terrestrial‐breeding species, to changes in soil water potential and temperature, and the importance of maintaining suitable hydrological conditions during the breeding period.
Rapid assessment of the biodiversity impacts of the 2019–2020 Australian megafires to guide urgent management intervention and recovery and lessons for other regions
Publisher: Wiley
Date: 21-10-2021
DOI: 10.1111/DDI.13428
Abstract: 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 bio ersity loss. Whilst the fires were still burning, the Australian Government convened a bio ersity 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. Forested biomes of subtropical and temperate Australia, with lessons for other regions. 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. 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. 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.
Geographic variation in adult and embryonic desiccation tolerance in a terrestrial-breeding frog
Publisher: Cold Spring Harbor Laboratory
Date: 04-05-2018
DOI: 10.1101/314351
Abstract: Intra-specific variation in the ability of in iduals to tolerate environmental perturbations is often neglected when considering the impacts of climate change. Yet this information is potentially crucial for mitigating any deleterious effects of climate change on threatened species. Here we assessed patterns of intra-specific 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 six populations, where selection on desiccation tolerance should be especially strong given that embryos cannot move to escape unfavourable microclimates. Embryos were reared on soil at three soil-water potentials, ranging from wet to dry (ψ = −10, −100 & −400 kPa), and their desiccation tolerance was assessed across a range of traits including survival, time to hatch after inundation, wet mass at hatching, hatchling malformations and swimming performance. We found significant and strong patterns of intra-specific 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 embryos and hatchlings was significantly greater in populations from xeric sites. Taken together, our findings suggest that populations within this species will respond differently to the regional reduction in rainfall predicted by climate change models. We emphasise the importance of considering geographic variation in phenotypic plasticity when predicting how species will respond to climate change.
Reconstructed paternal genotypes reveal variable rates of multiple paternity at three rookeries of loggerhead sea turtles (Caretta caretta) in Western Australia
Publisher: CSIRO Publishing
Date: 2014
DOI: 10.1071/ZO14076
Abstract: Female sea turtles are promiscuous, with clutches of eggs often sired by multiple males and rates of multiple paternity varying greatly within and across species. We investigated levels of multiple paternity in loggerhead sea turtles (Caretta caretta) from three rookeries in Western Australia by analysing polymorphic species-specific genetic markers. We predicted that the level of multiple paternity would be related to female population size and hence the large rookery at Dirk Hartog Island would have higher rates of multiple paternity than two smaller mainland rookeries at Gnaraloo Bay and Bungelup Beach. Contrary to our prediction, we found highly variable rates of multiple paternity among the rookeries that we s led, which was unrelated to female population size (25% at Bungelup Beach, 86% at Gnaraloo Bay, and 36% at Dirk Hartog Island). Approximately 45 different males sired 25 clutches and the average number of sires per clutch ranged from 1.2 to 2.1, depending on the rookery s led. The variance in rates of multiple paternity among rookeries suggests that operational sex ratios are variable in Western Australia. Periodic monitoring would show whether the observed patterns of multiple paternity for these three rookeries are stable over time, and our data provide a baseline for detecting shifts in operational sex ratios.
The Effects of Nest Temperature, Nest Substrate, and Clutch Size on the Oxygenation of Embryos and Larvae of the Australian Moss Frog,Bryobatrachus nimbus
Publisher: University of Chicago Press
Date: 2003
DOI: 10.1086/345486
Abstract: The jelly around hibian eggs presents a formidable barrier to oxygen diffusion. Therefore, egg capsules must be thin enough, and the dimensions of globular egg masses small enough, to avoid oxygen limitation leading to developmental retardation or death. The eggs of the Australian moss frog, Bryobatrachus nimbus, have the thickest jelly capsule known for any anuran hibian. Laboratory measurements of respirometric variables predict that single prehatching embryos should be normoxic between 5 degrees and 20 degrees C, with Po(2 in) maintained above critical levels (10.2-17.0 kPa). However, numerical models of embryos amid larger egg masses (13-20 eggs) predict hypoxia at temperatures above 5 degrees C. Contrary to model predictions, however, B. nimbus embryos rarely experience hypoxia in natural nests, because embryos occur in one or two layers and the moss substrate permits aeration of the lower surface while photosynthesis probably supplies oxygen directly. After hatching, larvae move to oxygen-rich regions of the jelly mass and disperse more widely within the mass as temperatures increase. Although nest characteristics relieve diffusive constraints, small clutch sizes, low rates of embryonic and larval respiration, and the cool climate occupied by B. nimbus are the main characteristics that prevent hypoxia.
Animal population decline and recovery after severe fire: Relating ecological and life history traits with expert estimates of population impacts from the Australian 2019-20 megafires
Publisher: Elsevier BV
Date: 07-2023
Geographic and taxonomic patterns of extinction risk in Australian squamates
Publisher: Elsevier BV
Date: 10-2019
Genetic Consequences of Multiple Translocations of the Banded Hare-Wallaby in Western Australia
Publisher: MDPI AG
Date: 27-11-2020
DOI: 10.3390/D12120448
Abstract: 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 ersity. 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’s allelic ersity, 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—about 60 in iduals—are required to retain adequate allelic ersity in the translocated population. Our approach demonstrates how genetic data coupled with simulations of stochastic environmental events can address central questions in translocation programmes.
A Systematic Review of Metabolic Heat in Sea Turtle Nests and Methods to Model Its Impact on Hatching Success
Publisher: Frontiers Media SA
Date: 17-09-2020
PATTERNS OF GENETIC VARIATION IN DESICCATION TOLERANCE IN EMBRYOS OF THE TERRESTRIAL-BREEDING FROG, PSEUDOPHRYNE GUENTHERI
Publisher: Wiley
Date: 27-03-2012
DOI: 10.1111/J.1558-5646.2012.01616.X
Abstract: Environmental change often requires evolutionary responses, and therefore understanding the genetic architecture of susceptible populations is essential for predicting their capacity to respond adaptively. However, quantitative genetic studies are rarely targeted at populations considered vulnerable to such environmental perturbations. Here, we assess the level of heritable variation in the ability of embryos to tolerate desiccation stress in Pseudophryne guentheri, a terrestrial-breeding frog that is currently experiencing a drying climate. We applied a North Carolina II breeding design to identify sources of genetic and environmental variance, and genotype-by-environment interactions (GEIs), underlying the expression of embryo survival, hatching times, hatchling mass, size, and shape. Our analysis revealed highly significant effects of water potential and maternal effects on all measured traits, while additive genetic effects were significant for hatchling shape, and nonadditive effects were observed for embryo survival. Interestingly, GEIs, including for some traits complex three-way sire-by-dam-by-environment interactions, were significant, indicating that progeny from certain male-female crosses were more tolerant to water stress than others. These findings suggest a limited capacity of P. guentheri to respond to a drying climate, but also reveal that the detrimental effects of nonviable male-female crosses (i.e., genetic incompatibility) can be masked in benign environments.
A comparative study of cell growth on a cold sprayed Ti–Ta composite
Publisher: Elsevier BV
Date: 06-2020
Done but not dusted: Reflections on the first global reptile assessment and priorities for the second
Publisher: Elsevier BV
Date: 02-2023
The conservation impacts of ecological disturbance: time‐bound estimates of population loss and recovery for fauna affected by the 2019–2020 Australian megafires
Publisher: Wiley
Date: 03-2022
DOI: 10.1111/GEB.13473
Abstract: After environmental disasters, species with large population losses may need urgent protection to prevent extinction and support recovery. Following the 2019–2020 Australian megafires, we estimated population losses and recovery in fire‐affected fauna, to inform conservation status assessments and management. Temperate and subtropical Australia. 2019–2030 and beyond. Australian terrestrial and freshwater vertebrates one invertebrate group. From 1,050 fire‐affected taxa, we selected 173 whose distributions substantially overlapped the fire extent. We estimated the proportion of each taxon’s distribution affected by fires, using fire severity and aquatic impact mapping, and new distribution mapping. Using expert elicitation informed by evidence of responses to previous wildfires, we estimated local population responses to fires of varying severity. We combined the spatial and elicitation data to estimate overall population loss and recovery trajectories, and thus indicate potential eligibility for listing as threatened, or uplisting, under Australian legislation. We estimate that the 2019–2020 Australian megafires caused, or contributed to, population declines that make 70–82 taxa eligible for listing as threatened and another 21–27 taxa eligible for uplisting. If so‐listed, this represents a 22–26% increase in Australian statutory lists of threatened terrestrial and freshwater vertebrates and spiny crayfish, and uplisting for 8–10% of threatened taxa. Such changes would cause an abrupt worsening of underlying trajectories in vertebrates, as measured by Red List Indices. We predict that 54–88% of 173 assessed taxa will not recover to pre‐fire population size within 10 years/three generations. We suggest the 2019–2020 Australian megafires have worsened the conservation prospects for many species. Of the 91 taxa recommended for listing/uplisting consideration, 84 are now under formal review through national processes. Improving predictions about taxon vulnerability with empirical data on population responses, reducing the likelihood of future catastrophic events and mitigating their impacts on bio ersity, are critical.
Geographic variation in adult and embryonic desiccation tolerance in a terrestrial‐breeding frog
Publisher: Wiley
Date: 05-05-2020
DOI: 10.1111/EVO.13973
Impacts of Habitat Degradation on Tropical Montane Biodiversity and Ecosystem Services
Publisher: Frontiers Media SA
Date: 17-12-2019
Detecting Extinction Risk from Climate Change by IUCN Red List Criteria
Publisher: Wiley
Date: 11-02-2014
DOI: 10.1111/COBI.12234
Abstract: Anthropogenic climate change is a key threat to global bio ersity. To inform strategic actions aimed at conserving bio ersity 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.
A full life cycle Dynamic Energy Budget (DEB) model for the green sea turtle (Chelonia mydas) fitted to data on embryonic development
Publisher: Elsevier BV
Date: 2019
Assessing the spatial ecology and resource use of a mobile and endangered species in an urbanized landscape using satellite telemetry and DNA faecal metabarcoding
Publisher: Wiley
Date: 29-12-2016
DOI: 10.1111/IBI.12442
Red hot frogs: identifying the Australian frogs most at risk of extinction
Publisher: CSIRO Publishing
Date: 20-08-2021
DOI: 10.1071/PC21019
Abstract: More than a third of the world’s hibian 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 ( % 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 experts), while non-experts were more likely to rate extinction probability higher for better-known species. However, scores converged following discussion, indicating that there was greater consensus in the estimates of extinction probability. Increased resourcing and management intervention are urgently needed to avert future extinctions of Australia’s frogs. Key priorities include developing and supporting captive management and establishing or extending in-situ population refuges to alleviate the impacts of disease and climate change.
Sex Ratio Bias and Extinction Risk in an Isolated Population of Tuatara (Sphenodon punctatus)
Publisher: Public Library of Science (PLoS)
Date: 08-04-2014
Should we move species threatened by climate change?
Publisher: CSIRO Publishing
Date: 2013
DOI: 10.1071/EC13246
Meeting an expanding human population’s needs whilst conserving a threatened parrot species in an urban environment
Publisher: WIT Press
Date: 23-09-2014
DOI: 10.2495/SC141012
Key parameters describing temperature-dependent sex determination in the southernmost population of loggerhead sea turtles
Publisher: Elsevier BV
Date: 11-2013
Correction to: Drying microclimates threaten persistence of natural and translocated populations of threatened frogs
Publisher: Springer Science and Business Media LLC
Date: 11-11-2020
Evolutionary and natural history of the turtle frog, Myobatrachus gouldii, a bizarre myobatrachid frog in the southwestern Australian biodiversity hotspot
Publisher: Public Library of Science (PLoS)
Date: 15-03-2017
Assisted colonisation trials for the western swamp turtle show that juveniles can grow in cooler and wetter climates
Publisher: Inter-Research Science Center
Date: 17-09-2020
DOI: 10.3354/ESR01053
Abstract: 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 sw turtle Pseudemydura umbrina , persists naturally in only one seasonal sw that holds water in the Austral winter and spring. A marked reduction in winter rainfall in recent decades has shortened the sw 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.
The Energetics of Endotrophic Development in the FrogGeocrinia vitellina(Anura: Myobatrachinae)
Publisher: University of Chicago Press
Date: 11-2001
DOI: 10.1086/323989
Abstract: The energetics of endotrophic development, where the nutrition required to complete metamorphosis is provided solely by yolk, has seldom been quantified. The energy cost of development to metamorphosis of the endotrophic Australian frog Geocrinia vitellina was measured using bomb calorimetry and closed-system respirometry. Dry yolk had an energy density of 26.4 J x mg(-1), and an average 2.8-mm-diameter ovum contained 144 J. Incubation at 15 degrees C produced a froglet of 5.8 mm snout-vent length, containing 88 J in 87 d, with 11% of residual yolk in the gut, which is markedly less than the 50% recorded in another endotroph, Eleutherodactylus coqui. Geocrinia vitellina lost 56 J of metabolic energy during development to metamorphosis at 15 degrees C, and the total production efficiency was 61.0%. A review of published egg energy densities found a mean for hibians of 25.1 kJ x g(-1), significantly lower than the mean of 27.1 kJ x g(-1) for reptiles. Moreover, available hibian data suggest that endotrophic species have high yolk energy densities and low mass-specific rates of oxygen consumption relative to exotrophic species (with feeding larvae) consequently, large ovum size may not necessarily be prerequisite for endotrophic development.
Decision analysis for the planning and assessment of ex situ management: An application to the endangered mahogany glider
Publisher: Wiley
Date: 23-03-2023
DOI: 10.1111/AEC.13310
Abstract: Ex situ (‘off‐site’) management refers to keeping species in artificial conditions away from their natural habitat and includes captive breeding facilities, botanical gardens and seed banks. There is scope for ex situ programmes to be more commonly used for supplementing or establishing wild populations. However, undertaking ex situ management comes with risks, costs and uncertainties, which must be assessed in the context of available in situ (‘on‐site’) management options. The PACES (Planning and Assessment for Conservation through Ex situ management) tool tailors the principles of structured decision‐making to the specific problem of assessing and comparing ex situ and in situ management options. We applied the PACES tool to the mahogany glider ( Petaurus gracilis ), a threatened arboreal marsupial endemic to north Queensland, Australia. Through an expert elicitation process, we predicted the likely benefits of an ex situ and two in situ management options, as compared to a baseline ‘do‐nothing’ scenario. The ‘in situ plus’ alternative (where extra resources are dedicated to in situ management) was predicted to result in the largest population increase according to the participants' best estimates. However, this benefit came at a much larger cost than the ex situ alternative, and without the benefit of an ex situ insurance population. The PACES tool assessment allowed the Mahogany Glider Recovery Team to document and plan the financial costs, risks and benefits of potential future management options for the mahogany glider, laying a transparent basis for future assessment and decision‐making.
Using PVA and captive breeding to balance trade-offs in the rescue of the island dibbler onto a new island ark
Publisher: Springer Science and Business Media LLC
Date: 13-07-2022
DOI: 10.1038/S41598-022-14150-9
Abstract: In the face of the current global extinction crisis, it is critical we give conservation management strategies the best chance of success. Australia is not exempt from global trends with currently the world’s greatest mammal extinction rate (~ 1 per 8 years). Many more are threatened including the dibbler ( Parantechinus apicalis ) whose remnant range has been restricted to Western Australia at just one mainland site and two small offshore islands—Whitlock Island (5 ha) and Boullanger Island (35 ha). Here, we used 14 microsatellite markers to quantify genetic variation in the remaining island populations from 2013 to 2018 and incorporated these data into population viability analysis (PVA) models, used to assess factors important to dibbler survival and to provide guidance for translocations. Remnant population genetic ersity was low ( 0.3), and populations were highly ergent from each other (pairwise F ST s 0.29–0.52). Comparison of empirical data to an earlier study is consistent with recent declines in genetic ersity and models projected increasing extinction risk and declining genetic variation in the next century. Optimal translocation scenarios recommend 80 founders for new dibbler populations—provided by captive breeding—and determined the proportion of founders from parental populations to maximise genetic ersity and minimise harvesting impact. The goal of our approach is long-term survival of genetically erse, self-sustaining populations and our methods are transferable. We consider mixing island with mainland dibblers to reinforce genetic variation.
Fitness consequences of targeted gene flow to counter impacts of drying climates on terrestrial-breeding frogs
Publisher: Springer Science and Business Media LLC
Date: 18-10-2021
DOI: 10.1038/S42003-021-02695-W
Abstract: 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.
Mapping a new future: using spatial multiple criteria analysis to identify novel habitats for assisted colonization of endangered species
Publisher: Wiley
Date: 09-07-2014
DOI: 10.1111/ACV.12150
Conservation status of the world's skinks (Scincidae): Taxonomic and geographic patterns in extinction risk
Publisher: Elsevier BV
Date: 05-2021
A global reptile assessment highlights shared conservation needs of tetrapods
Publisher: Springer Science and Business Media LLC
Date: 27-04-2022
DOI: 10.1038/S41586-022-04664-7
Abstract: Comprehensive assessments of species’ extinction risks have documented the extinction crisis 1 and underpinned strategies for reducing those risks 2 . Global assessments reveal that, among tetrapods, 40.7% of hibians, 25.4% of mammals and 13.6% of birds are threatened with extinction 3 . Because global assessments have been lacking, reptiles have been omitted from conservation-prioritization analyses that encompass other tetrapods 4–7 . Reptiles are unusually erse in arid regions, suggesting that they may have different conservation needs 6 . 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 extrapolation 8 and representing 15.6 billion years of phylogenetic ersity. 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 hibians 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.
Degrees of population-level susceptibility of Australian terrestrial non-volant mammal species to predation by the introduced red fox (Vulpes vulpes) and feral cat (Felis catus)
Publisher: CSIRO Publishing
Date: 2018
DOI: 10.1071/WR18008
Abstract: Context Over the last 230 years, the Australian terrestrial mammal fauna has suffered a very high rate of decline and extinction relative to other continents. Predation by the introduced red fox (Vulpes vulpes) and feral cat (Felis catus) is implicated in many of these extinctions, and in the ongoing decline of many extant species. Aims To assess the degree to which Australian terrestrial non-volant mammal species are susceptible at the population level to predation by the red fox and feral cat, and to allocate each species to a category of predator susceptibility. Methods We collated the available evidence and complemented this with expert opinion to categorise each Australian terrestrial non-volant mammal species (extinct and extant) into one of four classes of population-level susceptibility to introduced predators (i.e. ‘extreme’, ‘high’, ‘low’ or ‘not susceptible’). We then compared predator susceptibility with conservation status, body size and extent of arboreality and assessed changes in the occurrence of species in different predator-susceptibility categories between 1788 and 2017. Key results Of 246 Australian terrestrial non-volant mammal species (including extinct species), we conclude that 37 species are (or were) extremely predator-susceptible 52 species are highly predator-susceptible 112 species are of low susceptibility and 42 species are not susceptible to predators. Confidence in assigning species to predator-susceptibility categories was strongest for extant threatened mammal species and for extremely predator-susceptible species. Extinct and threatened mammal species are more likely to be predator-susceptible than Least Concern species arboreal species are less predator-susceptible than ground-dwelling species and medium-sized species (35 g–3.5kg) are more predator-susceptible than smaller or larger species. Conclusions The effective control of foxes and cats over large areas is likely to assist the population-level recovery of ~63 species – the number of extant species with extreme or high predator susceptibility – which represents ~29% of the extant Australian terrestrial non-volant mammal fauna. Implications Categorisation of predator susceptibility is an important tool for conservation management, because the persistence of species with extreme susceptibility will require intensive management (e.g. predator-proof exclosures or predator-free islands), whereas species of lower predator susceptibility can be managed through effective landscape-level suppression of introduced predators.
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