Extinction In Australia Research Articles

Half a century of survey data reveal population recovery but persistent threats for the Vulnerable yellow-footed rock-wallaby in Queensland, Australia

Abstract The record of mammal declines and extinctions in Australia raises concerns regarding geographically restricted and poorly known taxa. For many taxa, the existing data are insufficient to assess their conservation status and inform appropriate management. Concerns regarding the persistence of the subspecies of yellow-footed rock-wallaby Petrogale xanthopus celeris, which is endemic to Queensland, have been expressed since the 1970s because of red fox Vulpes vulpes predation, competition with feral goats Capra hircus and land clearing. This rock-wallaby is rarely observed, occupies rugged mountain ranges and, prior to our surveys, had not been surveyed for 25 years. We surveyed 138 sites across the range of this rock-wallaby during 2010–2023, including revisiting sites surveyed in the 1970s–1980s and locations of historical records. We examined occurrence in relation to habitat variables and threats. Occupancy and abundance remained similar over time at most sites. However, by 2023 the subspecies had recolonized areas in the north-east of its range where it had disappeared between surveys in the 1980s and 2010s, and three south-western subpopulations that were considered extinct in the 1980s were rediscovered. Recolonization and increases in abundance at numerous sites between the 2010s and 2020s are associated with declines in feral goat abundance, indicating dietary and habitat competition are major threats. Exclusion fences erected since 2010 could limit genetic exchange between rock-wallaby subpopulations whilst allowing domestic goats to be commercially grazed. Petrogale xanthopus celeris should remain categorized as Vulnerable based on these ongoing threats. Repeated monitoring approximately every decade should underpin management of this endemic taxon.

No More Extinctions: Recovering Australia's Biodiversity.

Most conservation programs and laws aim to prevent extinction. However, there is a gulf between such aspirations and the current reality of escalating biodiversity loss. This review focuses on efforts to prevent extinctions in Australia, but much of this consideration is likely to apply globally. As context, we consider the reasons for trying to prevent extinction, review Australia's extinction record, and note that there are likely to be many more extinctions than formally recognized. We describe recent cases where conservation actions have prevented extinction. We note that extinction is a pathway rather than solely an endpoint, and many decisions made or not made on that pathway can determine the fate of species. We conclude that all looming extinctions can and should be prevented. This will require transformational change in legislation, increased resourcing, more consideration of poorly known species, and increased societal recognition of the need to be responsible for the care of country.

Evaluating the risk to Australia’s flora from Phytophthora cinnamomi

Context Phytophthora cinnamomi Rands is a destructive pathogen of Australian native vegetation, often causing permanent damage to ecosystems and threatening the survival of rare, susceptible species. Despite that, much information about the effects of P. cinnamomi on plant species remains unpublished and the risk of extinction to most species is unknown. Aims We aimed to classify the risk of extinction from P. cinnamomi to Australian native plants. Methods We used available data and personal knowledge about P. cinnamomi effects on plants, spatial data on plant species distribution and habitat suitability of P. cinnamomi to assign an extinction-risk category of low, moderate, high or very high. Key results There are currently 65 plant species at a very high risk of extinction in Australia as a result of P. cinnamomi infection. The genera Andersonia, Banksia, Darwinia, Daviesia, Epacris, Gastrolobium, Grevillea, Hibbertia, Isopogon, Lambertia, Latrobea, Leucopogon, Phebalium and Styphelia have multiple species at a very high risk of extinction, most of which occur in south-western Western Australia. Conclusions The available data confirmed the high risk to the Australian flora from P. cinnamomi and identified species in plant families not previously known to be affected, highlighting data gaps (e.g. lack of knowledge about effects and risk in orchids and grasses). Implications Much more work is required to fully understand the risk from P. cinnamomi (and other Phytophthora species) to the Australian flora.

Reimagining Extinction in Australia and Japan: ‘Voices’ of the Tasmanian Tiger and Hokkaido Wolf

ABSTRACT This is a comparative, cross-cultural, and multi-disciplinary study of two extinct animals, the Tasmanian tiger in Australia and the Hokkaido wolf in Japan, and their ongoing cultural ‘presence’. The thylacine was last documented in captivity in 1936, and the Hokkaido wolf became extinct around 1900. Both faced rapid extinction due to anthropogenic factors associated with colonisation and modernisation, including eradication policies. Nonetheless, both animals have ongoing cultural and conservation significance. In Australia, the thylacine has become a symbol of redemption and conservation advocated for by devoted citizens who do not believe the animal is extinct. In Japan, the story of the Hokkaido wolf has been kept alive by Tezuka Osamu, a legendary manga/anime artist. Tezuka’s life project was to change anthropocentric human-nature relationships through his work. These two animals have significant ongoing implications for conservation and sustainability. The Tasmanian tiger offers a new approach to conservation through the pursuit of ‘Lazarus species’. The Hokkaido wolf provides an alternative ontology useful for rethinking human-nature relationships. Both point to the significant roles that different worldviews and emotional commitments can play for sustainable futures. They present new possibilities for reimagining extinction in the Anthropocene, showing that even extinct animals can give us hope.

Forest Biodiversity Declines and Extinctions Linked with Forest Degradation: A Case Study from Australian Tall, Wet Forests

Tens of thousands of species are at risk of extinction globally. In many ecosystems, species declines are associated with deforestation. However, forest degradation also can profoundly affect biodiversity. I present a detailed case study of species declines associated with forest degradation in southeastern Australia’s montane ash (Eucalyptus spp.) forests. The case study is based on ~40 years of long-term monitoring focused on declines (and potential extinction trajectories) of arboreal marsupials and birds, with a particular emphasis on key drivers, especially logging, wildfire, habitat loss, climate change, and interactions among these drivers. I discuss policy failures contributing to species declines, including ongoing logging of high-conservation-value forests, poor regulation of forest management, and inadequate design of reserves. I conclude with general lessons for better conservation and forest management efforts aimed at reducing forest degradation and loss of ecosystem integrity. I contend that ongoing logging in already highly degraded montane ash forests is inconsistent with the Australian government’s commitment at the Glasgow COP26 meeting in 2021 on halting forest degradation. Similarly, the Australian Government has committed to preventing further extinctions in Australia, yet its current support for ongoing logging in montane ash forests through federal–state legislation will likely promote extinctions for some species. The inherent conflicts and contradictions between conservation and logging policies need to be addressed.

Pouch bacteria: an understudied and potentially important facet of marsupial reproduction

Australia is home to a rich biodiversity of marsupials that are found nowhere else. Unfortunately, many of these species are currently threatened with extinction due to introduced feral predators and other anthropogenic factors. There is growing recognition that host-associated microorganisms can play important roles for animal health, with billions of dollars currently being invested into human gut microbiome research and the development of microbiome-based therapeutics to improve human health. Can microorganisms also be harnessed to stem the tide of marsupial extinctions? In this review, we provide an overview of some of the challenges facing Australia’s marsupials, and our current understanding of the microbiology of the marsupial pouch. We also propose outstanding research questions pertaining to the marsupial pouch, which, if addressed, may provide actionable knowledge and novel microbial therapies that could help stem the tide of marsupial extinctions in Australia.

Poems: R package for simulating species' range dynamics using pattern‐oriented validation

Abstract Spatially explicit population models (SEPMs) can simulate spatiotemporal changes in species' range dynamics in response to variation in climatic and environmental conditions, and anthropogenic activities. When combined with pattern‐oriented modelling methods, ecological processes and drivers of range shifts and extinctions can be identified, and plausible chains of causality revealed. The open‐source multi‐platform R package poems provides functionality for simulating and validating projections of species' range dynamics using stochastic, lattice‐based population models. Built‐in modules allow parameter uncertainty to propagate through to model simulations, with their effects on species' range dynamics evaluated using Approximate Bayesian Computation. These validation procedures identify models with the structural complexity and parameterisation needed to simulate the effects of past changes in climate, environment and human activities on species' range shifts and extinction risk. We illustrate the features and versatility of poems by simulating the historical decline and extinction of the Thylacine Thylacinus cynocephalus, an icon of recent extinctions in Australia. We show that poems can reveal likely ecological pathways to extinction using pattern‐oriented methods, providing validated projections of the range collapse and population decline of threatened species. By providing flexible and extendable modules for building and validating SEPMs of species' range dynamics, poems allows the effects of past and future threats on species' populations to be quantified using well‐parameterised, structurally realistic models, with important generative mechanisms. Since poems can directly unravel ecological processes of species responses to global change, and strengthen predictions of range shifts and extinction risk—within a flexible, R‐based environment—we anticipate that poems will be of significant value to ecologists, conservation managers and biogeographers.

What determines the distribution of a threatened species, the brush‐tailed phascogale Phascogale tapoatafa (Marsupialia: Dasyuridae), in a highly modified region?

AbstractIdentifying factors that affect species’ distributions in highly modified landscapes, especially threatened species, is a key issue for conservation worldwide. Three types of factors commonly are considered important: the extent and pattern of suitable habitat at a landscape scale; the availability of key resources at a local scale; and interactions with other species. The brush‐tailed phascogale (Phascogale tapoatafa) has undergone range contractions and regional extinctions in Australia and falls within the critical weight range of mammal species with high risk of decline. Yet, in some regions, it persists despite marked habitat loss and disturbance. We investigated the distribution of the brush‐tailed phascogale in a highly modified region in central Victoria where it is a ‘flagship’ for community conservation. At 50 sites, stratified geographically and in relation to topography and surrounding forest cover, we carried out surveys using remotely sensed cameras (in parallel with nest box inspections). We used an occupancy modelling framework and information‐theoretic approach to analyse factors influencing detectability and occupancy. The brush‐tailed phascogale was widespread, recorded at 84% (42/50) of sites. The environmental space occupied by sites with camera records matched that of nest boxes containing established nests of this species. Detection probability was influenced by survey effort and site‐level measures of habitat quality (logs, litter, topographic position) likely reflecting population abundance. Dry forested slopes were favoured compared with gullies. The study area, with its dry forests of rough‐barked eucalypts, is a stronghold for this species. The broad distribution of the brush‐tailed phascogale in this highly modified region can be attributed to retention of ˜36% regional forest cover and a relatively high level of structural and functional connectivity. In such modified landscapes, complementary actions by land managers to sustain remaining large tracts of forest and also a mosaic of wooded vegetation across the rural landscape will help such species to persist.

Museum genomics reveals the rapid decline and extinction of Australian rodents since European settlement

Australia has the highest historically recorded rate of mammalian extinction in the world, with 34 terrestrial species declared extinct since European colonization in 1788. Among Australian mammals, rodents have been the most severely affected by these recent extinctions; however, given a sparse historical record, the scale and timing of their decline remain unresolved. Using museum specimens up to 184 y old, we generate genomic-scale data from across the entire assemblage of Australian hydromyine rodents (i.e., eight extinct species and their 42 living relatives). We reconstruct a phylogenomic tree for these species spanning ∼5.2 million years, revealing a cumulative total of 10 million years (>10%) of unique evolutionary history lost to extinction within the past ∼150 y. We find no evidence for reduced genetic diversity in extinct species just prior to or during decline, indicating that their extinction was extremely rapid. This suggests that populations of extinct Australian rodents were large prior to European colonization, and that genetic diversity does not necessarily protect species from catastrophic extinction. In addition, comparative analyses suggest that body size and biome interact to predict extinction and decline, with larger species more likely to go extinct. Finally, we taxonomically resurrect a species from extinction, Gould's mouse (Pseudomys gouldii Waterhouse, 1839), which survives as an island population in Shark Bay, Western Australia (currently classified as Pseudomys fieldi Waite, 1896). With unprecedented sampling across a radiation of extinct and living species, we unlock a previously inaccessible historical perspective on extinction in Australia. Our results highlight the capacity of collections-based research to inform conservation and management of persisting species.

Modelling the amphibian chytrid fungus spread by connectivity analysis: towards a national monitoring network in Italy

The emerging amphibian disease, Batrachochytrium dendrobatidis (Bd), is driving population declines worldwide and even species extinctions in Australia, South and Central America. In order to mitigate effects of Bd on amphibian populations, high-exposed areas should be identified at the local scale and effective conservation measures should be planned at the national level. This assessment is actually lacking in the Mediterranean basin, and in particular in Italy, one of the most relevant amphibian diversity hotspots in the entire region. In this study, we reviewed the available information on Bd in Italy, and conducted a 5-year molecular screening on 1274 individual skin swabs belonging to 18 species. Overall, we found presence of Bd in 13 species and in a total of 56 known occurrence locations for peninsular Italy and Sardinia. We used these occurrence locations and climate data to model habitat suitability of Bd for current and future climatic scenarios. We then employed electric circuit theory to model landscape permeability to the diffusion of Bd, using a resistance map. With this procedure, we were able to model, for the first time, the diffusion pathways of Bd at the landscape scale, characterising the main future pathways towards areas with a high probability of Bd occurrence. Thus, we identified six national protected areas that will become pivotal for a nationally-based strategic plan in order to monitor, mitigate and possibly contrast Bd diffusion in Italy.

Vertebrate Life, 10th edition

Vertebrate Life, 10th edition

Late survival of megafauna refuted for Cloggs Cave, SE Australia: Implications for the Australian Late Pleistocene megafauna extinction debate

Understanding of Late Pleistocene megafaunal extinctions in Australia and New Guinea (Sahul) suffers from a paucity of reliably dated bone deposits. Researchers are divided as to when, and why, large-bodied species became extinct. Critical to these interpretations are so-called ‘late survivors’, megafauna that are thought to have persisted for tens of thousands of years after the arrival of people. While the original dating of most sites with purported late survivors has been shown to have been erroneous or problematic, one site continues to feature: Cloggs Cave. Here we report new results that show that Cloggs Cave’s youngest megafauna were deposited in sediments that date to 44,500–54,160 years ago, more than 10,000 years older than previously thought, bringing them into chronological alignment with the emerging continental pattern of megafaunal extinctions. Our results indicate that the youngest megafauna specimens excavated from Cloggs Cave datedate to well before the Last Glacial Maximum (LGM), and their demise could not have been driven by climate change leading into the LGM, the peak of the last Ice Age.

Alec Chisholm and the extinction of the Paradise Parrot

Rediscovered in 1921 after several decades of feared extinction, the resurrection of the Paradise Parrot was brief. Within a few decades more, the parrot was actually extinct, making it the only mainland Australian bird species known to have suffered that fate since colonisation. This article explores the reasons for the paucity and ineffectuality of attempts to preserve the species in the interwar years. By examining the contemporary state of ornithological knowledge on endangered species and the limited repertoire of conservationist strategies then available, the article extends our understanding of early twentieth-century discourses on avian extinction in Australia. It also offers an assessment of the conservationist efforts of Alec Chisholm, an amateur ornithologist who had a major role in the rediscovery of the Paradise Parrot and in subsequently publicising its plight.

Development of the Mata Hari Judas Queen (Felis catus).

Simple SummaryPredation by introduced feral cats is one of the main drivers of extinction in Australian mammals and they have been implicated in reducing populations of birds, frogs and reptiles. Current control techniques e.g., fencing, baiting, trapping and shooting for the management of cats are costly, labour intensive and fail to eradicate entire populations which allows survivors to re-establish populations. The Mata Hari Judas (MHJ) technique i.e., inducing prolonged oestrus using hormone implants, can enhance the eradication of remnant feral animals after the majority of their population has been killed. The hypotheses tested in this study were that hormone implants could induce prolonged oestrus in queens (adult female cats), and that prolonging oestrus resulted in sustained attractiveness to toms (adult male cats). This study shows that it is possible to induce and prolong oestrus in queens using hormone implants where these queens are attractive to toms. The MHJ queen is a new tool with the potential to enhance detection and thus the control of feral cats in remnant populations.Cats (Felis catus) are significant predators of mammals, birds, frogs and reptiles and are implicated in mammal species extinctions in Australia. Current controls fail to eradicate entire populations allowing survivors to re-establish. The use of the Mata Hari Judas (MHJ) technique, i.e., inducing prolonged oestrus using hormone implants, can enhance the eradication of remnant animals and would greatly improve conservation efforts. The hypotheses tested were that hormone implants could induce prolonged oestrus in queens (adult female cats), and that prolonging oestrus would result in sustained attractiveness to toms (adult male cats). Queens (n = 14) were randomly allocated to five treatments including a control and four treatments using hormone implants. Queens were observed daily; alone and during indirect contact with a tom for 30 consecutive days. There were significant increases (p < 0.001) in oestrus duration (19 to 27 days) for entire and ovariohysterectomised queens given Compudose100™ implants (1/8 or 1/4 implant). This study shows that it is possible to induce and prolong oestrus in queens using Compudose100™ implants where these queens are attractive to toms. The MHJ queen is a new tool with the potential to enhance the detection and thus the control of feral cats in remnant populations.

Integrative taxonomic investigation ofPetaurus breviceps(Marsupialia: Petauridae) reveals three distinct species

AbstractThe Australian sugar glider, Petaurus breviceps s.l., is widely distributed across eastern and northern Australia. Examination of historical and contemporary collections of Petaurus specimens and phylogenetic analyses have revealed considerable taxonomic diversity within the genus. We aimed to utilize an integrative taxonomic approach, combining genetic and morphological evidence, to resolve the taxonomy of Australian gliders currently recognized as Petaurus breviceps. Herein, we confirm the existence of three distinct species: P. breviceps, P. notatus comb. nov. and P. ariel comb. nov.. Petaurus breviceps and P. notatus are each represented by major mtDNA lineages in P. breviceps, while P. ariel forms a sister-lineage to P. norfolcensis and P. gracilis. Subtle morphological differences distinguish P. breviceps from the closely related P. notatus, while the morphological distinctions between P. ariel and its genetically similar sister-taxa, P. norfolcensis and P. gracilis, are more obvious. Given the purported broad geographic distribution of the taxon, P. breviceps s.l. was not listed as threatened, but dividing this taxon into three species has important conservation implications for all taxa in the group, particularly given the lamentable record for mammal extinctions in Australia. Concerted and targeted conservation efforts are necessary to preserve these distinct, newly described species.

Index to Titles and Authors/Editors of Books Reviewed

Index to Titles and Authors/Editors of Books Reviewed

When all life counts in conservation.

Conservation science involves the collection and analysis of data. These scientific practices emerge from values that shape who and what is counted. Currently, conservation data are filtered through a value system that considers native life the only appropriate subject of conservation concern. We examined how trends in species richness, distribution, and threats change when all wildlife count by adding so-called non-native and feral populations to the International Union for Conservation of Nature Red List and local species richness assessments. We focused on vertebrate populations with founding members taken into and out of Australia by humans (i.e., migrants). We identified 87 immigrant and 47 emigrant vertebrate species. Formal conservation accounts underestimated global ranges by an average of 30% for immigrants and 7% for emigrants; immigrations surpassed extinctions in Australia by 52 species; migrants were disproportionately threatened (33% of immigrants and 29% of emigrants were threatened or decreasing in their native ranges); and incorporating migrant populations into risk assessments reduced global threat statuses for 15 of 18 species. Australian policies defined most immigrants as pests (76%), and conservation was the most commonly stated motivation for targeting these species in killing programs (37% of immigrants). Inclusive biodiversity data open space for dialogue on the ethical and empirical assumptions underlying conservation science.

Employing Green Roofs to Support Endangered Plant Species: The Eastern Suburbs Banksia Scrub in Australia

The purpose and context for the study relates to urban growth. Australian cities are experiencing particularly rapid urbanization, taking the form of land clearing to accommodate outward expansion as well as developing to higher densities in existing urban areas. Both forms of development degrade native biodiversity, resulting in loss of vegetation with the possibility that the remnant indigenous plants will become locally extinct. One endangered ecological community in Sydney, the Eastern Suburbs Banksia Scrub (ESBS), still survives along some sections of Sydney’s heavily urbanized coastline. At the time of European settlement, the ESBS covered approximately 5300 ha, but it is now a highly fragmented 146 ha across 24 sites with some sites under imminent threat of development. Conservation legislation enacted by the state of New South Wales (NSW), Australia has declared the ESBS as critically endangered. Despite recovery plans, in 2016 the NSW Threatened Species Scientific Committee indicated that the community faces an extremely high risk of extinction in Australia in the immediate future. A practical option in the face of declining open space in our cities is to examine the potential of urban rooftops for conserving and propagating threatened or endangered flora. While there is a limited amount of international research on using green roofs for endangered plant protection, there is no information from Australia about how green roofs perform in this geographic region. The approach taken in this research has been firstly, to review the current academic and “grey” literature from a global perspective to identify options for conserving endangered flora on green roofs. We derive an evidence-based research protocol to be used to test the green roof environment in Sydney for propagating the endangered ESBS. We establish the general applicability of green roofs for protecting vanishing flora through the literature review and conclude that our research design will be a suitable framework for the task for monitoring growth and germination performance over the ESBS community’s development cycle, with the longer-term objective of establishing a viable rooftop seed orchard.

Objectives versus realities: Spatial, temporal, financial and social deficiencies in Australia’s public revegetation investment model

SummaryPast and continuing fragmentation and modification of ecosystems, as well as other threatening processes, cause ongoing biodiversity losses and species extinctions in Australia. At the same time as biodiversity declines, government funding for conservation and restoration is diminishing, leading to reduced action and greater reliance on private investment and community groups. In order to maintain and restore biodiverse ecosystems and the essential services they provide, both conservation of existing vegetation and habitat reconstruction are required. In this paper, we summarise the available data on planting area and cost from the Australian Government’s 20 Million Trees programme (2014–2020), the largest recent national‐scale revegetation incentives programme in Australia. We find that the current spatial scale of effort and investment in habitat reconstruction is insufficient to match the scale required to meet national conservation objectives. Furthermore, the funding rate ($/ha) and contracting arrangements are inadequate for the establishment of high‐quality self‐sustaining vegetation needed for the recovery of Australia’s threatened species and ecological communities. We estimate that the minimum amount of funding required for habitat reconstruction is at least five times higher than is provided for current national flagship programmes such as 20 Million Trees. We provide recommendations, designed to assist future habitat reconstruction programmes achieve their long‐term biodiversity objectives.

The other side of the Sahulian coin: biogeography and evolution of Melanesian forest dragons (Agamidae)

AbstractNew Guinea has been considered both as a refuge for mesic rainforest-associated lineages that contracted in response to the late Cenozoic aridification of Australia and as a centre of biotic diversification and radiation since the mid-Miocene or earlier. Here, we estimate the diversity and a phylogeny for the Australo-Papuan forest dragons (Sauria: Agamidae; ~20 species) in order to examine the following: (1) whether New Guinea and/or proto-Papuan Islands may have been a biogeographical refuge or a source for diversity in Australia; (2) whether mesic rainforest environments are ancestral to the entire radiation, as may be predicted by the New Guinea refuge hypothesis; and (3) more broadly, how agamid ecological diversity varies across the contrasting environments of Australia and New Guinea. Patterns of lineage distribution and diversity suggest that extinction in Australia, and colonization and radiation on proto-Papuan islands, have both shaped the extant diversity and distribution of forest dragons since the mid-Miocene. The ancestral biome for all Australo-Papuan agamids is ambiguous. Both rainforest and arid-adapted radiations probably started in the early Miocene. However, despite deep-lineage diversity in New Guinea rainforest habitats, overall species and ecological diversity is low when compared with more arid areas, with terrestrial taxa being strikingly absent.