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... Invasive species rank among the greatest threats to biodiversity, and have been implicated in many cases of decline and extinction of native taxa [1,2]. The need to understand those threats has stimulated extensive research on the impacts of biological invasions, but the majority of those studies have focused on short-term impacts [3]. ...
... The location and timing of resource availability can greatly impact an animal's vulnerability to threatening ecological processes [58]. In this case, the invasive (toxic) cane toad may be one of the few large prey items available to yellow-spotted monitors at some times of year-especially, since the decline of small mammals across most of the range of this varanid species [2,[59][60][61]. In keeping with dietary analyses that report frequent consumption of small mammals the landscape (uninvaded-toads not present; recently invaded-toads present for 1-12 varanid generations; mid-term invaded-toads present for 13-29 varanid generations; long-term invaded-toads present for 30-80 varanid generations). ...
... The near-extirpation of large varanids induces mesopredator release, with potential impacts on smaller prey [6]. Hence, invasive toads may indirectly depress prey availability for varanids, via trophic cascades-exacerbating the dramatic reduction in prey resources caused by the disappearance of small mammals across most of tropical Australia [2,61]. ...
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Biological invasions can massively disrupt ecosystems, but evolutionary and ecological adjustments may modify the magnitude of that impact through time. Such post-colonisation shifts can change priorities for management. We quantified the abundance of two species of giant monitor lizards, and of the availability of their mammalian prey, across 45 sites distributed across the entire invasion trajectory of the cane toad (Rhinella marina) in Australia. One varanid species (Varanus panoptes from tropical Australia) showed dramatic population collapse with toad invasion, with no sign of recovery at most (but not all) sites that toads had occupied for up to 80 years. In contrast, abundance of the other species (Varanus var-ius from eastern-coastal Australia) was largely unaffected by toad invasion. That difference might reflect availability of alternative food sources in eastern-coastal areas, perhaps exacerbated by the widespread prior collapse of populations of small mammals across tropical (but not eastern) Australia. According to this hypothesis, the impact of cane toads on apex predators has been exacerbated and prolonged by a scarcity of alternative prey. More generally , multiple anthropogenically-induced changes to natural ecosystems may have syner-gistic effects, intensifying the impacts beyond that expected from either threat in isolation.
... Governments around the world have largely failed to produce or to implement policies, and to provide the necessary resources to effectively arrest and reverse the biodiversity declines [5,6]. In northern Australia, mammal species continue to decline [7], despite a mostly intact vegetation [8]. While much biodiversity loss can be attributed to direct human impacts, they are not always good predictors [9,10]. ...
... The extinctions and declines in apparently intact landscapes in Australian arid and semi-arid zones are well documented [7,20,25], but despite more than a century of records and studies, the status of biodiversity across these regions, and of the tropical savannas of northern Australia, is relatively poorly known. Since the 1990s, dramatic declines in mam-mal fauna richness and abundance have been observed in the northern part of the Northern Territory (NT) and the Kimberley region of Western Australia [7,[26][27][28] but the understanding of the trends across the region is based almost entirely on monitoring for around three decades in just three national parks in the NT [22,23,[29][30][31], plus a number of autecological studies of species [32][33][34][35]. ...
... The extinctions and declines in apparently intact landscapes in Australian arid and semi-arid zones are well documented [7,20,25], but despite more than a century of records and studies, the status of biodiversity across these regions, and of the tropical savannas of northern Australia, is relatively poorly known. Since the 1990s, dramatic declines in mam-mal fauna richness and abundance have been observed in the northern part of the Northern Territory (NT) and the Kimberley region of Western Australia [7,[26][27][28] but the understanding of the trends across the region is based almost entirely on monitoring for around three decades in just three national parks in the NT [22,23,[29][30][31], plus a number of autecological studies of species [32][33][34][35]. The currency of declines has been reinforced recently in Kakadu National Park [31,36]. ...
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Northern Australian biomes hold high biodiversity values within largely intact vegetation complexes, yet many species of mammals, and some other taxa, are endangered. Recently, six mammal species were added to the 20 or so already listed in the Australian endangered category. Current predictions suggest that nine species of mammal in northern Australia are in imminent danger of extinction within 20 years. We examine the robustness of the assumptions of status and trends in light of the low levels of monitoring of species and ecosystems across northern Australia, including monitoring the effects of management actions. The causes of the declines include a warming climate, pest species, changed fire regimes, grazing by introduced herbivores, and diseases, and work to help species and ecosystems recover is being conducted across the region. Indigenous custodians who work on the land have the potential and capacity to provide a significant human resource to tackle the challenge of species recovery. By working with non-Indigenous researchers and conservation managers, and with adequate support and incentives, many improvements in species' downward trajectories could be made. We propose a strategy to establish a network of monitoring sites based on a pragmatic approach by prioritizing particular bioregions. The policies that determine research and monitoring investment need to be re-set and new and modified approaches need to be implemented urgently. The funding needs to be returned to levels that are adequate for the task. At present resourcing levels, species are likely to become extinct through an avoidable attrition process .
... This may reflect, in part, differences in risk perception among participants who assessed extinction probability in frogs compared with those who assessed the other taxa. However, given that Australian mammals have had the highest historic rates of extinction (Woinarski et al. 2019), one explanation could be that many of the most vulnerable mammal taxa have already been lost. Additionally, a common management response for mammals is the exclusion of predators or translocation to predator-free islands . ...
... The historical pattern of frog declines in Australia is very different to that of the other taxonomic groups. Birds and mammals have experienced near constant rates of extinction over the past two centuries (Scheele and Gillespie 2018;Woinarski et al. 2019), which has been largely attributed to habitat loss and introduced predators Woinarski et al. 2015). Both these threats have contributed substantially to Australian frog declines, but they have not been directly and exclusively implicated in any amphibian extinctions to date (Scheele et al. 2017). ...
... In the past few decades, several frog species have become extinct (attributable to B. dendrobatidis). By contrast, the first documented Australian reptile and freshwater fish extinctions were recorded only recently; the Christmas Island forest skink (Emoia nativitatis) and the Kangaroo River Macquarie Perch (Macquaria sp.), both of which were attributed to invasive species (Woinarski et al. 2019;Lintermans et al. 2020). ...
Article
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More than a third of the world’s amphibian species are listed as Threatened or Extinct, with a recent assessment identifying 45 Australian frogs (18.4% of the currently recognised species) as ‘Threatened’ based on IUCN criteria. We applied structured expert elicitation to 26 frogs assessed as Critically Endangered and Endangered to estimate their probability of extinction by 2040. We also investigated whether participant experience (measured as a self-assigned categorical score, i.e. ‘expert’ or ‘non-expert’) influenced the estimates. Collation and analysis of participant opinion indicated that eight species are at high risk (>50% chance) of becoming extinct by 2040, with the disease chytridiomycosis identified as the primary threat. A further five species are at moderate–high risk (30–50% chance), primarily due to climate change. Fourteen of the 26 frog species are endemic to Queensland, with many species restricted to small geographic ranges that are susceptible to stochastic events (e.g. a severe heatwave or a large bushfire). Experts were more likely to rate extinction probability higher for poorly known species (those with <10 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.
... Australia's distinctive mammal fauna has especially suffered over this period with 34 endemic land mammals (more than 10% of ca. 320 native land mammal species) now rendered extinct (Woinarski et al., 2019b), and a further 66 recognised as threatened, while many more species continue to decline (Stobo-Wilson et al., 2019;Woinarski et al., 2001). ...
... We derived a list of Australian land mammal species from the comprehensive taxonomic review by Jackson and Groves (2015), and updated this following some recent taxonomic changes (see Supplementary material, Table S1). We included extinct, marine and introduced mammal species in the compilation but, unless otherwise stated, excluded them from analyses because our focus related to the conservation of extant native land mammals and all fox dietary studies in our collation post-dated Australian mammal extinctions within the fox's range (Woinarski et al., 2019b). ...
... Note that the timing of extinction of some Australian mammal species may have pre-dated the arrival of the fox within the species' range. To identify such species, we matched the likely extinction date given in Woinarski et al. (2019b) for every extinct Australian mammal species to the historical spread of the fox given in Fairfax (2019). We used binomial GLMs to explore whether threatened and extinct non-flying mammal species had a greater predicted likelihood of predation by the fox (species outside the fox's range were given a zero risk of predation by the fox) and/or cat compared to species that are not threatened. ...
Article
Two introduced carnivores, the European red fox Vulpes vulpes and domestic cat Felis catus, have had, and continue to have, major impacts on wildlife, particularly mammals, across Australia. Based mainly on the contents of almost 50,000 fox dietary samples, we provide the first comprehensive inventory of Australian mammal species known to be consumed by foxes, and compare this with a similar assessment for cats. We recorded consumption by foxes of 114 species of Australian land mammal (40% of extant species), fewer than consumed by cats (173 species). Foxes are known to consume 42 threatened mammal species (50% of Australia's threatened land mammals and 66% of those within the fox's Australian range). Reflecting the importance of mammals in their diet, foxes are known to consume a far higher proportion of Australian mammal species (40%) than of Australian birds (24%) and reptiles (16%). Both foxes and cats were most likely to consume medium-sized mammals, with the likelihood of predation by foxes peaking for mammals of ca. 280 g and by cats at ca. 130 g. For non-flying mammals, threatened species had a higher relative likelihood of predation by foxes than non-threatened species. Using trait-based modelling, we estimate that many now-extinct Australian mammal species had very high likelihoods of predation by foxes and cats, although we note that for some of these species, extinction likely pre-dated the arrival of foxes. These two predators continue to have compounding and complementary impacts on Australian mammals. Targeted and integrated management of foxes and cats is required to help maintain and recover the Australian mammal fauna.
... Other anthropogenic extinction drivers include climate change, agricultural expansion and pesticides, logging, environmental mismanagement, pollution and overexploitation, over-hunting/fishing, and the introduction of invasive species (Dexter et al. 1995, Hooper et al. 2012, Hoffmann et al. 2019. A lack of government action to save species -particularly in Australia -is a further challenge (Woinarski et al. 2017, 2019a, Wintle et al. 2019. Mammal species are particularly vulnerable to extinction and approximately one quarter of all global mammal species are threatened (Ceballos and Ehrlich 2002, Johnson 2006, Hoffmann et al. 2011, IUCN 2020. ...
... Since its European colonisation, 34 Australian mammal species have been confirmed as extinct or extinct in the wild (Woinarski et al. 2019a(Woinarski et al. , 2019b (Fig. 1-2). squares include subspecies. ...
... Rapid anthropogenic climate change is a key threat to many arid zone species globally (Peterson and Vieglais 2001, Beaumont and Hughes 2002, Peterson et al. 2002, Thuiller et al. 2006, Steffen 2009, IPCC 2014, McLean 2015 Recovery Reserve 2019, Woinarski et al. 2019a). In Australia, recent and rapid climatic changes have already caused mass population crashes and extinctions (Hughes 2003, Holmgren et al. 2006, Welbergen et al. 2007, Steffen 2009, Adams-Hosking et al. 2011, Waller et al. 2017). ...
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We are experiencing a global biodiversity and climate crisis that is rapidly causing the extinction of species. Mammal species have been disproportionately affected; however, this trend is considerably worse in Australia. Since Australia’s occupation by Europeans, 34 mammal species have been declared extinct. Australian mammals in deserts are particularly at risk of extinction. Many arid zone mammals have specialised adaptations to their hostile, unpredictable ecosystems. For example, they use thermally insulative refuges, prefer habitats that reduce predation risk, or have large home ranges and broad diets to maximise energy intake. Understanding these adaptations is essential for informed conservation management. However, little ecological data is known for the sandhill dunnart, Sminthopsis psammophila, an endangered and charismatic marsupial that now remains within just a few natural refugial habitats in Australia’s southern deserts. To address conservation biology knowledge gaps, an integrated, evidence-based approach (i) quantified the diurnal and nocturnal ecology of S. psammophila in the Western Australian Great Victoria Desert (WAGVD), (ii) estimated the past, present and future distributions of S. psammophila throughout Australia, (iii) examined the key threats to S. psammophila - particularly wildfires and anthropogenic climate change - and (iv) proposed conservation management solutions for a) S. psammophila and b) sympatric arid zone species. Between 2015 and 2019, radio tracking and global positioning system (GPS) technologies examined the sheltering, foraging, dietary and habitat preferences of S. psammophila in the WAGVD. In contrast to its previously reported habitat preferences, S. psammophila preferred burrowing within long unburned (32+ years since a wildfire) spinifex (Triodia spp.) grassland habitats. Dense lower stratum swale, sand plain and dune slope habitats were preferred, whereas habitats lacking spinifex and open dune crest habitats were rarely used. Hence, wildfires were identified as a significant threat to the species. The sheltering preferences of S. psammophila agreed with the premise that small desert mammals often use shelters with thermal advantages and anti-predation benefits, such as burrows, Lepidobolus deserti hummocks and logs. Conversely, spinifex hummocks were not found to be insulative against extreme temperatures and were not preferred. The foraging adaptations of S. psammophila agreed with the premise that arid zone species often have large home ranges to exploit resource patches or islands. The 100 % home ranges of S. psammophila [mean: 70 ha; range: 6-274 ha; minimum convex polygon (MCP)] were influenced by sex and reproductive status. In addition, a Formicine-rich diet indicated that ants are an important dietary resource for S. psammophila. Species distribution models (SDMs) predicted the past, present, and future distributions of S. psammophila, evaluated the environmental parameters that determine the species’ distribution and identified habitats of high conservation value. The past model supported evidence that S. psammophila was widespread but has recently contracted to more climatically favourable areas of its geographic range. Ground-validation of the present model’s predictions discovered a population 150 km north of the species’ known range. Future models identified that climate change is a potential catastrophic threat for S. psammophila. By 2050, under Representative Concentration Pathway (RCP) 8.5 (our current pathway) there is a predicted 95 % reduction in suitable habitat for S. psammophila in the WAGVD. By 2070 (RCP 8.5), only the Eyre Peninsula population may remain viable and the continental distribution of S. psammophila may contract by up to 80 %. However, this contraction is predicted to be halved if global greenhouse gas emissions peak in 2040 then reduce (RCP 4.5). Due to specific habitat preferences for long unburned habitats, S. psammophila is further restricted within its climatically and geographically suitable range. As a semi-arid specialist, it is also vulnerable to drought-related population crashes. Hence, S. psammophila should remain listed as endangered at the state and federal level, and its status should be revised by the International Union for Conservation of Nature.
... The severity of anthropogenic extinction is well illustrated in Australia, where 34 species of mammals have become extinct since European colonization of the island continent in 1788 (10,11). ...
... Body size has previously been associated with extinction risk in Australian mammals, especially in the "critical weight range" of between 35 and 5,500 g (14,(47)(48)(49), which includes the majority of native rodents (∼8 to 1,200 g; ref. 12) and suggests that larger rodents are at greater risk. Patterns of post-1788 extinctions in both Australian plants and animals also suggest that extinction has been highest in the arid biome (11), where lower and more variable productivity can cause species to be more susceptible to ecosystem disturbances and competition with introduced species (47). While the majority of previous studies have focused on marsupials, Smith and Quin (48) found that range declines in Australian rodents increased with body size and were most severe in arid and temperate mesic biomes. ...
... In synonymizing the extant P. fieldi with P. gouldii, we taxonomically resurrect a species from an otherwise increasing list of mammalian extinctions in Australia since European settlement (10,11). However, this species survived extinction via persistence on a single predator-free offshore island in Shark Bay, Western Australia, thereby only retaining remnant genetic diversity. ...
Article
Significance Native rodents represent 41% of Australian mammal extinctions since European colonization. To determine the scale and timing of their decline, we used museum specimens to generate genome-scale data from eight extinct Australian rodents and their 42 living relatives. Relatively high genetic diversity in extinct species immediately prior to extinction in the 19th or 20th century indicates that their populations were previously large and that declines began after European colonization of Australia. This demonstrates that genetic diversity does not necessarily provide insurance against catastrophic extinction events. Our results show that extinction risk was elevated for larger-bodied rodents and varied among biomes. In addition, we taxonomically resurrect an extinct species, Gould’s mouse, which survives on an island in Shark Bay, Western Australia.
... Adequate assessment of the conservation status of many wildlife species in Australia and around the world is hampered by limited information on abundance and distribution (Joppa et al., 2011;Pimm et al., 2014;Woinarski et al., 2015). Biodiversity loss is increasing globally (Butchart et al., 2010) and on the Australian continent is likely worse than we currently realise (Wayne et al., 2017;Woinarski et al., 2019). Historical causal factors of decline such as habitat loss, introduced predators and a range of anthropogenic influences are now being exacerbated by changes to climate (Bradshaw, 2012;Urban, 2015;Woinarski et al., 2019). ...
... Biodiversity loss is increasing globally (Butchart et al., 2010) and on the Australian continent is likely worse than we currently realise (Wayne et al., 2017;Woinarski et al., 2019). Historical causal factors of decline such as habitat loss, introduced predators and a range of anthropogenic influences are now being exacerbated by changes to climate (Bradshaw, 2012;Urban, 2015;Woinarski et al., 2019). In Australia, there have been multiple species extinctions (Woinarski et al., 2019(Woinarski et al., , 2015 and 580 extant plant and animal species are classified as endangered or critically endangered (IUCN, 2020). ...
... Historical causal factors of decline such as habitat loss, introduced predators and a range of anthropogenic influences are now being exacerbated by changes to climate (Bradshaw, 2012;Urban, 2015;Woinarski et al., 2019). In Australia, there have been multiple species extinctions (Woinarski et al., 2019(Woinarski et al., , 2015 and 580 extant plant and animal species are classified as endangered or critically endangered (IUCN, 2020). Many speciesʼ populations are in decline while the status of many others remains unknown (IUCN, 2020). ...
Article
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Short-beaked echidna (Tachyglossus aculeatus) are a cryptic and iconic monotreme found throughout the continent of Australia. Despite observational records spanning many years aggregated in national and state biodiversity databases, the spatial and temporal intensity of sightings is limited. Although the species is of least conservation concern at the global level, a subspecies has been declared endangered on Kangaroo Island in South Australia. We need better population data over the whole continent to inform this species’ conservation management. To increase the temporal and spatial resolution of observations which may be used for more accurate population assessments, we developed a mobile app for citizen scientists to easily record echidna sightings and improve the quantity, quality and distribution of data collected for monitoring this species. EchidnaCSI is a free, cross-platform (Android & iOS), open-source app that we developed to collect echidna observational data around Australia. EchidnaCSI has been in use since September 2017 and uses mobile phone sensors to transparently and automatically record metadata, such as species observation location and time and GPS location precision. We examine differences in spatial coverage between these observations and those in existing data repositories in the Atlas of Living Australia and state biodiversity databases, especially in relation to observations in protected areas and to an index of remoteness and accessibility. EchidnaCSI has contributed over 8000 echidna observations from around Australia, more than recorded in all state systems combined, with similar spatial distribution. Although coverage was more limited in some protected areas than the reference data sources, numbers of observations in all remote areas were greater than the reference scientific data except for very remote regions. EchidnaCSI has improved the spatial and temporal intensity of observations for this iconic species and provides a complement to scientific surveys, which might usefully focus on highly protected areas and very remote regions.
... Quenda (Isoodon fusciventer), recently recognised as a species distinct from the southern brown bandicoot (Isoodon obesulus, Marsupialia, Peramelidae;Travouillon and Phillips (2018)), is a medium-sized, crepuscular and nocturnal marsupial (400-1850 g) that has been extirpated from much of its historical range (Department of Sustainability 2011) largely as a result of habitat loss (Paull 1995;Bryant et al. 2017;Ramalho et al. 2018). Predation by introduced species is also a key driver of population declines and extinctions of other native Australian mammals (Woinarski et al. 2015(Woinarski et al. , 2019, and presumably has played a role in the plight of Quenda, although published support of this is lacking. This bandicoot, and related species prefer dense understory vegetation in heathlands and treed habitats (Stoddart and Braithwaite 1979a;Haby et al. 2013;Robinson et al. 2018), and Quenda forages for fungi and invertebrates through leaf-litter and by digging small, and highly distinctive pits in the soil (Valentine et al. 2018). ...
... The Quenda population at Kings Park has apparently survived well following an unauthorised introduction, and has expanded to use most areas of the reserve and adapt to disturbances therein. The decline of Quenda populations, and their contraction from a much broader distribution prior to European settlement have typically been associated with land use change (Paull 1995;Bryant et al. 2017;Ramalho et al. 2018), and presumably Quenda are also susceptible to predation by introduced cats and foxes, as have been implicated in the decline of so many other Australian native mammals (Woinarski et al. 2015(Woinarski et al. , 2019. Kings Park, however, is managed as an A-Class conservation reserve, and these pressures may be less threatening to Quenda as a result (despite the presence of a population of foxes in the Park; (Jackson et al. 2007)). ...
Article
Although urbanisation can result in habitat loss, some species persist within urban vegetation remnants. Due to urban development, these species are often the targets of mitigation translocation; for example, the Quenda (Isoodon fusciventer, Marsupialia, Peramelidae), native to southwestern Australia. We assessed the foraging patterns and habitat preferences of a population of Quenda recently introduced by unknown agents to Kings Park, a large urban bushland remnant. Quenda foraged actively throughout our study area, but foraged most intensively in dense, low vegetation, with a significant preference for communities dominated by Banksia sessilis. This study joins other literature indicating that Quenda are able to persist in modified urban vegetation remnants despite the presence of predators, and human activity. Given the Quenda's clear adaptability to introduction into this urban remnant, we suggest that the greatest threat to continued persistence of urban populations of this species within remnants is likely to relate to difficulties in dispersing through surrounding urban areas. Nevertheless, the successful return of Quenda to a site that has traditionally been discounted from translocation programs suggests that other reserves in the region could also host introductions. Further research is required to determine whether Quenda can disperse through the surrounding suburbs, and whether it is possible to modify novel habitats to support Quenda populations within urban areas. Additionally, further research on facilitating dispersal through managing meta-populations in urban areas is required. Nevertheless, Quenda have successfully established at Kings Park, surrounded by dense urban areas. With ongoing management, urban remnants may be useful in Australia's protected area network.
... Introduced predators have been a major cause of bird extinctions and declines globally (Blackburn et al. 2004, Szabo et al. 2012. The European red fox Vulpes vulpes (hereafter fox) and domestic cat Felis catus (hereafter cat) have had catastrophic impacts on Australian biodiversity, causing numerous extinctions and ongoing declines of many native animal species (Johnson 2006, Abbott, Peacock and Short 2014, Woinarski et al. 2019a. The Australian fox population derives from introductions in the 1870s, with subsequent spread across most of the mainland: it also now occurs on about 40 islands (Abbott et al. 2014). ...
... Following Woinarski et al. (2017b), we categorise bird species as threatened if, at the species or subspecies level, they are listed as Critically Endangered, Endangered or Vulnerable under Australian national legislation or by the International Union for the Conservation of Nature (IUCN), as at October 2020. We also note any confirmed records of predation by foxes on now extinct Australian birds, but exclude extinct birds from analyses as almost all Australian bird extinctions preceded the set of fox dietary studies that form the main component of our collation (Woinarski et al. 2019a). ...
Article
Two introduced carnivores, the European red fox Vulpes vulpes and domestic cat Felis catus , have had extensive impacts on Australian biodiversity. In this study, we collate information on consumption of Australian birds by the fox, paralleling a recent study reporting on birds consumed by cats. We found records of consumption by foxes on 128 native bird species (18% of the non-vagrant bird fauna and 25% of those species within the fox’s range), a smaller tally than for cats (343 species, including 297 within the fox’s Australian range, a subset of that of the cat). Most (81%) bird species eaten by foxes are also eaten by cats, suggesting that predation impacts are compounded. As with consumption by cats, birds that nest or forage on the ground are most likely to be consumed by foxes. However, there is also some partitioning, with records of consumption by foxes but not cats for 25 bird species, indicating that impacts of the two predators may also be complementary. Bird species ≥3.4 kg were more likely to be eaten by foxes, and those <3.4 kg by cats. Our compilation provides an inventory and describes characteristics of Australian bird species known to be consumed by foxes, but we acknowledge that records of predation do not imply population-level impacts. Nonetheless, there is sufficient information from other studies to demonstrate that fox predation has significant impacts on the population viability of some Australian birds, especially larger birds, and those that nest or forage on the ground.
... Australia has one of the worst mammal extinction records of any country over the past 200 years (Woinarski et al. 2019), and the northern part of the continent, widely considered ecologically 'intact', is currently experiencing a drastic decline of its native mammal fauna, most likely due to habitat degradation , introduced species (Stobo-Wilson et al. 2020; Radford et al. 2020), inappropriate fire regimes (Woinarski et al. 2011;) and a changing climate (Kutt et al. 2009;Traill et al. 2011). In northern Australia, there have been very few range-wide studies of population genetics using nextgeneration sequencing with large genome-wide singlenucleotide polymorphism (SNP) datasets. ...
... albipes) and the Capricorn rabbit-rat (C. capricornensis) (Cramb and Hocknull 2010;Woinarski et al. 2019). The brush-tailed rabbit-rat is known from both Australia and Papua New Guinea (PNG), although very little is known about the species in PNG. ...
Article
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Conservation management is improved by incorporating information about the spatial distribution of population genetic diversity into planning strategies. Northern Australia is the location of some of the world's most severe ongoing declines of endemic mammal species, yet we have little genetic information from this regional mammal assemblage to inform a genetic perspective on conservation assessment and planning. We used next-generation sequencing data from remnant populations of the threatened brush-tailed rabbit-rat (Conilurus penicillatus) to compare patterns of genomic diversity and differentiation across the landscape and investigate standardised hierarchical genomic diversity metrics to better understand brush-tailed rabbit-rat population genomic structure. We found strong population structuring, with high levels of differentiation between populations (F ST = 0.21-0.78). Two distinct genomic lineages between the Tiwi Islands and mainland are also present. Prioritisation analysis showed that one population in both lineages would need to be conserved to retain at least~80% of alleles for the species. Analysis of standardised genomic diversity metrics showed that approximately half of the total diversity occurs among lineages (δ = 0.091 from grand total γ = 0.184). We suggest that a focus on conserving remnant island populations may not be appropriate for the preservation of species-level genomic diversity and adaptive potential, as these populations represent a small component of the total diversity and a narrow subset of the environmental conditions in which the species occurs. We also highlight the importance of considering both genomic and ecological differentiation between source and receiving populations when considering translocations for conservation purposes.
... However, the magnitude, rate and geographical extent of the declines are not well understood. There is abundant evidence from multiple sources (rates of extinction (Woinarski et al. 2019), expert opinion (Valentine 2004;Pickrell 2019), historical records (Braby 2019) and temporal replication of surveys (Newland 2006;Rix et al. 2017;James & James 2019)) to demonstrate the extinction of species, extirpation of local populations or decline in population size, but this is highly context dependent on the spatial and temporal scales studied ( Fig. 1) (Braby 2019). Thus, in historical times (40-100 years ago) and in the recent past (10-40 years ago), there is evidence from historical records (data from museum collections, field notebooks and/or scientific literature), expert opinion (anecdotal evidence by naturalists/entomologists), survey replication (snapshot comparison of two or more points in time) and documented extinctions that insects and other invertebrates have declined at relatively small spatial scales (from site, through landscape to the bioregional scale). ...
... The examples of the Bogong Moth, Green Carpenter Bee, Banksia Montane Mealybug and butterflies threatened nationally emphasise a more general problem and that is the decline and extinction of insects and allied invertebrates are frequently unknown and poorly documented (Braby 2019;Woinarski et al. 2019). This general lack of knowledge is largely due to a data deficiency feedback loop that maintains a cycle of ignorance and inaction. ...
Article
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In this special issue of Austral Entomology, we draw together a collection of nine papers, most of which were presented at a joint scientific conference hosted by the Australian Entomological Society, the Society of Australian Systematic Biologists and the Australasian Arachnological Society in Brisbane in December 2019 for a symposium entitled ‘Population declines and the conservation of insects and other terrestrial invertebrates in Australia’. We felt that this symposium was not only essential but also timely given the recent worldwide attention and public interest in the decline of terrestrial insects and other invertebrates. There has also been considerable scientific debate on this topic, as well as on methods of data collection and analysi. The reason for the focus on Australia was because our knowledge of insect population trends and the underlying drivers of those trends are poorly known. Moreover, recent reviews documenting changes in insect populations over time have almost all been based on studies carried out in the Northern Hemisphere, particularly in Europe and North America, where there has been considerable long-term monitoring of insect abundance, richness, occupancy or biomass. Comparable long-term studies from the Southern Hemisphere are, for the most part, lacking or have remained unpublished. Thus, there is a critical need for data from countries like Australia to: (1) assess trends in insect richness, distribution and abundance; (2) identify the drivers of change; and (3) implement mitigation measures to alleviate declines where these are detected.
... Ten percent of endemic mammal species known to be present in the 18th century are now extinct, and many others survive only on offshore islands and fragmented habitat [1]. Further, some 38 species of vascular plants, 10 invertebrates, 4 frogs, 3 reptiles, 1 fish, and 9 bird species have been confirmed extinct since European arrival in 1788 [2]. These impacts have been attributed to a number of factors, most notably land management changes (including land clearing for cropping and grazing), alterations to fire regimes, and the introduction of feral predators, including cats (Felis catus) and red foxes (Vulpes vulpes), and feral herbivores such as European rabbits (Oryctolagus cuniculus) [2][3][4]. ...
... Further, some 38 species of vascular plants, 10 invertebrates, 4 frogs, 3 reptiles, 1 fish, and 9 bird species have been confirmed extinct since European arrival in 1788 [2]. These impacts have been attributed to a number of factors, most notably land management changes (including land clearing for cropping and grazing), alterations to fire regimes, and the introduction of feral predators, including cats (Felis catus) and red foxes (Vulpes vulpes), and feral herbivores such as European rabbits (Oryctolagus cuniculus) [2][3][4]. However, extinction risk is being further exacerbated by human-induced climate change [5], with rapidly warming temperatures and increased frequency and magnitude of extreme weather events such as drought and fire resulting in phenological shifts, range contractions, and population declines in many taxa [5][6][7]. ...
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Conservation genetics has informed threatened species management for several decades. With the advent of advanced DNA sequencing technologies in recent years, it is now possible to monitor and manage threatened populations with even greater precision. Climate change presents a number of threats and challenges, but new genomics data and analytical approaches provide opportunities to identify critical evolutionary processes of relevance to genetic management under climate change. Here, we discuss the applications of such approaches for threatened species management in Australia in the context of climate change, identifying methods of facilitating viability and resilience in the face of extreme environmental stress. Using genomic approaches, conservation management practices such as translocation, targeted gene flow, and gene-editing can now be performed with the express intention of facilitating adaptation to current and projected climate change scenarios in vulnerable species, thus reducing extinction risk and ensuring the protection of our unique biodiversity for future generations. We discuss the current barriers to implementing conservation genomic projects and the efforts being made to overcome them, including communication between researchers and managers to improve the relevance and applicability of genomic studies. We present novel approaches for facilitating adaptive capacity and accelerating natural selection in species to encourage resilience in the face of climate change.
... As a result of its isolation for around 100 million years and its distinctive environment, Australia's fauna and flora are rich and unique, exhibiting high degrees of endemism. Human influence has led to significant loss and/or transformation of this biodiversity (Woinarski et al. 2019). Environmental challenges and human consumption place unprecedented and increasing stresses on the environment and species. ...
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The Atlas of Living Australia (ALA) is Australia’s national biodiversity database, delivering data and related services to more than 80,000 Australian and international users annually. Established under the Australian Government’s National Collaborative Research Infrastructure Strategy to provide trusted biodiversity data to support the research sector, its utility now extends to government, higher education, non-government organisations and community groups. These partners provide data to the ALA and leverage its data and related services. The ALA has also played an important leadership role internationally in the biodiversity informatics and infrastructure space, both through its partnership with the Global Biodiversity Information Facility and through support for the international Living Atlases programmes which has now delivered 24 instances of ALA software to deliver sovereign biodiversity data capability around the world. This paper begins with a historical overview of the genesis of the ALA from the collections, museums and herbaria community in Australia. It details the biodiversity and related data and services delivered to users with a primary focus on species occurrence records which represent the ALA's primary data type. Finally, the paper explores the ALA's future directions by referencing results from a recently completed national consultation process.
... Currently we are in the midst of the sixth mass extinction (Ceballos et al. 2015). In Australia, between 30 and 34 mammalian taxa have become extinct since European settlement in 1788 (Legge et al. 2018;Woinarski et al. 2015Woinarski et al. , 2019. Conservation biologists utilise a range of methods to manage species, including captive breeding programs that aim to preserve a species in the safety of a managed captive environment (Courtney Jones et al. 2017), often with a view to supplementing or re-establishing wild populations (Frankham 2008;Oliveira et al. 2016). ...
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The increased availability of genomic resources for many species has expanded perspectives on problems in conservation by helping to design management strategies for threatened species. Tasmanian devils (Sarcophilus harrisii) are an iconic and endangered marsupial with an intensively managed breeding program aimed at preventing extinction in the wild caused by devil facial tumour disease. Between 2015 and 2017, 85 devils from this program were released to three sites in Tasmania to support wild populations. Of these, 26 were known to have been killed by vehicles shortly after release. A previous analysis indicated that increased generations in captivity was a positive predictor of vehicle strike, with possible behavioural change hypothesised. Here we use 39 resequenced devil genomes to characterise diversity at 35 behaviour-associated genes, which contained 826 single nucleotide polymorphisms (24 were non-synonymous). We tested for a predictor of survival by examining three genes (AVPR1B, OXT and SLC6A4) in 62 released devils with known fates (survived, N = 39; died, N = 23), and genome-wide associations via reduced-representation sequencing (1727 single nucleotide polymorphisms [SNPs]), in 55 devils with known fates (survived, N = 38; died, N = 17). Overall, there was little evidence of an association between genetic profile and probability of being struck by a vehicle. Despite previous evidence of low genetic diversity in devils, the 35 behaviour-associated genes contained variation that may influence their functions. Our dataset can be used for future research into devil behavioural ecology, and adds to the increasing body of research applying genomics to conservation problems.
... Amphibians are particularly vulnerable to extinction under current environmental conditions. Since 1980 Australia has lost at least four frog species (Woinarski et al. 2019) and as many as another 46 frog species are at risk of extinction (Hero et al. 2006;Gillespie et al. 2020). This requires management action and intervention on a range of fronts but also requires long-term monitoring to inform and guide management responses. ...
Article
Population monitoring is required to guide conservation programs. We conducted a capture–mark–recapture study of a population of the vulnerable green and golden bell frog (Litoria aurea) at the northern end of its range. Frogs were captured and marked over three breeding seasons (2015/16, 2016/17, 2017/18) in a large coastal lagoon. We aimed to: (1) produce annual estimates of population size to describe population trajectory, and (2) investigate monthly variation in abundance, capture probability, and temporary emigration to understand how these factors change at a finer temporal scale. Frog abundance varied across the three annual breeding seasons: 60–280 adult males, 120–190 adult females, and 90–420 subadults. We infer that the population is stable because adult abundance estimates were higher after 2015/16. Because our study sampled only half the available breeding habitat, the overall population may number 350–850 adults. Our modelling revealed >40 males but <20 females were detected in the sample area in our monthly samples. Estimates of temporary emigration were high (males: 0.54; females: 0.79), suggesting behaviour that made frogs unavailable for capture between months. Our results suggest that monitoring at greater than annual intervals should be adequate to monitor the future trend of this population.
... In Australia, 1892 species or subspecies are presently nationally listed as threatened under the Australian Environment Protection and Biodiversity Conservation Act 1999, and the list of threatened species is growing. Australia has one of the highest recent extinction rates of vertebrates of any country worldwide (Szabo, Butchart, Possingham, & Garnett, 2012;Woinarski et al. 2017a;Woinarski et al., 2019;Woinarski, Burbidge, & Harrison, 2015), with three vertebrate species lost in the past decade alone. Urgent actions are needed to stem declines and prevent further extinctions (Geyle et al., 2018). ...
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Protected areas are important for preventing biodiversity declines, yet indicators of species' trends in protected areas rarely include threatened species. We use data from the first national Threatened Species Index developed in Australia to report on trends for threatened and near‐threatened birds inside and outside terrestrial and marine protected areas. We adopted the Living Planet Index to calculate trends for 39 bird taxa at 16,742 monitoring sites (11,539 inside and 5,203 outside PAs) between 1985 and 2016. At a continental scale, the overall decline in the national index was smaller inside protected areas (66% decrease in average population abundance) than outside (77%), although after 2000 declines were greater within (36%) versus outside (26%) protected areas. Five out of seven jurisdictions showed similar switching in patterns over time. Protected areas initially had a greater net positive effect on trends of more imperiled birds than less imperiled birds, but between 2000 and 2016 declines of the most imperiled birds were greater inside protected areas than outside. Our analyses suggest that the effectiveness of Australia's protected area network at improving trends in threatened species has weakened, and support the hypothesis that trends for terrestrial birds outside PAs might be improving due to increased conservation efforts on private land. Although this study represents the most comprehensive collation of threatened species population time series and trends ever for Australia, the number of monitoring sites inside PAs was double that outside PAs, even though on average, more than 70% of threatened bird distributions occur outside PAs, with important gaps in monitoring across space, time and taxa that need to be filled to fully understand the effectiveness of public and private conservation actions at a national level. The results underline the importance of active management plus monitoring to track and report on long‐term trends across species.
... Impacts on native wildlife have also been devastating. The fox has contributed to the extinction of an estimated 14 native mammal species and one bird species (Woinarski et al. 2019), and to the ongoing suppression or decline of many others , Woinarski et al. 2021. ...
Article
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The red fox Vulpes vulpes is one of the world’s most widespread carnivores. A key to its success has been its broad, opportunistic diet. The fox was introduced to Australia about 150 years ago, and within 30 years of its introduction was already recognised as a threat to livestock and native wildlife. We reviewed 85 fox diet studies (totalling 31693 samples) from throughout the species’ geographic range within Australia. Mammals were a major component of fox diet, being present in 70 ± 19% of samples across n = 160 locations. Invertebrates (38 ± 26% n = 130) and plant material (26 ± 25% n = 123) were also both staple foods and often the dominant food category recorded. Birds (13 ± 11% n = 137) and reptiles (10 ± 15% n = 132) were also commonly reported, while frogs were scarcely represented (1.6 ± 3.6% n = 111) in fox diet studies. Biogeographical differences reveal factors that likely determine prey availability. Diet composition varied with ecosystem, level of vegetation clearing and condition, and climate zone. Sample type (i.e. stomach versus scat samples) also significantly influenced reporting of diet composition. Livestock and frogs were underrepresented in records based on analysis of scats, whereas small mammals (native rodents, dasyurid marsupials, and bats) were more likely to be recorded in studies of scats than in studies of stomach contents. Diet varied seasonally, reflecting activity patterns of prey species and food availability. This synthesis also captures temporal shifts in fox diet over 70 years (1951–2020), as foxes have switched to consuming more native species in the wake of successful broadscale biological control of the invasive European rabbit Oryctolagus cuniculus. Diet analyses, such as those summarised in this review, capture the evidence required to motivate for greater control of foxes in Australia. This synthesis also highlights the importance of integrated pest species management to meet biodiversity conservation outcomes.
... However, this assumes that our current understanding of biogeography and species diversity can be applied to the deep past. At least 34 Australian mammal species have become extinct since 1788 while others are in severe decline and have become increasingly rare (Woinarski et al. 2019). Ongoing research continues to alter our understanding of the current, and historical, distribution and diversity of our native taxa (Bino et al. 2019;Burbidge et al. 2014;Cramb et al. 2009;Eldridge & Potter 2019;Haouchar et al. 2016;Travouillon et al. 2019;Travoullin & Phillips 2018). ...
Article
en We review current zooarchaeological practice in Australia, identifying major research themes and key methodological gaps where opportunities exist for the development of Australian zooarchaeology as a discipline. We demonstrate that marsupial remains form a significant component of Australian zooarchaeological assemblages, yet high resolution taxonomic identification of these remains continues to prove challenging, owing to a combination of high species diversity and few resources which provide diagnostic criteria for discriminating morphologically similar, but ecologically variable taxa. The lack of robust protocols for discriminating marsupial taxa significantly impacts our ability to effectively integrate zooarchaeological data into broader narratives of Aboriginal colonisation, resilience and adaptation across Australia. Publication of identification protocols would help refine and standardise diagnostic criteria used between analysts, improve the methodological transparency of zooarchaeological analysis and provide resources for the training of a new generation of specialists. A range of opportunities currently exist, utilising qualitative and quantitative techniques, to significantly contribute towards the methodological robustness of zooarchaeological practice in Australia. Résumé fr Nous passons en revue la pratique de l'archéozoologie en Australie afin d'identifier les grands thèmes de recherche et les principales lacunes méthodologiques où existent des occasions de développement de l'archéozoologie australienne en tant que discipline. Nous démontrons que les restes de marsupiaux constituent une composante significative des assemblages archéozoologiques australiens. Néanmoins, l'identification taxonomique en haute résolution de ces restes demeure un défi, car la grande diversité des espèces se combine à la modicité des ressources qui offrent des critères de diagnostic permettant une discrimination de taxons semblables sur le plan morphologique, mais variables au point de vue écologique. L'absence de protocoles robustes pour la discrimination des taxons marsupiaux a un impact significatif sur notre capacité à intégrer efficacement les données archéozoologiques dans des récits plus vastes de colonisation, de résilience et d'adaptation des Aborigènes sur l'ensemble de l'Australie. La publication de protocoles d'identification contribuerait à affiner et standardiser les critères de diagnostic utilisés par les différents analystes, à améliorer la transparence méthodologique de l'analyse archéozoologique, et à procurer des ressources permettant de former une nouvelle génération de spécialistes. À l'heure actuelle, on trouve une gamme de possibilités qui, en faisant appel à des techniques qualitatives et quantitatives, peuvent contribuer de façon significative à la robustesse méthodologique de la pratique de l'archéozoologie en Australie.
... Mammals have been particularly hard hit: 34 species have gone extinct since the 1850s (Geyle et al., 2018;Woinarski et al., 2019). Nine species of Australian bird have become extinct since colonisation , with the additional loss of many regionally restricted subspecies (Geyle et al., 2018). ...
Article
Aim: Identification of particular traits that predispose species to elevated extinction risk is an important component of proactive conservation. We capitalise on a recent strategic extinction risk assessment of all Australian squamate reptiles to identify intrinsic life history traits and extrinsic threats that correlate with extinction risk. We further assess whether extinction risk correlates differ between species impacted by different threatening processes (habitat loss vs. invasive species). Location: Australia. Taxon: Squamate reptiles. Methods: We used the IUCN Red List data for Australian squamates, and publicly available datasets for 14 intrinsic and extrinsic traits. We used phylogenetically controlled Bayesian inference to test hypotheses regarding relationships between extinction risk and species traits, environment, and threat measures. Results: We found that intrinsic characteristics (habitat specialisation, small range size and large body size), as well as extrinsic factors (high human footprint, accessibility from human population centres, cold temperatures and high rainfall), predispose a species to extinction. Similar predictors were important in threat-specific analyses, although relationships were generally more uncertain. Conclusions: Our results largely accord with those of global and regional studies of extinction risk in reptiles and of terrestrial vertebrates more broadly. Our findings illustrate that there is no single pathway to extinction among Australian squamates.
... Since European settlement, Australia's terrestrial mammal fauna has suffered a severe and continued decline ( Burbidge et al. 2009 ;Geyle et al. 2018 ), and 30 of 273 Australian endemic mammal species have become extinct ( Woinarski et al. 2015 ). Arid zone mammal species within the critical weight range (CWR) of 35 g-5.5 kg have suffered disproportionately in the decline, with up to 50% of species now extinct ( McKenzie et al. 2007 ;Moseby et al. 2009 ) including two in the past decade ( Woinarski et al. 2019 ). ...
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The greater bilby (Macrotis lagotis) once occupied much of Australia's mainland. Bilbies are now listed as vulnerable and only occur in 20% of their former range. Operation Rangeland Restoration aims to to restore an ex −pastoral lease; reintroduce several species of locally extirpated fauna, including the bilby; and maintain the area in perpetuity for the conservation of Australian arid zone species. Bilbies were reintroduced to the Matuwa Indigenous Protected Area between 2007 and 2010 and, with ongoing landscape-scale control of feral predators, herbivores, and fire, have thrived. Here, we present a detailed account of the methods used during the reintroduction, showing that between 2007 and 2019 there has been an 88% increase in the area of occupancy by bilbies at Matuwa. The results of 2-ha track plot surveys conducted by the traditional owners of Matuwa suggest that the reintroduced bilbies are emigrating out of Matuwa. In addition, in 2018 and 2019 we used 120 camera-traps over 18 mo and occupancy analysis to confirm the widespread presence of bilbies across Matuwa and define significant habitat correlates. Bilbies were more likely to be detected on sandplains with Eucalyptus species as overstorey vegetation and Triodia as understorey vegetation. Bilbies were not detected in habitats with ≥ 75% bare ground. We attribute the success of the bilby reintroduction at Matuwa to the consistent implementation of landscape-scale control of feral predators.
... In the period since, Australia has experienced the highest recent mammal extinction rate in the world, with most "critical weight range" species (i.e., 35-5,500 g; Burbidge & McKenzie, 1989) now extinct, either regionally or globally (Moseby, 2012;Woinarski et al., 2014). Predation by foxes is regarded as a major driver of the decline and extinction for many of these species (Dickman, 1996;Fleming et al., 2014;Woinarski et al., 2015Woinarski et al., , 2019, as well as having impacts on the composition and diversity of communities of small terrestrial vertebrates (mammals and reptiles) (Moseby et al., 2009;Roshier et al., 2020). ...
Article
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The introduced red fox (Vulpes vulpes) now occupies most of the Australian continent outside the tropics, including arid and semiarid ecosystems. Information on the water requirements of foxes is scant, but free water is not thought to be required if adequate moisture-containing food is available. The frequency and duration of visits by foxes fitted with GPS collars to known artificial watering points in semiarid Australia were recorded for 22 individual foxes across four austral seasons between October 2015 and November 2017, providing >93,000 location fixes. We modeled home range and the distance traveled by range-resident foxes beyond their home range to reach known water sources. We used recurse analysis to determine the frequency of visitation and step-selection functions to model the speed and directionality of movement inside and outside the home range. Our study demonstrates that some foxes in this semiarid environment utilize free-standing water. The findings suggest that artificial watering points can be used as a focal point for conducting strategic fox control in arid and semiarid environments. Additionally, strategies that restrict access to water by foxes may reduce their duration of occupancy and/or long-term abundance in parts of the landscape, thus providing benefits for conservation and agriculture.
... Biodiversity is in the midst of a human-driven extinction crisis (Pimm et al. 1995;Jenkins 2003;Pimm et al. 2014;Ceballos et al. 2015;Woinarski et al. 2019;Cardoso et al. 2020). Modern extinctions have occurred at a rate that far exceeds the background rate estimated from the fossil record (Ceballos et al. 2015;Johnson et al. 2017), comparable in magnitude to the five previous mass extinctions that have occurred throughout Earth's history (Dirzo et al. 2014). ...
Article
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The diversity and abundance of native invertebrates is declining globally, which could have significant consequences for ecosystem functioning. Declines are likely to be at least as severe as those observed for vertebrates, although often are difficult to quantify due to a lack of historic baseline data and limited monitoring effort. The Lepidoptera are well studied in Australia compared with other invertebrates, so we know that some species are imperilled or declining. Despite this, few butterfly taxa are explicitly listed for protection by legislation. Here we aim to identify the butterfly taxa that would most benefit from listing by determining the Australian butterflies at most immediate risk of extinction. We also identify the research and management actions needed to retain them. For 26 taxa identified by experts and various conservation schedules, we used structured expert elicitation to estimate the probability of extinction within 20 years (i.e. by 2040) and to identify key threatening processes, priority research and management needs. Collation and analysis of expert opinion indicated that one taxon, the laced fritillary (Argynnis hyperbius inconstans), is particularly imperilled, and that four taxa (Jalmenus eubulus, Jalmenus aridus, Hypochrysops piceatus and Oreisplanus munionga larana) have a moderate–high (>30%) risk of extinction by 2040. Mapped distributions of the 26 butterflies revealed that most are endemic to a single state or territory, and that many occupy narrow ranges. Inappropriate fire regimes, habitat loss and fragmentation (through agricultural practices), invasive species (mostly through habitat degradation caused by weeds and rabbits) and climate change were the most prevalent threats affecting the taxa considered. Increased resourcing and management intervention will be required to prevent these extinctions. We provide specific recommendations for averting such losses.
... A further 20 taxa have been assessed as threatened but only at smaller, regional scales under various state-based legislation. Thus, declines and extinctions of insects and other invertebrates are frequently unknown, poorly documented and grossly underestimated (Woinarski et al. 2019). ...
Article
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Conservation biology is a field of science that is heavily biased against insects and allied invertebrates, largely due to a data deficiency feedback loop that maintains a cycle of ignorance and inaction. Because many invertebrate groups are, and remain, extremely data poor, it is frequently difficult to conduct even the most basic conservation actions, such as status evaluation, listing, recovery and monitoring of threatened species. Thus, declines and extinctions of invertebrates are frequently undetected and poorly documented. To address this data deficiency, we have developed a new national database – Butterflies Australia – for one insect taxon that integrates citizen science (data collectors) with global, standardised monitoring protocols and emerging tools in technology and biodiversity informatics. The database is created from a platform, which consists of a phone app and website, that offers the potential to rapidly increase data availability on the occurrence of Australian butterflies at a far greater scale than was previously possible, as well as to monitor trends in their distribution and abundance over time. We discuss the attributes and importance of successful citizen science projects and quantitative methods for monitoring butterflies, both from an Australian perspective and in an international context, and then outline the operational aspects of the Butterflies Australia platform. A review of survey methods that have been used for monitoring or inventorying butterflies in Australia over the past 50 years revealed a diverse array of sampling techniques, with little standardisation between studies and wide variation in space (sampling unit) and time (sampling effort). Transect counts, in particular, have rarely followed the international guidelines recommended for standardised global butterfly monitoring. Finally, we discuss the benefits of our new citizen science tool for butterflies and potentially other invertebrates. We envisage that our platform will engender increased community awareness, improved quantity and quality of data collection, better conservation policy and planning, as well as enhanced resourcing and research for the conservation management of butterflies.
... These qualitative approaches include estimating the extent of change based on: (1) expert opinion (personal records and anecdotal evidence from naturalists/entomologists); (2) historical records (data from museum collections and/or scientific literature); and (3) temporal replication of surveys (i.e. snapshot comparison of two or more points in time); as well as (4) estimating the extent and rate of extinction (see Pimm et al. 2014;Régnier et al. 2015;Woinarski et al. 2019;Cardoso et al. 2020). ...
Article
Although changes, particularly declines, in Australian terrestrial insects and other invertebrates have long been suspected and well‐documented for some species, the magnitude, rate and spatial extent of decline remain unclear. Here we use a combination of alternative, qualitative approaches (expert opinion, historical records and temporal replication of surveys) to standardised monitoring and mapping programs to investigate the extent of change of a peri‐urban butterfly assemblage. This assemblage, comprising 52 species, of which 46 are residents or seasonal immigrants, was studied at three spatial scales (local ~0.01 km2, intermediate ~9 km2 and regional ~100 km2) in the Eltham district near Melbourne based on presence/absence data over the past 40 (1981–2020) and 80 years (1941–2020). We then consider the causal factors or drivers that have led to changes, and we explore the timing and ecological patterns underpinning extirpations. Long‐term records reveal substantial changes (mostly decline) in composition and species richness of the 46 breeding species at all spatial scales and time frames analysed. Although the magnitude and rate of decline were higher at the smaller, local to intermediate scales (29–43% decline over 40 years, loss rate of 0.20–0.25 species/year) compared with the larger, regional scale (26% decline over 80 years, loss rate of 0.15 species/year), extirpations at the larger scale were more alarming because they are indicative of widespread population collapse. Declines in relative abundance and occupancy were also recorded at the intermediate and regional spatial scales. Further decline (extinction debt) is anticipated for several ecological specialists currently known from very few sites. Historical extirpations mostly involved obligate myrmecophilous lycaenids and appear to have been largely driven by an interaction of urbanisation (habitat loss, degradation and fragmentation) and vegetation encroachment. More recent extirpations consist mainly of grass‐feeding and mistletoe‐feeding specialists and are more worrying because they have predominantly occurred within the past 20–30 years. An interaction of urbanisation (tree canopy death and decline of mistletoes and their host trees from ecosystem dysfunction) and climate change (water stress and heat waves) are considered to be the most likely drivers for these ecological guilds.
... Some ecological communities have been disproportionately affected, such as box-gum grassy woodlands of which 92% has been cleared (Threatened Species Scientific Committee, 2006). At least 100 species have become extinct in Australia in the last 230 years, of which two-thirds of mammal extinctions and half of bird extinctions were driven by feral cats (Felix catus) and red foxes (Woinarski et al., 2017;Woinarski et al., 2019). These statistics read as a dire clinical eulogy to "wild" Australia, and whilst conservationists have documented these losses, precious little has been done to remedy the situation. ...
Thesis
This thesis provides a case-study using an initial reintroduction to inform tactic selection for future translocations. Warabin (Burhinus grallarius) have declined substantially in southern Australia due to habitat loss and predation by feral predators (largely foxes, Vulpes vulpes) and now occupy a subset of their former niche. They have been successfully reintroduced to a fenced reserve, Mulligans Flat Woodland Sanctuary (MFWS), which provides an opportunity to assess their habitat requirements and movement behaviours.
... If one or more taxa are increasing over time, this could produce a positive overall trend even though some taxa might still be decreasing in that group (e.g., terrestrial birds). These positive sub-trends provide modest grounds for encouragement in the face of the current global biodiversity crisis: Australia alone has lost 100 species over the last 230 years (Woinarski, Burbidge, & Harrison, 2015), 9 of which were birds (Woinarski et al., 2019) while global species extinctions are 1,000 times the background rate (Pimm et al., 2014). ...
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Abstract Quantifying species population trends is crucial for monitoring progress towards global conservation targets, justifying investments, planning targeted responses and raising awareness about threatened species. Many global indicators are slow in response and report on common species, not on those at greatest risk of extinction. Here we develop a Threatened Species Index as a dynamic tool for tracking annual changes in Australia's imperiled birds. Based on the Living Planet Index method and containing more than 17,000 time series for 65 bird taxa surveyed systematically, the index at its second iteration shows an average reduction of 59% between 1985 and 2016, and 44% between 2000 and 2016. Decreases seem most severe for shorebirds and terrestrial birds and least severe for seabirds. The index provides a potential means for measuring performance against the Convention on Biological Diversity's Aichi Target 12, enabling governments, agencies and the public to observe changes in threatened species.
... Studying dietary preferences of mammals is key to understanding their biology and developing appropriate conservation measures. With recent population declines among small and mediumsized mammals throughout Australasia (Hoffmann et al. 2011;Woinarski et al. 2019;Vernes et al. 2021), it is increasingly important to thoroughly understand the biology of poorly known species. Assessing dietary components and nutritional requirements is vital to understanding species; feeding behaviours can also reveal overlooked ecosystem services. ...
Article
Little is known about the diets and ecology of New Guinea's 14 bandicoot species. In order to better understand the diet and digestive morphology of these marsupials, we reviewed the literature, studied the dental morphology, conducted analysis of gastrointestinal contents, and measured the digestive tracts of: Echymipera clara, E. davidi, E. kalubu, E. rufescens, Isoodon macrourus, Microperoryctes ornata, M. papuensis and Peroryctes raffrayana. These species consume a mix of fungi, insects and plant material that is broadly consistent with the omnivorous diet characteristic of most Australian bandicoots; however, morphological observations reveal variation between species that likely reflect finer-scale differences in diet. Dental morphology suggests a wider variety of diets (insectivore, omnivore, frugivore) than on the Australian mainland (mostly omnivore). Dissections and measurements of the digestive tract of seven New Guinean species indicate variation linked to diet. The relatively short caecum in all New Guinean species, but especially in E. clara and E. kalubu, is particularly suggestive of limited consumption of fibrous plant material; the relative length of the large intestine suggests variable capacity for water reabsorption. Our dietary data also suggest that some of these species also play an important role in the dispersal of hypogeous fungi.
... 30 They include a variety of ecomorphological forms, such as the widespread aquatic carnivore Hydromys, the bipedal Notomys of arid Australia, and the large-bodied, wooly Mallomys in the New Guinea highlands. At least eleven hydromyine rodent species have been officially declared extinct due to recent anthropogenic impact in the region, 31,32 and many further species are known from small numbers of historically collected museum specimens (e.g., Thomas 33,34 ). With methodological advances amenable to historical DNA, 35 we can now leverage centuries of museum collections to unlock genomic data from the entire assemblage of historically extant species across Sahul. ...
Article
Sahul unites the world’s largest and highest tropical island and the oldest and most arid continent on the backdrop of dynamic environmental conditions. Massive geological uplift in New Guinea is predicted to have acted as a species pump from the late Miocene onward, but the impact of this process on biogeography and diversification remains untested across Sahul as a whole. To address this, we reconstruct the assembly of a recent and diverse radiation of rodents (Murinae: Hydromyini) spanning New Guinea, Australia, and oceanic islands. Using phylogenomic data from 270 specimens, including many recently extinct and highly elusive species, we find that the orogeny and expansion of New Guinea opened ecological opportunity and triggered diversification across a continent. After a single over-water colonization from Asia ca. 8.5 Ma, ancestral Hydromyini were restricted to the tropical rainforest of proto-New Guinea for 3.5 million years. Following a shift in diversification coincident with the orogeny of New Guinea ca. 5 Ma and subsequent colonization of Australia, transitions between geographic regions (n = 24) and biomes (n = 34) become frequent. Recurrent over-water colonization between mainland and islands demonstrate how islands can play a substantial role in the assembly of continental fauna. Our results are consistent with a model of increased ecological opportunity across Sahul following major geological uplift in New Guinea ca. 5 Ma, with sustained diversification facilitated by over-water colonization from the Pleistocene to present. We show how geological processes, biome transitions, and over-water colonization collectively drove the diversification of an expansive continental radiation.
... Introduced species have become a key threat to Australian mammals, having directly caused or contributed to 34 extinctions since European settlement (Woinarski et al. 2019). The black rat (Rattus rattus) is amongst these and has been known to cause serious ecological impacts in areas where they have been introduced (Martin et al. 2000;Stokes et al. 2009;Ringler et al. 2015), and in some cases even the total extirpation of native species (Towns et al. 2006;St Clair 2011;Banks & Hughes 2012). ...
Article
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Introduced rodents, particularly the black rat (Rattus rattus), have caused serious ecological impacts due to their ability to interact with native species as both predators, and by eliciting competitive pressure. However , impacts of black rats upon many Australian mammals have yet to be determined, particularly when those mammals are arboreal. Here, we present novel observations in the form of camera trap footage and photographs of interspecific competition between the introduced black rat and two species of arboreal gliding marsupial (sugar gliders (Petaurus breviceps) and squirrel gliders (Petaurus norfolcensis)) in urban bushland reserves in New South Wales, Australia. Gliders were found to flee or were prevented from exploiting food resources due to antagonistic posturing and physical attacks by black rats. While interspecific aggression and interference competition between black rats and native mammal species has been demonstrated previously, this appears to be the first observation of such interactions for Australian gliders. Our findings may have implications for the future management of glider populations in urban bushland where they co-occur with rats; however, further research needs to be undertaken to determine the extent of this potential threat.
... Introduced mammalian predators have caused globally significant ecological impacts, including the decline and extinction of native species (Doherty et al. 2016). For instance, the 19th century introduction of the European red fox (Vulpes vulpes) into Australia has had well documented and continental-scale biodiversity impacts (Glen and Dickman 2008;Saunders et al. 2010;Woinarski et al. 2019). Since the 1980s, landscape-scale poison baiting programmes have been a key management action used to suppress the density of introduced fox populations across Australia (Kinnear et al. 2002;Hayward and Somers 2012;Braysher 2017;Legge et al. 2018). ...
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Context. Management actions that suppress introduced predator densities can benefit the population recovery of native species. Nevertheless, ensuring that predator management produces measurable population-level benefits can be influenced by multiple factors affecting species detection. Monitoring designs using multiple survey methods may perform better than increasing sampling effort with single-method protocols. Aims. This study aimed to estimate individual and cumulative detection probabilities and site occupancy estimates from the use of five different monitoring methods to survey a native mesopredator, the lace monitor (Varanus varius). Second, we assessed the effect of lethal red fox (Vulpes vulpes) baiting on lace monitor detection probabilities and site occupancy estimates collected from each monitoring method. Methods. Multi-method sampling for Varanus varius occurred at 76 sites across lethal fox baited and non-baited habitats in East Gippsland, Victoria. Bayesian site occupancy models were used to estimate the effects of detection method and fox-baiting treatments on Varanus varius detection probability and site occupancy. Key results. Method-specific detection probabilities (P = 0.00-0.12) and site occupancy estimates (Ψ = 0-0.53) varied considerably among methods, but combinations of multi-method monitoring improved lace monitor detection probability (P = 0.11-0.18) and site occupancy (Ψ = 0.87 ± [0.66-0.93]−0.91 ± [0.76-0.97] mean ± [95% credible intervals]) above any single method. However, there was extreme heterogeneity in the size and direction of the introduced predator baiting effect on method-specific lace monitor detection. Three methods (box traps and two different visual search surveys) all indicated lace monitor detection probabilities increased in fox-baited sites. However, sand pads reported a decrease in lace monitor detection at fox-baited sites, whereas pipe traps obtained no detections. Conclusions. Combining detection data from all methods led to the inference of a positive fox-baiting effect, albeit with a smaller magnitude and better certainty than that estimated using a reduced method monitoring design, which had fewer detection data after excluding biased detection from sand pads. Implications. Using a multi-method monitoring approach improved lace monitor detection and reduced sampling effort. However, depending on sampling methodology, the management effects on lace monitors can change.
... In the 220+ years since European colonisation of Australia, at least 33 species of native terrestrial mammal have been rendered extinct on the continent and its territories (Woinarski et al. 2014(Woinarski et al. , 2015(Woinarski et al. , 2019. Patterns of extinction on the continent are taxonomically uneven, with rodents and marsupials most affected, and a disproportionate number of extinct species falling within a critical weight range between 35 and 5500 g (Burbidge and McKenzie 1989;Woinarski et al. 2015). ...
Article
Australia has suffered more modern mammal extinctions than any nation. Among the list of extinct species is the blue-grey mouse (Pseudomys glaucus), a rodent known from just three specimens (two from southern Queensland and one from northern New South Wales). We investigated circumstances of collection for the three specimens referred to this species to better illuminate optimal habitats and climatic conditions for continuing rediscovery efforts. No additional information could be found on two specimens from southern Queensland sent to the Natural History Museum, London. However, we recorded a first-hand account of how the northern New South Wales specimen was collected and have established that the collection year was 1956. We also obtained a copy of correspondence from Ellis Le G. Troughton thanking the collector for the contribution. The northern New South Wales specimen was from a pastoral property formerly dominated by woodland vegetation communities on alluvial soils. It was captured during a mouse plague following consecutive seasons of above average rainfall. Pseudomys glaucus is likely already extinct, but our results help better direct any future survey efforts. Surveys should be targeted in woodland communities on alluvial floodplains in the Darling Riverine Plains bioregion, following periods of above average rainfall conducive to the irruption of rodent populations.
... In the past two centuries Australia's mammals have experienced a higher rate of extinction compared to the mammal fauna of any other nation (Woinarski et al. 2015). Thirty-four of Australia's 273 endemic mammal species have become extinct in the past 200 years (Woinarski et al. 2019) and at present, there are 30 species listed as endangered under Federal legislation with a further 46 listed as vulnerable (Environment Protection and Biodiversity Conservation Act 1999). Among those particularly affected are medium-sized terrestrial mammals (Burbidge and McKenzie 1989;Cardillo and Bromham 2001). ...
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Invasive predators, land clearing and altered fire regimes have been implicated in species decline and extinction worldwide. Enhanced knowledge of how these factors interact and influence medium-sized mammals is warranted. We tested three hypotheses using occupancy data for a diverse mammal assemblage including three threatened species, five common species, two introduced mesopredators and an apex predator in eastern Australia. We hypothesised that occupancy of mammal species within the assemblage would be influenced by (i) the physical environment (rainfall, vegetation type and elevation), (ii) habitat disturbance (number of fires and habitat fragmentation) and (iii) mesopredator release, whereby occupancy and/or detection of medium-sized mammals are influenced by mesopredators, the feral cat ( Felis catus ) and the red fox ( Vulpes vulpes ), which are influenced by an apex predator, the dingo ( Canis familiaris ). We utilised camera-trapping data from 173 sites (692 camera locations) across a north–south gradient spanning ~ 1500 km in eastern Australia. Although hypotheses i (physical environment) and ii (habitat disturbance) are not mutually exclusive, we show that the variables considered in each were only weakly correlated. We conducted occupancy modelling to investigate the physical environment and habitat disturbance hypotheses. We conducted co-occurrence modelling to investigate interactions between species. The physical environment hypothesis best supported occupancy models for six mammal species: red-necked pademelon ( Thylogale thetis ), bandicoots ( Isoodon macrourus and Perameles nasuta ), swamp wallaby ( Wallabia bicolor ), red-necked wallaby ( Macropus rufogriseus ), eastern grey kangaroo ( Macropus giganteus ) and feral cat. The disturbance hypothesis best supported occupancy models for four mammal species: long-nosed potoroo ( Potorous tridactylus ), red-necked pademelon and both mesopredators. Support for the mesopredator release hypothesis was equivocal. Large macropods showed site avoidance towards the red fox. Four species showed higher detection at sites where mesopredators were not detected. The fox showed a negative detection interaction to the dingo and the cat did not. Our study highlights how factors such as rainfall, land clearing, elevation and number of fires influence the occupancy of species within a diverse mammal assemblage at the macroecological scale. Our findings have implications for the conservation of threatened species in managed landscapes and suggestions for further research following the recent 2019–2020 wildfires.
... While we have some indication of the pre-European fauna occurrence (and abundance) (Miller et al 2005, Kaars et al 2017, we require a better understanding of how species have responded to environmental and management changes through time, which will strengthen our ability to recover species. In this regard, the findings we present should be considered incomplete-a preliminary exploration of how patterns in Australia's avifauna have changed with the rapid and extraordinary transformation of the continent's land cover post-European colonization (Woinarski et al 2019). ...
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Habitat loss is driving the extirpation of fauna across Earth. Many species are now absent from vast areas where they once occurred in inhabited continents, yet we do not have a good understanding of the extent to which different species have been extirpated, nor the degree to which range contractions and habitat loss has contributed to this local extirpation. Here, for the first time, we use a combination of scientific literature, historical sources, spatial data, and expert elicitation to map the past extent of potential habitats, and changes thereto, of 72 of Australia’s most imperilled terrestrial birds. By comparing the area of potential habitat within the past and current ranges of these taxa, we quantify the extent over which each of Australia’s threatened terrestrial birds have likely been extirpated and assess the amount and configuration of potential habitat that remains. Our results show that since 1750 (before European colonization), at least one extant taxon of threatened bird has disappeared from over 530 million hectares (69%) of Australia, through both range contractions and loss of potentially suitable habitat (noting these are not mutually exclusive phenomena). Ten taxa (14%) have likely been extirpated from >99% of their past potential habitat. For 56 taxa (78%), remaining habitat within their current potential habitats has become fragmented. This research paints a sobering picture of the extent of local extirpation of threatened birds from much of Australia over a 250-year time period. By mapping and quantifying this loss, these findings will help refine scientific understanding about the impact of habitat removal and other pervasive threats that are driving this observed extirpation.
... Unfortunately, around 20 Australian rodent species have become extinct since European arrival and many more have experienced significant range declines (Woinarski et al. 2015;Roycroft et al. 2021). Predation by the introduced mesopredators the red fox (Vulpes vulpes) and the cat (Felis catus) are key drivers of previous and ongoing rodent extinction (Smith and Quin 1996;Woinarski et al. 2019). As an arid-zone rodent specialist, the letter-winged kite may be threatened indirectly by rodent extinctions. ...
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Nomadism is an advantageous life history strategy for specialised predators because it enables the predator to respond rapidly to changes in prey populations. The letter-winged kite (Elanus scriptus) is a nomadic nocturnal bird of prey endemic to arid and semi-arid zones of Australia. Letter-winged kites prey almost exclusively on nocturnal rodents and are often associated with rodent irruptions, but little is known about the ecology of letter-winged kites inside their core range. The Strzelecki Desert contains a known dingo-mediated predation refuge for native rodents. In this manuscript, we compare kite sightings, predator activity, and small mammal populations across survey sites in the Strzelecki Desert where dingoes were common and where dingoes were rare and use publicly available data from the Atlas of Living Australia (ALA) to assess trends in the occurrence of kites in the region. Ninety-five percent of ALA observations occurred in areas where dingoes were common. Similarly, all our observations of kites occurred where dingoes were common and during an extended population irruption of Notomys fuscus. Notomys fuscus was the most frequent item in the letter-winged kite diet at our study sites. We suggest that there is significant evidence that these sites in the Strzelecki Desert form part of the core range for the letter-winged kite whose use of this area is facilitated by a predation refuge for rodents mediated by the dingo. We conclude that predation refuges mediated by dingoes could be a factor driving the distributions of letter-winged kites and other predators of rodents, particularly nomadic predators.
... Australia holds the embarrassing title for the country with (by far) the most mammal extinctions in modern history, and many more threatened fauna species are predicted to become extinct over the next few decades 111,112 . ...
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Removal or loss of top-predators has been predicted to cause cascading negative effects for ecosystems, including mesopredator release. However, reliable evidence for these processes in terrestrial systems has been mixed and equivocal due, in large part, to the systemic and continued use of low-inference study designs to investigate this issue. Even previous large-scale manipulative experiments of strong inferential value have been limited by experimental design features (i.e. failure to prevent migration between treatments) that constrain possible inferences about the presence or absence of mesopredator release effects. Here, we build on these previous strong-inference experiments and report the outcomes of additional large-scale manipulative experiments to eradicate Australian dingoes from two fenced areas where dingo migration was restricted and where theory would predict an increase in extant European red foxes, feral cats and goannas. We demonstrate the removal and suppression of dingoes to undetectable levels over 4–5 years with no corresponding increases in mesopredator relative abundances, which remained low and stable throughout the experiment at both sites. We further demonstrate widespread absence of negative relationships between predators, indicating that the mechanism underpinning predicted mesopredator releases was not present. Our results are consistent with all previous large-scale manipulative experiments and long-term mensurative studies which collectively demonstrate that (1) dingoes do not suppress red foxes, feral cats or goannas at the population level, (2) repeated, temporary suppression of dingoes in open systems does not create mesopredator release effects, and (3) removal and sustained suppression of dingoes to undetectable levels in closed systems does not create mesopredator release effects either. Our experiments add to similar reports from North America, Asia, Europe and southern Africa which indicate that not only is there a widespread absence of reliable evidence for these processes, but there is also a large and continually growing body of experimental evidence of absence for these processes in many terrestrial systems. We conclude that although sympatric predators may interact negatively with each other on smaller spatiotemporal scales, that these negative interactions do not always scale-up to the population level, nor are they always strong enough to create mesopredator suppression or release effects.
... The Endangered Species Act in the USA has adopted the ambition to prevent all extinctions and has been highly successful because adequate funding to allow recovery is tied to the Act (Taylor et al., 2005). Australian threatened species legislation is more equivocal about prevention of extinction, funding has been lower (Wintle et al., 2019) and extinctions have continued (Woinarski et al., 2019). As noted in the USA, the public appear to be less tolerant of extinction risk than policy makers (Offer-Westort et al., 2020). ...
Article
Conservation management is a rapidly evolving field in which scientific innovation and management practice can run ahead of social acceptability, leading to dispute and policy constraints. Here we use best-worst scaling (BWS) to explore the social preferences for two broad areas of threatened species management in Australia as well as support for extinction prevention as a whole. Of the 2430 respondents to an online survey among the Australian general public, 70% stated that extinction should be prevented regardless of the cost, a sentiment not fully reflected in existing policy and legislation. There was strong support for existing measures being taken to protect threatened species from feral animals, including explicit support for the killing of feral animals, but the demographic correlations with the results suggest approval is lower among women and younger respondents. There was a particularly high level of support for moving species to new places, which does not match current capabilities of managers responsible for assisted migration, suggesting messaging about the current limitations needs to be improved, or for resources to overcome them greatly increased. There was less support for genetic interventions than the feral animal control and other land management measures. A small majority of respondents thought it would be better for a species to cope without assistance than invasively alter their genome. This suggests that greater community consultation is desirable before applying genetic management approaches more interventionist than interbreeding subspecies.
... However, when comparing the percentage of threatened bioturbator species occurring on each continent, Oceania clearly has the highest percentage of threatened (27%) and Extinct (11%) bioturbator species (Fig. 4). Australia is considered to have the world's worst record of recent mammal extinction (Woinarski et al. 2015b(Woinarski et al. , 2019: about 22% of the mammal fauna have become extinct since European settlement, including many bioturbator species (Fleming et al. 2014). Gilbert's potoroo Potorous gilbertii is a small native Australian marsupial that lives in small groups and has curved claws on its forefeet that it uses to dig to search for food. ...
Article
• The action of biological reworking of soils is referred to as bioturbation, and many species of mammals globally have an important role in soil disturbance, modifying ecosystem characteristics. • We examined global patterns in the distribution, conservation status, and threats to the world’s bioturbator mammals and illustrated the relevant roles these species play in ecosystem engineering related to soil processes and services. We searched the data available on 3932 non-flying land-dwelling mammals included in the International Union for Conservation of Nature’s (IUCN) Red List. • Using existing literature and online databases, we determined that 869 (22%) of the non-flying land-dwelling mammals accessed can be considered as bioturbators in three distinct groups: foragers (n = 123), semi-fossorial species (n = 652), and strictly fossorial species (n = 94). Of the world’s bioturbator mammal species, 16% are threatened, 2% are already Extinct, and 8% are classified as Data Deficient. Foragers have the highest percentage of threatened (35%) and Extinct (5%) species, while strictly fossorial species have the highest percentage of Data Deficient species (12%). Although the majority of bioturbator mammal species are found in Asia (32%), Oceania is the continent with the highest percentage of threatened (27%) and Extinct (11%) bioturbator species, while Central and South America have the highest percentage of species classified as Data Deficient (24%). The threats experienced by the greatest number of bioturbator mammal species are activities related to agriculture and aquaculture (29%), and biological resource use (22%). • Soil bioturbation can improve ecosystem health by reducing soil compaction, increasing nutrient cycling, soil moisture, microbe diversity, plant recruitment, and carbon storage. The loss of bioturbator mammals could trigger cascading effects throughout the ecosystems they inhabit. A better understanding of their conservation status is important so that effective conservation measures can be developed.
... Australia's contemporary mammal extinction rate is the globe's highest (Woinarski et al. 2019a). Yet more Australian mammals are forecast to become extinct within the next two decades (Geyle et al. 2018). ...
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In response to Australia's current extinction crisis, substantial research efforts have been targeted towards some of the most imperilled species. One such species is the northern quoll (Dasyurus hallucatus), a marsupial predator that has recently suffered substantial declines in range and is now listed as Endangered. We conducted a systematic review of all literature relevant to the conservation and ecology of northern quolls. We reviewed 143 studies, including research articles, government and industry reports, theses, and books, and quantified research effort in terms of topic, location, and publication period. We then summarised research relevant to northern quoll taxonomy, genetics, distribution, habitat associations, diet, reproduction, movement, threats, management, and Indigenous knowledge. Research effort was higher between 2011 and 2020 than the previous four decades combined. Northern quolls in the Northern Territory were the most studied, followed by the Pilbara, the Kimberley, and Queensland populations. Most studies focused on northern quoll distribution and habitat, management, and threats-primarily cane toads, predation, and fire. We conclude with a non-exhaustive list of ten future research directions. If pursued, these future research directions should provide information critical to managing and conserving northern quolls.
... Since European colonisation, Australia has lost 30 mammal species, with 56 others now threatened, due to the combined impacts of introduced predators and habitat modification (Woinarski et al. 2015;Woinarski et al. 2019). In the same period, around 40 mammal species have been introduced to Australia, with 23 successfully establishing (Forsyth et al. 2004). ...
Article
The loss of species from ecosystems can have cascading impacts on species interactions and ecosystem function. Australia has experienced the greatest loss of mammals globally in the past 200 years, but we know little of how the loss of this suite of ecosystem engineers and herbivores has affected vegetation. We used a threatened mammal reintroduction sanctuary to investigate effects of ecologically extinct mammals on plant assemblages. First, we tested the net effects of mammals using a long-term exclusion experiment within the sanctuary. Second, we used a three-year disturbance experiment to determine the relative roles of herbivory and physical disturbance in driving changes in plant assemblages. Third, we compared outcomes inside and outside the sanctuary to determine how effects of reintroduced mammals differed from contemporary mammal assemblages. Plant species richness was greatest in mammal exclusion plots and declined across all treatments from 2011 to 2018, probably due to drought. Plant composition changed in response to mammal exclusion, with six species increasing significantly, shrubs and myrmecochorous plants becoming more common and large-seeded species less common. Responses to experimental disturbance were less clear. Grass and resprouters were more common, and palatable and large-seeded plants were less common outside the sanctuary (exposed to contemporary mammal assemblage). Our study shows that reintroductions of ecologically extinct mammals have substantial impacts on plant assemblages, both through ecosystem engineering and herbivory, and these impacts differ from those of contemporary mammal faunas, suggesting that pre-European Australian ecosystems were markedly different from contemporary ecosystems.
Article
Monitoring of threatened species is a critical part of conserving biodiversity. It is needed to understand population trajectories, threatening processes, and the type and effectiveness of management responses needed to ensure persistence and recovery. Characteristics of some plant species (e.g. immobility) should render them amenable to monitoring, whereas other characteristics (e.g. ephemeral life histories) will make plant monitoring challenging. We evaluated monitoring adequacy and extent for a large sample (839 taxa) of Australia's threatened plants (1336 taxa) and compared this assessment with a similar evaluation for threatened vertebrates. We found 37.2% of threatened plants are monitored, half the rate found for vertebrates. For monitored plants, monitoring quality as assessed using a set of nine criteria was generally low, similar to results for vertebrates. Plants with more imperilled conservation status were more likely to be monitored and tended to have higher quality monitoring. Plants with recovery plans were more likely to be monitored than those without. The likelihood a species was monitored decreased the longer a taxon had been listed under threatened species legislation. Monitoring longevity was poor but inclusion of demographic data and linkages to management were better than for vertebrates. Our assessment highlighted a lack of collated monitoring data for plants, and we recognise there are exemplary programs for threatened plants that can guide improvements in monitoring for other species. Plants are overwhelmingly represented in threatened species lists worldwide and a determined focus to improve the extent and quality of plant monitoring should underpin biodiversity conservation targets.
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Native mammals are suffering widespread and ongoing population declines across northern Australia. These declines are likely driven by multiple, interacting factors including altered fire regimes, predation by feral cats, and grazing by feral herbivores. In addition, the loss of tree hollows due to frequent, intense fires may also be contributing to the decline of hollow-dependent mammals. We currently have little understanding of how the availability of tree hollows influences populations of hollow-dependent mammals in northern Australian savannas. Here, we test the hypothesis that the abundance of hollow-dependent mammals is higher in areas with a greater availability of tree hollows. We used camera-trap data from 82 sites across the savannas of Melville Island, the largest island in monsoonal northern Australia. Royle–Nichols abundance-induced heterogeneity models were used to investigate the biophysical correlates of the abundance of three threatened mammals: northern brushtail possum ( Trichosurus vulpecula arnhemensis ), black-footed tree-rat ( Mesembriomys gouldii ), and brush-tailed rabbit-rat ( Conilurus penicillatus ). Our analyses included two variables that reflect the availability of tree hollows: the density of tree hollows, estimated from the ground, and the density of large eucalypt trees ( Eucalyptus and Corymbia spp.). We found no evidence that the abundance of the three hollow-dependent mammals is positively associated with the availability of tree hollows on Melville Island. Despite their reliance on hollow-bearing trees for denning, the abundance of these mammals appears to be more strongly associated with other factors, such as the characteristics of the understory (i.e., shrub density), which affords protection from predators (including feral cats) and access to food resources. Future conservation management should aim to maintain a dense, diverse understory by managing fire and feral herbivores to facilitate the persistence of hollow-dependent mammals across northern Australia.
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Abstract. Introduced mammalian predators are drivers of species decline and extinction globally. The successful management and control of introduced mammalian predators is dependent on some knowledge of space use and movements in order to target a population and monitor outcomes. In Australia, these tasks are made complex as there is more than one significant introduced mammalian predator, namely the European red fox Vulpes vulpes and feral cat Felis catus, the landscapes are vast, and individual-level interactions between predators are little studied. The impact of these two introduced predators is large and a significant factor in the extinction of many of the country's small-to medium-sized mammals, either regionally or globally. In a three-year study, we used high-frequency location data, the deployment of the latest GPS tracking technologies, and recent advances in statistical modeling to examine how these two species distributed themselves in space, the degree to which individual distributions overlapped, intra-and interspecific interactions, and temporal patterns of activity in an arid landscape. In the absence of an apex predator, the two introduced mesopredators showed large differences in how they distribute themselves across the landscape and interact with conspecifics. The red fox mostly occupies defined territories, while most feral cats roam apparently independent of each other with occasional periods of frequent interaction with conspecifics of either sex. Intraspecific attraction was strongest in cats, while interspecific avoidance was observed in both directions. The home ranges of feral cats that were range-resident were 3-3.5 times larger than foxes in the same landscape. Notably, we observed long-distance movements in feral cats and some were displaced up to 164 km from their point of release. A greater portion of the feral cat population were non-sedentary and therefore likely less amenable to local control efforts than foxes. Given the different patterns of distribution in time and space, the reliable monitoring of population trends or estimates of abundance will necessarily differ in extent, intensity, or duration for the same level of precision and/or require a different method for monitoring each population.
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The rise in global commitments to restore habitat underlines its importance to halt biodiversity loss and abate climate change. To effectively plan for landscape-scale restoration efforts, decision makers need to prioritise where restoration should occur and have a method to estimate its cost. Here, we describe a systematic approach to determine where cost-effective restoration actions should be located to achieve targeted levels of ecosystem coverage across Australia without compromising agricultural production. We find that spending approximately AU$2 billion (0.1% of Australia's 2019 Gross Domestic Product) annually for 30 years could restore 13 million ha of degraded land without affecting intensive agriculture and urban areas. This initiative would result in almost all (99.8%) of Australia's degraded terrestrial ecosystems reaching 30% vegetation coverage, enabling a trajectory to recover critical ecological functions, abate almost one billion tonnes of carbon dioxide equivalent and produce AU$12–46 billion net present value in carbon offset revenue. The carbon market revenue is estimated to cover up to 111% of the investment required for the restoration. Our research shows that the recovery of degraded ecosystems in Australia is both attainable and affordable. Synthesis and applications. With growing international restoration commitments, governments and environmental organisations need methods to plan and budget their commitments. Here, we present a systematic approach to determine where restoration actions should be located in Australia to achieve targeted vegetation coverage and quantify the expected costs, carbon abatement and revenue. This study is an important advance that will aid governments and environmental organisations by providing financial and spatial planning methods to progress their restoration commitments.
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Introduced mammalian predators can have devastating impacts on recipient ecosystems and disrupt native predator–prey relationships. Feral cats ( Felis catus ) have been implicated in the decline and extinction of many Australian native species and developing effective and affordable methods to control them is a national priority. While there has been considerable progress in the lethal control of feral cats, effective management at landscape scales has proved challenging. Justification of the allocation of resources to feral cat control programs requires demonstration of the conservation benefit baiting provides to native species susceptible to cat predation. Here, we examined the effectiveness of a landscape-scale Eradicat® baiting program to protect threatened northern quolls ( Dasyurus hallucatus ) from feral cat predation in a heterogeneous rocky landscape in the Pilbara region of Western Australia. We used camera traps and GPS collars fitted to feral cats to monitor changes in activity patterns of feral cats and northern quolls at a baited treatment site and unbaited reference site over four years. Feral cat populations appeared to be naturally sparse in our study area, and camera trap monitoring showed no significant effect of baiting on cat detections. However, mortality rates of collared feral cats ranged from 18–33% after baiting, indicating that the program was reducing cat numbers. Our study demonstrated that feral cat baiting had a positive effect on northern quoll populations, with evidence of range expansion at the treatment site. We suggest that the rugged rocky habitat preferred by northern quolls in the Pilbara buffered them to some extent from feral cat predation, and baiting was sufficient to demonstrate a positive effect in this relatively short-term project. A more strategic approach to feral cat management is likely to be required in the longer-term to maximise the efficacy of control programs and thereby improve the conservation outlook for susceptible threatened fauna.
Article
Increasingly threatened species and their habitats require multiple successful management actions to ensure persistence. Introduced predator exclusion and suppression programs are key conservation actions used to retain or restore Australian ecosystems. Nevertheless, few direct comparisons are made to ascertain the individual and combined efficacy of multiple introduced predator conservation actions to benefit biodiversity. When co‐located, both management actions could generate additive conservation benefits that greatly assist the recovery or persistence of threatened native species. Varanid lizards are key functional components in Australian predator guilds and could benefit, via ecological release, when introduced predator management actions are successful. Here we tested the effects of a co‐located predator‐exclusion fence and lethal fox baiting on varanid site occupancy in a semiarid protected area. Varanid site occupancy was higher at sites inside (Ψ =0.90 ± 0.26) compared to sites outside (Ψ = 0.61 ± 0.28) the introduced predator‐proof fenced enclosure. There was only weak evidence of increased varanid site occupancy at fox baited sites (Ψ = 0.037 ± 0.024) compared to non‐fox baited (Ψ = 0.00) sites. Overall, co‐located introduced predator management actions achieved some additive benefits via possible spillover fencing effects for native mesopredator populations. However, most potential benefits to varanid populations outside of the predator proof fenced enclosure were absent due to unsuccessful lethal‐baiting effects on fox populations. The fenced predator fenced enclosure nevertheless provides important habitat refugia for future source populations for reintroduction once adjacent protected areas become suitable. This article is protected by copyright. All rights reserved.
Chapter
Declines and losses of insects throughout the world have wide ramifications for the sustainability of terrestrial and inland water ecosystems, and for humanity. Recent accounts and estimates of declines in insect richness and abundance in many parts of the world pose serious concerns for the future of global biodiversity. Some have been claimed to be sensationalistic and many such claims are difficult to validate. This summary of concerns demonstrates difficulties of interpreting data against insecure historical baselines and incomplete taxonomic and ecological information, features that introduce ambiguities and uncertainties in interpreting observed changes and may reduce credibility.
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Aim Introduced predators negatively impact biodiversity globally, with insular fauna often most severely affected. Here, we assess spatial variation in the number of terrestrial vertebrates (excluding amphibians) killed by two mammalian mesopredators introduced to Australia, the red fox (Vulpes vulpes) and feral cat (Felis catus). We aim to identify prey groups that suffer especially high rates of predation, and regions where losses to foxes and/or cats are most substantial. Location Australia. Methods We draw information on the spatial variation in tallies of reptiles, birds and mammals killed by cats in Australia from published studies. We derive tallies for fox predation by (i) modelling continental‐scale spatial variation in fox density, (ii) modelling spatial variation in the frequency of occurrence of prey groups in fox diet, (iii) analysing the number of prey individuals within dietary samples and (iv) discounting animals taken as carrion. We derive point estimates of the numbers of individuals killed annually by foxes and by cats and map spatial variation in these tallies. Results Foxes kill more reptiles, birds and mammals (peaking at 1071 km⁻² year⁻¹) than cats (55 km⁻² year⁻¹) across most of the unmodified temperate and forested areas of mainland Australia, reflecting the generally higher density of foxes than cats in these environments. However, across most of the continent – mainly the arid central and tropical northern regions (and on most Australian islands) – cats kill more animals than foxes. We estimate that foxes and cats together kill 697 million reptiles annually in Australia, 510 million birds and 1435 million mammals. Main conclusions This continental‐scale analysis demonstrates that predation by two introduced species takes a substantial and ongoing toll on Australian reptiles, birds and mammals. Continuing population declines and potential extinctions of some of these species threatens to further compound Australia's poor contemporary conservation record.
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The likelihood of extinction within the next 20 years was determined for 47 Australian mammal, bird, reptile, frog and freshwater fish taxa previously identified as being highly imperilled. A 14-member expert elicitation panel, consisting of a mix of taxon experts and government managers of threatened species, estimated that there was a > 50% chance that nine taxa would be extinct by 2041. The panel estimated that there was a > 50% likelihood that a further 16 taxa (considered extant under Australian legislation), for which there are no recent independently verified records, are already extinct, with four almost certainly extinct. For five of these taxa, there was a > 50% chance that they would persist for 20 more years if they are currently extant, notwithstanding the lack of recent records. Most of the taxa considered occur within conservation areas and in south-eastern Australia, where human population density is highest. All the highly imperilled taxa occur wholly or partly in conservation reserves, within a total reserved area of 1994 km2, 0.13% of the total area conserved in Australia. Highly imperilled taxa also occur on 313 km2 of non-conservation government-owned land, and 242 km2 of private land. The total area that needs management intervention to prevent extinction of Australia's most imperilled vertebrate taxa in the next 20 years represents 0.06% of the area of Australia's terrestrial and freshwater environments.
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Myrtle rust is caused by the fungus Austropuccinia psidii and impacts some species in the extremely large and mostly Gondwanic plant family, the Myrtaceae. Given the location of its wild relatives, the fungal pathogen originated in South America and spread rapidly across the Pacific. Here we report on extensive surveys from Australian rainforest to predict a plant extinction event of unprecedented magnitude. The results predict the imminent extinction of 16 rainforest tree species in the wild due to myrtle rust within a generation. A further 20 species may be at risk, but further monitoring is required to determine their fate. Myrtle rust retards growth and precludes reproduction on these severely affected species. To avoid total extinction, strategies for in-situ and ex-situ rescue are presented.
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Abstract Mammal declines across northern Australia are one of the major biodiversity loss events occurring globally. There has been no regional assessment of the implications of these species declines for genomic diversity. To address this, we conducted a species‐wide assessment of genomic diversity in the northern quoll (Dasyurus hallucatus), an Endangered marsupial carnivore. We used next generation sequencing methods to genotype 10,191 SNPs in 352 individuals from across a 3220 km length of the continent, investigating patterns of population genomic structure and diversity, and identifying loci showing signals of putative selection. We found strong heterogeneity in the distribution of genomic diversity across the continent, characterised by (1) biogeographic barriers driving hierarchical population structure through long‐term isolation, and (2) severe reductions in diversity resulting from population declines, exacerbated by the spread of introduced toxic cane toads (Rhinella marina). These results warn of a large ongoing loss of genomic diversity and associated adaptive capacity as mammals decline across northern Australia. Encouragingly, populations of the northern quoll established on toad‐free islands by translocations appear to have maintained most of the initial genomic diversity after 16 years. By mapping patterns of genomic diversity within and among populations, and investigating these patterns in the context of population declines, we can provide conservation managers with data critical to informed decision‐making. This includes the identification of populations that are candidates for genetic management, the importance of remnant island and insurance/translocated populations for the conservation of genetic diversity, and the characterisation of putative evolutionarily significant units.
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Extinction is a profound biological event, yet despite its finality it can be difficult to verify and many frameworks have been proposed to define formally that extinction has occurred. For most taxonomic groups and regions there is no reliable list of species considered to be probably or possibly extinct. The record of plant extinctions in Australia is no exception, characterized by high turn-over within lists, low transparency of attribution and lack of consistency between jurisdictions. This makes it impossible to evaluate how many plant taxa have become extinct in Australia. We present an ecological framework for assessing the likelihood of plant extinctions, based on taxonomic soundness, degree of habitat modification, detectability and search effort, underpinned by the best available expert knowledge. We show that, in sharp contrast to both the fate of the Australian fauna and prevailing assumptions, only 12 of 71 plant taxa currently listed as or assumed to be extinct are considered probably extinct, and a further 21 possibly extinct. Twenty taxa listed as or assumed to be extinct have dubious taxonomy or occurrence in Australia, and the remaining 18 taxa are considered possibly extant and further surveys are required to ascertain their status. The list of probably and possibly extinct plants is dwarfed by the number thought extinct but rediscovered since 1980. Our method can be used for vascular floras in other regions characterized by well-documented and curated floras and high levels of expert knowledge, and provides a transparent platform for assessing changes in the status of biodiversity.
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Conservation scientists and practitioners usually focus on understanding and managing individual threats to biodiversity. However, threats may interact, making management outcomes unpredictable. Here, we investigated whether interactions between fire regimes and introduced livestock affect the conservation goal of population recovery for small mammals in Australia's tropical savannas, using a long‐term and landscape‐scale study. Mammal richness and abundance increased as management reduced the average annual fire extent and frequency at large and medium scales. However, these relationships between fire and richness and abundance were only evident in areas where introduced livestock were removed. This interaction may arise because predation by feral cats is amplified in areas with reduced vegetation ground cover, and cover is reduced over longer periods when livestock have access to burnt areas, because they selectively graze regenerating grass. Fire management for conservation receives substantial investment across northern Australia, and in savannas worldwide; this study shows that without appropriate management of other factors, this investment may be ineffective. More broadly, managing single threats to biodiversity may be compromised if interactions between threats are not explicitly considered. This study provides an example of how such interactions can be evaluated for improved biodiversity conservation.
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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- A nd 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 diverse 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 >25 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 (2152 km² versus 346 km²), and reach larger sizes (largest island 325 km², with another island of 628 km² becoming available from 2018; largest fence: 123 km²). 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.
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Since European occupation of Australia, human activities have caused the dramatic decline and sometimes extinction of many of the continent's unique species. Here we provide a comprehensive review of threats to species listed as threatened under Australia's Environment Protection and Biodiversity Conservation Act 1999. Following accepted global categories of threat, we find that invasive species affect the largest number of listed species (1257 species, or 82% of all threatened species); ecosystem modifications (e.g. fire) (74% of listed species) and agricultural activity (57%) are also important. The ranking of threats was largely consistent across taxonomic groups and the degree of species' endangerment. These results were significantly different (P < 0.01) from recent analyses of threats to threatened species globally, which highlighted overexploitation, agriculture and urban development as major causes of decline. Australia is distinct not only in the biodiversity it contains but also in the extent and mixture of processes that threaten the survival of these species. Notably, the IUCN threat classification scheme separates the numerous threats (e.g. urban development, agriculture, mining) that cause habitat loss, fragmentation and degradation, hence further research is required to quantify the net impact of these types of habitat change. We provide feasible suggestions for a more coordinated national approach to threatened species conservation, which could provide decision makers and managers at all levels with improved resources and information on threats and management. Adequate policy, legislative support and funding are critical for ensuring that on-ground management is successful in halting the decline of Australia's threatened species.
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While invertebrate conservation is attracting increased funding and interest, research remains heavily skewed towards ‘flagship’ insect groups like bees and butterflies. This has resulted in a knowledge gap relating to less popular but equally imperilled groups like fleas. Methods for the risk assessment of host specific parasites were used to determine the conservation status of all host specific flea species distributed in Australia. The results indicated one species apparently extinct, two critically endangered, two endangered, and three vulnerable. Based on these results, novel methods for the conservation of threatened fleas are outlined, including the concepts of holistic conservation and the cryptic loss effect.
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Despite progress in recent decades, the conservation management of insects and allied invertebrates in Australia is challenging and remains a formidable task against a background of poor taxonomic and biological knowledge, limited resources (funds and scientific expertise) and a relatively low level of community engagement, education and awareness. In this review, we propose a new, strategic national approach for the conservation of insects and allied invertebrates in Australia to complement and build on existing actions and increase awareness with the general public and government. A review of all species listed under relevant State and Territory Acts, national legislation (EPBC Act) and on international lists (IUCN Red List) indicated that of the 285 species currently listed under these conservation schedules, 10 (3%) are considered extinct, 204 (72%) threatened (Critically Endangered, Endangered or Vulnerable) and 71 (25%) are classified as other (Threatened, Near Threatened, Rare or Least Concern). Comparison of the geographic ranges of listed species in relation to bioregions (IBRA regions) shows a striking discordance in spatial representation across the Australian landscape, reflecting an ad hoc approach to threatened species conservation and the concentration of invertebrate biologists in urban centres of temperate coastal Australia. There is a positive relationship between the number of threatened species and extent of protection according to the National Reserve System within each IBRA region, exemplifying the anomaly in spatial representativeness of listed species. To overcome these shortfalls, we propose a novel educational, regional approach based on selecting, for each of the 89 IBRA *
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A critical step towards reducing the incidence of extinction is to identify and rank the species at highest risk, while implementing protective measures to reduce the risk of extinction to such species. Existing global processes provide a graded categorisation of extinction risk. Here we seek to extend and complement those processes to focus more narrowly on the likelihood of extinction of the most imperilled Australian birds and mammals. We considered an extension of existing IUCN and NatureServe criteria, and used expert elicitation to rank the extinction risk to the most imperilled species, assuming current management. On the basis of these assessments, and using two additional approaches, we estimated the number of extinctions likely to occur in the next 20 years. The estimates of extinction risk derived from our tighter IUCN categorisations, NatureServe assessments and expert elicitation were poorly correlated, with little agreement among methods for which species were most in danger-highlighting the importance of integrating multiple approaches when considering extinction risk. Mapped distributions of the 20 most imperilled birds reveal that most are endemic to islands or occur in southern Australia. The 20 most imperilled mammals occur mostly in northern and central Australia. While there were some differences in the forecasted number of extinctions in the next 20 years among methods, all three approaches predict further species loss. Overall, we estimate that another seven Australian mammals and 10 Australian birds will be extinct by 2038 unless management improves.
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Australia has contributed a disproportionate number of the world's mammal extinctions over the past 200 years, with the greatest loss of species occurring through the continent's southern and central arid regions. Many taxonomically and ecologically similar species are now undergoing widespread decline across the northern Australian mainland, possibly driven by predation by feral cats and changed fire regimes. Here, we report marked recent declines of native mammal species in one of Australia's few remaining areas that support an intact mammal assemblage, Melville Island, the largest island off the northern Australian coast. We have previously reported a marked decline on Melville Island of the threatened brush‐tailed rabbit‐rat (Conilurus penicillatus) over the period 2000–2015, linked to predation by feral cats. We now report a 62% reduction in small mammal trap‐success and a 36% reduction in site‐level species richness over this period. There was a decrease in trap‐success of 90% for the northern brown bandicoot (Isoodon macrourus), 64% for the brush‐tailed rabbit‐rat and 63% for the black‐footed tree‐rat (Mesembriomys gouldii), but no decline for the common brushtail possum (Trichosurus vulpecula). These results suggest that populations of native mammals on Melville Island are exhibiting similar patterns of decline to those recorded in Kakadu National Park two decades earlier, and across the northern Australian mainland more generally. Without the implementation of effective management actions, these species are likely to be lost from one of their last remaining strongholds, threatening to increase Australia's already disproportionate contribution to global mammal extinctions.
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The phylogenetic relationships of bandicoots and bilbies have been somewhat problematic, with conflicting results between morphological work and molecular data. This conflict makes it difficult to assess the taxonomic status of species and subspecies within this order, and also prevents accurate evolutionary assessments. Here, we present a new total evidence analysis, combining the latest cranio-dental morphological matrix containing both modern and fossil taxa, with molecular data from GenBank. Several subspecies were scored in the morphological dataset to match the molecular data available. Both parsimony and Bayesian analyses were performed, giving similar topologies except for the position of four fossil taxa. Total evidence dating places the peramelemorphian crown origin close to the Oligocene/Miocene boundary, and the radiations of most modern genera beginning in the Late Miocene or Early Pliocene. Our results show that some species and subspecies require taxonomic reassessment, and are revised here. We also describe a new, extinct species from the Nullarbor region. This suggests that the number of recently extinct peramelemorphian species is likely to further increase.
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We created a new dataset of spatially interpolated monthly climate data for global land areas at a very high spatial resolution (approximately 1 km 2). We included monthly temperature (minimum, maximum and average), precipitation, solar radiation, vapour pressure and wind speed, aggregated across a target temporal range of 1970–2000, using data from between 9000 and 60 000 weather stations. Weather station data were interpolated using thin-plate splines with covariates including elevation, distance to the coast and three satellite-derived covariates: maximum and minimum land surface temperature as well as cloud cover, obtained with the MODIS satellite platform. Interpolation was done for 23 regions of varying size depending on station density. Satellite data improved prediction accuracy for temperature variables 5–15% (0.07–0.17 ∘ C), particularly for areas with a low station density, although prediction error remained high in such regions for all climate variables. Contributions of satellite covariates were mostly negligible for the other variables, although their importance varied by region. In contrast to the common approach to use a single model formulation for the entire world, we constructed the final product by selecting the best performing model for each region and variable. Global cross-validation correlations were ≥ 0.99 for temperature and humidity, 0.86 for precipitation and 0.76 for wind speed. The fact that most of our climate surface estimates were only marginally improved by use of satellite covariates highlights the importance having a dense, high-quality network of climate station data.
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Context: Since European settlement in 1788, much of the Australian terrestrial mammal fauna has declined or become extinct. The pattern of, and reason for, that decline was little documented, and is now difficult to decipher. Many mammal species are still declining, providing (an unfortunate) opportunity to better document the process, identify the causal factors and attempt to redress the problem. Aim: We compare trends in mammal abundance reported in three recent longitudinal studies in conservation reserves in Australia. The studies were not established with the intention of documenting mammal decline, but marked simultaneous decline of co-existing species was the most striking feature of their results. Methods: Long-term monitoring in Kakadu National Park, Northern Territory (2001–04 and 2007–09), the Upper Warren region of Western Australia (since 1974) and the Great Otway National Park, Victoria (since 1975) principally relied on trapping, but also some spotlighting and sand plots, to document changes and trends in abundance in their respective mammal assemblages. Key results: Decline was reported in most mammal species, across taxonomic groups, diets and size classes, but mostly involved species <5500 g. The studies differed in their monitoring protocols and varied in the degree to which potential causal factors were monitored, thereby constraining interpretation of the drivers of declines. Inappropriate fire regimes and predation by feral cats are likely contributing factors in at least two study areas, and periods of markedly below-average rainfall are implicated in two areas. Conclusions: We conclude the following: (1) conservation reserves in Australia may be failing to maintain at least some elements of the biodiversity that they were established to protect, and substantially enhanced management is required to redress this problem; (2) with current threats, mammal assemblages in Australia may be highly unstable; (3) substantial increase in effective long-term biodiversity monitoring programs in an adaptive management framework is needed; and (4) such monitoring programs will be more insightful if they also monitor factors driving population change. Implications: Native mammal species declines and community disassembly may be occurring elsewhere. Long-term monitoring is critical for assessing trends in biodiversity and if done well, it can guide more effective and efficient management to deliver better conservation outcomes.
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As with many islands, Christmas Island in the Indian Ocean has suffered severe biodiversity loss. Its terrestrial lizard fauna comprised five native species, of which four were endemic. These were abundant until at least the late 1970s, but four species declined rapidly thereafter and were last reported in the wild between 2009 and 2013. In response to the decline, a captive breeding programme was established in August 2009. This attempt came too late for the Christmas Island forest skink Emoia nativitatis , whose last known individual died in captivity in 2014, and for the non-endemic coastal skink Emoia atrocostata . However, two captive populations are now established for Lister's gecko Lepidodactylus listeri and the blue-tailed skink Cryptoblepharus egeriae . The conservation future for these two species is challenging: reintroduction will not be possible until the main threats are identified and controlled.
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The threats of old are still the dominant drivers of current species loss, indicates an analysis of IUCN Red List data by Sean Maxwell and colleagues.
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Each year, two or three species that had been considered to be extinct are rediscovered. Uncertainty about whether or not a species is extinct is common, because rare and highly threatened species are difficult to detect. Biological traits such as body size and range size are expected to be associated with extinction. However, these traits, together with the intensity of search effort, might influence the probability of detection and extinction differently. This makes statistical analysis of extinction and rediscovery challenging. Here we use a variant of survival analysis known as cure rate modelling to differentiate factors that influence rediscovery from those that influence extinction. We analyse a global dataset of 99 mammals that have been categorised as extinct or possibly extinct. We estimate the probability that each of these mammals is still extant, and thus estimate the proportion of missing (presumed extinct) mammals that are incorrectly assigned extinction. We find that body mass and population density are predictors of extinction, and body mass and search effort predict rediscovery. In mammals, extinction rate increases with body mass and population density, and these traits act synergistically to greatly elevate extinction rate in large species that also occurred in formerly dense populations. However, when they remain extant, larger-bodied missing species are rediscovered sooner than smaller species. Greater search effort increases the probability of rediscovery in larger species of missing mammals, but has a minimal effect on small species, which take longer to be rediscovered, if extant. By separating the effects of species characteristics on extinction and detection, and using models with the assumption that a proportion of missing species will never be rediscovered, our new approach provides estimates of extinction probability in species with few observation records and scant ecological information.
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Since European arrival in Australia the murid genus Conilurus Ogilby has suffered severe decline, the causes of which are still uncertain. Knowledge of the distribution of the genus during the Quaternary may be useful in understanding why Conilurus has declined and thus inform efforts to conserve remaining populations. The late Quaternary distribution of species of Conilurus is here revised with the extension of the known ranges of two species, C. albipes and C. penicilattus, to the north and east of their previously known ranges, respectively. An additional species, C. capricornensis sp. nov., is described on the basis of Pleistocene and Holocene dental remains. Conilurus capricornensis is large for the genus and can be distinguished from C. penicillatus and C. albipes by molar dimensions, a posteriorly narrow anterior palatal foramina, the presence of a T3 and anterior cingulum on M 1, and small or absent posterior cingula on M 1-2. The southern-most occurrence of C. capricornensis overlaps the northern-most record of C. albipes. The temporal ranges of C. capricornensis and C. penicillatus overlap, but they have not been found in sympatry. Recently recovered fossil and subfossil specimens from the Broken River area, near Townsville, Queensland and Mount Etna (eastern Queensland) indicate that C. capricornensis had a temporal range from the late Pleistocene to very recent time. Preservation of some specimens from the Broken River area indicates that C. capricornensis may still be extant in that area.
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Phillip Island is near Norfolk Island, halfway between Sydney and Fiji. Before feral animals were released on Phillip Island, the island retained its natural sub-tropical vegetation and native fauna. The first disastrous action was release of pigs on the island in 1793. The settlers also introduced goats and rabbits to Phillip Island by 1830. By around 1860 the island had almost no vegetation apart from a few remnant trees. The pigs and goats appear to have died out when inadequate food remained to support them but the rabbits survived, preventing the growth of vegetation and allowing unrestricted erosion to continue. Rabbit eradication efforts between 1979 and 1986 succeeded, allowing the environment to rebound spectacularly. Although only about 200 hectares the island is extremely rugged with cliffs 200 metres high, necessitating unusual methods to reach inaccessible areas – swimming, rock climbing, even archery. This book describes the island’s history and natural history, explaining how geological and geomorphological events helped shape the ecosystem. With a diversity of breeding seabirds and some of the world’s rarest plants, Phillip Island is a real natural treasure. Numerous photographs and maps show the wildlife and the spectacular revegetation. This is a landmark ecological case study. 136 pages with index and bibliography Further information and the book are available from www.petaurus.com/PI . A brief 2015 update is at https://www.researchgate.net/publication/299441767_Dramatic_vegetation_response_to_ending_rabbit_grazing_-_Phillip_Island_South_Pacific
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The mammals of inland Australia were seriously affected by European settlement, and a high proportion declined dramatically in range or became extinct. Native birds fared much better, and no species are certainly extinct. Reptiles have suffered no extinctions and no apparent reductions of range. Among the mammals there are clear biases in the species which suffered most; medium-sized species, most of them herbivorous or omnivorous, were devastated. It proposed that the environment of inland Australia was originally difficult for herbivorous and omnivorous mammals to inhabit because of the infertility of the soils, and the consequent restriction of digestible production to small fertile areas. This problem was exacerbated by the uncertain climate with its droughts of irregular length. The consequent restriction of these types of mammals to scattered pockets of suitable habitat during droughts exposed them to high probabilities of local disappearance. The arrival of grazing stock and the rabbit Oryctolagus cuniculus upset the balance between local disappearance and reinvasion after drought. The introduced herbivores maintained extraordinarily high populations for a short time and, in doing so, altered the vegetational composition of the very habitats upon which the native species had been dependent for refuge during droughts. This degradation, together with the pressure of introduced predators and, in some places, altered patterns of fire, caused increased probabilities of local disappearance. Several droughts later, extinctions resulted. -from Author
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Islands make up 5.3% of Earth's land area yet maintain an estimated 19% of bird species, 17% of rodents, 17% of flowering plants, and 27% of human languages. Species diversity is disproportionately threatened on islands in relation to the islands’ proportion of both global land area and species, with 61% of all extinct species and 37% of all critically endangered species confined to islands. Languages are disproportionately threatened on islands in relation to land area with 11% of extinct languages and 25% of critically endangered languages on islands. Islands are a priority area for integrated conservation efforts because they have 14 times greater density of critically endangered terrestrial species and 6 times greater density of critically endangered languages than continental areas. Invasive species and habitat loss are the largest threats to island terrestrial species diversity. Proven management actions can reduce these threats, benefiting both local peoples and species diversity on islands.
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Introduction: Recent studies at sites in northern Australia have reported severe and rapid decline of several native mammal species, notwithstanding an environmental context (small human population size, limited habitat loss, substantial reservation extent) that should provide relative conservation security. All of the more speciose taxonomic groups of mammals in northern Australia have some species for which their conservation status has been assessed as threatened, with 53 % of dasyurid, 47 % of macropod and potoroid, 33 % of bandicoot and bilby, 33 % of possum, 30 % of rodent, and 24 % of bat species being assessed as extinct, threatened or near threatened. However, the geographical extent and timing of declines, and their causes, remain poorly resolved, limiting the application of remedial management actions.