Science for Saving Species Research findings factsheet Project 2.1

The Australian most at risk of extinction and the actions needed to save them

In brief

This project has identified the We found that four of the 26 The fungal disease Australian species at greatest species may already be extinct. Four chytridiomycosis and climate risk of extinction, the likelihood more species are more likely than not change are the primary threats to of extinctions by 2040 with no (>50% probability) to become extinct Australian frogs. For some species, improvements to management, by 2040 unless there are substantial loss, invasive fish and and the highest priority management improvements in resourcing, pigs are also major threats. actions needed to prevent monitoring and management. extinctions. An additional five species have Urgent management actions are a moderate to high (30–50%) required to prevent extinctions We examined 26 frog species probability of extinction before 2040. of Australian frogs. Key priorities previously identified as meeting include developing captive breeding or Endangered We identified species at risk in every criteria on the IUCN Red List. state and territory except South and management programs and We used available data on ecology, Australia and Tasmania. Most of establishing wild population refuges, threats and trends, and then the imperilled species, including 10 of where the impacts of disease, 28 researchers with varying skills the top 15, are found in Queensland. climate change and pest species and backgrounds participated New South Wales has nine species. are reduced sufficiently to allow in an elicitation process. Many are found only in small areas. populations to survive.

Background More than one-third of the world’s Climate change has also been Australian species due to predation are listed as threatened identified as an emerging major and . or extinct. This is a greater threat, especially for range-restricted The IUCN Red List is the most widely proportion than for mammals, montane frogs. Many frog species used tool for measuring extinction birds, reptiles and fish. Even in are restricted to the uplands of risk to biodiversity globally. The list areas with reasonably intact habitat mountains along the east coast of does, however, have limitations for there have been major declines. Australia, especially in the north- identifying and prioritising species at east. Cool, moist environments also In Australia, chytridiomycosis, immediate risk of extinction, such as provide the optimal conditions for the disease caused by chytrid determining relative risks between pathogen growth; subsequently, fungus (Batrachochytrium multiple Critically Endangered these montane, stream-dwelling dendrobatidis) has been implicated species. For this reason, there is frogs are at the greatest risk in the decline of 43 species, value in undertaking an additional from chytridiomycosis. representing nearly one-fifth process that more explicitly estimates of the country’s amphibian diversity. Habitat loss and invasive species extinction probability within the near It is also the primary cause of (particularly fish and feral pigs) future, as this will assist in allocating the known extinctions to date. are significant threats for some resources to prevent extinction.

#2 #3 #4

#5 #6 #7

#8 #9 #10

#11 #12 #13

#15 #20 #21

#22 #25 #1

The most imperilled Australian frogs (from top, left to right): #1 The northern gastric-brooding frog # 8 The armoured mist frog (Litoria lorica) #15 The Kuranda tree frog (Litoria myola) is (Rheobatrachus vitellinus) is likely already is among the top 10 Australian frogs at risk found in a very small area near Cairns and is extinct, primarily due to chytrid fungus of extinction by 2040. Populations were unusual on the list in that the primary threat disease. Image: Hal Cogger decimated by chytrid fungus disease. Without is loss and degradation of habitat due to #2 The mountain mist frog (Litoria effective action it is likely to become extinct development. Image: Conrad Hoskin nyakalensis) is likely already extinct, within 20 years. Image: Conrad Hoskin #20 The white-bellied frog ( alba) primarily due to chytrid fungus disease. #9 The mountain-top nursery frog is the Western Australian frog at greatest Image: Stephen Richards (Cophixalus monticola) is among the top 10 risk of extinction. The tadpoles of this tiny #3 The yellow-spotted tree frog (Litoria Australian frogs at risk of extinction by 2040. terrestrial breeding frog rely on wet soil to castanea) is likely already extinct. It is sensitive The species is found on a single mountain- develop. Reduced rainfall in south-west to chytrid fungus disease and also impacted top and is threatened by climate change. Western Australia is believed to be a major by climate change, habitat loss and invasive Image: Conrad Hoskin contributor to the decline of this species fish. Image: David Hunter / DPIE NSW #10 The beautiful nursery frog (Cophixalus over recent decades. Image: Emily Hoffmann #4 Northern tinker frog ( concinnus) is restricted to the top of #21 Littlejohn’s tree frog (Litoria littlejohni) rheophilus) is likely already extinct. Thornton Peak, in the Daintree rainforest only occurs in in relatively undisturbed Chytrid fungus disease has been the of north Queensland. It is threatened by forested areas with infrequent natural fires. main cause of declines but climate climate change. Image: Conrad Hoskin Increased bushfire frequency may be the cause of its disappearance from national change has also played a role. #11 The northern corroboree frog parks around Sydney. Chytrid fungus disease #5 The Kroombit tinker frog (Taudactylus (Pseudophryne pengilleyi) is badly impacted is also strongly implicated in the decline of Pleione) is close to extinction. Without new by chytrid fungus disease and its alpine this species. Image: David Hunter / DPIE NSW action it is deemed far more likely than not habitat was burned in the 2019-20 bushfires. (70% chance) to become extinct by 2040. It The ACT Government has a captive breeding Watson’s tree frog (Litoria watsoni) was is threatened by chytrid fungus disease, feral program underway and is working with recently separated from Littlejohn’s tree frog pigs and climate change. Image: HB Hines / The Australian National University to identify (Litoria littlejohni) as a distinct species. It is Queensland Parks and Wildlife Service. of wild refuge sites. Image: David Hunter / threatened by logging, hot fires and probably also chytrid fungus disease. It is at high risk of #6 The southern corroboree frog DPIE NSW extinction. Image: Matthew West (Pseudophryne corroboree) is close to #12 The spotted tree frog (Litoria spenceri) extinction. Without new action it is deemed is found in Victoria and New South Wales. #22 Sloane’s froglet ( sloanei) was more likely than not (66% chance) to It is badly impacted by chytrid fungus disease once found over a wide area within the become extinct by 2040. It is very and predation of tadpoles by introduced Murray-Darling Basin. It has suffered extensive vulnerable to chytrid fungus disease. trout species. Image: Michael Williams/Its declines due to habitat loss and degradation. Image: David Hunter / DPIE NSW a Wildlife Image: David Hunter / DPIE NSW #7 The Baw Baw frog ( frosti) is #13 The Kroombit tree frog (Litoria #25 The giant burrowing frog ( close to extinction. Without new action it is kroombitensis) is restricted to Kroombit australiacus) is threatened primarily by deemed more likely than not (65% chance) Tops in south-eastern Queensland and habitat loss and altered fire regimes. to become extinct by 2040. The main threat is threatened by chytrid fungus disease Image: David Hunter / DPIE NSW to this species is chytrid fungus disease and climate change. Image: HB Hines / followed by changed climate and fire. Queensland Parks and Wildlife Service Image: Damian Goodall Beautiful nursery frog Armoured mist frog* Northern tinker frog** Howard River toadlet Tapping nursery frog Kuranda tree frog Rattling nursery frog Bellenden Ker nursery frog Mountain top nursery frog MAP: The locations of the top 26 Australian Mountain mist frog** frogs at risk of extinction. ** Species likely Mt Elliot nursery frog to be recently extinct. * Species more likely Northern gastric-brooding frog** than not to become extinct by 2040 unless Eungella day frog there is action. Image: Recovery Hub Kroombit tinker frog* Kroombit tree frog

Richmond Range Yellow-spotted mountain frog tree frog** Northern corroboree Mahony’s toadlet frog Littlejohn’s tree frog Sloane’s White-bellied frog froglet Southern corroboree frog* Giant burrowing frog Spotted tree frog The 26 Australian frogs Baw Baw frog* at greatest risk of extinciton Research aims We aimed to identify the Australian frog species at greatest risk of extinction, and to estimate their probabilities of extinction in the wild by 2040. We also aimed to identify the highest priority regions, research areas and management actions to prevent any future extinctions of Australian frogs.

Climate change is a major threat to three-quarters (19) of the imperilled frogs. Species that depend on damp mountain-top habitat, such as this nursery frog habitat, are particularly impacted. Image: Conrad Hoskin

What we did Our study focused on 26 highly We gathered all available We also asked participants to provide imperilled frog species. This information on the frogs’ ecology, a level of confidence associated with included 22 species identified as threats, and trends. We provided this estimate based on the available meeting IUCN (International Union this information to a panel of 28 information. Assessments were for the Conservation of Nature) experts, which included researchers based on the assumption that there Red List criteria as Endangered or and frog biologists from academic would be a continuation of current Critically Endangered in a recent institutions, state or federal management with no new actions review of the of government agencies and implemented beyond what all 243 Australian frog species. We NGOs from every Australian is currently occurring. also included four possibly extinct state and territory. For the four possibly extinct species because surveys have not species, we first asked participants been undertaken in important parts We used a structured expert to estimate the probability that of their potential ranges, which elicitation method to ask panel each of these species is already means they could be persisting as members to estimate the probability extinct. We then asked participants small populations in remote areas. of extinction in the next 20 years. to assume that one or more undiscovered populations Invasive species, especially invasive fish and feral pigs, are a threat to 10 of the frog species. persists, and to assess extinction For example, predation of tadpoles by brown and rainbow trout has caused declines of spotted tree frog populations. Image: Aaron Gustafson CC BY SA 2.0 probability by 2040. We obtained information on threats, research and management actions from published literature. Research and management actions were scored based on extinction probability, relative value, feasibility and current level of implementation. This allowed for prioritisation of the most important actions. We mapped the distribution of the most imperilled frogs to identify regions with many highly threatened species. RIGHT: Mountain-top frog habitat in north Queensland. Image: Conrad Hoskin

Key findings The findings of this study indicate Australian and global examples of (Philoria frosti) and armoured a dire situation for Australia’s most ‘missing’ frogs being rediscovered mist frog (Litoria lorica). threatened frogs. We found that in recent decades. Targeted surveys Chytridiomycosis is also the four species are likely already are thus a high priority, particularly in primary threat to these four species. extinct. Four more species have areas that are likely to provide refuge An additional five species are at a greater than 50% probability of from disease-driven declines. moderate to high risk of extinction extinction. Seven species are more If there are surviving undetected (30–50%) without improvements to likely than not to become extinct populations of any of these species, current management practises. The by 2040 unless there are substantial the panel of experts considered primary threats to these species are improvements in resourcing, that without major new action the climate change, chytridiomycosis monitoring and management. future outlook is very poor, with and invasive fish. Probably extinct already probabilities of extinction surpassing 90% by 2040 for all four species. Locations Of the 26 frog species examined, Most of the 26 threatened frogs we found that four species are The amphibian fungal disease are endemic to a single state highly likely to be extinct already. chytridiomycosis is the primary or territory, with the majority This includes the northern gastric- threat to these four species. occurring only in Queensland. brooding frog (Rheobatrachus Next at greatest risk The regions with the most at-risk vitellinus), mountain mist frog (Litoria species are: nyakalensis), yellow-spotted tree A further four species were frog (Litoria castanea) and northern considered more likely than not • Queensland wet tropics - tinker frog (Taudactylus rheophilus). (greater than 50% probability) to 9 species go extinct by 2040 if only current • Queensland south-eastern - Nevertheless, there remain some management continues. These poorly surveyed areas within 3 species include the Kroombit tinker frog their ranges, and there is a small • Queensland central Mackay (Taudactylus pleione), southern possibility that remnant populations coast - 2 species corroboree frog (Pseudophryne may be discovered. There are corroboree), Baw Baw frog • Australian Alps (NSW/VIC) - 3 species Ten of the top 15 most threatened frogs are restricted to Queensland.

Threats The most prevalent threats facing the 26 frogs considered are: • climate change - 19 species • chytridiomycosis - 15 species • changing fire regimes - 13 species • habitat loss - 11 species • invasive species (primarily invasive fish and pigs) - 10 species

Captive breeding programs will be critical to preventing extinctions. Shown here, part of the ACT Government’s captive breeding program for the northern corroboree frog. Image: Peter Taylor Dr Matthew West surveying spotted tree frogs in Victoria. Image: Michael Williams Its a wildlife photography

Key findings(continued) Management priorities Climate change and chytridiomycosis How do frogs compare? To both prevent extinctions and are the biggest threats to the Estimated extinction probabilities support populations to survive surviving species on our list. for frogs are similar to results for in the wild, the most important Currently, options are limited for birds and terrestrial reptiles, higher management actions are: directly mitigating either of than for mammals, and lower these threats, though research • developing and supporting than for freshwater fish using on refuges offers hope to identify the same methods. captive breeding and sites where species may persist management in the wild. Additionally, research Similar levels of imperilment • establishing and/or extending investigating gene-mixing offers predicted for frogs, birds and wild population refuges hope to increase the drying terrestrial snakes and lizards that alleviate impacts from tolerance of some species. could be due to these species all occupying very restricted ranges, diseases, climate change Some of the other threats (e.g., and consequently being highly and non-native fish. invasive species) are more feasible susceptible to random events There has been great progress to manage with existing knowledge such as the 2019–20 megafires for threatened frogs in Australia, and thus should be prioritised. across the eastern Australian coast. demonstrated through population Doing so may make it more likely They are also vulnerable to many supplementations, re-introductions that populations can persist despite of the same threats (e.g., climate and provision of insurance disease or climate change impacts. change and invasive species), populations for several species. The most important research actions although chytridiomycosis is Additionally, gene banking needed for these 26 species are unique to amphibians. technologies have been developed investigating and identifying wild and implemented for threatened population refuges, and undertaking frogs, potentially enabling surveys and/or modelling to improve future reintroduction and knowledge of species distributions, supplementation of genetically ecological requirements and diverse wild populations. conservation status. RIGHT: Chrytrid disease has killed this green-eyed tree frog. Image: Rob Puschendorf

Table 1: The 26 Australian frogs at greatest risk of extinction; their estimated probabilities of extinction in the wild by 2040; their national (Environmental Protection and Biodiversity Conservation Act 1999) and relevant state or territory status; and their location. Critically Endangered (CR), Endangered (EN), Vulnerable (VU), and Not listed (-). NB: Conservation statuses listed were current at the time that the study was undertaken and published.

National (EPBC) State/ State/ Rank Species Extinction probability by 2040 Status Territory Status Territory Northern gastric-brooding frog, 1 95% Likely extinct EX EN QLD Rheobatrachus vitellinus Mountain mist frog, 2 94% Likely extinct CR CR QLD Litoria nyakalensis Yellow-spotted tree frog, 3 93% Likely extinct CR CR/CR NSW/ACT Litoria castanea Northern tinker frog, 4 92% Likely extinct EN EN QLD Taudactylus rheophilus Kroombit tinker frog, 5 70% CR CR QLD Taudactylus pleione Southern corroboree frog, 6 66% CR CR NSW Pseudophryne corroboree

7 Baw Baw frog, 65% CR CR VIC Philoria frosti

8 Armoured mist frog, 57% CR CR QLD Litoria lorica

9 Mountain-top nursery frog, 47% CR CR QLD Cophixalus monticola

10 Beautiful nursery frog, 45% CR CR QLD Cophixalus concinnus

11 Northern corroboree frog, 38% CR CR/CR NSW/ACT Pseudophryne pengilleyi

12 Spotted tree frog, 36% EN CR/CR NSW/VIC Litoria spenceri

13 Kroombit tree frog, 31% CR CR QLD Litoria kroombitensis

14 Mt Elliot nursery frog, 29% CR CR QLD Cophixalus mcdonaldi Kuranda tree frog, 15 29% CR CR QLD Litoria myola Eungella day frog, 16 27% EN EN QLD Taudactylus eungellensis Bellenden Ker nursery frog, 17 26% CR CR QLD Cophixalus neglectus Rattling nursery frog, 18 20% CR CR QLD Cophixalus hosmeri Tapping nursery frog, 19 16% EN NT QLD Cophixalus aenigma White-bellied frog, 20 15% CR CR WA Geocrinia alba Littlejohn’s tree frog, 21 12% VU VU/EN NSW/VIC Litoria littlejohni Sloane’s froglet, 22 10% EN VU NSW Crinia sloanei Richmond Range mountain frog, 23 9% - EN NSW Philoria richmondensis Howard River toadlet, 24 8% - VU NT Uperoleia daviesae Giant burrowing frog, 25 8% VU VU/CE NSW/VIC Heleioporus australiacus Mahony’s toadlet, 26 4% EN EN NSW Uperoleia mahonyi LEFT: Dr Emily Hoffmann from the University of Western Australia undertaking research to benefit white-bellied frog conservation in Western Australia. Image: Emily Hoffmann

Research implications Our findings are most important to Some good action is already required through further research to decision-makers, funding bodies, happening for these species; determine the most effective ways of state and federal government such as population supplementation increasing resilience in these species, agencies, conservation land work for southern corroboree such as with with chytridiomycosis. managers, and researchers frogs that has stopped the Climate change is more intractable, looking to prioritise research species from going extinct. but solutions might include assisted and management actions for Fundamentally, urgent investment colonisation of new , or threatened Australian frogs. and more strategic conservation targeted and assisted gene flow Identifying the species at greatest effort are required to avert the among populations. risk of extinction is important impending extinction of Australia’s Given current trends, a contingency to forewarn governments, most imperilled frogs. Without plan should be developed to conservation managers and the new, targeted action, at least ensure adequate monitoring, and community about which species 8 species are likely to be lost to identify thresholds for action are most highly imperilled. to extinction by 2040. and planning for interventions This enables emergency care Some extinctions may be averted that might be required, such as and recovery actions to be using well-established approaches captive management and breeding implemented, helping to to threat management, such as programs of additional species prevent extinctions. feral control in key habitats. beyond those already maintained More knowledge and insights are successfully in captivity.

Changed fire patterns are a threat to half Cited material (13) of the imperilled frog species. Image: Doug Becker CC BY SA 2.0 Flickr Geyle, H.M., Hoskin, C.J., Bower, D.S., Catullo, R., Clulow, S., Driessen, M., Daniels, K., Garnett, S.T., Gilbert, D., Heard, G.W., Hero, J-M., Hines, H.B., Hoffman, E.P., Hollis, G., Hunter, D.A., Lemckert, F., Mahony, M., Marantelli, G., McDonald, K.R., Mitchell, N.J., Newell, D., Roberts, J.D., Scheele, B.C., Scroggie, M., Vanderduys, E., Wassens, S., West, M., Woinarski, J.C.Z. and Gillespie, G.R. (2021). Red hot frogs: identifying the Australian frogs most at risk of extinction. Pacific Conservation Biology. https://doi.org/10.1071/PC21019. Gillespie, G.R., Roberts, J.D., Hunter, D., Hoskin, C.J., Alford, R.A., Heard, G.W., Hines, H., Lemckert, F., Newell, D., and Scheele, B.C. (2020) Status and priority conservation actions for Australian frog species. Biological Conservation 247, 108543.

Further Information Hayley Geyle, Charles Darwin University - [email protected] Graeme Gillespie, NT Department of Environment, Parks and Water Security - [email protected] Conrad Hoskin, James Cook University - [email protected]

Cite this publication as NESP Threatened Species Recovery Hub. 2021. The Australian frogs most at risk of extinction and the actions needed to save them, Project 2.1 research findings factsheet.

This project is supported through funding from the Australian Government’s National Environmental Science Program.