Consultation on Species Listing Eligibility and Conservation Actions

Pseudophryne dendyi (Dendy’s Toadlet)

You are invited to provide your views and supporting reasons related to:

1) the eligibility of Pseudophryne dendyi (Dendy’s Toadlet) for inclusion on the EPBC Act threatened species list; and

2) the necessary conservation actions for the above species.

The purpose of this consultation document is to elicit additional information to better understand the status of the species and help inform on conservation actions and further planning. As such, the below draft assessment should be considered to be tentative as it may change following responses to this consultation process.

Evidence provided by experts, stakeholders and the general public are welcome. Responses can be provided by any interested person.

Anyone may nominate a native species, ecological community or threatening process for listing under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) or for a transfer of an item already on the list to a new listing category. The Threatened Species Scientific Committee (the Committee) undertakes the assessment of species to determine eligibility for inclusion in the list of threatened species and provides its recommendation to the Australian Government Minister for the Environment.

Responses are to be provided in writing by email to: [email protected]. Please include species scientific name in Subject field. or by mail to:

The Director Marine and Freshwater Species Department of Agriculture, Water and the Environment John Gorton Building, King Edward Terrace GPO Box 858 Canberra ACT 2601

Responses are required to be submitted by 28 May 2021. Contents of this information package Page General background information about listing threatened species 2 Information about this consultation process 3 Consultation questions specific to the assessment 3 Information about the species and its eligibility for listing 5 Conservation actions for the species 14 Listing assessment 27 References cited 18

Department of Agriculture, Water and the Environment 1 Pseudophryne dendyi (Dendy’s Toadlet) Conservation Advice

General background information about listing threatened species The Australian Government helps protect species at risk of extinction by listing them as threatened under Part 13 of the EPBC Act. Once listed under the EPBC Act, the species becomes a Matter of National Environmental Significance (MNES) and must be protected from significant impacts through the assessment and approval provisions of the EPBC Act. More information about threatened species is available on the department’s website at: http://www.environment.gov.au/biodiversity/threatened/index.html.

Public nominations to list threatened species under the EPBC Act are received annually by the department. In order to determine if a species is eligible for listing as threatened under the EPBC Act, the Threatened Species Scientific Committee (the Committee) undertakes a rigorous scientific assessment of its status to determine if the species is eligible for listing against a set of criteria. These criteria are available on the Department’s website at: http://www.environment.gov.au/system/files/pages/d72dfd1a-f0d8-4699-8d43- 5d95bbb02428/files/tssc-guidelines-assessing-species-2018.pdf.

As part of the assessment process, the Committee consults with the public and stakeholders to obtain specific details about the species, as well as advice on what conservation actions might be appropriate. Information provided through the consultation process is considered by the Committee in its assessment. The Committee provides its advice on the assessment (together with comments received) to the Minister regarding the eligibility of the species for listing under a particular category and what conservation actions might be appropriate. The Minister decides to add, or not to add, the species to the list of threatened species under the EPBC Act. More detailed information about the listing process is at: http://www.environment.gov.au/biodiversity/threatened/nominations.html.

To promote the recovery of listed threatened species and ecological communities, conservation advices and where required, recovery plans are made or adopted in accordance with Part 13 of the EPBC Act. Conservation advices provide guidance at the time of listing on known threats and priority recovery actions that can be undertaken at a local and regional level. Recovery plans describe key threats and identify specific recovery actions that can be undertaken to enable recovery activities to occur within a planned and logical national framework. Information about recovery plans is available on the department’s website at: http://www.environment.gov.au/biodiversity/threatened/recovery.html.

Privacy notice The Department will collect, use, store and disclose the personal information you provide in a manner consistent with the Department’s obligations under the Privacy Act 1988 (Cth) and the Department’s Privacy Policy.

Any personal information that you provide within, or in addition to, your comments in the threatened species assessment process may be used by the Department for the purposes of its functions relating to threatened species assessments, including contacting you if we have any questions about your comments in the future.

Further, the Commonwealth, State and Territory governments have agreed to share threatened species assessment documentation (including comments) to ensure that all States and Territories have access to the same documentation when making a decision on the status of a potentially threatened species. This is also known as the ‘Common Assessment Method’ (CAM). As a result, any personal information that you have provided in connection with your comments may be shared between Commonwealth, State or Territory government entities to assist with their assessment processes.

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The Department’s Privacy Policy contains details about how respondents may access and make corrections to personal information that the Department holds about the respondent, how respondents may make a complaint about a breach of an Australian Privacy Principle, and how the Department will deal with that complaint. A copy of the Department’s Privacy Policy is available at: https://www.awe.gov.au/about/commitment/privacy .

Information about this consultation process Responses to this consultation can be provided electronically or in hard copy to the contact addresses provided on Page 1. All responses received will be provided in full to the Committee and then to the Australian Government Minister for the Environment.

In providing comments, please provide references to published data where possible. Should the Committee use the information you provide in formulating its advice, the information will be attributed to you and referenced as a ‘personal communication’ unless you provide references or otherwise attribute this information (please specify if your organisation requires that this information is attributed to your organisation instead of yourself). The final advice by the Committee will be published on the department’s website following the listing decision by the Minister.

Information provided through consultation may be subject to freedom of information legislation and court processes. It is also important to note that under the EPBC Act, the deliberations and recommendations of the Committee are confidential until the Minister has made a final decision on the nomination, unless otherwise determined by the Minister.

Consultation questions 1. Do you agree with the current taxonomic position of the Australian Faunal Directory for this taxon (as identified in the draft conservation advice)?

2. Can you provide any additional references, information or estimates on longevity, age of maturity, average life span and generation length?

3. Has the survey effort for this taxon been adequate to determine its national distribution and adult population size? Can you provide further details on surveys conducted that are not presented in the document?

4. Do you accept the estimate provided in the nomination for the current population size of the taxon?

5. For any population with which you are familiar, do you agree with the population estimate provided? If not, are you able to provide a plausible estimate based on your own knowledge? If so, please provide in the form: Lower bound (estimated minimum): Upper bound (estimated maximum): Best Estimate: Estimated level of Confidence: %

6. Can you provide any additional data, not contained in the current draft conservation advice, on declines in population numbers over the past or next 10 years or 3 generations, whichever is the longer?

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7. Is the distribution as described in the nomination valid? Can you provide an estimate of the current geographic distribution (extent of occurrence or area of occupancy in km2) of this taxon?

8. Has this geographic distribution declined and if so by how much and over what period of time?

9. Do you agree that the taxon is ineligible for inclusion on the threatened species list as detailed in the draft conservation advice?

10. Do you agree that the threats listed are correct and that their effects on the taxon are significant?

11. To what degree are the identified threats likely to impact on the taxon in the future?

12. Can you provide additional or alternative information on threats, past, current or potential that may adversely affect this taxon at any stage of its life cycle?

13. In seeking to facilitate the recovery of this taxon, can you provide management advice for the following:

What individuals or organisations are currently, or need to be, involved in planning to abate threats and any other relevant planning issues? What threats are impacting on different populations, how variable are the threats and what is the relative importance of the different populations? Would the development and implementation of a translocation strategy be of benefit? What recovery actions are currently in place, and can you suggest other actions that would help recover the taxon (e.g. Recovery Plan)? Please provide evidence and background information.

14. Can you provide additional data or information relevant to this assessment?

15. Can you advise as to whether this species is of cultural significance to Indigenous Australians?

Threatened Species Scientific Committee 4 Pseudophryne dendyi (Dendy’s Toadlet) Conservation Advice

Conservation Advice for Pseudophryne dendyi (Dendy’s Toadlet)

This document combines the approved conservation advice and listing assessment for the species. It provides a foundation for conservation action and further planning.

Dendy’s Toadlet from Wonboyn, NSW © Copyright, Kerri-Lee Harris (from Life in a Southern Forest) Conservation status Pseudophryne dendyi (Dendy’s Toadlet) is currently not listed in any category of the threatened species list under the Environment Protection and Biodiversity Conservation Act 1999 (Cwth) (EPBC Act).

Dendy’s Toadlet is being assessed by the Threatened Species Scientific Committee (the Committee) due to concerns of potential impacts from the 2019-20 bushfires. The Committee’s assessment (at Attachment A) finds the species likely to be not eligible for listing under the EPBC Act.

Species can also be listed as threatened under state and territory legislation. For information on the current listing status of this species under relevant state or territory legislation, see the Species Profile and Threat Database.

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Species information Taxonomy Conventionally accepted as Pseudophryne dendyi Lucas, 1892. However, the taxonomic status of Dendy’s Toadlet is being clarified (Donnellan et al. 2012; Anstis 2017). The precise distributional and taxonomic boundaries of Dendy’s Toadlet and related taxa are complex and are the subject of ongoing studies (S. Donnellan 2020 unpub.; G. Webster 2020, 2021 unpub.). However, for the purposes of this assessment, Dendy’s Toadlet is treated as it is currently described and understood.

Description Dendy’s Toadlet is a small terrestrial, ground dwelling frog, members of whose genus are commonly referred to as “toadlets” or “brood frogs” (Queensland), and are from the Family Myobatrachidae. Females are slightly larger than males, with a snout-to-vent length up to 32 mm (30 mm for males) (Anstis 2017). Adults are small, stout, short-limbed, have no webbing in the toes, have a short head that is wider than it is long, horizontal pupils, small raised tubercles on the back, smooth belly skin, black and white marbling on the belly, and lack a tympanum (Cogger 2014; Anstis 2017). Because of a high level of conservatism in body shape within the genus (Vidal-García 2014), species are generally differentiated by dorsal colouring, differences in the male breeding calls, and geographic distribution (Anstis 2017). The dorsal surface of Dendy’s Toadlet is usually dark grey to almost black or grey-brown, with bright yellow patches on the upper arms, the hind limbs, and rump (Tyler & Knight 2011; Cogger 2014; Anstis 2017). Dendy’s Toadlet is most similar to Pseudophryne bibronii (Brown Toadlet), differentiated only by the placement of some of the coloured patches, and in some locations the species are hard to distinguish (Pengilley 1966). Males of Dendy’s Toadlet produce a short, harsh breeding call, but calls of other members of the genus are similar, and so not easily assigned to species (Pengilley 1971a).

Terrestrial egg masses consist of approximately 50-150 moderately large, pigmented ova (diameter of 2.2 mm), enclosed in a jelly capsule (6.1 mm) (Woodruff 1976a; Anstis 2017).

The tadpole of Dendy’s Toadlet is relatively small (total length to 30 mm), with a small, oval body and a rounded snout. The eyes are gold flecked with a gold ring that surrounds the pupil. The back is dark grey-black to lighter grey-brown, with very small gold iridophores and a pale copper coloured stripe along the length of the back. The fins are shallow and similarly shaped. The dorsal fin starts near the end of the body and tapers to a rounded tip. The description of the tadpole is drawn from Anstis (2017).

Distribution Dendy’s Toadlet occurs in south-eastern New South Wales (NSW), western areas of the Australian Capital Territory (ACT), and in eastern Victoria (Cogger 2014; Anstis 2017) (Map 1). This includes upland areas of the Great Dividing Range in the Snowy Mountains, Brindabella Ranges, and Australian Alps (IBRA regions: Australian Alps, South Eastern Highlands), and coastal lowlands in south-eastern NSW and Victoria (IBRA regions: South East Corner, South East Coastal Plain). This spans a relatively wide elevational range from near sea-level to over 1600 m (Pengilley 1971b; ALA 2020; DELWP 2020a; DPIE 2020). Most sites are within the South-east Coast Drainage Division; however, a number of western sites are over the range in the upper portions of the Murray-Darling Drainage Division (Murrumbidgee, Upper Murray,

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Goulburn Rivers). Dendy’s Toadlet is found in a number of national parks, in particular in higher elevation areas such as Kosciuszko, Snowy River, Alpine, and Deua National Parks.

Dendy’s Toadlet is sympatric with other Pseudophryne species across parts of its range, overlapping with Pseudophryne semimarmorata (Marbled Toadlet) in eastern Victoria at lowland sites in western and central Gippsland, where a number of narrow hybrid zones exist (Woodruff 1979). In Victoria, Dendy’s Toadlet is largely allopatric with the Brown Toadlet, which is generally found at lower elevations to the north and west of the divide (Brook 1982; N. Clemann 2020 pers comm 14, 15 Oct). However, in NSW the two species are sympatric at some low coastal sites, and at upland sites in NSW and the ACT, where they are known to hybridise (Woodruff 1972 cited in Rauhala 1997; Littlejohn & Watson 1993).

The distribution of Dendy’s Toadlet described above is likely to reflect its historic distribution, which may or may not accurately reflect its current distribution. There is anecdotal evidence that this species declined in upland areas, potentially due to disease (chytridiomycosis), and may be declining in the wake of the 2019–20 bushfires (see Criterion 1, Attachment A).

Map 1 Modelled distribution of Dendy’s Toadlet

Source: Base map Geoscience Australia; species distribution data Species of National Environmental Significance database.

Cultural and community significance Dendy’s Toadlet has no known cultural significance to Indigenous communities.

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Relevant biology and ecology The biology and ecology of Dendy’s Toadlet has not been the subject of specific ecological studies since the 1970s. However, Dendy’s Toadlet is recognised as being similar to other species in the Pseudophryne genus, particularly the Brown and Marbled Toadlets (Woodruff 1976a, 1979; Rauhala 1997), and to a lesser extent to Corrobboree Frogs (Pseudophryne corroboree Southern Corroboree Frog, Pseudophryne pengilleyi Northern Corroboree Frog) (Anstis 2017). Therefore habitat, breeding, and behaviour can be described in general.

Habitat The elevational range over which Dendy’s Toadlet occurs is very wide (from almost sea-level to over 1600 m), and so the environments in which it is found are correspondingly varied, being both wet and dry sclerophyll forests, montane bogs and grasslands (Pengilley 1966; Hero et al. 2004). At the microhabitat scale, Dendy’s Toadlet occurs in a number of terrestrial habitats, including damp leaf litter and inundated grassy areas, adjacent to small seepages, bogs and seasonal ponds (Pengilley 1971b; Anstis 2017). During the breeding season, adults are found at sites that are inundated by autumn-winter rains, with males calling from under dense vegetation or in a mud burrow among grass roots (Pengilley 1971b; Anstis 2017). In higher elevation areas, breeding sites are often montane sphagnum bogs and wet heath (Pengilley 1971b), which is listed as an Endangered Ecological Community under the EPBC Act (Commonwealth of Australia 2009). The Southern Corroboree Frog, which is also found in similar montane areas, chooses nest sites based on the vegetation structure and substrate moisture, rather than the particular vegetation species (Hunter et al. 2009), and Dendy’s Toadlet is likely to be similar. Outside of breeding periods, adults and sub-adults retreat under rocks, logs, and vegetation in areas adjacent to breeding sites (up to 150 m away), hunting invertebrates amongst the leaf litter (Pengilley 1971b; White 1993; Gillespie et al. 1995). Subadults disperse further afield, to areas around one kilometre away from breeding sites (Legge et al. 2020).

Breeding Dendy’s Toadlet reproductive cycle is typical of Pseudophryne species (Anstis 2017). The timing of breeding is summer and autumn in alpine areas, with some variation at lower elevations (Anstis 2017), which is related to the onset of rainfall. Males move into breeding sites first and prepare a nest site in areas that will flood with winter rains, amongst grass roots, leaf litter, fallen logs, or muddy holes. Peak calling occurs between February and March (Lemckert & Mahony 2008), with males calling for a number of weeks (Woodruff 1976a). The calls are a short “ark” call, made irregularly, with some subtle variation for courtship and territorial purposes (Tyler & Knight 2011; Anstis 2017).

Males remain at nest sites, while females move in and out of the males’ territories, mating, depositing eggs in the moist nest, and then departing (Woodruff 1977). The number of eggs per nest varies (generally 48-129), some of which are likely the result of a single mating, and some of multiple matings with the same female, or several females (Woodruff 1976a). Fewer than half of females lay all their eggs at once, and this staggered release may be a response to irregular rain (Woodruff 1976a) as a way of ensuring some eggs are in high quality nests (Byrne & Keogh 2009). Embryos can enter diapause to await rainfalls that trigger nest flooding and hatching (Seymour & Bradford 1987).

Males are territorial, vocalising and guarding (brooding) eggs for up to 40 days, which may contribute to the low rate of embryonic mortality (< 5%) (Woodruff 1977). Tadpoles develop to

Threatened Species Scientific Committee 8 Pseudophryne dendyi (Dendy’s Toadlet) Conservation Advice a relatively advanced stage within the egg capsule (Anstis 2017). After hatching, the tadpoles develop in a nearby waterbody and are fairly sedentary as they graze on sediments (Anstis 2017). Metamorphosis occurs after 180–210 days (Pengilley 1973; Anstis 2017).

Behaviour Dendy’s Toadlet is ground dwelling, and usually walks rather than jumps (Anstis 2017). It has a similar diet to the Brown Toadlet and Corroboree Frogs, eating mostly ants, termites and beetles (Pengilley 1971b). Most males do not feed when they are in the breeding area (Pengilley 1971b). Dendy’s Toadlet does not actively pursue its prey, but rather waits until slow moving prey move near to its hidden position under vegetation or rocks (Pengilley 1971b).

Habitat critical to the survival It was not possible to define habitat critical to the survival of Dendy’s Toadlet as there are insufficient data, with the species having poorly defined habitat preferences beyond a requirement for seasonal drainages and pools for breeding at the right time of year.

No Critical Habitat as defined under section 207A of the EPBC Act has been identified or included in the Register of Critical Habitat.

Threats The impacts of specific threats to amphibians do not exist in isolation, but interact, compound, and intensify. Climate change will result in hotter temperatures, more frequent and severe droughts, and larger and more intense bushfires (Nolan et al. 2020). Compounding the threat from climate change, past and present land management practices (grazing, logging) also lead to an increase in bushfire frequency (Zylstra 2018). Following bushfires, the number of predators and predator activity increase in recently burnt areas (Leahy et al. 2015). However, the interactions can be complex, as some threats are inversely correlated, for example a hotter climate is disadvantageous to the spread of the amphibian chytrid fungal pathogen Batrachochytrium dendrobatidis (Bd) (Scheele et al. 2012).

Individually, as well in combination, these threats can result in fragmentation of populations, with small, isolated subpopulations being more vulnerable to stochastic events (Hunter et al. 2009; Scheele et al. 2016, 2017a). Further, high mortality resulting from any threat (e.g. Bd, bushfire) can make a subpopulation more vulnerable to subsequent threats (e.g. invasive species), that in isolation may not have presented an existential threat (Clemann 2013).

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Table 1 Threats impacting Dendy’s Toadlet

Threat Status and severity Evidence Climate Change Increased Status: current Climate change is expected to cause a pronounced intensity/frequency Confidence: inferred increase in extinction risk for frog species over the of bushfire coming century (Hagger et al. 2013; Pearson et al. 2014; Consequence: severe Gillespie et al. 2020). Climate projections for Trend: increasing south-eastern Australia include a decrease in annual Extent: across the entire range average rainfall, increased average temperatures, and more frequent droughts (CSIRO 2007; Hobday & Lough 2011; CSIRO & Bureau of Meteorology 2015). These conditions will increase the scale, frequency, and intensity of bushfires, and under the worst scenario, severe fire days are predicted to be 2–3 times more frequent by 2090 (Grose et al. 2015). Potential direct impacts from bushfires on frogs are large-scale mortality and habitat destruction or degradation (Carey et al. 2003). In addition, there are many potentially long-lasting indirect, post-fire impacts, including run-off of ash, nutrients, and fire retardant into breeding habitats, potentially adversely affecting embryos and tadpoles (Brown et al. 1998; Alexandra & Finlayson 2020; Ward et al. 2020; N. Clemann 2020 pers comm 14 Oct). Another by-product of bushfire is loss or reduction in leaf litter and more complex vegetation, which provides protection for Dendy’s Toadlets from heat and predators, is where their prey items live, and is where many males build nests (Brown et al. 1998; Rauhala 1997; Carey et al. 2003). A further impact is on genetic diversity amongst surviving frog populations, as even apparently healthy post-fire frog populations have been shown to have a reduced genetic diversity with more inbreeding, which can make them more prone to extinction (Potvin et al. 2017).

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Threat Status and severity Evidence Change to Status: current Climate change is projected to cause a decrease in precipitation Confidence: inferred annual average rainfall but with an increase in days of patterns and extreme rainfall, and less snow across high elevation Consequence: severe increased drought ranges in Victoria and NSW (Grose et al. 2015). This Trend: increasing change to precipitation patterns will likely lower water Extent: across the entire range tables (Hunter et al. 2009) and result in more frequent, longer, and more severe droughts. Calling of related Brown Toadlets is triggered by soil moisture post rainfall, and populations may not breed, or have very low rates of breeding if rainfall declines during the typical breeding period (Mitchell 2001). The aquatic tadpole stage is the riskiest period for Pseudophryne in times of drought (Woodruff 1976b). Eggs/embryos are initially protected in a moist nest, but in dry years embryos may desiccate and die before hatching (Woodruff 1976b). Even if recently hatched tadpoles reach a waterbody, if this dries out before metamorphosis is achieved, then all tadpoles will likely perish, and the entire cohort will possibly be lost (Hunter et al. 2009). Fewer pool habitat across an area will likely mean a reduced breeding success across a subpopulation for the year (Scheele et al. 2012). If drought lasts longer than a typical adult lifespan, local extinctions are likely (Scheele et al. 2012). Previous droughts (such as the Millennium drought of the late 1990s-2000s) had deleterious effects on Pseudophryne subpopulations (De Angelis & Cleeland 2019), for example a 42 % loss of Northern Corroboree Frog breeding sites (Scheele et al. 2012). In addition, erosion may become more common with predicted more intense heavy rainfall events (Grose et al. 2015), and associated flooding may wash away eggs (G. Gillespie 2020 pers comm 4 Dec).

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Threat Status and severity Evidence Disease Chytridiomycosis Status: current Chytridiomycosis is an infectious disease caused by the caused by chytrid Confidence: inferred amphibian chytrid fungal pathogen Batrachochytrium fungus dendrobatidis (Bd). Infected subpopulations exhibit Consequence: severe diverse susceptibility to Bd. Some species do not exhibit (uplands)/ moderate any apparent symptoms while others are extremely (lowlands) vulnerable, resulting in mass die-off and extinction Trend: unknown (Commonwealth of Australia 2016). Mortality Extent: across the entire range associated with Bd erodes the capacity of the population to sustain loss of recruitment associated with drought and reduces resilience to climate change (Scheele et al. 2016). Bd was first detected in the Southern Highlands and Alps, areas which are central to the Dendy’s Toadlet distribution, in the 1980s (Scheele et al. 2017b). Here, at higher elevations, the cold and wet temperate conditions provide the optimal environment for Bd growth (Skerratt et al. 2016). The arrival of Bd coincided with observed frog population declines (N. Clemann 2020 pers comm 4 Nov). Despite there being almost no specific data on the impact of Bd on Dendy’s Toadlet (N. Clemann 2020 pers comm 14 Oct), impacts can be inferred from its congeners in the Australian Alps, which have a similar biological, ecological, and distributional profile to Dendy’s Toadlet. These species include the Northern and Southern Corroboree Frogs (at higher elevations), which have been severely impacted by the disease (Osborne et al. 1999; Hunter et al. 2010), and the Brown Toadlet and Marbled Toadlet (at lower elevations), which have a moderate risk from Bd (Howard et al. 2010; Scheele et al. 2017b; Victorian Government 2020a, 2020b). Consequently, there may be two population trajectories for Dendy’s Toadlet linked to elevation, with subpopulations at higher elevations more severely impacted than those at lower elevations, which may have stabilised and recovered (Skerratt et al. 2016).

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Threat Status and severity Evidence Invasive species Introduced fauna Status: current Introduced fauna are found throughout the range of Confidence: known Dendy’s Toadlet. Feral horses (Equus caballus), Deer (Dama dama, Rusa unicolor), Domestic cattle (Bos Consequence: moderate taurus), and Feral pigs (Sus scrofa) have all caused Trend: unknown extensive habitat damage to frog breeding areas in peat Extent: across the entire range bog systems of the Australian Alps in both Victoria and NSW (Hunter et al. 2009; Clemann 2013; Foster & Scheele 2019; N. Clemann 2020 pers comm 14 Oct). In Kosciuszko National Park, past damage from historical cattle and sheep grazing is being compounded by growing numbers of feral horses (Hunter et al. 2009; Foster & Scheele 2019). Horses and cattle graze and trample the vegetation (Clemann 2013; Foster & Scheele 2019), amongst which Dendy’s Toadlet retreats and makes its nests. Male Southern Corroboree Frogs (and likely Dendy’s Toadlets) do not readily utilise bare substrate or compacted vegetation (Hunter et al. 2009), and may be forced to make nests in suboptimal locations (Foster & Scheele 2019). Stream banks are also damaged, siltation in ponds increased, and the chances of ephemeral pools drying out early is increased (Foster & Scheele 2019), which is fatal to tadpoles. These large animals are also a plausible vector of Bd spores (Clemman 2013; N. Clemman 2020 pers comm 14 Oct). As well as damaging habitat, introduced fauna predate directly on amphibians. The extent of this predation by the Feral cat (Felis catus), the European red fox (Vulpes vulpes) and Feral pig (Sus scrofa) on Dendy’s Toadlet is unknown, however a study by Woinarski et al. (2020) indicated that nearly 100 million frogs are killed annually in Australia by feral cats. Also, recent bushfires may have led to increased predation of Dendy’s Toadlet, as in the aftermath of a fire, survivors are easier to catch by predators (Leahy et al. 2015). Further, predator activity increases where habitat has been modified through frequent or intense burning (Leahy et al. 2015).

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Threat Status and severity Evidence Habitat loss and fragmentation Vegetation Status: current Disturbance to habitat can result in the mortality of clearance/habitat Confidence: known individual frogs and the loss of suitable habitat for fragmentation shelter, foraging, and dispersal. Habitat loss or Consequence: moderate modification is a major threat to frog species (Hero et al. Trend: unknown 2006). Much of the distribution of Dendy’s Toadlet is Extent: across part of the range within reserves, particularly at higher elevations, affording it some protection from substantial vegetation clearance, but not from impacts of visitors. Further reserves do not afford protection from larger, landscape-wide processes like climate change, disease, or large bushfires. Many areas within the distribution of Dendy’s Toadlet are or have been subject to disturbance from primary industries, especially forestry and pastoralism. The Brown Toadlet is more often found in landscapes modified by sheep grazing (Pengilley 1971b) than Dendy’s Toadlet. Human induced landscape change is considered a major threat to both the Brown and Marbled Toadlets (Victoria Government 2020a, 2020b). In particular, a change to local hydrology can prevent the formation of the seasonal waterbodies that Pseudophryne species need to breed (Rauhala 1997; Howard et al. 2010).

Status—identify the temporal nature of the threat; Confidence—identify the extent to which we have confidence about the impact of the threat on the species; Consequence—identify the severity of the threat; Trend—identify the extent to which it will continue to operate on the species; Extent—identify its spatial content in terms of the range of the species.

Conservation and recovery actions Although this species has been assessed as not eligible for listing, it likely has experienced population declines due to Bd and bushfires. There is also a lack of knowledge regarding its distribution, taxonomy, fire response, and field data on actual bushfire impacts. This means that some conservation and recovery actions may be warranted for this species, perhaps in concert with sympatric species that have been assessed as threatened. Primary conservation outcome

2019-20 bushfire response • Conduct on-ground surveys to establish the response of populations to the 2019-20 bushfires and to provide a baseline for ongoing monitoring. The design of these surveys should reflect considerations in Southwell (2020).

• In the aftermath of the bushfires, manage unburnt areas within or adjacent to recently burnt areas from further fire, in order to provide refuge sites, as well as unburnt areas that are not adjacent to burnt areas.

• Control introduced predators to support the recovery of populations affected by fires, or populations near areas that have been affected by fire.

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• Control introduced herbivores to support the regeneration of forest habitat at some localised sites.

• Remove weeds and conduct habitat restoration works to support the regeneration of forest habitat at some localised sites. Note: this should be undertaken by cutting and pasting/painting methods, as herbicide formulations can be toxic to frogs and tadpoles, particularly if they contain glyphosate and surfactants (Mann et al. 2003).

• Establish the impact of fire retardants used to fight bushfires on frog populations. Conservation and management priorities Climate change-induced intensified drought • Investigate options for enhancing the resilience of the species’ current habitat to climate change.

• Investigate options for providing new habitat that would be suitable for the species under climate change scenarios. Disease • Investigate measures for minimising the impact of Bd on Dendy’s Toadlet subpopulations. In particular:

o Establish the susceptibility of Dendy’s Toadlet to Bd and whether the species has developed an immune response, or if the Bd strain is reduced in virulence.

o Conduct research into mechanisms of frogs’ resistance to Bd, with any identified mechanisms considered for use in selective breeding to produce Bd-resistant frogs for release.

o Investigate the availability of Bd refuge sites, either within or outside of the natural known range of the species.

o Establish the precise habitat preferences of potential vectors of Bd (e.g. Common Eastern Froglet, Crinia signifera), to better understand the location of areas of refuge from them (and by extension from Bd) (Scheele et al. 2017a; Brannelly et al. 2018). • Minimise the spread of Bd.

o Implement suitable hygiene protocols (Murray et al. 2011) to protect priority subpopulations as described in the threat abatement plan for infection of amphibians with chytrid fungus resulting in chytridiomycosis (Commonwealth of Australia 2016).

o Provide disease identification and prevention protocols (methods of handling, diagnostic keys, etc.) to researchers and land managers for use in the field. Invasive species (including threats from grazing, trampling, predation) • In areas burnt by the 2019-20 bushfires, control introduced species (including predators, herbivores, and weeds) to support population recovery. Habitat loss disturbance and modifications • Undertake surveys to determine the current distribution and spatial, temporal, and demographic characteristics of the population.

• Determine habitat critical to the survival of the species.

Threatened Species Scientific Committee 15 Pseudophryne dendyi (Dendy’s Toadlet) Conservation Advice

• Identify the species’ breeding and non-breeding habitat requirements, and evaluate factors influencing the quality and availability of suitable habitat across its distribution.

• Identify key sites and protect and maintain a sufficient amount of high-quality habitat to ensure the species viability.

• Identify and conserve landscape characteristics that facilitate movement between subpopulations.

• Minimise human disturbance to Dendy’s Toadlet and its habitat. Activities permitted in protection zones should be dictated by further monitoring and research into the effects of disturbance on the species.

• Assess the effectiveness of current forestry management practices in ameliorating disturbance to the habitat of Dendy’s Toadlet, and revise management practices if necessary.

• Encourage landholders to enter land management agreements, particularly in-perpetuity covenants, that promote the protection and maintenance of key distribution areas. Stakeholder engagement/community engagement

• Work with landowners and managers to raise awareness of the importance of maintaining seasonal waterbodies as critical habitat for the survival of the species by completing their life-cycle, and integrating habitat protection into land management regulations.

• Provide input into the various impact assessment and planning processes on measures to protect Dendy’s Toadlet and its habitat. These include water resource plans, park management plans, and environmental impact assessments.

• Engage interested nature conservation, land management, and landholder groups in conservation management activities and citizen science projects, such as non-invasive monitoring through the FrogID project (Rowley & Callaghan 2020). Activities need to be carefully managed to prevent disturbance to frogs (particularly during the breeding season) and participants should be made aware of the need to follow correct field practices and hygiene protocols to mitigate the risks of trampling and disease transmission. If necessary, use workshops to aid stakeholders in developing the skills and knowledge required to manage threats to this species while undertaking these activities.

• Provide advice to private landholders and community groups on how to protect and restore habitat and to ameliorate the impacts of introduced species.

• Engage with trail bike riding associations to raise awareness about the potential damage to habitat from bikes in particularly sensitive locations.

• Engage with local indigenous groups to investigate if traditional burning practices may ameliorate impacts on local biodiversity (Kelly et al. 2020). Survey and monitoring priorities

• Monitor the species to detect any change in population size and understand how different subpopulations are responding in different environmental and management

Threatened Species Scientific Committee 16 Pseudophryne dendyi (Dendy’s Toadlet) Conservation Advice

settings and in response to various threats or ecological loads. Ensure surveys are conducted when detection is most likely (peak calling period between February-March, but with some variation with elevation). In addition, searches for tadpoles can be conducted outside this period, as tadpoles can be found during a large proportion of the year, or eDNA could be used to assess the presence or absence of individuals.

• Assess the distribution, and long-term population trends using the established modelling and analytical methods. Develop models to evaluate critical life history stages and the roles of key threatening processes.

• Survey sites within the known distribution range of the species where the environment is likely to be suitable for the species to identify whether populations exist that were previously unknown. Establish long-term monitoring sites so the response of Dendy’s Toadlet to future perturbations can be assessed.

Information and research priorities • Conduct taxonomic research to clearly delineate the species boundaries of Dendy’s Toadlet and other closely related taxa.

• Conduct distributional surveys to better understand the distribution of Dendy’s Toadlet relative to other sympatric described species of Pseudophryne, undescribed Pseudophryne species, and hybrid subpopulations, to delineate more clearly the actual distribution and environmental preferences of the various taxa.

• Identify all potential threatening processes that may have affected the species’ distribution and abundance, then evaluate their relative contribution to the species decline and any impediment to recovery. In particular:

o Assess the effects of fire on survival and reproduction, including: . The impact of altered sediment loads, hydrological regimes, and riparian vegetation structure and composition. . The species’ long-term response to major fire events or altered fire regimes, through identifying those parts of its range that are most vulnerable, or conversely, where there are opportunities to enhance refuges from fire.

o Improve understanding of the extent and impact of infection by Bd on Dendy’s Toadlet to better inform how to apply existing or new management actions relevant to the recovery.

o Understand the influence of climate change on the long-term survival of the species, due to altered temperatures, rainfall patterns, bushfire frequency and intensity, environmental stressors and disease prevalence, through maintaining robust population and environmental monitoring.

Threatened Species Scientific Committee 17 Pseudophryne dendyi (Dendy’s Toadlet) Conservation Advice

Links to relevant implementation documents Commonwealth of Australia (2009). Alpine Sphagnum Bogs and Associated Fens – A nationally threatened ecological community, Commonwealth Department of the Environment, Water, Heritage and the Arts. Viewed 15 December 2020. Available at: https://www.environment.gov.au/system/files/resources/b08acec6-6a27-4e71-8636- 498719b253b4/files/alpine-sphagnum-bogs.pdf

Commonwealth of Australia (2016). Threat abatement plan for infection of amphibians with chytrid fungus resulting in chytridiomycosis, Commonwealth Department of the Environment & Energy. Viewed 25 October 2020 Available at: http://www.environment.gov.au/biodiversity/threatened/publications/tap/infection- amphibians-chytrid-fungus-resulting-chytridiomycosis-2016 Conservation Advice and Listing Assessment references Alexandra J & Finlayson CM (2020) Floods after bushfires: rapid responses for reducing impacts of sediment, ash, and nutrient slugs. Australian Journal of Water Resources 24, 9–11.

Anstis M (2017) Pseudophryne dendyi Dendy’s Toadlet. In: Tadpoles and Frogs of Australia, New Holland Publishers, Sydney, pp 654–656.

Bachman S, Moat J, Hill AW, de la Torre J & Scott B (2011) Supporting red list threat assessments with GeoCAT: Geospatial conservation assessment tool. ZooKeys 150, 117–126.

Brannelly LA, Webb RJ, Hunter DA, Clemann N, Howard K, Skerratt LF, et al. (2018) Non- declining amphibians can be important reservoir hosts for amphibian chytrid fungus. Animal Conservation 21, 91–101.

Brook AJ (1982) Atlas of Frogs of Victoria. University of Melbourne, Melbourne.

Brown KL, Gadd LS, Norton TW, Williams JE & Klom NI (1998) The effects of fire on fauna in the Australian alps national parks: a database. Charles Sturt University, Albury.

Byrne PG, & Keogh JS (2009) Extreme sequential polyandry insures against nest failure in a frog. Proceedings of the Royal Society B: Biological Sciences 276, 115–120.

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Clemann N (2013) Survey and monitoring of threatened Victorian alpine herpetofauna: annual report for the 2010- 2011 season. Arthur Rylah Institute for Environmental Research, Heidelberg.

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Cogger HG (2014) Reptiles & Amphibians of Australia. New Holland Publishers, Sydney.

De Angelis D & Cleeland C (2019) Observations of recruitment failure and success in relation to rainfall for an isolated population of the Southern Toadlet Pseudophryne semimarmorata. Victorian Naturalist 136, 112–116.

Donnellan SC, Mahony MJ & Bertozzi T (2012) A new species of Pseudophryne (Anura: Myobatrachidae) from the central Australian ranges. Zootaxa 3476, 69–85.

Foster CN & Scheele BC (2019) Feral-horse impacts on corroboree frog habitat in the Australian Alps. Wildlife Research 46, 184–190.

Gillespie GR, Osborne WS & McElhinney NA (1995) The conservation status of frogs in the Australian Alps: a review. Report to the Australian Alps Liaison Committee, Canberra.

Gillespie GR, Roberts JD, Hunter D, Hoskin CJ, Alford RA, Heard GW, et al. (2020) Status and priority conservation actions for Australian frog species. Biological Conservation 247, 108543.

Hagger V, Fisher D, Schmidt S & Blomberg S (2013) Assessing the vulnerability of an assemblage of subtropical rainforest vertebrate species to climate change in south-east Queensland. Austral Ecology 38, 464-475.

Hero JM, Morrison C, Gillespie G, Roberts JD, Newell D, Meyer E, et al. (2006) Overview of the conservation status of Australian frogs. Pacific Conservation Biology 12, 313–320.

Hobday AJ & Lough JM (2011) Projected climate change in Australian marine and freshwater environments. Marine and Freshwater Research 62, 1000-1014.

Howard K, Cleeland C & Clemann N (2010) Assessment of the status of the threatened Bibron’s Toadlet and Southern Toadlet in areas affected by the Kilmore East-Murrindindi fires: Black Saturday, Victoria 2009 - Natural values fire recovery program. Arthur Rylah Institute for Environmental Research, Heidelberg, VIC.

Hunter DA (2000) Population demography and conservation of the Southern Corroboree Frog. Master of Applied Science Thesis. University of Canberra.

Hunter D, Osborne W, Smith M & McDougall K (2009) Breeding habitat use and the future management of the critically endangered Southern Corroboree Frog. Ecological Management and Restoration 10, S103–S109.

Hunter DA, Speare R, Marantelli G, Mendez D, Pietsch R & Osborne W (2010) Presence of the amphibian chytrid fungus Batrachochytrium dendrobatidis in threatened corroboree frog populations in the Australian alps. Diseases of Aquatic Organisms 92, 209–216.

Threatened Species Scientific Committee 19 Pseudophryne dendyi (Dendy’s Toadlet) Conservation Advice

Kelly LT, Giljohann KM, Duane A, Aquilué N, Archibald S, Batllori E, et al. (2020) Fire and biodiversity in the Anthropocene. Science 370, eabb0355.

Lau M (1986) Species relations in the genus Pseudophryne (Anura: Myobatrachidae). Honours Thesis, Australian National University.

Leahy L, Legge SM, Tuft K, McGregor HW, Barmuta LA, Jones ME, et al. (2015) Amplified predation after fire suppresses rodent populations in Australia’s tropical savannas. Wildlife Research 42, 705–716.

Lemckert F & Mahony M (2008) Core calling periods of the frogs of temperate New South Wales, Australia. Herpetological Conservation and Biology 3, 71–76.

Littlejohn MJ & Watson GF (1993) Hybrid zones in Australian frogs: their significance for conservation. In: Lunney D & Ayers D (eds), Herpetology in Australia, Royal Zoological Society of New South Wales, pp 239–249.

Mann R, Tyler M & Bidwell J (2003) Toxicity of herbicide formulations to frogs and the implications for product registration: A case study from Western Australia. Applied Herpetology 1, 13–22.

Mitchell NJ (2001) Males call more from wetter nests: effects of substrate water potential on reproductive behaviours of terrestrial toadlets. Proceedings of the Royal Society of London. Series B: Biological Sciences 268, 87-93.

Morgan MJ, Hunter D, Pietsch R, Osborne W & Keogh JS (2008) Assessment of genetic diversity in the critically endangered Australian corroboree frogs, Pseudophryne corroboree and Pseudophryne pengilleyi, identifies four evolutionarily significant units for conservation. Molecular Ecology 17, 3448–3463.

Murray BR & Hose GC (2005) Life-history and ecological correlates of decline and extinction in the endemic Australian frog fauna. Austral Ecology 30, 564–571.

Nolan RH, Boer MM, Collins L, Resco de Dios V, Clarke H, Jenkins M, et al. (2020) Causes and consequences of eastern Australia’s 2019–20 season of mega-fires. Global Change Biology 26, 1039–1041.

Osborne W, Hunter D & Hollis G (1999) Population declines and range contraction in Australian alpine frogs. In: Declines and Disappearances of Australian Frogs, pp 145–157.

Pearson RG, Stanton JC, Shoemaker KT, Aiello-Lammens ME, Ersts PJ, Horning N, Fordham DA, Raxworthy CJ, Ryu HY, McNees J & Akçakaya HR (2014) Life history and spatial traits predict extinction risk due to climate change. Nature Climate Change 4, 217–221.

Threatened Species Scientific Committee 20 Pseudophryne dendyi (Dendy’s Toadlet) Conservation Advice

Pengilley RK (1966) The Biology of the species of the Genus Pseudophryne (Anura: Leptodactylidae). MSc Thesis. Australian National University.

Pengilley RK (1971a) Calling and associated behaviour of some species of Pseudophryne (Anura: Leptodactylidae). Journal of Zoology 163, 73–92.

Pengilley RK (1971b) The food of some Australian anurans (Amphibia). Journal of Zoology 163, 93–103.

Pengilley RK (1973) Breeding biology of some species of Pseudophryne (Anura: Leptodactylidae) of the southern highlands, New South Wales. Australian Zoologist 18, 15–30.

Potvin DA, Parris KM, Smith Date KL, Keely CC, Bray RD, Hale J, et al. (2017) Genetic erosion and escalating extinction risk in frogs with increasing wildfire frequency. Journal of Applied Ecology 54, 945–954.

Rauhala MA (1997) Frog Fauna of the Australian Capital Territory: a Review. ACT Parks & Conservation Service, Tuggeranong, ACT.

Rowley JJL & Callaghan CT (2020) The frogID dataset: Expert-validated occurrence records of Australia’s frogs collected by citizen scientists. ZooKeys 2020, 139–151.

Scheele BC, Driscoll DA, Fischer J & Hunter DA (2012) Decline of an endangered amphibian during an extreme climatic event. Ecosphere 3, art101.

Scheele BC, Hunter DA, Banks SC, Pierson JC, Skerratt LF, Webb R, et al. (2016) High adult mortality in disease-challenged frog populations increases vulnerability to drought. Journal of Animal Ecology 85, 1453–1460.

Scheele BC, Hunter DA, Brannelly LA, Skerratt LF & Driscoll DA (2017a) Reservoir-host amplification of disease impact in an endangered amphibian. Conservation Biology 31, 592– 600.

Scheele BC, Skerratt LF, Grogan LF, Hunter DA, Clemann N, McFadden M, et al. (2017b) After the epidemic: Ongoing declines, stabilizations and recoveries in amphibians afflicted by chytridiomycosis. Biological Conservation 206, 37–46.

Seymour RS & Bradford DF (1987) Gas exchange through the jelly capsule of the terrestrial eggs of the frog, Pseudophryne bibroni. Journal of Comparative Physiology B 157, 477–481.

Skerratt LF, Berger L, Clemann N, Hunter DA, Marantelli G, Newell DA, et al. (2016) Priorities for management of chytridiomycosis in Australia: Saving frogs from extinction. Wildlife Research 43, 105–120.

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Tyler MJ & Knight F (2011) Field Guide to the Frogs of Australia. CSIRO Publishing, Collingwood, VIC.

Vidal-García M, Byrne PG, Roberts JD & Keogh JS (2014) The role of phylogeny and ecology in shaping morphology in 21 genera and 127 species of Australo-Papuan myobatrachid frogs. Journal of Evolutionary Biology 27, 181–192.

Ward M et al (2020) Impact of 2019–2020 mega-fires on Australian fauna habitat. Nature Ecology & Evolution 4, 1321–1326.

Westgate MJ, MacGregor C, Scheele BC, Driscoll DA & Lindenmayer DB (2018) Effects of time since fire on frog occurrence are altered by isolation, vegetation and fire frequency gradients. Diversity and Distributions 24, 82–91.

White AW (1993) Ecological and behavioural observations on populations of the toadlets Pseudophryne coriacea and Pseudophryne bibronii on the central coast of New South Wales. In: Lunney D & Ayers D (eds), Herpetology in Australia, Royal Zoological Society of New South Wales, pp 139–149.

Woinarski JCZ, Legge SM, Woolley LA, Palmer R, Dickman CR, Augusteyn J, et al. (2020) Predation by introduced cats Felis catus on Australian frogs: Compilation of species records and estimation of numbers killed. Wildlife Research 47, 580–588.

Woodruff DS (1972) The evolutionary significance of hybrid zones in Pseudophryne (Anura: Leptodactylidae), PhD Thesis. University of Melbourne.

Woodruff DS (1976a) Courtship, Reproductive Rates, and Mating System in Three Australian Pseudophryne. Journal of Herpetology 10, 313–318.

Woodruff DS (1976b) Embryonic Mortality in Pseudophryne (Anura: Leptodactylidae). Copeia 1976, 445–449.

Woodruff DS (1977) Male Postmating Brooding Behavior in Three Australian Pseudophryne (Anura: Leptodactylidae). Herpetologica 33, 296–303.

Woodruff DS (1979) Postmating Reproductive Isolation in Pseudophryne and the Evolutionary Significance of Hybrid Zones. Science 203, 561–563.

Zylstra PJ (2018) Flammability dynamics in the Australian Alps. Austral Ecology 43, 578–591.

Other sources cited in the advice

ALA (Atlas of Living Australia) (2020) Records of Pseudophryne dendyi. Downloaded 14 October 2020, Available at:

Threatened Species Scientific Committee 22 Pseudophryne dendyi (Dendy’s Toadlet) Conservation Advice

https://bie.ala.org.au/species/urn:lsid:biodiversity.org.au:afd.taxon:f30c9f98-0427-44ac- 8e84-01d3713b9cc3

Clemann N (2020) Personal communication by email, 14, 15 October, 4, 6 November 2020. Program Leader: Threatened Fauna, Arthur Rylah Institute for Environmental Research.

Commonwealth of Australia (2020) Australian Google Earth Engine Burnt Area Map. A Rapid, National Approach to Fire Severity Mapping. Canberra. Viewed 14 October 2020, Available at: https://www.environment.gov.au/system/files/pages/a8d10ce5-6a49-4fc2-b94d- 575d6d11c547/files/ageebam.pdf

CSIRO (2007) Climate Change in Australia. Viewed 24 December 2020, Available at: http://www. climatechangeinaustralia.gov.au/

CSIRO and Bureau of Meteorology (2015) Climate Change in Australia Information for Australia’s Natural Resource Management Regions: Technical Report. CSIRO and Bureau of Meteorology, Australia. Viewed 24 December 2020, Available at: https://www.climatechangeinaustralia.gov.au/en/publications-library/technical-report/

DAWE (Department of Agriculture Water & the Environment) (2020) National Indicative Aggregated Fire Extent Datasets – NIAFED (Metadata Date: 2020-06-23). Downloaded 16 November 2020. Available at: http://www.environment.gov.au/fed/catalog/search/resource/details.page?uuid=%7B9AC DCB09-0364-4FE8-9459-2A56C792C743%7D

Department of Sustainability and Environment (2013) Advisory list of threatened Vertebrate fauna in Victoria. Viewed 15 October 2020, Available at: https://www.environment.vic.gov.au/__data/assets/pdf_file/0014/50450/Advisory-List-of- Threatened-Vertebrate-Fauna_FINAL-2013.pdf

DELWP (Victorian Department of Environment, Land, Water and Planning) (2020a). Victorian Biodiversity Atlas – Records of Pseudophryne dendyi. Downloaded 16 October 2020, Available at: https://vba.dse.vic.gov.au/vba/index.jsp

DELWP (Victorian Department of Environment, Land, Water and Planning) (2020b) Victoria’s bushfire emergency: biodiversity response and recovery - Version 2 (August 2020). Viewed 13 October 2020, Available at: https://www.wildlife.vic.gov.au/__data/assets/pdf_file/0030/484743/Victorias-bushfire- emergency-Biodiversity-response-and-recovery-Version-2-1.pdf

Donnellan S (2020) Unpublished genetic data on Pseudophryne species. In possession of author, Adelaide.

Threatened Species Scientific Committee 23 Pseudophryne dendyi (Dendy’s Toadlet) Conservation Advice

Donnellan S (2020, 2021) Personal communication by telephone 22 October 2020, email 1 March 2021. Chief Research Scientist of the Evolutionary Biology Unit at the South Australian Museum.

DPIE (NSW Department of Planning, Industry and Environment) (2020). NSW BioNet Biodiversity Atlas – Records of Pseudophryne dendyi. Downloaded 16 October 2020, Available at: https://www.environment.nsw.gov.au/atlaspublicapp/UI_Modules/ATLAS_/AtlasSearch.as px

Gillespie G (2020) Personal communication by telephone, 4 December 2020. Senior Director Ecosystem Management, Department of Environment, Parks and Water Security, NT.

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Hero J, Lemckert F & Robertson P (2004) Pseudophryne dendyi. The IUCN Red List of Threatened Species 2004: e.T41187A10399066. Viewed 13 October 2020, Available at: https://dx.doi.org/10.2305/IUCN.UK.2004.RLTS.T41187A10399066.en.

Hunter D (2020) Personal communication by email 4 November 2020. Senior Threatened Species Officer, NSW Office of Environment and Heritage.

IUCN Standards and Petitions Committee (2019) Guidelines for Using the IUCN Red List Categories and Criteria. Version 14. Viewed 15 October 2020, Available at: https://www.iucnredlist.org/resources/redlistguidelines

Legge S, Woinarski J, Garnett S, Nimmo D, Scheele B, Lintermans M, et al. (2020) Rapid analysis of impacts of the 2019-20 fires on animal species, and prioritisation of species for management response – preliminary report (14 March 2020). Viewed 15 October 2020, Available at: https://www.environment.gov.au/biodiversity/bushfire-recovery/research- and-resources

Murray KA, Skerratt L, Marantelli G, Berger L, Hunter D, Mahony M & Hines H (2011) Hygiene protocols for the control of diseases in Australian frogs. Viewed 24 December 2020,

Threatened Species Scientific Committee 24 Pseudophryne dendyi (Dendy’s Toadlet) Conservation Advice

Available at: http://www.environment.gov.au/biodiversity/invasive- species/publications/hygiene-protocols-control-diseases-australian-frogs

Osborne W (2020) Personal communication by telephone 4 November, and email 6 November. Adjunct Professor, Institute for Applied Ecology, University of Canberra.

Scheele B (2020) Personal communication by email 14 December 2020. Research Fellow, Australian National University.

Southwell D (2020). Design considerations for post natural disaster (fire) on-ground assessment of status of species, ecological communities, habitats and threats. Threatened Species Recovery Hub. Viewed 17 December 2020 Available at: http://www.environment.gov.au/system/files/pages/a8d10ce5-6a49-4fc2-b94d- 575d6d11c547/files/draft-post-fire-rapid-assessment-guide.pdf

Threatened Species Scientific Committee (TSSC) (2013a) Commonwealth Listing Advice on Pseudophryne corroboree (Southern Corroboree Frog). Department of Sustainability, Environment, Water, Population and Communities. Canberra. Viewed 24 December 2020, Available at: http://www.environment.gov.au/biodiversity/threatened/species/pubs/1915-listing- advice.pdf.

Threatened Species Scientific Committee (TSSC) (2013b). Commonwealth Listing Advice on Pseudophryne pengilleyi (Northern Corroboree Frog). Department of Sustainability, Environment, Water, Population and Communities. Canberra. Viewed 24 December 2020, Available from: http://www.environment.gov.au/biodiversity/threatened/species/pubs/66670-listing- advice.pdf.

Victorian Government (2020a) Preliminary Threatened Species Assessment - Pseudophryne semimarmorata Southern Toadlet. Downloaded 15 October 2020, Available at: https://www.environment.vic.gov.au/conserving-threatened-species/conservation-status- assessment-project

Victorian Government (2020b) Preliminary Threatened Species Assessment - Pseudophryne bibronii Brown Toadlet. Downloaded 15 October 2020, Available at: https://www.environment.vic.gov.au/conserving-threatened-species/conservation-status- assessment-project

Webster G (2020, 2021) Unpublished genetic and morphological data on Pseudophryne species. In possession of author, Sydney.

Threatened Species Scientific Committee 25 Pseudophryne dendyi (Dendy’s Toadlet) Conservation Advice

Webster G (2020, 2021) Personal communication by telephone 4 November 2020, email 2 March 2021 Research student, Macquarie University.

Threatened Species Scientific Committee 26 THREATENED SPECIES SCIENTIFIC COMMITTEE

Established under the Environment Protection and Biodiversity Conservation Act 1999 Attachment A: Listing Assessment for Pseudophryne dendyi Reason for assessment This assessment follows provision of new information to the Committee.

Assessment of eligibility for listing This assessment uses the criteria set out in the EPBC Regulations. The thresholds used correspond with those in the IUCN Red List criteria except where noted in criterion 4, sub- criterion D2. The IUCN criteria are used by Australian jurisdictions to achieve consistent listing assessments through the Common Assessment Method (CAM).

Key assessment parameters Table 3 includes the key assessment parameters used in the assessment of eligibility for listing against the criteria.

Table 2 Key assessment parameters

Metric Estimate used in Minimum Maximum Justification the assessment plausible plausible value value Number of No estimate used There are insufficient data available to mature determine the number of mature individuals individuals. However, given the widespread distribution, and apparently healthy subpopulations in coastal forests, the number of mature individuals is likely to be large.

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Metric Estimate used in Minimum Maximum Justification the assessment plausible plausible value value Generation 4 4 7 The generation length of Dendy’s Toadlet time (years) is unknown, but the related Southern and Northern Corroboree Frogs are estimated to have generations of approximately 7 years (TSSC 2013a, 2013b). Southern Corroboree Frogs attain sexual maturity at about 3–5 years, with individuals recorded reaching 9 years old (Pengilley 1973; Hunter 2000). However, sexual maturity is later in Corroboree frogs than Dendy’s Toadlet (B. Scheele 2020 pers comm 14 Dec), and consequently, generation length will likely be correspondingly shorter in Dendy’s toadlet. Using the simplest generation length formula (IUCN Standards and Petitions Committee 2019) and life history estimates for Dendy’s Toadlet from Legge et al. (2020) (age at first reproduction = 2 years, length of reproductive period = 5 years), gives an estimate of a generation of 4.5 years. If the full generation length calculator is used (IUCN Standards and Petitions Committee 2019), with the additional assumptions of 65 independent young per year (Legge et al. 2020) and 55% annual survivorship for adults (Hunter 2000), a generation of 4 years results. This is adopted as the estimate used in this assessment, with the 7 year figure of the Corroboree frogs used as the maximum plausible value as these frogs have been well studied. Extent of 78 445 74 253 91 729 Extent of occurrence (EOO) was calculated occurrence as a minimum convex hull in GeoCat (km2) (Bachman et al. 2011). The minimum plausible value includes only post-2000 records of Dendy’s Toadlet from the highly vetted Victorian Biodiversity Atlas (VBA) (DELWP 2020a) and NSW BioNet (includes ACT) (DPIE 2020) databases. The maximum plausible value includes all collection records since 1960 from the Atlas of Living Australia (ALA 2020), which incorporates the previous databases as well as records from museums, wildlife atlases, and citizen science projects (after the removal of a few anomalous points that were either clearly errors [Bass Strait] or probable mis-identifications [northern NSW, Blue Mountains, northern Melbourne]). The estimate used in the assessment uses the records from VBA and NSW BioNet but with records collected from 1960, as much survey work on Dendy’s Toadlet pre-dates 2000. Trend stable See Criterion 2.

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Metric Estimate used in Minimum Maximum Justification the assessment plausible plausible value value Area of 2 632 824 2 680+ Area of occupancy (AOO) was calculated in Occupancy GeoCat (Bachman et al. 2011) with the (km2) standard IUCN cell size of 2 km2 (IUCN Standards and Petitions Committee 2019). The minimum, maximum and estimate used in the assessment for AOO were calculated as for EOO above. The upper bound for AOO should probably be higher given a lack of survey effort for the species across its range (see Criterion 1). Trend stable See Criterion 1. Number of No estimate used There are insufficient data available to subpopulations determine the number of subpopulations as there are no clearly delineated subpopulations. As the species does not qualify under Criterion 2, the number of subpopulations is not relevant to the current assessment. No. locations No estimate used There are insufficient data available to determine the number of locations as there are no clearly delineated locations based on threatening processes. One possibility could be upland versus lowlands in relation to the threat of Bd; however, the major recent threat for this species is bushfire, and the 2019-20 bushfires burned fairly evenly in both uplands and lowlands. As the species does not qualify under Criterion 2, the number of locations is not relevant to the current assessment. Fragmentation Dendy’s Toadlet has a widespread distribution, having been recorded at many sites in different environments and elevations. However, given the lack of long-term monitoring at any sites across its distribution range, it is unclear how vulnerable individual subpopulations are to extirpation. In particular, whether the population is severely fragmented, requiring > 50 % of the AOO to be in patches that are too small to support a viable population (IUCN Standards and Petitions Committee 2019). Fluctuations The species is not known to be subject to extreme fluctuations in EOO, AOO, number of subpopulations, locations or mature individuals. No parameter has been shown to have changed by an order of magnitude by the 2019-20 bushfires.

Threatened Species Scientific Committee 29 Pseudophryne dendyi (Dendy’s Toadlet) Conservation Advice

Criterion 1 Population size reduction

Reduction in total numbers (measured over the longer of 10 years or 3 generations) based on any of A1 to A4

– Critically Endangered Endangered Vulnerable Very severe reduction Severe reduction Substantial reduction

A1 70%

A2, A3, A4 ≥ 90% ≥ ≥ 50%

A1 Population reduction observed, estimated,≥ 80% inferred or suspected in ≥the 50% (a) direct≥ 30% observation [except past and the causes of the reduction are clearly reversible AND A3] understood AND ceased. (b) an index of abundance appropriate to the taxon A2 Population reduction observed, estimated, inferred or suspected in the (c) a decline in area of past where the causes of the reduction may not have ceased OR may not occupancy, extent of be understood OR may not be reversible. occurrence and/or quality of habitat A3 Population reduction, projected or suspected to be met in the future (up Based on (d) actual or potential levels of any of the to a maximum of 100 years) [(a) cannot be used for A3] exploitation following (e) the effects of introduced A4 An observed, estimated, inferred, projected or suspected population taxa, hybridization, reduction where the time period must include both the past and the pathogens, pollutants, future (up to a max. of 100 years in future), and where the causes of competitors or parasites reduction may not have ceased OR may not be understood OR may not be reversible.

Criterion 1 evidence Not eligible

Dendy’s Toadlet has not been the subject of any previous systematic attempt to quantify its population size. The species in Victoria was considered Data Deficient in 2013 (Department of Sustainability and Environment 2013) and so was not fully assessed then. The existence of multiple hybrid zones, as well as taxonomic uncertainty, provides a challenge in establishing an accurate population size or distribution. This is compounded by the fact that Dendy’s Toadlet has not been the focus of any specific fieldwork, systematic survey, or monitoring for a number of decades, and most site records tend to be incidental chance encounters made by field workers (Gillespie et al. 1995; N. Clemann 2020 pers comm 6 Nov; W. Osborne 2020 pers comm 4 Nov). Dendy’s Toadlet breeds at a different time to many south-eastern Australian frogs, including intensely studied species such as the Northern Corroboree Frog, and so male calls from Dendy’s Toadlet are often not detected in surveys focusing on other species (Howard et al. 2010; N. Clemann 2020 pers comm 6 Nov; W. Osborne 2020 pers comm 4 Nov).

The distribution described and shown in Map 1 likely represents the historical distribution of Dendy’s Toadlet. As Dendy’s Toadlet has not been the object of targeted surveys, its potentially dynamic population size and distribution through time is problematic to establish. However, multiple lines of anecdotal evidence point to a suspected decline in the species. Primary amongst these are the observations of experienced field workers, who have noted that Dendy’s Toadlet has been recorded less frequently, especially in alpine and subalpine areas, particularly at sites where they had been common in the 1970s (N. Clemann 2020 pers comm 4 Nov; W. Osborne

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2020 pers comm 6 Nov; D. Hunter 2020 pers comm 4 Nov). This decline seems to have begun in the 1980s (N. Clemann 2020 pers comm 4,6 Nov; W. Osborne 2020 pers comm 6 Nov; Scheele et al. 2017b).

For a population decline to be considered under Criterion 1, it must have taken place within three generations, or 12 years for Dendy’s Toadlet (21 years maximum plausible value). In an attempt to establish a specific timeframe for the suspected upland population decline, records of Dendy’s Toadlet collected since 1960 from state databases (DELWP 2020a; DPIE 2020) were analysed after removing any duplicates (Figure 1). Each record represents a site sampled at least once during that year (total 853 sites; elevations for all sites were derived using GPS Visualizer [2020]). The overall number of records of the species has mostly increased through time, with the exception of 2000-09, when survey effort seems to have been lower. The relatively high percentage of records over 1200 m from 2000-09 may be an artefact of the small number of records from those years, when overall survey effort may have been lower but was likely disproportionately focused on high elevation sites. When considered before and after the hypothesised mid-1980s population decline, the percentage of sites located above 1200 m declined from being 16 percent of the total sites (1960-84) to only 9 percent (1985-2020). This is notable as there were likely to have been concentrated surveys of higher elevation areas at the time, in response to declines in numerous other Alpine frog species occurring throughout the 1980s and 1990s (Osborne et al. 1999).

Figure 1: Dendy’s Toadlet site records from State Databases (DELWP 2020a; DPIE 2020)

A second way of quantifying a decline is by tracking changing AOO through time in 20-year blocks (Figure 2), which incorporates not just the raw number of sites but also their geographic spread across the landscape. Seen this way, the AOO of Dendy’s Toadlet is fairly stable over time, although a decline in high elevation sites would be masked by the larger number of low elevation sites. However, it is unlikely that the whole species distribution was adequately sampled within any one 20-year block.

Threatened Species Scientific Committee 31 Pseudophryne dendyi (Dendy’s Toadlet) Conservation Advice

Figure 2: Dendy’s Toadlet Area of Occupancy through time.

A limitation of these analyses is that the data behind them were not systematically collected to represent the full distribution of the currently recognised species. However, the timing of the onset of decline, its concentration in higher elevation areas, and the stabilisation of lower elevation populations fits with current understanding of the chronology and nature of the fungal pathogen Batrachochytrium dendrobatidis (Bd), which is responsible for the decline and extinction of many frog species (Hunter et al. 2010; Scheele et al. 2017b).

Contemporaneous population declines have been documented in closely related Pseudophryne species found in similar areas, both at higher (Southern and Northern Corroboree Frogs, Brown Toadlet) (Gillespie et al. 1995; Osborne et al. 1999) and to a lesser extent at lower elevations (Brown Toadlet, Marbled Toadlet) (Howard et al. 2010). This increases the likelihood that Dendy’s Toadlet, whose biology and ecology is very similar (Woodruff 1979; Anstis 2017), has responded similarly to the same threat or threats (N. Clemann 2020 pers comm 14 Oct).

However, this population decline likely occurred slightly too far in the past to be considered in this assessment, as it began about 35 years before (c. 1985; Scheele et al. 2017b), and the decline was widespread through high elevation areas in multiple species of frog by more than 20 years ago (Osborne et al. 1999). The situation by 2020 may have stabilised to a degraded but steady state, with Dendy’s Toadlet now rarely encountered at higher elevations, but relatively common at lower elevations nearer the coast (W. Osborne 2020 pers comm 4, 6 Nov; D. Hunter 2020 pers comm 4 Nov).

Another threat that may have caused a population decline is bushfire, specifically the megafires of 2019-20, which followed a severe drought (Nolan et al. 2020). The fires burned more than 10 million hectares from South Australia to Queensland (Alexandra & Finlayson 2020). This was the largest fire season since European settlement, burning across varied landscapes (forests, woodlands, heathland, grassland, farmland), some of which very rarely burn (i.e. rainforest) (Nolan et al. 2020; Ward et al. 2020). There are currently no specific data on the impact of these fires on Dendy’s Toadlet. Any population decline could be direct, through mortality due to fire, as

Threatened Species Scientific Committee 32 Pseudophryne dendyi (Dendy’s Toadlet) Conservation Advice well as indirect and ongoing, via habitat destruction and degradation (Brown et al. 1998; Alexandra & Finlayson 2020; Ward et al. 2020; N. Clemann 2020 pers comm 14 Oct).

The response of populations of Dendy’s Toadlet and other Pseudophryne species to bushfire is not well known, but the terrestrial lifestyle of members of this genus may make them more susceptible to fire than some aquatic frogs. Dendy’s Toadlet is likely to have a similar level of risk from fire mortality as other species of Pseudophryne, in particular the Brown Toadlet (B. Scheele 2020 pers comm 14 Dec), but a slightly lower risk of post-fire population decline than the Corroboree Frogs due to its less specialised habitat requirements (Legge et al. 2020) and Corroboree Frogs having a smaller clutch size (B. Scheele 2020 pers comm 14 Dec). Individuals of Dendy’s Toadlet are known to have survived past bushfires (Carey et al. 2003; Howard et al. 2010; B. Scheele 2020 pers comm 14 Dec). Northern Corroboree Frogs persisted and bred after moderate to high severity fires in 2003 burned 70–95 percent of all known breeding sites (Carey et al. 2003). Calling Dendy’s Toadlet males were also recorded after the Black Saturday fires in 2009 in East Gippsland, and some fires may even benefit the species by raising water tables (G. Gillespie 2020 pers comm 4 Dec). Post-2009 fire surveys for Brown and Marbled Toadlets to the north of Melbourne found a few surviving toadlets, but a lack of pre-fire distributional data and a probable pre-fire decline made it hard to define the impact of the fires (Howard et al. 2010).

It is not straightforward to estimate the magnitude of possible population declines due to the 2019-20 bushfires. One way is to overlay the distribution of Dendy’s Toadlet with a GIS layer of the fire extent (National Indicative Aggregated Fire Extent Dataset – NIAFED; DAWE 2020) (Figure 3). This was done by Ward et al. (2020), who calculated that 33.3 percent of Dendy’s Toadlet’s distribution was within the fire zone, whereas Legge et al. (2020) estimated 53.7 percent (alpha hull) to 61.7 percent (gridded observation points). For Victoria only, the overlap between the fire extent and Dendy’s Toadlet distribution was calculated as 46 percent when using modelled habitat (23 percent high severity fire), and 64 percent when using VBA records (DELWP 2020b). However, the NIAFED dataset does not reflect levels of fire severity and includes some unburnt areas (Commonwealth of Australia 2020). Further, about half of the fire extent that overlaps with Dendy’s Toadlet distribution is at higher elevations, where Dendy’s Toadlet was likely already at a relatively low population density due to the earlier impacts of Bd. The overwhelming proportion of Dendy’s Toadlet sites sampled since 1985, and therefore likely highest population densities, are below 400 m (69 percent of sites).

A subsequent preliminary analysis by a team from the NESP Threatened Species Recovery (TSR) Hub used a fire severity dataset (AUS GEEBAM; Commonwealth of Australia 2020), intersected with a modelled species distribution, to produce population decline estimates due to the 2019- 20 bushfires. These analyses show that just over half of the range of Dendy’s Toadlet was affected by these fires: 27 percent was burnt in high to very high severity fire, and a further 25 percent was burnt in low to moderate severity fire. A structured expert elicitation process was used to estimate the proportional population change from pre-fire levels to immediately after the fire, and then out to three generations after the fire, when exposed to fires of varying severity. The TSSC has used elicited judgements for the Brown Toadlet (from Kangaroo Island) as a proxy for Dendy’s Toadlet, as it is ecologically similar and closely related (Donnellan et al. 2012), to the extent that hybrids between the species are common (Littlejohn & Watson 1993). The Brown Toadlet outside Kangaroo Island also shares a wide altitudinal distribution with Dendy’s Toadlet. Therefore, its fire response may resemble that of Dendy’s Toadlet.

Threatened Species Scientific Committee 33 Pseudophryne dendyi (Dendy’s Toadlet) Conservation Advice

Figure 3: Dendy's Toadlet sites from State Databases (1960-2020) (DELWP 2020a; DPIE 2020) overlapped with Fire Extent in red (NIAFED; DAWE 2020) (yellow: sites <600m, green: 600- 1200m, blue >1200m) (produced in Google Earth Pro).

The NESP TSR Hub results for the Brown Toadlet, combined with the spatial analyses of fire severity overlap for Dendy’s toadlet suggest that one year after the fire, Dendy’s Toadlet has experienced an overall decline from pre-fire levels of 18 percent, but that the population loss could be as large as 34 percent, i.e. 66 percent surviving (bound of 80 percent confidence limits). After three generations, the best estimate for the overall population decline relative to the pre- fire population is 15 percent, but the population loss could be as much as 35 percent (bound of 80 percent confidence limits). The structured elicitation also generated estimates of the proportional population change over time in the absence of fire; by three generations after fire, the overall population of Dendy’s Toadlet was estimated to be 9 percent lower than it would have been had the 2019-20 bushfires not occurred. The Committee will update the description of the fire impacts in this Conservation Advice to incorporate the latest evidence, prior to providing its advice on the assessment of this species to the Minister for the Environment.

Given the above assumptions, there are a number of estimated possible total population size reductions, with the most extreme being 35 percent over three generations. However, nearly all of the estimates are well below the 30 percent level that makes a species potentially eligible for

Threatened Species Scientific Committee 34 Pseudophryne dendyi (Dendy’s Toadlet) Conservation Advice the Vulnerable category, suggesting that it is not eligible. This would be in line with Hero et al. (2004) and Gillespie et al. (2020), which both categorised the species as Least Concern (but without considering the impact of the 2019-20 bushfires). Dendy’s Toadlet was relatively common and widespread with a seemingly stable population before the fires (Legge et al. 2020), and its large geographic range and wide environmental tolerance may make it less prone to extinction (Murray & Hose 2005).

The taxonomy of Dendy’s Toadlet and other Pseuophryne species is in a state of flux, with the high likelihood that Dendy’s Toadlet is composed of a number of taxa that probably represent different species (S. Donnellan 2020 pers comm 22 Oct; G. Webster 2020 pers comm 4 Nov). This would result in these new species having smaller distributions, as well as potentially higher levels of fire overlap. However, the situation is very complex and is still unclear (S. Donnellan 2021 pers comm 1 March; G. Webster 2021 pers comm 2 March), and so formal taxonomic redescriptions are not likely in the near future until more data are collected to define species boundaries accurately. Dendy’s Toadlet and any new taxa should be (re)assessed when they have been defined clearly after a formal taxonomic redescription.

The data presented above appear to demonstrate that the species is not eligible for listing under this criterion. However, the purpose of this consultation document is to elicit additional information to better understand the species’ status. This conclusion should therefore be considered to be tentative at this stage, as it may be changed as a result of responses to this consultation process.

Criterion 2 Geographic distribution as indicators for either extent of occurrence AND/OR area of occupancy

– Critically Endangered Vulnerable Endangered Restricted Limited Very restricted

B1. Extent of occurrence (EOO) < 100 km2 < 5,000 km2 < 20,000 km2

B2. Area of occupancy (AOO) < 10 km2 < 500 km2 < 2,000 km2

AND at least 2 of the following 3 conditions:

(a) Severely fragmented OR Number = 1 ≤ 5 ≤ 10 of locations

(b) Continuing decline observed, estimated, inferred or projected in any of: (i) extent of occurrence; (ii) area of occupancy; (iii) area, extent and/or quality of habitat; (iv) number of locations or subpopulations; (v) number of mature individuals

(c) Extreme fluctuations in any of: (i) extent of occurrence; (ii) area of occupancy; (iii) number of locations or subpopulations; (iv) number of mature individuals

Criterion 2 evidence Not eligible

Threatened Species Scientific Committee 35 Pseudophryne dendyi (Dendy’s Toadlet) Conservation Advice

The extent of occurrence (EOO) for Dendy’s Toadlet has been calculated as a range between 74 253 km2 and 91 729 km2 (see Table 1). The minimum EOO value was calculated using the methods outlined in the IUCN guidelines using record data (DELWP 2020a, DPIE 2020) from the last 20 years (i.e. records from 2000-20), which would only include records from the last three generations (12-21 years for Dendy’s Toadlet) and would also exclude the effects of earlier population declines. EOO calculations do not vary significantly through time (e.g. pre-2000 records = 75 557 km2, post-2000 records = 74 253 km2; DELWP 2020a, DPIE 2020). Therefore, the broad distribution of the species is likely to have been largely encompassed by these records.

However, the impact of the 2019-20 bushfires is likely to have reduced the EOO. A further worst- case EOO value was therefore calculated that excluded any sites that overlapped with the fire extent layer (NIAFED), assuming total site and subpopulation destruction without considering the actual fire severity. This calculation used only higher quality VBA (DELWP 2020a) and NSW BioNet (DPIE 2020) records from the last 20 years and did not include any high elevation sites (highest included site below 800m) that could potentially still be highly Bd-affected, yielding an EOO of 64 020 km2. This lowest calculated value of EOO is three times larger than the threshold value for listing (20 000 km2 for Vulnerable), therefore Dendy’s Toadlet is likely not eligible for listing under sub-criterion B1.

Calculating the area of occupancy (AOO) for Dendy’s Toadlet is more problematic than EOO, as AOO can be a surrogate for survey effort when a species has not been adequately sampled (IUCN Standards & Petitions Committee 2019), which is the case for Dendy’s Toadlet (see Criterion 1). When VBA (DELWP 2020a), NSW BioNet (DPIE 2020) and Atlas of Living Australia (ALA 2020) records are included from 1960 - 2020, the calculated AOO (using 2x2 km2 grid) is 2680 km2. It changes little (2632 km2) when only the more highly vetted VBA and NSW BioNet databases are used, but is 824 km2 when only the last 20 years’ worth of records are considered. This difference is because the whole species distribution was not adequately sampled within the last 20 years (or in any 20-year block; see Criterion 1 above, Figure 2).

These values span the threshold between not eligible and Vulnerable. The modelled known and likely to occur distribution (Map 1) is extensive (37 525 km2; Geospatial & Information Analytics, Department of Agriculture, Water and the Environment), and Dendy’s Toadlet is plainly extant in many different habitats, areas, and at a wide range of elevations (see Criterion 1 and Figure 3). This, combined with limited survey effort over both time and space, suggests that all of the calculated AOO values for Dendy’s Toadlet are likely considerable underestimates. The widespread nature and number of Dendy’s Toadlet records is relatively high given that this species was not the focus of any of the surveys. Even if all the modelled known or likely habitat that intersects with the fire extent layer (disregarding severity) was no longer viable for the species (approximately 19 725 km2), there still remains at least 17 800 km2, most of which has not been surveyed adequately for Dendy’s Toadlet. Therefore, AOO for Dendy’s Toadlet is very likely to be above the threshold of 2000 km2 for a listing of Vulnerable, and so the species is considered not eligible for listing under sub-criterion B2.

While not currently meeting Criterion 2 as the species is currently described, Dendy’s Toadlet and any new taxa should be (re)assessed for EOO/AOO after taxonomic revisions have been completed.

Threatened Species Scientific Committee 36 Pseudophryne dendyi (Dendy’s Toadlet) Conservation Advice

The data presented above appear to demonstrate that the species is not eligible for listing under this criterion. However, the purpose of this consultation document is to elicit additional information to better understand the species’ status. This conclusion should therefore be considered to be tentative at this stage, as it may be changed as a result of responses to this consultation process.

Criterion 3 Population size and decline

– Critically Endangered Vulnerable Endangered Low Limited Very low

Estimated number of mature individuals < 250 < 2,500 < 10,000

AND either (C1) or (C2) is true

C1. An observed, estimated or projected Very high rate High rate Substantial rate continuing decline of at least (up to a 25% in 3 years or 1 20% in 5 years or 2 10% in 10 years or max. of 100 years in future) generation generation 3 generations (whichever is (whichever is (whichever is longer) longer) longer)

C2. An observed, estimated, projected or inferred continuing decline AND its geographic distribution is precarious for its survival based on at least 1 of the following 3 conditions:

(i) Number of mature individuals ≤ 50 ≤ 250 ≤ 1,000 in each subpopulation (a) (ii) % of mature individuals in one 90 – 100% 95 – 100% 100% subpopulation =

(b) Extreme fluctuations in the number of mature individuals

Criterion 3 evidence Insufficient data to determine eligibility

There is no estimate of the number of adult Dendy’s Toadlets. However, its known distribution in many widespread environments, locations, and elevations across a large geographic area suggest there are probably many mature individuals (Fig. 3). In particular, there appear to be abundant subpopulations in the coastal forests (W. Osborne 2020 pers comm 4, 6 Nov), which is also the case for coastal subpopulations of the closely related Brown Toadlet (Westgate et al. 2018). While there are no systematic data for local abundances of Dendy’s Toadlet, dozens of records by experienced frog researchers indicate large numbers of toadlets (up to 200) at multiple sites (ALA 2020; DELWP 2020a; DPIE 2020), suggesting that it is likely that there are far more adult toadlets across the entire distribution than the minimum number required for listing.

Threatened Species Scientific Committee 37 Pseudophryne dendyi (Dendy’s Toadlet) Conservation Advice

The data presented above appear to demonstrate that there are insufficient data to demonstrate if the species is eligible for listing under this criterion. However, the purpose of this conservation advice is to elicit additional information to better understand the species’ status. This conclusion should therefore be considered to be tentative at this stage, as it may be changed as a result of responses to this consultation process.

Criterion 4 Number of mature individuals

– Critically Endangered Endangered Vulnerable Extremely low Very Low Low

D. Number of mature individuals < 50 < 250 < 1,000

D2.1 Only applies to the Vulnerable category D2. Typically: area of Restricted area of occupancy or number occupancy < 20 km2 or - - of locations with a plausible future threat number of locations that could drive the species to critically 5 endangered or Extinct in a very short time ≤

1 The IUCN Red List Criterion D allows for species to be listed as Vulnerable under Criterion D2. The corresponding Criterion 4 in the EPBC Regulations does not currently include the provision for listing a species under D2. As such, a species cannot currently be listed under the EPBC Act under Criterion D2 only. However, assessments may include information relevant to D2. This information will not be considered by the Committee in making its recommendation of the species’ eligibility for listing under the EPBC Act, but may assist other jurisdictions to adopt the assessment outcome under the common assessment method.

Criterion 4 evidence Insufficient data to determine eligibility

There is no estimate for the number of adult Dendy’s Toadlets. However, the species is relatively widespread, and it is likely that more than 1000 mature individuals exist across its entire distribution (see Criterion 3).

The data presented above appear to demonstrate that there are insufficient data to demonstrate if the species is eligible for listing under this criterion. However, the purpose of this conservation advice is to elicit additional information to better understand the species’ status. This conclusion should therefore be considered to be tentative at this stage, as it may be changed as a result of responses to this consultation process.

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Criterion 5 Quantitative analysis

– Critically Endangered Vulnerable Endangered Near future Medium-term future Immediate future

years or Indicating the probability of generations, 5 generations,

extinction in the wild to be: whichever≥ 50% in 10 is years longer or 3 whichever≥ 20% in 20 is longer (100 years max.) (100 years max.) ≥ 10% in 100 years

Criterion 5 evidence Insufficient data to determine eligibility

Population viability analysis has not been undertaken. Therefore, there is insufficient information to determine the eligibility of the species for listing in any category under this criterion. However, the purpose of this conservation advice is to elicit additional information to better understand the species’ status. This conclusion should therefore be considered tentative at this stage, as it may be changed as a result of responses to this consultation process.

Adequacy of survey The survey effort has been considered adequate and there is sufficient scientific evidence to support the assessment. While there are issues regarding the level of survey effort for this species (see Criterion 1), the number of incidental records is large enough and widespread enough to give reasonable estimates for the purposes of this assessment.

Listing and Recovery Plan Recommendations No recovery plan is in place for Dendy’s Toadlet.

A decision about whether there should be a recovery plan for this species has not yet been determined. The purpose of this consultation document is to elicit additional information to help inform this decision.

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© Commonwealth of Australia 2021

Ownership of intellectual property rights Unless otherwise noted, copyright (and any other intellectual property rights) in this publication is owned by the Commonwealth of Australia (referred to as the Commonwealth).

Creative Commons licence All material in this publication is licensed under a Creative Commons Attribution 4.0 International Licence except content supplied by third parties, logos and the Commonwealth Coat of Arms.

Inquiries about the licence and any use of this document should be emailed to [email protected].

Cataloguing data This publication (and any material sourced from it) should be attributed as: Department of Agriculture, Water and the

Environment 2021, Conservation advice for Pseudophryne dendyi (Dendy’s Toadlet), Canberra.

This publication is available at the SPRAT profile for Pseudophryne dendyi (Dendy’s Toadlet). Department of Agriculture, Water and the Environment GPO Box 858, Canberra ACT 2601 Telephone 1800 900 090 Web awe.gov.au

The Australian Government acting through the Department of Agriculture, Water and the Environment has exercised due care and skill in preparing and compiling the information and data in this publication. Notwithstanding, the Department of Agriculture, Water and the Environment, its employees and advisers disclaim all liability, including liability for negligence and for any loss, damage, injury, expense or cost incurred by any person as a result of accessing, using or relying on any of the information or data in this publication to the maximum extent permitted by law.

Acknowledgements This assessment was only possible because various researchers kindly share their unpublished data (see text for details).

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