Consultation Document on Listing Eligibility and Conservation Actions

Zoothera lunulata halmaturina (Western Bassian Thrush)

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

1) the eligibility of Zoothera lunulata halmaturina (Western Bassian Thrush) for inclusion on the EPBC Act threatened species list in the Endangered category; and

2) the necessary conservation actions for the above species.

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 either by email to: [email protected] or by mail to:

The Director Migratory Species Section Biodiversity Conservation Division Department of Agriculture, Water and the Environment PO Box 858 Canberra ACT 2601

Responses are required to be submitted by 27 August 2021 Contents of this information package Page

General background information about listing threatened species 2

Information about this consultation process 3

Draft information about the Western Bassian Thrush and its eligibility for listing 4

Conservation actions for the species 13

References cited 15

Collective list of questions – your views 26

Department of Agriculture, Water and the Environment 1 Zoothera lunulata halmaturina (Western Bassian Thrush) Consultation Document

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 (Cwth) 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

Threatened Species Scientific Committee 2 Zoothera lunulata halmaturina (Western Bassian Thrush) Consultation Document the status of a potentially threatened species. This is also known as the ‘common assessment method’. 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.

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: http://environment.gov.au/privacy-policy .

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.

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Consultation document for Zoothera lunulata halmaturina (Western Bassian Thrush)

Adult Bassian Thrush © Copyright, Gregory J Smith via Shutterstock Conservation status Zoothera lunulata halmaturina (Western Bassian Thrush) is listed in the Vulnerable category of the threatened species list under the Environment Protection and Biodiversity Conservation Act 1999 (Cwth) (EPBC Act) effective from 8 July 2015.

Zoothera lunulata halmaturina is being reassessed by the Threatened Species Scientific Committee to be eligible for listing as Endangered under criterion 1. The Committee’s preliminary assessment is at Attachment A. The Committee assessment of the species’ eligibility against each of the listing criteria is:

• Criterion 1: A2c: Endangered • Criterion 2: Not eligible • Criterion 3: C1a(ii)+C2a(ii) Vulnerable

Department of Agriculture, Water and the Environment 4 Zoothera lunulata halmaturina (Western Bassian Thrush) Consultation Document

• Criterion 4: Not eligible • Criterion 5: Insufficient data The main factor that appears to make the species eligible for listing in the Endangered category is that the population has declined by an estimated 50 to 80 percent in the last three generations (11.6 years) (Bird et al. 2020; Boulton et al. 2021). This severe reduction in population was caused by the 2019/2020 bushfires on Kangaroo Island. Both the extent of occurrence (14,000 km2) and area of occupancy (510 km2) are estimated to be contracting. There are estimated to be 3,300 mature individuals in the wild with a declining trend (Boulton et al. 2021).

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. Species information Taxonomy Conventionally accepted as Zoothera lunulata halmaturina (Cambel, 1906).

The South Australian subspecies is one of three in Australia. The nominate subspecies Z. l. lunulata (Latham, 1801) found in south-east Australia, and the north-east Queensland subspecies Z. l. cuneata (De Vis, 1890), are both considered Least Concern.

Description Bassian Thrush (Zoothera lunulata) have a body length of 25–30 cm and a body mass of around 100 g. The birds have large straight bills, with a slight hook at the tip, long wings, a short tail with rounded tip, and very long strong legs. Adults are olive-brown to mottled brown, with black crescent-shaped bards on the back, rump, and head. Their underparts are white with brown- black scalloping and narrow white eye-rings (Higgins et al. 2006; Menkhorst et al. 2017). In flight, a broad dark diagonal bar across the white underside of its wing can be seen (Higgins et al. 2006). The subspecies Z. l. halmaturina have very similar plumage to the nominate subspecies (Ford 1983), but adult males of Z. l. halmaturina have shorter wing, tarsus and tail than the adult male nominate found in south-east Australia (Higgins et al. 2006).

Distribution Western Bassian Thrush can be found on Kangaroo Island, the adjacent mainland, Mt Lofty Ranges, and southern Flinders Ranges (Schodde & Mason 1999; Garnett et al. 2011; Boulton et al. 2021) (Map 1). They are known to occur along the damper gullies of the western half of the Kangaroo Island (Baxter 1995). There are around 300 to 500 birds throughout the Fleurieu Peninsula and Mount Lofty Ranges, with a north-south decline in density (RL Boulton unpublished data). The population in southern Flinders Ranges may also be around 100 individuals (Garnett et al. 2011), but this population has possibly at least halved as there are no recent records and over 90 percent of the forest block containing Telowie Gorge was burnt in 2014 (Boulton et al. 2021), where most birds from Flinders Ranges could be found previously. On mainland in Mt Lofty Ranges and Fleurieu Peninsula region, no decline was evident from 1974–1975 to 1984–1985 (Paton et al. 1994), but the subspecies was thought to have declined by 30 percent by 2000 (Possingham & Possingham 2008).

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Movement behaviour of other subspecies suggest that the mainland and Kangaroo Island birds are likely to constitute a single subpopulation (Garnett 1992). The subspecies is confined to remnant habitats on the mainland and was considered to be widespread on Kangaroo Island (Garnett et al. 2011). However, Kangaroo Island was severely impacted during the 2019/2020 bushfires, where around half of the island was burnt (DEW 2020; Todd & Maurer 2020). It is estimated that around 85 percent of suitable habitat for the subspecies on Kangaroo Island was lost (K Hermann unpublished data cited in Boulton et al. 2021). Surveys conducted immediately after the fires located only a single pair at one site, near a burnt-out swamp along Bull Creek (Boulton et al. 2020), although birds have been found at more sites since (R Boulton unpublished data). The population size and extent of occurrence is unknown post 2019/2020 fires. Further surveys and monitoring programs, using standardised methods across the range of the subspecies, are required.

There is insufficient information available to describe the distribution in more detail.

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Map 1 Modelled distribution of Western Bassian Thrush

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

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Cultural and community significance The majority of the Adelaide-Mount Lofty Ranges region occurs in Ngarrindjeri Nation, and the southern edge of Peramangk and Kaurna Nations. Southern Flinders Ranges occurs in the Nukunu Nation. The cultural and community significance of the subspecies is not known. Further research into the subject area may benefit the subspecies by providing insights about traditional land management.

Relevant biology and ecology The subspecies mostly inhabits damp eucalypt forest or woodland (Garnett et al. 2011). Their habitat comprises of densely forested areas and gullies, usually with a thick canopy overhead, a thick understorey of small trees and tall shrubs, and leaf-litter below (Higgins et al. 2006). However, birds have also been recorded breeding in exotic Monterey Pine (Pinus radiata) plantations (Edington 1983), and on Kangaroo Island within mature mallee eucalypt woodland (Baxter 1995). In much of the subspecies’ range, suitable habitat is confined to creek lines or dune swales (Garnett et al. 2011) where birds forage for worms among damp leaf litter. Damp habitats have been suggested to be particularly important in summer (Edington 1983).

Western Bassian Thrush are mostly sedentary, although there is some evidence for seasonal movements especially altitudinally (Higgins et al. 2006). The subspecies is described as shy and secretive with a low flight, its mottled pattern also makes it inconspicuous in leaf-litter (Pizzey & Knight 1997). Birds feed on invertebrates such as earthworms and beetles, and occasionally on fruit. The subspecies mainly forages on the ground by probing leaf litter, but sometimes takes fruit from low shrubs (Higgins et al. 2006). Individuals have been observed foraging singly, or in small groups (possibly family groups) of two to five, and they are probably territorial (Higgins et al. 2006).

Breeding occurs from May to November, with 2–3 eggs laid once a year in a large, bowl-shaped nest (made of moss, bark, or grass) which is usually placed in the fork of a tree, or occasionally on a thick horizontal branch. Nest sites are hidden amongst dense foliage with placement ranging from near ground level to up to 15 m above the ground. The young are fed by both parents (Higgins et al. 2006). They have an estimated generation length of 3.9 years (Bird et al. 2020).

Habitat critical to the survival On the mainland in South Australia, the subspecies prefers damp eucalypt forest or woodland. On Kangaroo Island, it occurs in damp eucalypt forests, but also uses mature mallee eucalypt woodland. Throughout its range, suitable habitat is mostly confined to creeklines or dune swales (Garnett et al. 2011). Damp habitats have been suggested to be particularly important in summer (Edington 1983).

Based on the available information, there is insufficient information to compose a comprehensive, clear-cut definition of habitat critical to the survival. For the purpose of this Conservation Advice, all known occupied areas and suitable habitats within the known range of the subspecies could be considered as habitat critical to the survival. Additionally, areas that are not currently occupied by the subspecies because they have been burnt (either in the 2019/20, or in future fires), but should became suitable again in the future, should also be considered habitat critical to survival.

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Key considerations in environmental impact assessments Habitat critical to the survival of the Western Bassian Thrush occurs across a range of land tenures. Habitat critical to the survival of the subspecies should not be destroyed or modified. Actions that have indirect impacts on habitat critical to the survival should be minimised (e.g., noise and light pollution). Actions that compromise adult and juvenile survival should also be avoided, such as the introduction of new diseases, weeds or predators.

When considering habitat loss, alteration or significant impacts to habitat in any part of the Western Bassian Thrush’s range, including in areas where the subspecies ‘may occur’ and any potential future habitat (i.e. that are currently not occupied due to the fires, but may become suitable in the future), surveys for occupancy at the appropriate times of the year and identifying preferred habitat remain an important tool in refining understanding of the area’s important for the subspecies.

Actions that remove habitat critical to the survival would interfere with the recovery of Western Bassian Thrush and reduce the area of occupancy of the subspecies. If removal of habitat critical to the survival cannot be avoided or mitigated, then an offset should be provided. Actions should not be assessed in isolation and consideration must be given to existing and future activities that may impact the subspecies to ensure conservation outcomes on a landscape scale are achieved.

Suitable offsets may include:

• Inclusion of unprotected areas of habitat critical to the survival in permanent nature reserves and provision of funding for the management of these areas. • Increase the extent and quality of habitat. • Restoration of native forest and woodlands adjacent to habitat critical to the survival to reduce edge effects. • Management of threats (see Threats) in and adjacent to habitat critical to the survival. • Other compensatory measures that will help address knowledge gaps to improve and maximise efficiency of the recovery of the species. No Critical Habitat as defined under section 207A of the EPBC Act has been identified or included in the Register of Critical Habitat.

Important populations Although there are substantial gaps or barriers between Kangaroo Island, Fleurieu Peninsula and Mt Lofty Ranges, and Flinders Ranges, Boulton et al. (2021) considers the subspecies to be panmictic, therefore being one subpopulation.

Threats Threats differ for Western Bassian Thrush on the mainland of South Australia and Kangaroo Island. On the mainland, much of the habitat has been cleared due to human activity. Current major threats for the subspecies include wildfire and inappropriate fire regimes, which could render the remaining habitat unsuitable. Additionally, reduced natural water flow due to increased water use and interception by dams also threatens the habitats that are further downstream. On Kangaroo Island much of the decline in the past decade is due to below-average

Threatened Species Scientific Committee 9 Zoothera lunulata halmaturina (Western Bassian Thrush) Consultation Document rainfall. Drought impacts on the subspecies are likely to be far higher if moist gullies become less productive (van Weenen pers comm).

Grazing and trampling by livestock and other herbivores further degrade habitats. Other potential threats include weed invasion, Phytophthora cinnamomi induced dieback, introduced predators such as cats and foxes, and competition with the Common Blackbird. With climate change, more variable and extreme climate anomalies will occur; this includes increased likelihood of wildfire, drought, flood, and storm.

Table 1 Threats impacting Western Bassian Thrush

Threat Status and severity a Evidence Fire Wildfire and inappropriate • Status: current & future Currently the most significant threat faced fire regimes • Confidence: known by Western Bassian Thrush is wildfire, as it causes direct catastrophic loss of habitat and • Consequence: severe individuals. Inappropriate fire regimes (i.e., • Trend: increasing too frequent fires) can make habitat • Extent: across the entire range unsuitable through: changes in composition and/or structure of vegetation; increased weed invasion following fire; loss of woody debris; reduction in leaf litter; and decline in invertebrate abundance (Spencer & Baxter 2006). Several fires in close succession can also prevent plants and animals from returning to an area (particularly in fragmented landscapes), and prevent soil seed set (Wilson & Bignall 2009). With 48 percent of their distribution burnt in the 2019/2020 fires (Legge et al. 2021), the subspecies has been identified as requiring urgent management intervention (Legge et al. 2020; Department of Agriculture, Water and the Environment unpublished data). Inappropriate fire regimes (i.e. too intense or too frequent) may also significantly impact the subspecies’ habitat, rendering areas unsuitable for a long periods of time or slowing the regeneration rate. Habitat loss and degradation Increased water use and • Status: current Change of natural flow regimes contribute to interception by dams and • Confidence: known habitat loss and degradation. Up to 80 other urban, industry and percent of water flows in the Adelaide-Mt agricultural use • Consequence: severe Lofty Ranges region have been diverted, • Trend: static significantly affecting downstream flows, • Extent: across part of its range and consequently the ecosystems downstream (Willson & Bignall 2009). Grazing and trampling by • Status: current Grazing by livestock and other herbivores livestock and native and • Confidence: known such as kangaroos (Marcropus spp.; Triggs introduced herbivores 2017; DEW 2018), feral pigs (Sus scrofa; • Consequence: moderate Commonwealth of Australia 2017a), deer • Trend: static (Dama dama; mainland only), rabbits • Extent: across part of its range (Oryctolagus cuniculus; mainland only; Commonwealth of Australia 2016a) and goats (Capra hircus; mainland only; DEWHA 2008c) may lead to further habitat degradation (Willson & Bignall 2009; Garnett et al. 2011). Larger species (e.g.,

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Threat Status and severity a Evidence cattle) may also affect the vegetation near ground level through compaction and trampling (Willson & Bignall 2009). Weed invasion • Status: current Invasive weeds are a potential minor threat • Confidence: inferred as they can change the availability of resources, reducing the quality of habitat. • Consequence: moderate Additionally, due to the flammability nature • Trend: unknown of the weeds, the risk and severity of wildfire • Extent: across part of its range is also increased (Willson & Bignall 2009; Invasive Plants and Animals Committee 2016). Phytophthora cinnamomi • Status: future Phytophthora cinnamomi is a plant pathogen induced dieback • Confidence: inferred which infects a wide range of native plants, altering structural and floristic • Consequence: moderate characteristics of the vegetation • Trend: unknown (Commonwealth of Australia 2018a; • Extent: across part of its range Hardham and Blackman 2018). Phytophthora is a potential threat that may impact the suitable habitat of Western Bassian Thrush, causing further habitat degradation. Climate change Increased likelihood of • Status: current & future Global temperatures are expected to rise by extreme events (i.e., fire, • Confidence: known up to 1.5 to 2 degrees Celsius by 2050 (IPCC heatwave, drought, flood, 2018). More frequent and extreme and storm) • Consequence: severe heatwaves are also expected across • Trend: increasing Australia. Rainfall patterns have also been • Extent: across the entire range affected, with record low rainfall recorded across parts of South Australia (BOM & CSIRO 2020). One of the major contributions to the pre- fire decline of birds on Kangaroo Island is the below-average rainfall as many sites had become unsuitable habitat from drying out (Garnett et al. 2011). The cumulative effect of the climate anomalies has led to, and will continue to increase the likelihood of extreme events such as wildfire, drought, flood and storms (BOM & CSIRO 2020), which will likely have a detrimental effect on the subspecies and their habitats. Predation and resource competition Predation by cats and foxes • Status: current Feral cats (Felis catus; Commonwealth of • Confidence: known Australia 2015a) and foxes (Vulpes vulpes; DEWHA 2008a) are both potential threats to • Consequence: moderate the subspecies on the main island (Willson & • Trend: static Bignall 2009). Kangaroo Island birds are • Extent: across the entire range only threatened by cats (Garnett et al. 2011). The threat of cats is also amplified by bushfires as they take advantage of recently burnt areas (McGregor et al. 2016), as they prefer to hunt in open habitats (McGregor et al. 2015). Management actions are in place. The current goal is to eradicate feral cats from Kangaroo Island by 2030 (Kangaroo Island Landscape Board 2015).

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Threat Status and severity a Evidence Predation by Common • Status: current Common Brushtail Possums (Trichorurus Brushtail Possums • Confidence: known vulpecula) on Kangaroo Island is potentially a minor predation threat to Western Bassian • Consequence: low Thrush nests and eggs (Garnett et al. 2011). • Trend: static • Extent: across parts of its range Resource competition with • Status: current Competition with the introduced Common Common Blackbird • Confidence: inferred Blackbird (Turdus merula) has been identified as a potential threat to Western • Consequence: low Bassian Thrush (Turner 2001; Garnett et al. • Trend: unknown 2011). However, more information is needed • Extent: across part of its range to assess the seriousness of this threat, and its potential impact on the subspecies. 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.

Each threat has been described in Table 1 in terms of the extent that it is operating on the species. The risk matrix (Table 3) provides a visual depiction of the level of risk being imposed by a threat and supports the prioritisation of subsequent management and conservation actions. In preparing a risk matrix, several factors have been taken into consideration, they are: the life stage they affect; the duration of the impact; and the efficacy of current management regimes, assuming that management will continue to be applied appropriately (Table 2). The risk matrix (Table 3) and ranking of threats has been developed in consultation with experts, community consultation and by using available literature.

Table 2 Risk prioritisation

Likelihood Consequences Not significant Minor Moderate Major Catastrophic Almost certain Low risk Moderate risk Very high risk Very high risk Very high risk Likely Low risk Moderate risk High risk Very high risk Very high risk Possible Low risk Moderate risk High risk Very high risk Very high risk Unlikely Low risk Low risk Moderate risk High risk Very high risk Unknown Low risk Low risk Moderate risk High risk Very high risk

Categories for likelihood are defined as follows: Almost certain – expected to occur every year Likely – expected to occur at least once every five years Possible – might occur at some time Unlikely – such events are known to have occurred on a worldwide basis but only a few times Rare or Unknown – may occur only in exceptional circumstances; OR it is currently unknown how often the incident will occur Categories for consequences are defined as follows: Not significant – no long-term effect on individuals or populations Minor – individuals are adversely affected but no effect at population level Moderate – population recovery stalls or reduces Major – population decreases Catastrophic – population extinction

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Table 3 Western Bassian Thrush risk matrix

Likelihood Consequences Not significant Minor Moderate Major Catastrophic Almost certain Increase water Wildfire & use and inappropriate interception fire regime Climate change Likely Predation by Predation by native species introduced species Grazing and Trampling Possible Competition Weed invasion with Common P. cinnamomi Blackbird induced diebacks Unlikely Unknown

Priority actions have then been developed to manage the threat particularly where the risk was deemed to be ‘very high’ or ‘high’. For those threats with an unknown or low risk outcome it may be more appropriate to identify further research or maintain a watching brief. Conservation and recovery actions Primary conservation outcome • Stable or increasing population numbers in the Mt Lofty Ranges and southern Flinders Ranges. • Stable or increasing population on Kangaroo Island Conservation and management priorities Wildfire & inappropriate fire regime • Develop a landscape-scale fire management strategy (considering both prescribed burning and fire suppression activities) with local authorities which considers the ecological needs of the subspecies. • Protect unburnt areas within or adjacent to recently burnt ground that may provide refuge. • Prioritise fire management activities to protect key sites ad those identified as most at risk from wildfires. • Ensure risk mitigation and suppression strategies consider prevention of population or habitat loss due to wildfires. • Apply adaptive management to inform future fire management plans and actions. • Consider impact of predation on species and implement control programs if populations are likely to be significantly impacted by predation after fire.

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Increased water use and interception by dams and other human activities • Liaise with state and local government in order to facilitate consideration in future development assessment policies and procedures. Grazing and introduced herbivores • Review site-specific risks during visits and surveys, and identify specific areas under threat. • Control feral pigs in habitat critical for the survival of the Western Bassian Thrush. • Kangaroo management protocols have been active in parts of South Australia (DEW 2018). Weed invasion and P. cinnamomi induced diebacks • Consult with local authorities to determine the appropriate methods and the effectiveness of weed control and implement recommendations. • Review risk of P. cinnamomi and monitor for sites of infection regularly. Predation and resource competition with introduced species • Continue ongoing feral predator control programs on the mainland. • Continue current Kangaroo Island Feral Cat Eradication Program (Kangaroo Island Landscape Board 2015), with the aim of eradicating feral cats on the island by 2030 (for updates and progress reports see Kangaroo Island Landscape Board (2020)). Stakeholder engagement/community engagement • Liaise with landholders to encourage their involvement in conservation. • Coordinate conservation efforts with other species affected by the 2019/2020 bushfires. Consider the development for a regional plan which includes all fire affected species in the region if appropriate. • Continue to generate awareness alongst landholders of potential impacts of stock grazing, as well as legislative requirements. Provide advice on management options, and facilitate installation of protective fencing where required to protect habitat from livestock. • Continue to raise awareness with the public on the impacts of P. cinnamomi and pest animals have on native vegetation and species. • Encourage the community to be involved with research and citizen science (e.g., submit sighting of birds and report signs of P. cinnamomi infection), on both mainland and Kangaroo Island. • Engage Indigenous landholders, where appropriate, to undertake conservation planning and in implementation activities. Survey and monitoring priorities • Monitor sites throughout the range to track changes in the overall population, changes at sites affected by wildfire, and the impacts of changes in threats and management of those threats. • Conduct surveys to identify sites which have been affected by dams and other human activities affecting the natural flow regimes.

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• Undertake survey to assess the effectiveness of the current control programs. Including threat abatement plans (TAPs) for: − Predation by feral cats (Commonwealth of Australia 2015b); − Predation by foxes (DEWHA 2008b); − Land degradation by rabbits (Commonwealth of Australia 2016b); − Land degradation by goats (DEWHA 2008d); and − Disease in natural ecosystems caused by P. cinnamomi (Commonwealth of Australia 2018b). Information and research priorities • Use climate modelling techniques to investigate potential impact of climate change on the subspecies’ trajectory, distribution, and habitat critical for survival. • Improve knowledge of the impact of wildfire have on the subspecies and their habitat, and their ability to re-colonise recently burnt areas. • Conduct further research to identify the main threats to the key sites and the subspecies, and the techniques to manage them. • Further research should be conducted to characterise favoured habitat. • When sufficient data is available, undertake a population viability analysis. Recovery plan decision 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. Links to relevant implementation documents Threat Abatement Plans: • Threat abatement plan for competition and land degradation by unmanaged goats (DEWHA 2008d) • Threat abatement plan for competition and land degradation by rabbits (Commonwealth of Australia 2016b) • Threat abatement plan for predation, habitat degradation, competition and disease transmission by feral pigs (Sus scrofa) (Commonwealth of Australia 2016b) • Threat abatement plan for disease in natural ecosystems caused by Phytophthora cinnamomi (Commonwealth of Australia 2018b) • Threat abatement plan for predation by European red fox (DEWHA 2008b) • Threat abatement plan for predation by feral cats (Commonwealth of Australia 2015b) Other relevant implementation documents: • Australian Weeds Strategy 2017-2027 (Invasive Plants and Animals Committee 2016). • Feal cat eradication on Kangaroo Island 2015-2030 PROSPECTUS (Kangaroo Island Landscape Board 2015).

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• Kangaroo Island biosecurity strategy 2017-2027 (Triggs 2017). • Kangaroo Island Feral Cat Eradication Program (Kangaroo Island Landscape Board 2020). Conservation Advice and Listing Assessment references Baxter C (1995). An Annotated List of Birds of Kangaroo Island. Department of Environment and Natural Resources, Kingscote.

Bird JP, Martin R, Akçakaya HR, Gilroy J, Burfield IJ, Garnett ST, Symes A, Taylor J, ¸Sekercio˘glu, ÇH & Butchart SHM (2020) Generation lengths of the world’s birds and their implications for extinction risk. Conservation Biology 34, 5, 1252-1261.

BOM & CSIRO (2020) State of the Climate 2020. CIRO, Acton.

Boulton RL, Hunt TJ, Ireland LJ & Thomas JL (2020) Kangaroo Island Rapid Bird Assessments, February 2020. BirdLife Australia, Melbourne.

Boulton RL, Paton DC, Hermann K, Ehmke G & Garnett ST (2021) Western Bassian Thrush Zoothera lunulata halmaturina. In The Action Plan for Australian Birds 2020. (Eds ST Garnett and GB Baker) pp. XXX–XXX. CSIRO Publishing, Melbourne.

Commonwealth of Australia (2015a). Background document for the Treat abatement plan for predation by feral cats. Department of Environment and Energy, Canberra.

Commonwealth of Australia (2015b). Treat abatement plan for predation by feral cats. Department of Environment and Energy, Canberra.

Commonwealth of Australia (2016a). Background document to the Threat abatement plan for competition and land degradation by rabbits. Department of Environment and Energy, Canberra.

Commonwealth of Australia (2016b). Threat abatement plan for competition and land degradation by rabbits. Department of Environment and Energy, Canberra.

Commonwealth of Australia (2017a) Background Document - Threat abatement plan for predation, habitat degradation, competition and disease transmission by feral pigs (Sus scrofa). Department of the Environment and Energy, Canberra.

Commonwealth of Australia (2017b) Threat abatement plan for predation, habitat degradation, competition and disease transmission by feral pigs (Sus scrofa). Department of the Environment and Energy, Canberra.

Commonwealth of Australia (2018a). Background document: Threat abatement plan for disease in natural ecosystems caused by Phytophthora cinnamomi. Department of the Environment and Energy, Canberra.

Commonwealth of Australia (2018b). Threat abatement plan for disease in natural ecosystems caused by Phytophthora cinnamomi. Department of the Environment and Energy, Canberra.

Department for Environment and Water (DEW) (2018). State of evidence: Kangaroos and their management in South Australia. DEW Technical report 2018/11. DEW, Adelaide.

Threatened Species Scientific Committee 16 Zoothera lunulata halmaturina (Western Bassian Thrush) Consultation Document

Department of Environment and Water (DEW) (2020) Kangaroo Island Bushfire 2019-20. DEW, Adelaide. Available at: https://arcg.is/0zSeWK.

Department of the Environment, Water, Heritage and the Arts (DEWHA) (2008a). Background document for the threat abatement plan for predation by the European red fox. DEWHA, Canberra.

DEWHA (2008b). Threat abatement plan for predation by the European red fox. DEWHA, Canberra.

DEWHA (2008c). Background document for the threat abatement plan for competition and land degradation by unmanaged goats. DEWHA, Canberra.

DEWHA (2008d). Threat abatement plan for competition and land degradation by unmanaged goats. DEWHA, Canberra.

Edinton JSL (1983) White's Thrush: Some aspects of its ecology and feeding behaviour. South Australian Ornithologist 29, 3, 57-59.

Ford J (1983) Speciation in the Ground-Thrush complex Zoothera dauma in Australia. Emu 83, 3, 141-151.

Garnett ST (1992) The Action Plan for Australian Birds. Australian National Parks and Wildlife Service, Canberra.

Garnett ST, Szabo JK & Dutson G (2011) The Action Plan for Australian Birds 2010. CSIRO Publishing, Collingwood.

Hardham AR & Blackman LM (2018) Phytophthora cinnamomi. Molecular Plant Pathology 19, 2, 260-285.

Higgins PJ, Peter JM & Cowling SJ (Eds) (2006). Handbook of Australian, New Zealand and Antarctic Birds. Volume 7 Boatbill to Starlings, Part B Dunnock to Starlings. Oxford University Press, Melbourne.

IPCC (2018). Summary for Policymakers. In: Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty. World Meteorological Organization, Geneva.

Kangaroo Island Landscape Board (2015) Feral cat eradication on Kangaroo Island 2015-2030 PROSPECTUS. Kangaroo Island Landscape Board & Kangaroo Island Council, South Australia.

Kangaroo Island Landscape Board (2020) Kangaroo Island Feral Cat Eradication Program. Viewed 04 November 2020. Available at: https://landscape.sa.gov.au/ki/plants-and- animals/pest-animals/Kangaroo-Island-Feral-Cat-Eradication-Program.

Legge S, Woinarski J, Garnett S, Geyle H, Lintermans M, Nimmo D, Rumpff L, Scheele B, Southwell D, Ward M & Whiterod N (2021) Estimation of population declines caused by the 2019-20 fires, for conservation status assessment. Unpublished report prepared for the Department of Agriculture, Water and the Environment, Canberra.

Threatened Species Scientific Committee 17 Zoothera lunulata halmaturina (Western Bassian Thrush) Consultation Document

Legge S, Woinarski J, Garnett S, Nimmo D, Scheele B, Lintermans M, Mitchell N, Whiterod N & Ferris J (2020). Rapid analysis of impacts of the 2019-20 fires on animal species, and prioritisation of species for management response. Report prepared for the Wildlife and Threatened Species Bushfire Recovery Expert Panel, Department of Agriculture, Water and the Environment, Canberra.

McGregor HW, Legge S, Jones ME & Johnson CN (2015) Feral Cats Are Better Killers in Open Habitats, Revealed by Animal-Borne Video. PLoS ONE 10, 8. doi:10.1371/journal. pone.0133915.

McGregor HW, Legge S, Jones ME & Johnson CN (2016) Extraterritorial hunting expeditions to intense fire scars by feral cats. Scientific Reports 6. https://doi.org/10.1038/srep22559

Menkhorst P, Rogers D, Clarke R, Davies J, Marsack P & Franklin K (2017). The Australian Bird Guide. CSIRO Publishing, Clayton South.

Paton DC, Carpenter G & Sinclair RG (1994) A second bird atlas of the Adelaide region. Part 1: Changes in the distribution of birds: 1974-1975 vs. 1984-1985. South Australian Ornithologist 31, 7, 151-193.

Pizzey G and Knight F (1997). The Field Guide to the Birds of Australia. Angus and Robertson, Sydney, Australia.

Possingham ML & Possingham HP (2008) Species richness and abundance of birds in Mt Lofty Ranges Gum woodland habitat: Year 2000 survey. South Australian Ornithologist 35, 3&4, 69-85.

Schodde R & Mason IJ (1999). The Directory of Australian Birds: Passerines. CSIRO Publishing, Melbourne.

Spencer R & Baxter GS (2006) Effects of fire on the structure and composition of open eucalypt forests. Austral Ecology, 31, 5, 638-646.

Triggs AS (2017). Biosecurity Strategy for Kangaroo Island 2017-2027. Department of Environment, Water and Natural Resources, South Australia.

Todd S & Maurer G (2020) Bushfire recovery where it matters most. Impacts and actions in Key Biodiversity Areas affected by the 2019/20 Bushfire Crisis. BirdLife Australia, Melbourne.

Turner MS (2001). Conserving Adelaide's Biodiversity: Resources. Urban Forest Biodiversity Program, Adelaide.

Ward M, Tulloch AIT, Radford JQ, Williams BA, Reside AE, Macdonald SL, Mayfield HJ, Maron M, Possingham HP, Vine SJ, O'Connor JL, Massingham EJ, Greenville AC, Woinarski JCZ, Garnett ST, Lintermans M, Scheele BC, Carwardine J, Nimmo DG, Lindenmayer DB, Kooyman RM, Simmonds JS, Sonter LJ & Watson JEM (2020). Impact of 2019-2020 mega-fires on Australian faun!a habitat. Nature Ecology & Evolution. https://doi.org/10.1038/s41559-020-1251-1.

Willson A & Bignall J (2009). Regional Recovery Plan for Threatened Species and Ecological Communities of Adelaide and the Mount Lofty Ranges, South Australia. Department for Environment and Heritage, South Australia.

Threatened Species Scientific Committee 18 THREATENED SPECIES SCIENTIFIC COMMITTEE

Established under the Environment Protection and Biodiversity Conservation Act 1999

The Threatened Species Scientific Committee finalised this assessment on DD Month Year. Attachment A: Listing Assessment for Zoothera lunulata halmaturina Reason for assessment This assessment follows prioritisation of a nomination from the public/TSSC.

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 4 includes the key assessment parameters used in the assessment of eligibility for listing against the criteria.

Table 4 Key assessment parameters

Metric Estimate used Minimum Maximum Justification in the plausible plausible assessment value value Number of mature 3,300 770 4,700 The population estimate of Western individuals Bassian Thrushes on Kangaroo Island (2,800) is based on average densities recorded across their range (Higgins et al. 2006), the area of vegetation types likely to have been occupied before the 2019/2020 fire, maps of fire severity in 2019/2020 within the pre fire range and initial assumptions about mortality at different fire severity classes (fire severity low: 10 percent; medium: 30 percent; high 80 percent; very high: 100 percent). Two months after the fire, it was detected in just one of 145 unburnt fragments within the burnt area and in none of 35 plots outside it (Boulton et al. 2020). The population estimate on the mainland, which was unaffected by fire, is likely to be higher than the estimate of 100 made nearly 15 years ago and which was likely to be an underestimate due to low detectability without dedicated surveys (Possingham & Possingham 2008; Boulton et al. (2020). The current estimate is that there are 300–500 birds throughout the Fleurieu Peninsula and Mount Lofty Ranges, with a north-south decline in density (RL Boulton unpublished data cited in Boulton et al. 2021).

Threatened Species Scientific Committee 19 Zoothera lunulata halmaturina (Western Bassian Thrush) Consultation Document

A decade ago, 100 mature individuals were estimated to live in the southern Flinders Ranges (Garnett et al. 2011), but the population has probably at least halved. There have been no recent records and over 90 percent of the forest block containing Telowie Gorge was burnt in 2014, where most birds could be found previously. Based on these assumptions, 56 percent of the total population was lost in the 2019/2020 fires, with a spread of estimates from 39 percent to 71 percent depending on the fire related mortality assumed under different scenarios. This decline is on top of a more gradual continuing decline on the mainland (Boulton et al. 2021). Trend Declining Boulton et al. (2021) Generation time 3.88 2.94 5.37 Bird et al. (2020) (years) Extent of 14,700 km2 14,200 km2 45,000 km2 Maximum EOO include records old occurrence records that have not been recorded since 2000 (Boulton et al. 2021). Trend Contracting Boulton et al. (2021) Area of 510 km2 352 km2 670 km2 AOO is estimated with the area of Occupancy habitat on Kangaroo island thought likely to have been supporting birds immediately after the 2019/2020 bushfires, plus the 88 2x2 km squares in which they have been seen on the mainland in the last decade. The minimum include only 2x2 squares that were unburnt, and the maximum is the area of suitable habitat before the fires (Boulton et al. 2021). About 85 percent of suitable habitat on Kangaroo Island was burnt in the 2019/2020 bushfires (K. Hermann unpublished data cited in Boulton et al. 2021). Trend Contracting Boulton et al. (2021) Number of 1 1 3 Boulton et al. (2021) subpopulations

Trend Stable Boulton et al. (2021) Basis of The population is assumed to be panmictic but there are substantial gaps or barriers assessment of between Kangaroo Island, Fleurieu peninsula/Mt Lofty Ranges, and Flinders Ranges subpopulation (Boulton et al. 2021). number

No. locations >10 Boulton et al. (2021)

Trend Not calculated Boulton et al. (2021)

Threatened Species Scientific Committee 20 Zoothera lunulata halmaturina (Western Bassian Thrush) Consultation Document

Basis of The spatial nature of the threats, although stochastic in space and time, is such that there are assessment of >10 geographically or ecologically distinct areas where a single fire could affect all location number individuals of the subspecies present within a period of three generations. The geographic position of unburnt locations will vary between fires, but there are always likely to be >10 (Boulton et al. 2021). Fragmentation Not severely fragmented (Boulton et al. 2021).

Fluctuations Not subject to extreme fluctuations in EOO, AOO, number of subpopulations, locations or mature individuals – no parameter was changed by an order of magnitude by the 2019/20 fire (Boulton et al. 2021).

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 ≥ 90% ≥ 70% ≥ 50%

A2, A3, A4 ≥ 80% ≥ 50% ≥ 30%

A1 Population reduction observed, estimated, inferred or suspected in the (a) direct 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 Eligible under Criterion 1 A2c for listing as Endangered

The Western Bassian Thrush is endemic to South Australia, occurring on Kangaroo Island and adjacent mainland. Kangaroo Island was heavily impacted during the 2019/2020 bushfires, where around half of the island was burnt (DEW 2020; Todd & Maurer 2020). This is especially detrimental as the majority of the population occurs on Kangaroo Island (Garnett et al. 2011). Both the extent of occurrence (EOO) and are of occupancy (AOO) are contracting (Boulton et al. 2021). A population decline of 56 percent has been estimated as a result of the 2019/2020 bushfires (range 39 – 71 percent; Boulton et al. 2021). The subspecies has undergone a severe reduction in numbers over three generations (11.64 years for this assessment), and the reduction and the cause of reduction has not ceased. Longer term (i.e. beyond three generation length) declines on the mainland (i.e. Mt Lofty Ranges and Fleurieu Peninsula) could also be

Threatened Species Scientific Committee 21 Zoothera lunulata halmaturina (Western Bassian Thrush) Consultation Document observed, where the subspecies is thought to have declined by 30 percent by 2000 (Possingham & Possingham 2008).

The data presented above appear to demonstrate that the subspecies is eligible for listing as Endangered under this criterion. However, the purpose of this consultation document is to elicit additional information to better understand the subspecies’ 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

The EOO and AOO for the subspecies are 14,700 km2 (range 14,200–45,000 km2) and 510 km2 (range 352–670 km2) respectively (Boulton et al. 2021). The maximum EOO is based on all observance records, including older records from Wirrabara Forest Reserve, Telowie Gorge Conservation park and Mt Remarkable National park, where there have been no documented record since 2000, resulting in a significantly larger maximum EOO (Schodde & Mason 1999; BirdLife Australia 2020; Cornell Lab 2020 cited in Boulton et al. 2021). The AOO is the area of habitat on Kangaroo Island thought likely to have been supporting birds immediately after the 2019/2020 bushfires plus the 88 2x2 km squares in which birds have been seen on the mainland in the last decade (Boulton et al. 2021). Both EOO and AOO for the subspecies is thought to be contracting. The subspecies is estimated to occur at more than 10 locations and is not severely fragmented. The subspecies is not subject to extreme fluctuations in EOO, AOO, number of subpopulations, locations or mature individuals. No parameter was changed by an order of magnitude by the 2019/2020 fire (Boulton et al. 2021). Although the geographic distribution is limited, there are insufficient data making the species’ geographic distribution precarious for its survival.

Threatened Species Scientific Committee 22 Zoothera lunulata halmaturina (Western Bassian Thrush) Consultation Document

The data presented above appear to demonstrate the subspecies is not eligible for listing under this criterion. However, the purpose of this consultation document is to elicit additional information to better understand the subspecies’ 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 Eligible under Criterion 3 C1a(ii)+C2a(ii) for listing as Vulnerable

The total number of mature individuals is estimated to be 3,300 (range 770–4,700) (Boulton et al. 2021). It is estimated that 56 percent of the total population was lost in the 2019/2020 bushfires, and a continuing decline is projected. The subspecies’ geographic distribution is precarious for its survival as all individuals are considered to be located in one subpopulation. The subspecies is not subject to extreme fluctuations in the number of mature individuals.

The data presented above appear to demonstrate that the subspecies is eligible to be listed as Vulnerable under this criterion. However, the purpose of this consultation document is to elicit additional information to better understand the subspecies’ 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.

Threatened Species Scientific Committee 23 Zoothera lunulata halmaturina (Western Bassian Thrush) Consultation Document

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 Not eligible

The total population size for the subspecies is estimated to be 3,300 mature individuals (range 770–4,700). The estimate is based on:

i) Kangaroo Island birds; ii) Fleurieu Peninsula and Mt Lofty Ranges birds; and iii) Flinders Ranges birds. An estimated 2,800 individuals are located on Kangaroo Island, based on average densities recorded across their ranges (Higgins et al. 2006), the area of vegetation types likely to have been occupied before the 2019/2020 fire, maps of fire severity in 2019/2020 within the pre-fire range and initial assumptions about mortality at different fire severity classes (fire severity low: 10 percent; medium: 30 percent; high 80 percent; very high: 100 percent).

The number of birds around the Fleurieu Peninsula and Mt Lofty Ranges was unaffected by 2019/2020 fires, and it is likely that there are a higher number of birds persisting in the area than the 100 birds estimated nearly 15 years ago (Possingham & Possingham 2008; Boulton et al. 2020). The Action Plan for Australian Birds 2020 estimates there to be 300–500 mature individuals in the Fleurieu Peninsula and Mt Lofty Ranges (Boulton et al. 2021).

In 2010, Garnett et al. (2011) estimated 100 birds in the southern Flinders Ranges region, but the population is thought to have at least halved with no recent records and with over 90 percent of the forest block containing Telowie Gorge having burnt in 2014 (Boulton et al. 2021).

Threatened Species Scientific Committee 24 Zoothera lunulata halmaturina (Western Bassian Thrush) Consultation Document considered to be tentative at this stage, as it may be changed as a result of responses to this consultation process.

Criterion 5 Quantitative analysis

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

≥ 50% in 10 years or 3 ≥ 20% in 20 years or Indicating the probability of generations, 5 generations, ≥ 10% in 100 years extinction in the wild to be: whichever is longer whichever is longer (100 years max.) (100 years max.)

Criterion 5 evidence Insufficient data to determine eligibility

Population viability analysis appears not to have been undertaken, and therefore there is insufficient data to demonstrate if the subspecies is eligible for listing under this criterion. However, the purpose of this consultation document is to elicit additional information to better understand the subspecies’ 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.

Adequacy of survey The survey effort has been considered adequate and there is sufficient scientific evidence to support the assessment.

Threatened Species Scientific Committee 25 Zoothera lunulata halmaturina (Western Bassian Thrush) Consultation Document

CONSULTATION QUESTIONS FOR Zoothera lunulata halmaturina (Western Bassian Thrush)

SECTION A - GENERAL

1. Is the information used to assess the nationally threatened status of the species/subspecies robust? Have all the underlying assumptions been made explicit? Please provide justification for your response.

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

3. Have you been involved in previous state, territory or national assessments of this species/subspecies? If so, in what capacity?

PART 1 – INFORMATION TO ASSIST LISTING ASSESSMENT

SECTION B DO YOU HAVE ADDITIONAL INFORMATION ON THE ECOLOGY OR BIOLOGY OF THE SPECIES/SUBSPECIES? (If no, skip to section C)

Biological information

4. Can you provide any additional or alternative references, information or estimates on longevity, average life span and generation length?

5. Do you have any additional information on the ecology or biology of the species/subspecies not in the current advice?

SECTION C ARE YOU AWARE OF THE STATUS OF THE TOTAL NATIONAL POPULATION OF THE SPECIES/SUBSPECIES? (If no, skip to section D)

Population size

6. Has the survey effort for this taxon been adequate to determine its national adult population size? If not, please provide justification for your response.

7. Do you consider the way the population size has been derived to be appropriate? Are there any assumptions and unquantified biases in the estimates? Did the estimates measure relative or absolute abundance? Do you accept the estimate of the total population size of the species/subspecies? If not, please provide justification for your response.

8. If not, can you provide a further estimate of the current population size of mature adults of the species/subspecies (national extent)? Please provide supporting justification or other information.

If, because of uncertainty, you are unable to provide a single number, you may wish to provide an estimated range. If so, please choose one of the ranges suggested in the table below of possible species/subspecies numbers, and also choose the level of confidence you have in this estimate:

Number of mature individuals is estimated to be in the range of: □ 1–1,000 □ 1,001–2,500 □ 2,501 – 5,000 □ >5,000 □ >10,000

Threatened Species Scientific Committee 26 Zoothera lunulata halmaturina (Western Bassian Thrush) Consultation Document

Level of your confidence in this estimate: □ 0–30% - low level of certainty/ a bit of a guess/ not much information to go on □ 31–50% - more than a guess, some level of supporting evidence □ 51–95% - reasonably certain, information suggests this range □ 95–100% - high level of certainty, information indicates quantity within this range □ 99–100% - very high level of certainty, data are accurate within this range

SECTION D ARE YOU AWARE OF TRENDS IN THE OVERALL POPULATION OF THE SPECIES/SUBSPECIES? (If no, skip to section E)

9. Does the current and predicted rate of decline used in the assessment seem reasonable? Do you consider that the way this estimate has been derived is appropriate? If not, please provide justification of your response.

Evidence of total population size change

10. Are you able to provide an estimate of the total population size during the late 2000s (at or soon after the start of the most recent three generation period)? Please provide justification for your response.

Number of mature individuals is estimated to be in the range of: □ 1–1,000 □ 1,001–2,500 □ 2,501 – 5,000 □ >5,000 □ >10,000

11. Are you able to comment on the extent of decline in the species/subspecies’ total population size over the last approximately 13 years (i.e., three generations)? Please provide justification for your response.

If, because of uncertainty, you are unable to provide an estimate of decline, you may wish to provide an estimated range. If so, please choose one of the ranges suggested in the table below of ranges of decline, and also choose the level of confidence you have in this estimated range.

Threatened Species Scientific Committee 27 Zoothera lunulata halmaturina (Western Bassian Thrush) Consultation Document

Decline estimated to be in the range of: □ 1–30% □31–50% □51–80% □81–100% □90–100%

Level of your confidence in this estimated decline: □ 0–30% - low level of certainty/ a bit of a guess/ not much information to go on □ 31–50% - more than a guess, some level of supporting evidence □ 51–95% - reasonably certain, suggests this range of decline □ 95–100% - high level of certainty, information indicates a decline within this range □ 99–100% - very high level of certainty, data are accurate within this range

12. Please provide (if known) any additional evidence which shows the population is stable, increasing or declining.

SECTION E ARE YOU AWARE OF INFORMATION ON THE TOTAL RANGE OF THE SPECIES/SUBSPECIES? (If no, skip to section F)

Current Distribution/range/extent of occurrence, area of occupancy

13. Does the assessment consider the entire geographic extent and national extent of the species/subspecies? If not, please provide justification for your response.

14. Has the survey effort for this species/subspecies been adequate to determine its national distribution? If not, please provide justification for your response.

15. Is the distribution described in the assessment accurate? If not, please provide justification for your response and provide alternate information.

16. Do you agree that the way the current extent of occurrence and/or area of occupancy have been estimated is appropriate? Please provide justification for your response.

17. Can you provide estimates (or if you disagree with the estimates provided, alternative estimates) of the extent of occurrence and/or area of occupancy.

If, because of uncertainty, you are unable to provide an estimate of extent of occurrence, you may wish to provide an estimated range. If so, please choose one of the ranges suggested in the table below of ranges of extent of occurrence, and also choose the level of confidence you have in this estimated range.

Current extent of occurrence is estimated to be in the range of: □ <10,000 km2 □ 10,001 – 25,000 km2 □ 25,001 – 50,000 km2 □ >50,000 km2

Level of your confidence in this estimated extent of occurrence □ 0–30% - low level of certainty/ a bit of a guess/ not much data to go on □ 31–50% - more than a guess, some level of supporting evidence

Threatened Species Scientific Committee 28 Zoothera lunulata halmaturina (Western Bassian Thrush) Consultation Document

□ 51–95% - reasonably certain, data suggests this range of decline □ 95–100% - high level of certainty, data indicates a decline within this range □ 99–100% - very high level of certainty, data is accurate within this range

If, because of uncertainty, you are unable to provide an estimate of area of occupancy, you may wish to provide an estimated range. If so, please choose one of the ranges suggested in the table below of ranges of area of occupancy, and also choose the level of confidence you have in this estimated range.

Current area of occupancy is estimated to be in the range of: □ <100 km2 □ 101 – 250 km2 □ 251 – 500 km2 □ >500 km2 □ >1,000 km2

Level of your confidence in this estimated extent of occurrence: □ 0–30% - low level of certainty/ a bit of a guess/ not much data to go on □ 31–50% - more than a guess, some level of supporting evidence □ 51–95% - reasonably certain, data suggests this range of decline □ 95–100% - high level of certainty, data indicates a decline within this range □ 99–100% - very high level of certainty, data is accurate within this range

SECTION F ARE YOU AWARE OF TRENDS IN THE TOTAL RANGE OF THE SPECIES/SUBSPECIES? (If no, skip to section G)

Past Distribution/range/extent of occurrence, area of occupancy

18. Do you consider that the way the historic distribution has been estimated is appropriate? Please provide justification for your response.

19. Can you provide estimates (or if you disagree with the estimates provided, alternative estimates) of the former extent of occurrence and/or area of occupancy.

If, because of uncertainty, you are unable to provide an estimate of past extent of occurrence, you may wish to provide an estimated range. If so, please choose one of the ranges suggested in the table below of ranges of past extent of occurrence, and also choose the level of confidence you have in this estimated range.

Past extent of occurrence is estimated to be in the range of: □ <10,000 km2 □ 10,001 – 25,000 km2 □ 25,001 – 50,000 km2 □ >50,000 km2

Threatened Species Scientific Committee 29 Zoothera lunulata halmaturina (Western Bassian Thrush) Consultation Document

□ 95–100% - high level of certainty, data indicates a decline within this range □ 99–100% - very high level of certainty, data is accurate within this range

If, because of uncertainty, you are unable to provide an estimate of past area of occupancy, you may wish to provide an estimated range. If so, please choose one of the ranges suggested in the table below of ranges of past area of occupancy, and also choose the level of confidence you have in this estimated range:

Past area of occupancy is estimated to be in the range of: □ <100 km2 □ 101 – 250 km2 □ 251 – 500 km2 □ >500 km2 □ >1,000 km2

Level of your confidence in this estimated extent of occurrence: □ 0–30% - low level of certainty/ a bit of a guess/ not much data to go on □ 31–50% - more than a guess, some level of supporting evidence □ 51–95% - reasonably certain, data suggests this range of decline □ 95–100% -high level of certainty, data indicates a decline within this range □ 99–100% - very high level of certainty, data is accurate within this range

PART 2 – INFORMATION FOR CONSERVATION ADVICE ON THREATS AND CONSERVATION ACTIONS

SECTION G DO YOU HAVE INFORMATION ON THREATS TO THE SURVIVAL OF THE SPECIES/SUBSPECIES? (If no, skip to section H)

20. Do you consider that all major threats have been identified and described adequately?

21. To what degree are the identified threats likely to impact on the species/subspecies in the future?

22. Are the threats impacting on different populations equally, or do the threats vary across different populations?

23. Can you provide additional or alternative information on past, current or potential threats that may adversely affect the species/subspecies at any stage of its life cycle?

24. Can you provide supporting data/justification or other information for your responses to these questions about threats?

SECTION H DO YOU HAVE INFORMATION ON CURRENT OR FUTURE MANAGEMENT FOR THE RECOVERY OF THE SPECIES/SUBSPECIES? (If no, skip to section I)

25. What planning, management and recovery actions are currently in place supporting protection and recovery of the species/subspecies? To what extent have they been effective?

Threatened Species Scientific Committee 30 Zoothera lunulata halmaturina (Western Bassian Thrush) Consultation Document

26. Can you recommend any additional or alternative specific threat abatement or conservation actions that would aid the protection and recovery of the species/subspecies?

27. Would you recommend translocation (outside of the species’ historic range) as a viable option as a conservation actions for this species/subspecies?

SECTION I DO YOU HAVE INFORMATION ON STAKEHOLDERS IN THE RECOVERY OF THE SPECIES/SUBSPECIES?

28. Are you aware of other knowledge (e.g., traditional ecological knowledge) or individuals/groups with knowledge that may help better understand population trends/fluctuations, or critical areas of habitat?

29. Are you aware of any cultural or social importance or use that the species/subspecies has?

30. What individuals or organisations are currently, or potentially could be, involved in management and recovery of the species/subspecies?

31. How aware of this species/subspecies are land managers where the species/subspecies is found?

32. What level of awareness is there with individuals or organisations around the issues affecting the species/subspecies?

a. Where there is awareness, what are these interests of these individuals/organisations?

b. Are there populations or areas of habitat that are particularly important to the community?

PART 3 – ANY OTHER INFORMATION

33. Do you have comments on any other matters relevant to the assessment of this species/subspecies?

Threatened Species Scientific Committee 31