Spring Hill Targeted Microbat Survey

August 2017 prepared for TM Gold Pty Ltd

Contact Information Details

Organisation Northern Resource Consultants Pty Limited Contact Person Marty Costello Phone 07 4772 6500 Email [email protected] Mail 12 Cannan Street, South Townsville QLD, 4810 ABN 55 126 894 693

Document Control Details including responsible party and date

Draft report DH – 15 August 2017 Version 2 ST – reviewed 16 August 2017

Limitations and Qualifications Client: TM Gold Pty Ltd Prepared by Northern Resource Consultants (NRC)

This document has been prepared for the sole and exclusive use of TM Gold Pty Ltd (the Client). It may not be updated, amended, distributed or disclosed to any third party without the express written consent of Northern Resource Consultants (NRC). NRC makes no representation or warranty (whether express or implied), undertakes no duty and accepts no responsibility to any third party who may use or rely upon this document or any part of it. If any reliance is placed on this document, or any part of it, by any third party, NRC hereby disclaims any and all liability for such reliance. This document has been prepared on the basis of instructions provided to NRC by the Client. It is limited by the scope of those instructions and any qualifications which have been agreed between NRC and the Client or otherwise communicated to the Client prior to the date of this document (Date), whether verbally or in writing. The scope of those instructions may have been limited by a range of factors including, but not limited to, time, budget and access constraints. Any statements, opinions, conclusions, advice or recommendations contained in this document (Conclusions) must be read and relied upon only in the context of the document as a whole. This document is current as at the Date and the Conclusions may differ if further investigation, observation or analysis is undertaken by NRC or if any data, information, designs, plans or analysis (Data) relied upon by NRC when preparing this document is subsequently found to be incorrect or incomplete. Unless otherwise specified in this document, NRC is not responsible for revising or updating this document if additional Data is obtained after the Date, through further investigation, observation, analysis or otherwise, which indicates that the content of this document, including any Conclusion, is inaccurate or incomplete. Unless otherwise stated in this document, where Data used in this document, or upon which the Conclusions were based, was obtained from the Client or any third party, the accuracy and completeness of that Data has not been independently verified by NRC. Such Data was used in good faith and NRC is not responsible for its quality, accuracy or completeness, nor does NRC warrant or represent that such Data is accurate, up-to-date or complete. Neither the Conclusions nor any part of this document constitutes legal advice, nor do they represent the opinions of the government or regulatory agencies responsible for the administration of the relevant legislation or regulatory regimes.

Contents

Introduction ...... 1

1. Purpose of this report ...... 1 2. Spring Hill project area ...... 2 2.1 Historical workings ...... 2 2.2 Recent activities ...... 2 2.3 Proposed activities ...... 3 3. Baseline ecological surveys ...... 3 4. Literature review ...... 4 4.1 Ghost bat ...... 4 4.2 Northern leaf-nosed bat ...... 8 4.3 Orange leaf-nosed bat ...... 8

Methods ...... 10

1. Overall approach ...... 10 2. Habitat assessment ...... 10 2.1 Desktop analysis ...... 10 2.2 Field survey ...... 10 3. Stope-watches ...... 12 4. Echolocation recordings ...... 13 5. Limitations ...... 14

Results ...... 15

1. Habitat assessment ...... 15 2. Stope-watches ...... 16 3. Echolocation recordings ...... 17 4. Conservation-significant species ...... 18 4.1 Ghost bat ...... 18 4.2 Northern leaf-nosed bat ...... 20

4.3 Orange leaf-nosed bat ...... 20

Discussion ...... 21

1. General habitat significance ...... 21 2. Vandalism at Spring Hill ...... 21 3. Conservation-significant species ...... 22 3.1 Ghost bat ...... 22 3.2 Northern leaf-nosed bat ...... 27 3.3 Orange leaf-nosed bat ...... 27

Impact Management ...... 29

1. Mine project design ...... 29 1.1 Site layout ...... 29 1.2 Timing and sequencing...... 29 1.3 Rehabilitation ...... 30 1.4 Education ...... 30 2. Monitoring program ...... 31

References ...... 33

List of Tables

Table 1: Stopes-watch record ...... 13 Table 2: Stopes where echolocation recording was conducted...... 14 Table 3: Number of bats counted leaving different stopes in the evening ...... 16 Table 4: Comparison of Ghost bat counts from visual observations and echolocation calls at stope 13 on 25 July 2017 ...... 19

List of Figures

Figure 1: Profile of microbat habitat in the Northern Territory showing different roost areas (from Churchill, 2008) ...... 6

List of Appendices

Appendix A Maps Appendix B Microbat Call Interpretation Report Appendix C Spring Hill Microbat Habitat Assessment

Introduction

1. Purpose of this report

Spring Hill is located approximately 25km north of Pine Creek in an area of mixed eucalypt woodland on steep ridges to undulating hills. Gold mining has occurred sporadically in this area for the past 130 years. The current proposed Spring Hill gold mine project area contains numerous old mine workings that provide habitat for cave-dependent bat species. Baseline ecological surveys have identified that some conservation-significant bat species occupy the habitat features within the project area. The baseline studies to date have focussed on presence/absence data to identify the presence of conservation-significant bat species. This report has the following objectives with respect to a targeted microbat survey conducted in July 2017: - Describe the Spring Hill project area, and the relevant habitat features and historical disturbances. - Detail the relevant outcomes of known baseline ecological surveys conducted to date. - Provide a literature review on the relevant biology and ecology of conservation-significant bat species relevant to the project area. - Detail the methodology and outcomes of a targeted assessment of historical mine workings as habitat for bat species. - Describe the quality of these habitats as roosting sites, particularly for locally occurring conservation-significant bat species. - Detail the methodology and outcomes of a targeted assessment of the populations of bat species occupying these habitats. - Describe preliminary insights into relevant conservation-significant microbat population dynamics and behaviour for impact assessment and management. - Provide recommendations for minimising impacts of the Spring Hill project on local bat populations, particularly those listed as threatened under Territory and Commonwealth legislation. The following generic terms are used throughout this report, and are defined here to provide a more specific context for their use and interpretation. - The term ‘microbat’ follows the use of this term by Churchill (2008) and refers to all bat species other than those within the family Pteropodidae (the megabats or fruit bats). - The term ‘conservation-significant’ refers to species, or populations of a species, that occur within the Northern Territory and are listed as threatened or near threatened under Territory or Commonwealth environmental legislation. - The term ‘stope’ refers to the opening of a below-surface historical mining excavation. Typically, the exact nature of the excavation could not be recorded due to safe-access limitations, and therefore this term is applied generally to the opening of all below-surface features.

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2. Spring Hill project area

2.1 Historical workings

Gold mining at Spring Hill was initiated by small-scale Chinese alluvial miners in the late 1870s followed by systematic mining of the hill crest undertaken in 1882 by a European owned company. Intensive mining activity continued until 1886, after which this operation was shut down. Multiple small diggings were conducted in the main adit shaft in 1890. In 1896, there were around 55 people sporadically mining throughout the Spring Hill area before it was abandoned again in 1903. Twice, in 1913 and 1938, companies tried to tunnel through the base of Spring Hill to connect to the bottom section of ore that was dug previously from the top but were unsuccessful. In 1937 a 1200-foot-long tunnel was dug under old Chinese workings with a connecting vertical air shaft located in the Hong Kong zone. Sporadic mining occurred for the next decade; then in 1950 and 1955 more coordinated tunnelling occurred (Low Ecological Services [LES], 2013).

2.2 Recent activities

Ross Mining acquired the project from Territory Resources in 1989 and formed an exploration joint venture with Billiton, who carried out a major program of work until it withdrew from the joint venture in March 1992. Ross Mining continued to explore the project area until 1994. In the mid- 1990s, Ross Mining was acquired by Placer Dome and in 1995 the project area was relinquished. During 2003, the subsequent owner of the Project, Tennant Creek Gold (NT) Pty Ltd, commissioned McDonald Speijers to undertake a first pass economic assessment of the mineralisation and to create a preliminary pit design for the Hong Kong, Main, Middle and East Zones on the southern part of the project area. The resulting resource estimate comprised 3.6Mt @ 2.34 g/t Au for a total of 274,000 ounces of gold. The current Spring Hill project area overlies mining licence (ML) 23812, which is a 1,035ha ML originally granted to Tenant Creek Gold (NT) Pty Ltd on 16 January 2004, contingent upon a boundary survey. The survey was completed in August 2005 and the lease was finally granted in March 2007. The ML was then acquired by Western Desert Resources (WDR) in July 2007. In mid-2011, WDR Gold entered a joint venture agreement with TM Gold Pty Ltd (TM Gold). TM Gold identified the presence of exposed stopes, legacy mullock heaps and waste dumps around the mining lease. The volume of oxide waste in the mullock heaps and waste dumps around site was estimated to be approximately 50,000 tonnes of material. Sampling of the dumps indicated the waste material was mineralised and contained economic quantities of gold. In early 2017, TM Gold completed a project focused on the movement of legacy waste material from the heaps where it was left up to 100 years ago. This material was assayed for economically viable mineralisation, and then either transferred to a mobile crusher where it was crushed and loaded onto trucks for haulage to the Union Reefs processing plant, or backfilled to one of numerous dry stopes in the vicinity of the project.

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Introduction 3

2.3 Proposed activities

TM Gold now intends to focus on mining known oxide resources at Spring Hill, through open-pit mining and trucking ore offsite for processing at the Union Reefs mill. The proposed Stage 1 mining schedule initially covers up to ten months of construction and excavation activity, followed by a further two months of offsite ore processing. The proposed site infrastructure will include pits, a waste rock dump, a ROM pad, a sediment dam, workshops and demountable offices and ablution blocks along with onsite access and haul roads. There will be no onsite accommodation, with workers accommodated at nearby Pine Creek and Emerald Springs. A map of the proposed infrastructure layout is included in Appendix A of this report. The resource areas identified are centred on an area of approximately 75ha in the central- eastern portion of the mining lease. The current project design includes three open-cut pits identified as Hong Kong 1, Hong Kong 3 and Main Pit 2 (see map in Appendix A).

3. Baseline ecological surveys

Surveys prior to 2016

LES conducted a baseline environmental survey within the Spring Hill project area in 1995 (LES, 2013). LES identified the cave-dependent Orange leaf-nosed bat (Rhinonicteris aurantia) inhabiting the historic main adit as well as an unidentified second bat species. The Orange leaf- nosed bat is listed as near threatened under the Territory Parks and Wildlife Conservation Act (TPWC Act). LES (2013) reported that in a subsequent site visit it was observed that a landslide that occurred in 2011 had covered the main entrance of the adit. LES did not report on any microbat survey effort within the currently proposed Spring Hill project disturbance footprint.

2016 baseline survey

Northern Resource Consultants (NRC) conducted baseline ecological surveys in October 2016, which focussed on the project area for the current proposed action. The objective of the baseline survey in 2016 was to add to the existing body of baseline information (i.e. from the survey by LES in 1995) and to provide data on current site conditions. The report by NRC (2016) also consolidated the relevant findings from all known baseline surveys conducted up to that point in time. The baseline survey program incorporated a systematic fauna trapping program within various location and habitats associated with the proposed project. The survey also incorporated the use of a bat echolocation call detector (Song Meter SM4 FS). The detector was placed near the entrance of different historical mine workings within the project area over four nights between 17 and 21 October 2016. The objective of this methodology was to provide baseline presence/absence data on bat species present within the project area and utilising old mine workings as habitat. Interpretation of the echolocation call data collected showed ten bat species were confirmed to occur within the project area. Of the bats positively identified to species level from the echolocation data, six of these species are commonly associated with cave habitats and the majority of these are considered ‘cave-dependent’. Some

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Introduction 4

of the species recorded (e.g. Orange leaf-nosed bat, Rhinonicteris aurantia) are indicative of important habitat features for cave-dependent microbats. Orange leaf-nosed bats are dependent on very hot and humid roost sites (28–32°C and 96–100% relative humidity), and caves and mines supporting these conditions are uncommon (Churchill, 2008). The echolocation call data also revealed the presence of several conservation-significant bat species within the project area at the time of the survey: - Ghost bat (Macroderma gigas) – Listed as vulnerable under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) and near-threatened under the TPWC Act. - Northern leaf-nosed bat (Hipposideros stenotis) – Listed as vulnerable under the TPWC Act. - Orange leaf-nosed bat (Rhinonicteris aurantia) – Listed as near threatened under the TPWC Act. Echolocation data from each of these species was recorded at multiple locations within the project area, with Ghost bat calls recorded at all four locations where the call detector was deployed. The results of this survey indicated the project area provides important habitat for a variety of microbat species and may support important populations of several conservation- significant species.

4. Literature review

The following sections detail the relevant aspects of the ecology of conservation-significant species known to occur within the project area, with a focus on populations within the Northern Territory.

4.1 Ghost bat

Description

The Ghost bat (Macroderma gigas) is Australia’s only representative of the family Megadermatidae (false vampire bats) and is also the only member of the monotypic genus Macroderma. It is a very large (10–13cm head-body length, to 150g) microbat, pale-grey to pale-brown dorsally and whitish beneath. It has long ears (to 50mm) that join in the centre, large eyes and a large but simple nose leaf (Threatened Species Scientific Committee [TSSC], 2016). It is a distinct species that is easily distinguished from other microbats by its large size.

Diet

Ghost bats are carnivorous and insectivorous, with a broad vertebrate diet including small mammals, birds, amphibians and reptiles. Its prey varies seasonally, taking more invertebrates during winter and turning to birds and other vertebrates in the warmer months. Although, it has been noted by Churchill (2008) that Orange leaf-nosed bats are heavily preyed upon by Ghost bats as they exit caves in the cooler months. Ghost bats eat far more Orange leaf-nosed bats when late in pregnancy or nursing young in June and July. It regularly takes prey more than half

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Introduction 5

its bodyweight (Boles, 1999) and large prey is taken back to the roost site for consumption, where characteristic piles of prey remains are deposited. Like other echolocating bats, the Ghost bat forages at night, but also relies on sight to a great extent, identifying prey by movement (Boles, 1999). It hangs from foliage and surveys for prey, before either gleaning (catching terrestrial prey on the wing), taking other microbats in-flight or dropping on prey from a perch, landing on and quickly subduing the animal by enclosing it in the wings and biting the head and neck (Boles, 1999). Ghost bats hunt over a wide area, averaging 61ha around a roost (Tidemann et al., 1985), leaving the roost an hour or so after dark and hunting for a few hours. After the initial hunting phase Ghost bats become more inactive before going through a second phase of activity around 01:00, which lasts until the early morning (Pettigrew et al., 1986).

Distribution

Ghost bats are sparsely distributed across northern Australia, with disjunct strongholds (often associated with a single maternity roost) on the central Queensland coast, Pine Creek and Kakadu in the Northern Territory, and the Pilbara and Kimberley regions in Western Australia. As recently as the mid-twentieth century, ghost bats were distributed in central and south Australia to south-eastern Western Australia, but their range appears to have completely retracted to the tropics and subtropics. This is likely due to a combination of increasing aridity in the late-Holocene restricting them to a few suitable locations, and recent anthropogenic disturbances (Milne & Pavey, 2011). Population trends among known roosts are poorly understood, with counts rare and by varying methods. Recent population estimates fall around 7,000 to 9,000 individuals (McKenzie & Hall, 2008), with certain individual roosts making up over 5% of that figure. Ghost bats are restricted to isolated populations throughout their range, which is likely due to specific habitat and roosting requirements (Churchill & Helman, 1990; see sections below). Populations are often separated by unsuitable habitat, and genetic divergence suggests that no confluence occurs on regional scales and that even local populations are distinct (Worthington Wilmer et al., 1999). Female Ghost bats are highly philopatric, remaining in or returning to the roosts of their birth, and male movement appears to dictate the sharing of genetic information between populations (Worthington Wilmer et al., 1999).

Habitat and roosting

Ghost bats utilise various sites as roosts depending on the purpose. Night roosts are temporary and used during foraging spells at night — these can include rock crevices and shallow overhangs or mine adits. Day roosts must be deeper and entirely dark through the day (generally by having small openings), holding stable temperatures and relatively high humidity (TSSC, 2016; see Figure 1). These can include large chambers in granite boulder scree, limestone and sandstone caves, mines and adits. When breeding, Ghost bats coalesce, sometimes forming large colonies (generally 30–200 individuals), which again require completely dark roosts. The entire regional population of Ghost bats can be represented at a single roost during breeding. However, males disperse widely during the wet season, occurring in pairs or small groups, and occupy a variety of dark higher humidity roost sites (TSSC, 2016). Information from Churchill (2008) is similar to observations made by Pettigrew et al. (1986) in

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Introduction 6

regard to the Ghost bat’s breeding season. Both state that mating occurs in May with pups born in late July and early August. This suggests that Northern Territory Ghost bats are likely to occur at higher densities during the onset of the mating season. The male component of the population then disperses as they leave the maternal roosts after mating, and therefore the density at maternal roosts begins to decrease (Pettigrew et al., 1986). The young start to fly around seven weeks and, soon after, begin to forage. Although they begin to forage after a few months, young Ghost bats are not fully weaned until March (Churchill, 2008).

Figure 1: Profile of microbat habitat in the Northern Territory showing different roost areas (from Churchill, 2008)

Threats

The Ghost bat was assigned vulnerable listing under the EPBC Act in 2016 due to its low estimated population size (7,000–9,000) and reduction thereof, with Woinarski et al. (2014) estimating a species-wide decline of >10% in three generations, possibly much more extreme in some areas. Mining — both reworking of disused mines and development of new mines — is widely considered the greatest threat to Ghost bats (TSSC, 2016). Old adits and mine shafts present excellent roost sites as they are often deeper and/or more narrowly entranced, and thus contain chambers completely absent of light, which is a requirement for Ghost bat roosts. Some such roosts (e.g. the historical Kohinoor Mine near Pine Creek) represent the largest single colonies known and the abandonment or collapse of such roosts may lead to the dispersal of more Ghost bats than the surrounding suitable habitat can accommodate. This could lead to significant decreases in population size as many populations depend on single, isolated roost sites. This, combined with highly specific habitat requirements (e.g. intolerance to dry and cold

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Introduction 7

day roosts) and resultant disinclination to disperse, makes the Ghost bat highly susceptible to localised extinction. As a high-tier endothermic predator hunting year-round, Ghost bats require consistent access to prey and are likely susceptible to changes in prey availability and foraging capacity. In this respect, other threats may include land clearing, spread of weeds and other habitat alteration for/by pastoral and invasive mammals. There is conflicting evidence regarding the Ghost bat’s susceptibility to noise and general disturbance. Woinarski et al. (2014) states that Ghost bats are at risk from even minor disturbance of passing vehicles, which can lead to the abandonment of roosts. However, Armstrong (2010) demonstrated that short-term drilling and the use of compressors and other motors as little as 85m from roosts did not lead to roost abandonment.

Ghost bats in the Northern Territory

Within the Northern Territory, substantial Ghost bat breeding populations have been identified to occur within Kakadu National Park, Claravale station and at the disused Kohinoor mine adit in the vicinity of Pine Creek (TSSC, 2016). The total population in the Northern Territory was estimated to be between 2500 and 3000 individuals in 1999, based on counts at known colonies (Worthington Wilmer et al., 1999). As Ghost bat populations are highly structured and genetically distinct at both a local and regional scale (TSSC, 2016), it is unlikely populations within Kakadu National Park interact regularly with the Claravale station and Kohinoor mine populations. A high degree of philopatry (remaining in, or returning to, an individual’s birthplace) has been recorded in this species and this likely emphasises regionalism between populations. As a result, loss of sites containing breeding females has the potential to reduce the area of occupancy and population size of this species dramatically (TSSC, 2016, and references therein). Approximately seven areas within Kakadu National Park have been identified as major Ghost bat sites, with a number of other small day-roost sites being recorded (TSSC, 2016). Four of these sites are known breeding sites with population studies conducted between 1984 and 1986 estimating 50–800+ individuals to occupy any one site. Subsequent population surveys conducted between 2014 and 2015 estimated 0–22 individuals to occupy any one of these sites, representing declines of over 90%. Currently, the overall population within Kakadu National Park is estimated to be 100 individuals (TSSC, 2016, and references therein). Declines in Kakadu National Park have been associated with the arrival of Cane toads in 2001 and remaining colonies are typically in areas remote from waterholes (TSSC, 2016, and references therein). The Kohinoor mine population is regarded as containing the largest known Ghost bat roost within Australia (DENR, 2016), with count estimates ranging from 300 to 1500 individuals over the 1981 to 2013 period. A study by Pettigrew et al. (1986) indicated an increased number of bats utilised the mine as breeding commenced in May, after which a large proportion of males left. Increased activity was again experienced from early August to the early wet season because of births. Sampling methodology and temporal differences in sampling timing has resulted in varied precision; however, declines of over 30% have been suggested within the Kohinoor mine over the sampling period. Recent population assessments estimated 550

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Introduction 8

individuals to occupy the Kohinoor mine (TSSC, 2016, and references therein). No direct causes have been proposed for these suggested declines; however, it has been suggested this population faces threats from unregulated human visitation, potential mine collapse and contaminated water sources (Woinarski et al., 2014). Gene flow of Ghost bats within Australia was examined by Worthington Wilmer et al. (1999 and references therein). Three sites were used in the Northern Territory, including Nourlangie Rock in Kakadu National Park, Pine Creek and Claravale station, for the purpose of these assessments. Nourlangie Rock is approximately 175km northeast of Pine Creek whereas Claravale station lies approximately 40km northwest of Pine Creek. Breeding populations are known at each site and in 1999 approximately 200 individuals were estimated at Nourlangie Rock, 150 at Claravale station and 1200 at Pine Creek. It was shown by Worthington Wilmer et al. (1999) that there is no gene flow between Nourlangie Rock and populations in Pine Creek or Claravale station. In contrast, the Claravale station and Pine Creek populations have nonsignificant differentiation of mtDNA and microsatellites, indicating gene flow between these populations. Additionally, it has been suggested that the Claravale station population may be contributing to the Pine Creek population, reflecting some changes in abundance measured at the Pine Creek adit over time.

4.2 Northern leaf-nosed bat

The Northern leaf-nosed Bat (Hipposideros stenotis) has only been recorded in the far north of Australia. In Queensland, this species has only been recorded in Mt Isa and there are only 31 records of this species in the Northern Territory. Since 2000, the species has only been recorded six times in the Northern Territory (Milne, 2012). Bats roosts alone or in small groups and have been found in sandstone caves, boulder piles, road culverts and disused mines. Roosts are normally in small, shallow overhangs or splits in cliffs where microclimates are characterised by moderate temperatures (approximately 27°C) and lower humidity (around 46%) (Churchill, 2008; EHP, 2017; Hourigan, 2011; see Figure 1). The Northern leaf-nosed bat is not easily disturbed by people when roosting but has been known to decline with reworking’s and destruction of mines. This species has disappeared from at least two sites where it was known to previously occur; Red Bank mine and Pine Creek (Milne & Ward, 2012).

4.3 Orange leaf-nosed bat

The Orange leaf-nosed bat (Rhinonicteris aurantia) is an endemic Australian species that inhabits the tropical regions of Western Australia and the Northern Territory, and the north- western parts of Queensland. The Orange leaf-nosed bat is a small cave- and deep mine- dependent species that is readily identifiable due to its elaborate rounded and scalloped nose- leaf and bright orange fur (Churchill, 2008). Similar to the Ghost bat, the Orange leaf-nosed bat has very particular roosting requirements especially during the dry season (Churchill, 2008), preferring deep caves or mines with very high relative humidity and high temperatures (see Figure 1). Caves and mines with these specific requirements are uncommon. This species disperses under more favourable conditions during the wet season (November–February), and it is thought that the species becomes forest-dwelling during this time (Churchill, 2008).

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Introduction 9

Orange leaf-nosed bats are extremely sensitive to roost disturbance (Hourigan, 2011) and will quickly fly away from an intruder to deeper parts of the cave (EHP, 2017). However, research conducted during exploratory drilling indicates that short-term high-noise and vibration disturbance at greater than 100m from roost entrances may not impact this species (Armstrong, 2010).

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Methods 10

Methods

1. Overall approach

The following sections detail the methodology employed for a targeted microbat survey conducted in July 2017. The survey incorporated a habitat assessment, which included a desktop component, whereby areas of potential habitat in the form of mine workings were identified, and a ground-truthing component to locate and describe suitable habitat features. The field component included a targeted survey program comprising direct observation of microbats and passive recording using echolocation detectors.

2. Habitat assessment

2.1 Desktop analysis

High-resolution aerial imagery was reviewed using GIS software during the desktop analysis to determine the location and extent of historical mining activity with respect to the current proposed project area. The location of historical mine workings within the general project area were recorded for later ground-truthing survey effort. Focus was given to workings located within the disturbance footprint and immediate surroundings; however, areas outside the disturbance footprint were also considered. Each mine stope/shaft/adit was labelled with a unique number to allow for consistent data to be recorded against the identifying number.

2.2 Field survey

Overall approach

The full extent of the project area was traversed on foot by three observers over the period from 24 to 28 July 2017. Focus was given to areas identified to be part of the disturbance footprint for the proposed action. The traverses were conducted to identify locations of mine workings that may provide potential habitat for microbat species. The traverses incorporated direct searches for stopes and the use of a hand-held GPS device with the locations of potential stopes identified during the desktop analysis. All features identified during the desktop analysis were assessed for their potential to provide habitat for microbat species. Where additional features were located during the field survey, these were added to the GPS record with a numeric identifier, and the relevant attributes of these features were recorded.

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Methods 11

Habitat categories

The suitability of each stope as habitat for cave-dependent microbats, especially conservation- significant species, was assessed against criteria identified during the literature review. Each stope was assigned to one of the following habitat categories:

Confirmed Roosting bats were observed, heard or ultimately recorded on the bat detector over the course of the field survey.

Moderate habitat potential Any two, or more, of the below habitat criteria were present.

Low habitat potential Any one of the below habitat criteria were present.

No habitat potential None of the below criteria were present. These ‘stopes’ were generally historical features that had been filled in with rock material or woody debris. Some of these features would never have supported microbat habitat, but were originally located from aerial imagery only. Only stopes that were labelled as low habitat potential or higher were included in further investigation.

Habitat criteria

Habitat criteria assessed for cave-dependent microbats were based on the following:

Stope depth It has been shown that Ghost bats and other cave-dependent bats prefer undisturbed deep caves or mineshafts (EHP, 2017). Deep stopes can provide stable temperatures and help maintain humidity levels, both of which are important criteria (Churchill, 2008; TSSC, 2016). Stopes were considered to support potential habitat if they were greater than 10m deep. Deeper stopes have the potential to be higher quality habitat as they can contain more complexity and increased abundance and variety of micro-habitat features. Hand torches were used to help determine the approximate depth of each stope. If the bottom was beyond visible range with the use of the torch the stope was considered deep (>20m).

Accessibility As Ghost bats are the largest microbat in Australia, with a wing span of up to 60cm (TSCC, 2016), they require larger stope entrances than other microbat species. Openings that are larger than 60cm and are clear of vegetation and other debris provide higher quality habitat.

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Methods 12

Each stope entrance was examined for overhanging vegetation and other debris, which may inhibit bats entering and leaving. Openings that were free of obstructions were considered higher quality than those partially or fully blocked by debris.

Connectivity Ghost bats prefer roosting habitats that contain multiple openings (EHP, 2017). Stopes connecting to the main horizontal drive would provide higher quality habitat as there may be multiple entrances available. The connectivity of stopes was generally unable to be assessed fully, as the stopes were inaccessible due to safety reasons and were often characterised by a vertical shaft descending from the opening. Stopes that were determined to be over 20m in depth or positioned close to stopes that were over 20m were considered higher quality habitat as they had potential for connectivity with other stopes or the horizontal adit.

Dark areas Straight vertical stopes do not provide high quality habitat for cave-dependent bat species as large areas would be subjected to either direct or indirect sunlight during the day. Many cave- dependent bat species require habitats with micro features that remain in near darkness throughout the day. Stopes with horizontal workings or microhabitat features, such as fissures, were considered to be of higher quality for cave-dependent species.

Impacts observed

Any recent impacts to the habitat features were recorded against the stope’s numerical identifier for further interpretation of habitat suitability (see further details in Limitations section below)

3. Stope-watches

Bats were counted from eight stopes during the targeted survey. These stopes were identified during the habitat assessment as having moderate microbat habitat potential. The majority of stopes were watched from before sunset until close to 21:00 (Table 1). Red filters were placed on lenses of torches, which were dimmed and placed adjacent to stope entrances. As Ghost bats are large and distinctive they were identified by sight and counted when leaving stope entrances. The time of emergence from the stope was recorded for each individual Ghost bat (to the minute level) and, where multiple Ghost bats emerged in a one-minute period, the total number for that minute was recorded. Other bat species were also counted while leaving stopes each night; however, given the limitations in identifying small mobile individuals to species level in low-light, counts for other species were pooled. A Song Meter SM4 echolocation call detector was placed at the stope entrance while bats were counted. The time on the SM4 detector was synchronised with the time devices used by each observer to enable correlations and confirm in-situ species identifications. Stopes 57/58/62 are different entrances to the same underground stope, with only 62 being watched. As this study represents the first attempt to provide quantitative data on the microbat populations occupying the various habitats present, the expected number of bats emerging from

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Methods 13

each stope was not known. Therefore, harp tarps and mist nets were not employed during the targeted survey program to reduce the risk of harm to bats from inadvertent high capture rates and to minimise interference with bats that may be breeding or carrying young. For example, Ghost bats are known to be sensitive to disturbance and may drop attached young if startled or captured and may not return to roosting/breeding areas (TSCC, 2016).

Table 1: Stopes-watch record

DATE STOPE START TIME END TIME

25/07/17 16 18:20 19:16

25/07/17 13 17:52 20:49

26/07/17 53 18:15 20:15

26/07/17 63 18:25 19:32

26/07/17 62 18:05 20:21

27/07/17 7 18:05 20:00

27/07/17 30 18:00 20:34

27/07/17 5 18:20 20:00

4. Echolocation recordings

Recording on the Song Meter SM4 echolocation call detector was continued after the watches and terminated at sunrise for each stope where it was deployed. This passive recording program was employed to achieve the following: - Identify activity over the duration of the night, including further emergence after the stope- watches ceased. - Verify the visual observations recorded during the stope-watches and support identification of unknown microbats that were observed during the watches. - Identify the presence of species that may not have emerged during the stope-watch period. - Provide data on the species composition within each stope where recording was conducted. - Provide indicative data on whether the number of individuals returning prior to sunrise is similar to the number that emerged at the start of the night (for Ghost bats). Table 2 details at which stopes echolocation recording was conducted and the date and times of recording.

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Methods 14

Table 2: Stopes where echolocation recording was conducted

DATE STOPE START TIME END TIME

24/07/17 5 20:45 6:30

25/07/17 13 19:00 8:00

26/07/17 63 18:05 19:30

27/07/17 30 18:00 20:34

26/07/17 62 19:40 7:00

5. Limitations

The field survey component of this study was limited by the inaccessibility of the habitats present within the project area and a number of recent impacts that likely confounded data interpretation and influenced the outcome of the survey. Almost all stopes surveyed were characterised by vertical shafts with unknown depths starting from the opening at the surface that could not be safely accessed. Loose rock and dirt around the bunds prevented examining them too closely. Any potential habitat features for bats below approximately 20m could not be visually assessed. The connectivity of stopes or the presence of any chambers or other sub-surface habitat conditions could not be assessed. Only bats that occupy habitats near the entrance of the stopes could be observed visually, and typically even these species could not be seen within the stope, even when confirmed present through other survey techniques. Quantitative data was restricted to counts at stope entrances in low light conditions, and was therefore typically focussed on detection of Ghost bats as this species is large enough to be identified when emerging. During the targeted microbat survey (July 2017) that is the subject of this report, there was widespread evidence of tampering with stopes that could present potential bat habitat on the site. Many stopes displayed some form of disturbance in the form of burnt tyres, smoke flares, signal flares, chemical propellant or were partially filled in with woody debris and rocks. Disturbance was most evident at Stope 1 and stopes 57/58/62, with thick soot covering walls and a burnt tyre photographed at the bottom of one of the only stopes where the inside of the stope could be accessed. During the first night of the survey, stope 1 was still smoking with a smell of burning rubber persisting throughout the remainder of the survey days. Other stopes still contained fine ash around bunds and openings, suggestive of disturbance occurring immediately prior to the commencement of the targeted survey. The nature, scale and timing of the activities indicated through the evidence remaining at site is such that the objectives of the targeted fauna survey program were most certainly impacted by this activity. The impacts cannot be quantified, but there is notable potential for the significance of the habitat offered by these stopes and occupation of the stopes by cave-dependent bat species to be underestimated by the survey program. These limitations need to be considered when interpreting the results of the targeted survey. A summary of the recent impacts observed for each habitat feature has been included in this report.

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Results 15

Results

1. Habitat assessment

A total of 67 stopes potentially providing habitat for bats were identified during the desktop analysis. The field survey revealed many of these features were only shallow depressions or excavations that did not provide suitable roosting habitat for bats. These features have all been excluded from further description and mapping, as they have no relevance as bat habitat. Of the stopes assessed during the field survey program, three were determined to have low habitat potential, six had moderate habitat potential and ten contained at least one bat species. All stopes identified as potential habitat (low, moderate or confirmed) are shown in the maps in Appendix A of this report. Appendix C presents the location of each habitat stope, the relevant habitat category as defined above, a description of the habitat features and disturbance observed and a representative photograph.

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Results 16

2. Stope-watches

Table presents the outcomes of the stope-watches conducted at various locations within the project area. Microbats were observed emerging after dusk at the majority of stopes where visual observations were conducted. Noteworthy observations from the stope-watches include: - On 25 July 2017, 96 Ghost bats were visually observed emerging from stope 13. - On 25 July 2017, approximately 135 small microbats (i.e. excluding Ghost bats) were visually observed emerging from stope 16. - On 26 July 2017, at least three species of microbats, including two individual Ghost bats were visually observed emerging from stope 62. - On 27 July 2017, at least three species of microbats, including five individual Ghost bats were visually observed emerging from stope 30.

Table 3: Number of bats counted leaving different stopes in the evening

STOPE DATE TOTAL BATS NOTES NUMBER COUNTED

5 27/07/17 10 Mix of small brown microbats (probably Miniopterus orianae) and larger microbats (probably Taphozous georgianus) were recorded emerging intermittently over the stope-watch period between 18:55 and 19:40. Echolocation call data was recorded at this stope on a different night.

7 27/07/17 10 Small dark microbats (probably Miniopterus orianae) flying out of the stope at 19:10 and actively feeding at the stope entrance. No echolocation recording conducted.

13 25/07/17 96 Significant colony of Ghost bats. Emerged at 19:09 with the majority leaving the stope before 20:00, but continued to emerge until the stope watch ended at 21:00. Echolocation call data obtained simultaneously with the stope-watch and continued after the watch ended.

16 25/07/17 135 Small dark microbats (probably Miniopterus orianae) with the first leaving at 18:49 and the majority leaving between 18:55 and 19:00. No echolocation recording conducted.

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Results 17

STOPE DATE TOTAL BATS NOTES NUMBER COUNTED

30 27/07/17 74 Approximately 65 small brown microbats (probably Miniopterus orianae), 4 larger microbats (probably Taphozous georgianus) and 5 Ghost bats recorded emerging intermittently over the stope-watch period. Smaller microbats left the stope between 18:49 and 19:25. At 19:29 a group of five Ghost bats emerged and caught a microbat that was feeding at the stope entrance. Two Ghost bats flew off while three stayed on the walls of the stope entrance until 20:08. Echolocation call data obtained simultaneously with the stope-watch.

53 26/07/17 1 One small microbat observed emerging from the stope at 19:41.

62 26/07/17 23 Approximately 15 small brown microbats (probably Miniopterus orianae), 5 larger microbats (probably Taphozous georgianus) and 2 Ghost bats observed emerging from this stope over the watch period. Smaller bats left the stope between 18:49 and 19:10. The first Ghost bat left at 19:43 and another at 19:54. Echolocation call data obtained simultaneously with the stope-watch and continued after the watch ended.

63 26/07/17 0 No bats observed emerging from this stope. Echolocation recording was conducted simultaneously with the stope-watch and no calls of emerging bats were recorded.

3. Echolocation recordings

The Microbat Call Interpretation Report prepared by Balance Environmental (2017) is included in Appendix B. More than 3000 bat call sequences were recognised from the total dataset, with two species (Taphozous georgianus and Miniopterus orianae) responsible for over half of all identified calls. A total of six cave-dependent species were recorded within the project area: - Northern leaf-nosed bat (Hipposideros stenotis) - Orange leaf-nosed bat (Rhinonicteris aurantia) - Ghost bat (Macroderma gigas) - Large bent-winged bat (Miniopterus orianae) - Common sheath-tailed bat (Taphozous georgianus) - Northern cave bat (Vespadelus caurinus) Three of these species (Northern leaf-nosed bat, Orange leaf-nosed bat and Ghost bat) are conservation-significant species, as identified in the Introduction section of this report. The Microbat Call Interpretation Report identifies calls from up to five additional species that are not normally associated with cave-type roosts: - Gould’s wattled bat (Chalinolobus gouldii)

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Results 18

- Hoary wattled bat (Chalinolobus nigrogriseus) - Little broad-nosed bat (Scotorepens greyii) - Greater northern free-tailed bat (Chaerephon jobensis) - Yellow-bellied sheath-tailed bat (Saccolaimus flaviventris) Balance Environmental (2017) reported that ‘most of these calls had relatively low amplitude (i.e. weaker signals than the cave-bats) and were probably all recorded from bats that happened to fly directly over the stope opening’. The Microbat Call Interpretation Report (Appendix B) includes a section presenting the species composition, based on proportion of total calls, for each stope where echolocation recording was conducted. Conservation-significant species were recorded at all stopes where recording took place and these species formed a significant component of calls recorded at stopes 13, 30 and 62.

4. Conservation-significant species

4.1 Ghost bat

Ghost bats were recorded, either through direct observation or echolocation data, at four stope habitats within the project area. This species was observed emerging from stopes 13, 30 and 62 during the stope watches, and it can be assumed all of these stopes are currently utilised as day-roosting habitat for this species. No Ghost bats were observed emerging from stope 5 and the echolocation recording at this stope showed only two calls recorded. These calls were recorded at approximately 02:30 and, on this basis, it can be assumed the calls recorded were likely from one or two individuals foraging within or near the stope entrance. At total of 96 individual Ghost bats were recorded emerging from stope 13 over the stope-watch period between 18:30 and 21:00 on 25 July 2017. The first individual emerged at 19:09 and individuals continued to emerge sporadically over the watch period, with the majority leaving the stope before 20:00. However, Ghost bats were recorded emerging occasionally until the stope watch ended at 21:00. Echolocation recordings were collected simultaneously with the counts and the results presented in the call interpretation report (Appendix B) generally support the count data. Table presents the number of visual observations and the number of calls recorded for 15-minute intervals over the duration of the watch. As identified in the interpretation report, the difference between the number of calls recorded and the number of bats observed may be due to individuals moving near the entrance but not emerging from the stope. Individuals within the stope may have been audible to the detector without being visible to the observers. Observers only recorded individuals that exited the stope completely without returning immediately. The observers did observe Ghost bats moving near the entrance, but not emerging completely from the stope, perhaps influenced by the dim artificial light or the presence of the observers. Only individuals that emerged completely and departed were recorded in the counts.

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Results 19

Table 4: Comparison of Ghost bat counts from visual observations and echolocation calls at stope 13 on 25 July 2017

TIME INTERVAL NUMBER OF GHOST BAT NUMBER OF GHOST BATS CALLS RECORDED OBSERVED EMERGING

19:00 – 19:14 5 6

19:15 – 19:29 35 33

19:30 – 19:44 39 24

19:45 – 19:59 18 10

20:00 – 20:14 6 3

20:15 – 20:29 15 15

20:30 – 20:44 6 3

20:45 – 21:00 7 2

The call interpretation report also presents a graphical representation of the number of Ghost bat call recordings over time at each stope. From this figure (Figure 2 in Balance Environmental (2017) report), it appears that almost all bats had emerged from stope 13 by the time the visual observations ended at 21:00. A further 6 calls were recorded in the 15-minute period after 21:00, with 3 calls at approximately 22:00 and 1 call at approximately 22:45. The visual observations and echolocation call data confirm that a colony of at least 96 individual Ghost bats was present within stope 13 on 25 July 2017, and the total number was likely to be approximately 100 individuals. The number of Ghost bats within this roost and the timing of the targeted survey indicate a high potential this stope supports a maternal roost for Ghost bats. The significance of this roost is addressed further in the latter sections of this report. No further counts were conducted at this site during the targeted survey program to minimise the potential for disturbance to this relatively large colony. Two Ghost bats were observed emerging from stope 62 during the stope-watch on 26 July 2017 and echolocation calls from this species were recorded during this period. A total of 8 echolocation calls from this species were recorded from stope 62 between 19:30 and 21:15. These results indicate a relatively small number of Ghost bats, probably about four individuals, emerged from a day roost within this stope. A total of 22 calls were recorded between 04:30 and 06:30 the following morning, indicating either a number of passes by the same individuals or a greater number of bats returning to this roost than the number departed at the start of the night. Five Ghost bats were observed emerging from stope 30 during the stope-watch on 2 July 2017 and echolocation data recorded simultaneously with the observations supports these counts. The Ghost bats emerged at 19:29 and at least some of the individuals that emerged remained at the stope entrance until 20:08. The individuals at the stope entrance were observed capturing a small microbat that was foraging near the stope entrance. No further observations were recorded, and both the stope-watch and echolocation recording ended at 20:20. No data are available on the pre-dawn return-to-roost for this stope.

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Results 20

Stopes 5, 7, 16, 53 and 63 were observed using the stop-watching methodology described above and no Ghost bats were recorded emerging from these stopes during the targeted survey program. These stopes do not appear to be currently occupied as roosting sites for Ghost bats. However, see the ‘Limitations’ section above for confounding influences that impact interpretation of ‘absence’ data.

4.2 Northern leaf-nosed bat

While the Northern leaf-nosed bat is a morphologically distinct species, it was not able to be distinguished from other small microbats during the stope-watch visual observations. The presence of this species was only able to be determined from the echolocation call analysis. Two calls from this species were recorded from Stope 30 at 19:00 on 27 July 2017. Echolocation call recording at this stope ended at 20:30, so there are no data available after this time, including for pre-dawn returns. It is likely a small number of this species is utilising this stope as day-roosting habitat. This species was not recorded anywhere else from the echolocation data collected during the targeted survey program. Echolocation call data was recorded from two locations within the project area during the systematic fauna survey program in October 2016. At least one call from this species was recorded from the northern portion of the study area on 17 October 2016. Call/s from this species were also recorded from the entrance to stope 19 on 20 October 2016. During the targeted survey program in July 2017 stope 19 was observed to be partially filled and obstructed by woody debris, and therefore unlikely to support significant microbat roosting habitat. It is noteworthy that echolocation recording was conducted at stope 30 during the systematic surveys in 2016 and no calls from this species were recorded at this location.

4.3 Orange leaf-nosed bat

Interpretation of the presence and habitat utilisation of this species was limited to echolocation recordings from the four stopes detailed above. A relatively large total number of calls (217) from this species were recorded from stope 62 on 26 July 2017. Calls were continually recorded throughout the night and it is highly likely the total number of calls recorded reflects numerous passes by the same individuals. On this basis, it is not possible to estimate the number of individuals utilising this roost habitat, but the total call count does indicate this stope represents important habitat for this species. Two calls were recorded from stope 5 on 24 July 2017 (21:00 and 21:15) and four calls were recorded from stope 13 on the night of 25 July 2017 (21:00, 01:15, 03:30 and 04:45). Most of these calls likely represent an individual foraging within or near the entrance of the stope, rather than individuals that are occupying the stopes as roosting habitat. No calls were recorded from the echolocation recording period at stope 30.

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Discussion 21

Discussion

1. General habitat significance

The results of the targeted bat survey program demonstrate that the Spring Hill project site supports significant roosting habitat for multiple cave-dependent microbat species. Up to five cave-dependent species were recorded in some of the habitats surveyed. Many of these species would occupy different zones within the stope habitat, and therefore some of the features assessed likely represent a complex habitat structure. Furthermore, some of these species require very specific cave roost microclimates (e.g. see section on Orange leaf-nosed bat below). Overall, the diversity of bat species recorded, the apparent population sizes for at least some of these species and the number of stopes providing potential habitat, all suggest the Spring Hill project area represents a significant site for microbat biodiversity. The significance of the site at the species level depends on the scale at which populations/habitats are assessed and the conservation-significance of the species. The three conservation- significant species recorded from the project area are discussed in detail below. It is important to note the potential for the survey to underestimate the biodiversity values of these habitats as a consequence of the influences described in the ‘Limitations’ section of this report. Absence data or low population numbers should be interpreted carefully given the nature of impacts that occurred shortly prior to the survey. Disturbance from tyres and smoke flares ignited within the stopes prior to the survey may have caused species to abandon roosts and either move to alternate roosts within the project area or disperse from the local area completely. Stopes that provide potential microbat habitat where disturbance was recorded that did not produce any evidence of roosting may in fact provide significant habitat values, and these habitats may be recolonised if no further disturbance occurs.

2. Vandalism at Spring Hill

During the targeted bat survey program at Spring Hill, it was noted that several adit locations which have a high and moderate potential for hosting significant roosting habitats have been impacted through tampering from unknown parties and local prospectors. Spring Hill is only 8km from the Stuart Highway and sits on the corner of Mt Wells Road and Spring Hill Road. Despite TM Gold’s best efforts (installing locked gates at known access points) the site is frequently visited and used for recreational purposes (has good mobile reception, is a local sight-seeing point and prospectors) which regularly results in vandalism, fires and disturbance occurring. Access to adits into the future will need to be restricted by utilising security fencing around an 85 metre buffer zone, utilising more stringent fencing around the broader site area and bunding and fencing of all historical access roads to prevent access.

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Discussion 22

3. Conservation-significant species

3.1 Ghost bat

Habitat use

The results of the targeted survey program indicate that the Ghost bat utilises habitat within the project area for multiple purposes. The historical mine workings were confirmed as day-roost habitat for this species. Based on visual observations and echolocation recording from one night at stope 13, this stope is considered to be currently supporting a day roost of at least 96 Ghost bat individuals and the total number is estimated to be approximately 100 individuals. The size of the population occupying this roost, and the timing of the survey, suggest this stope is likely supporting a Ghost bat maternal roost. The Ghost bat commences breeding in May, after which males leave the roost and young are born late July to early August (Churchill, 2008). The timing of the survey, therefore, corresponds to the period in which females congregate and the size of this congregation reflects a likely maternal roost. Three other areas with maternal roosts are known from the region: Pine Creek, Claravale Station and Kakadu National Park. The Pine Creek roost at the abandoned Kohinoor mine adit is the largest known maternal roost (Pettigrew et al., 1986), with numerous counts conducted over the last 30 years (summarised by Grant et al., 2010). Recent counts from this site identified a population of approximately 550 Ghost bats at this roost (Grant et al., 2010). Worthington Wilmer et al. (1999) conducted studies on a maternal roost at Claravale Station, approximately 40km northwest of Pine Creek and identified the population to be approximately 150 Ghost bats. No current estimates of the population at this site are available. There are varying values on counts from Kakadu National Park, with recent studies showing large declines and many roosts abandoned (TSSC, 2016, and references therein). The current population estimate for the Kakadu population is around 100, with the highest count at any one site being 22 individuals (TSSC, 2016, and references therein). The size of the roost within stope 13 in the Spring Hill project area is therefore consistent with the size of maternal roosts in the region, and the broader Ghost Bat population. Further survey work is required to confirm the presence of a maternal roost at Spring Hill and to improve certainty around population counts; however, these early findings suggest at least one stope within the project area is being utilised as maternal roost habitat. Smaller numbers of Ghost bats were recorded emerging from stope 30 (five individuals) and stope 62 (at least two individuals), suggesting these stopes provide at least some suitable day- roost habitat for this species. The results from these stopes indicate they do not currently represent maternal roost sites for this species (but see section on Limitations). Rather, these stopes may represent day-roost habitat for male Ghost bats that are roosting separately from the maternal colony after breeding. These individuals may also move between different day- roost stopes within the area, as indicated by the greater number of pre-dawn calls recorded at stope 62 compared to the dusk fly-out period. The presence of a significant number of Orange leaf-nosed bats in stope 62 (see further discussion on this specie below) indicates this stope likely supports significant roost habitat that is suitable for Ghost bats. Orange leaf-nosed bats have highly specialised roosting preferences and habitat for this species often overlaps with roosting preferences for Ghost bats.

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Discussion 23

The habitat characteristics of stope 66 appear superficially similar to those recorded at stope 62 and, therefore, this stope may also support habitat for Ghost bats. This stope is located outside the project area of the currently proposed action, but represents an important consideration for impact and risk assessment, and future studies on the local population. While Ghost bats were not recorded at some stopes where other microbat species were recorded, these stopes still represent important features for the local Ghost bat population in terms of supporting populations of prey species. Ghost bats were observed actively feeding on other microbat species at stopes 30 and 62. Churchill (2008) describes Orange leaf-nosed bats as an important prey item for Ghost bats during the late pregnancy or nursing stage. The Northern bentwing bat was recorded as common in multiple habitats surveyed and this species is often predated upon by Ghost bats (Churchill, 2008). Echolocation data suggest a significant population of this species is associated with stope 62. Retention of these habitats and associated prey populations may be important factors for the sustainability of any Ghost bat maternal roost. The findings of this study with respect to the use of roosting habitat in the project area by Ghost bats must be considered carefully in the context of the limitations described previously in this report. Numerous stopes that provide potentially suitable roosting habitat for Ghost bats and other microbats were impacted shortly prior to the survey. The nature of these impacts is such that the habitat use and behaviour of Ghost bats may have been influenced. For example, unoccupied habitats may provide the most suitable habitat (including for maternal roosting), but were not being used due to the recent disturbance. The main roost at stope 13 is one of only a few stopes in the central zone that had not been impacted by recent disturbance and, therefore, this stope may not represent the most optimal roosting habitat, but rather a refuge site utilised as a consequence of the disturbance. The population size observed may have underestimated the actual local population as individuals may have dispersed from the project area in response to the disturbance. On this basis, it is recommended that all stopes identified as moderate quality habitat, or higher, should be assumed to support suitable roosting habitat for Ghost bats, at least until further survey work with temporal separation from disturbance can be conducted.

Significance of the Spring Hill habitat and population

The size of the population recorded at Spring Hill is significant at all scales when considered in the context of regional declines and populations sizes at major Ghost bat sites in the Northern Territory and Queensland. Milne and Pavey (2011) reported Ghost bats are relatively common and secure in the wet-dry tropics of the Northern Territory. However, recent data from the region suggests that Ghost bat populations have declined at major sites. Grant et al. (2010) provided a summary of counts conducted at Kohinoor adit and, although there are limitations with inconsistent count methods, the current estimate of 550 indicates a decline of 60% compared to previous decades (see TSSC, 2016). Substantial population declines have also been reported from roosts in Kakadu National Park, with numbers reduced by as much as 96%, and a current total population estimate of 100 (see TSSC, 2016, and references therein). Worthington Wilmer et al. (1999) reported on a maternal roost at Claravale Station, approximately 40km northwest of Pine Creek, comprising approximately 150 Ghost bats, but a review of current literature did not reveal any more recent population estimates. The size of the population currently recorded at

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Discussion 24

Spring Hill represents a significant population for this species and may be the second largest roost currently known in the region. The large population at Kohinoor adit in Pine Creek has been identified as vulnerable to a variety of threats, including collapse. It is likely the population from Kohinoor adit has some genetic linkage with the Spring Hill population (see below) and the Spring Hill site has some potential to support displacement from the Kohinoor adit if that habitat is compromised. Outside any active mining period, the Spring Hill site may be less vulnerable to other threats such as human visitation. As discussed previously, the number of individuals occupying the roost in stope 13 and the timing of the targeted survey program indicate the Spring Hill project area potentially supports a maternal roost for Ghost bats. Confirmation of pregnant or lactating females was not possible at this early stage, as the roost habitat was not accessible. Capture techniques were not employed as the number of individuals within each stope was not known and, therefore, the study incorporated less invasive techniques to avoid disturbance to a potential breeding population. Maternal roosts represent important sites for the survival of this conservation-significant species. There are very few known maternal roosts for Ghost bats and they are reported to be limited within the range of the species (McKenzie & Hall, 2008). Identification and direct protection of unprotected maternity colonies has been identified as a conservation priority (McKenzie & Hall, 2008). Maternal roosts sites are significant because a high degree of philopatry (remaining in, or returning to, an individual’s birthplace) has been recorded for this species. Worthington-Wilmer et al. (1994, 1999) reported high levels of population structure at the regional scale for this species. However, it was identified there is less structure among populations within regions in the Northern Territory, which implied greater connectivity occurring via male mediated gene flow (Worthington-Wilmer et al., 1999). Genetic studies of the Pine Creek population and the nearby Claravale Station population (separated by 40km), showed nonsignificant differentiation for mtDNA as well as microsatellites (Worthington-Wilmer et al., 1999). It is therefore likely the Spring Hill population (approximately 25km from Pine Creek) is part of the Pine Creek regional population. This population appears to be distinct from the Kakadu National Park population, as Worthington-Wilmer et al. ( 1999) reported that none of the mtDNA alleles at Nourlangie Rock (approximately 175km from Pine Creek) were shared with the Pine Creek or Claravale Station populations. Further study is required to confirm the presence of a maternal roost within the Spring Hill project area. It is possible that disturbance to the Spring Hill population may be mediated through connectivity with the major roost in Pine Creek. Conversely, the Spring Hill project area may also represent important habitat to mediate the risk of impacts (e.g. collapse) to the major roost in Pine Creek. Assuming the three sites described above for the collective regional population (Pine Creek, Claravale Station and Spring Hill) do support maternal roosts, then this regional population likely represents one of the more stable Ghost bat metapopulations. The sustainability of this metapopulation could be critical for the long-term survival of the species.

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Discussion 25

Impact assessment and risks

Historical workings within the Spring Hill project area are concentrated in, and mostly restricted to, the central ‘main’ zone. This area supports the majority of workings that support roosting habitat for microbats, including stope 13, where the main Ghost bat roost was identified (see maps in Appendix A). This central main zone has been identified to contain economically viable quantities of gold that could be extracted through open-cut style mining. While there are limitations regarding knowledge of the subsurface structure of historical mine workings, it is highly likely that open-cut mining in this zone would destroy the majority of microbat habitat within the project area. Mining within this central main zone likely represents a high risk of significant impacts to the vulnerable (EPBC Act) listed Ghost bat, and potentially other conservation-significant species. Relevant criteria from the Matters of National Environmental Significance – Significant Impact Guidelines include whether there is a real chance or possibility the action will: - Lead to a long-term decrease in the size of an important population of the species. - Reduce the area of occupancy for an important population. - Adversely affect habitat critical to the survival of the species. - Disrupt the breeding cycle of an important population. - Modify, destroy, remove or isolate or decrease the availability or quality of habitat to the extent the species is likely to decline. - Interfere substantially with the recovery of the species. Given the current study represents only an early-stage scientific understanding of the population of the vulnerable listed Ghost bat within the project area, the ‘precautionary principle’ is applicable in this circumstance. On this basis alone, development within the central zone where the main historical workings are present represents a risk of significant impacts to this species. Furthermore, the nature of the habitat and the size of the population recorded within this zone indicates disturbance in the central zone represents a risk of significant impacts in accordance with at least one of the criteria outlined above. Given the risk of significant impacts from development within this zone, it is recommended disturbance to this area be avoided wherever possible. On this basis, resource extraction from this area has been excluded from the currently proposed action (see maps in Appendix A). The ‘Hong Kong’ zone is located in the southern and western sections of the project area, where fewer historical workings providing microbat habitat were identified during the targeted survey. The eastern ridge in the Hong Kong zone has been identified to contain economically viable quantities of gold suitable for extraction through open-cut mining. However, given the presence of stopes supporting microbat habitat, including Ghost bats (e.g. stope 62; see map in Appendix A), development in this area has been excluded from the design of the currently proposed action. As identified previously, stopes within this area (e.g. 62/57/58) support habitat that is potentially suitable as roosting habitat for the Ghost bat, with at least two individuals currently occupying this habitat. This area also represents important habitat for several species that the Ghost bat preys upon and are known to be important food items for supporting maternal colonies. The currently proposed action includes three open-cut pits located outside the main areas of historical workings that support microbat habitat. Two of these pits (Hong Kong 1 and Hong

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Discussion 26

Kong 3) are located in the southern/western Hong Kong zone, within which no stopes supporting microbat habitat were identified. The northern edge of the Hong Kong 1 pit shell is located approximately 130–140m from microbat habitat stopes identified in the main central zone (e.g. 140m to stope 13 and 130m to stope 2). The eastern side of the Hong Kong 1 pit shell is approximately 130m from the microbat habitat recorded from stopes 57/58/62. Stopes 53 and 63 are located closer to the pit shell of Hong Kong 1 (approximately 65m); however, observations at these stopes did not identify a significant colony of any microbat species present and no disturbance was recorded from these stopes. The location of the Hong Kong 1 pit with respect to stopes 53 and 63 (which therefore place the northern edge of the pit slightly within the 85m buffer zone – see below), is not considered to represent a risk of significant impacts to the Ghost bat. The edge of the Hong Kong 3 pit shell is located approximately 140m from the nearest stope identified as microbat habitat, which is stope 13, the main Ghost bat roost. Main Pit 2 is located in the northeast portion of the project area, on the eastern side of the main historical workings zone where the majority of microbat habitat was located. There are historical workings within the Main Pit 2 shell, but none of these workings provide habitat for any microbat species. The nearest recorded microbat habitat was stope 30, which is located approximately 85m from the edge of the pit shell for Main Pit 2. Observations and echolocation recordings at stope 30 revealed this habitat is currently occupied by multiple conservation-significant microbat species. This stope is currently supporting at least a small day-roost for Ghost bats and is also the only location where echolocation data for the Northern leaf-nosed bat was recorded. The open pits that form the main disturbance of the proposed action avoid direct disturbance to the identified microbat habitat features. The proposed pit shells maintain a buffer of at least 85m from the nearest habitat features known to be currently supporting microbat colonies. The current main Ghost bat roost site is located at least 140m from the edge of the nearest pit shells. There is limited information available on the sensitivity of Ghost bats to mechanical activities outside the roost entrance. Ghost bats are reported to be easily disturbed when roosting, with young potentially dislodged in rapid take-offs and abandonment of roosts sites (TSSC, 2016, and references therein). However, Armstrong (2010) reported on a study of the short-term effect of exploration drilling on a Ghost bat colony in Western Australia. The study did not identify any correlations between the drilling program and roost occupancy or colony size for Ghost bats. Armstrong (2010) identified that significant impacts were unlikely for short-term disturbance from drilling further than 25m from a roost entrance and 85m from the roost location within the mine. The Ghost bat colony recorded from stope 13 appeared to be located reasonably near to the entrance of the stope (based on vocalisations heard); therefore, the 85m distance is considered relevant for this roost. The duration of the drilling program in this study (for context on defining ‘short-term’) was two days for pad construction and seven days of drilling. Armstrong (2010) noted, however, that pad construction resulted in a lower count suggesting the use of a bulldozer within 50m of a roost entrance might represent a greater disturbance. It was further noted that site-specific conditions would need to be considered for the relevance of these values. On this basis, there is some evidence that, for a short-term activity, a buffer of 140m between the pit shells and confirmed significant microbat habitat would avoid a significant disturbance to the roosts. However, given the lack of significant precedent for buffer zone size and application, a monitoring program prior to, and concurrent with, any

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Discussion 27

proposed disturbance will be critical for informing appropriate management strategies and responses. At the time of writing, no designs were available for ancillary mine infrastructure such as waste rock dump sites, haul roads or a ROM pad. This infrastructure has greater flexibility for siting; however, there are limitations associated with the steep terrain of the project area. It is recommended that, wherever possible, ancillary infrastructure be located outside the mapped buffer zone and as far as possible from microbat habitat features. Focus should be given to avoiding locating infrastructure or vehicle movements near the main central zone, particularly where the potential Ghost bat maternal roost is located.

3.2 Northern leaf-nosed bat

The ecology of this species is poorly known and there are relatively few records of this species. Only two echolocation calls from this species were recorded within the project area during the targeted survey program, which were both from stope 30. Calls from this species were also recorded within the project area during the systematic survey program in October 2016, but at two different locations nearby (at the entrance of stope 19 and near stope 22). From the data obtained to date, it appears this species likely occurs in low numbers within the project area. However, the current data needs to be considered in the context of the limitations described in previous sections, and it is possible greater numbers of this species and/or other habitats were occupied prior to the recent impacts to microbat habitat. This species does not require such specialised roost microclimates (cf. Ghost bat or Orange leaf-nosed bat) and occupies small cracks and crevices near the entrance of caves and mines (Churchill, 2008). Noting the limitations of this study, the current data indicates there are no specific habitat features recorded that should be retained specifically for this species. Given other species require more complex habitat, the retention of microbat habitat as described above will avoid direct disturbance to suitable roost habitat features for this species.

3.3 Orange leaf-nosed bat

This species was recorded from multiple stopes where echolocation recording was conducted, with the majority of calls recorded from stope 62 (217). Only low numbers of calls were recorded from other stopes (2 calls at stope 5 and 4 calls at stope 13), which likely reflect low numbers foraging over the stope entrance rather than roost sites for this species. Echolocation data cannot be used to accurately quantify roost numbers for this species; however, the number of calls recorded indicates high levels of activity at stope 62 and this stope likely represents important roost habitat for this species. Given echolocation data was the only mechanism for identifying potential habitat for this species, it is possible that this species is occupying other stopes where recording was not conducted during the targeted survey. It is also important to note the previously identified limitation of this survey and, therefore, recently impacted stopes may provide suitable habitat, but have been recently and/or temporarily abandoned due to disturbance. The presence of this species is noteworthy, as it has highly specialised roosting habitat preferences. This species prefers very hot and humid roost sites and these habitat types are

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Discussion 28

limited and therefore important to retain. The habitat avoidance approach described above for Ghost bats means that all roost habitat that is potentially suitable for this species will be retained. This species is not known to have strong population structuring like the Ghost bat and therefore, even if disturbance causes this species to abandon roosts in the project area, the habitat will likely be recolonised at the completion of the project. Careful management of the timing for disturbance within the project area could be utilised as a mechanism for minimising potential impacts to this species. This species disperses seasonally, abandoning dry season roost between November and February, when outside climate conditions are similar to the dry season roost microclimate (Churchill, 2008). Disturbance could be timed to occur during this period to minimise disturbance to this species. However, it is considered more important for the timing of disturbance to coincide with optimal timeframes for the Ghost bat, as this species is likely more susceptible to disturbance. In any case, there are limitations associated with development during the wet season with respect to accessibility, surface water management and erosion-sediment control.

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Impact Management 29

Impact Management

1. Mine project design

1.1 Site layout

The primary approach to avoiding impacts to conservation-significant microbat species is through the retention of habitat features within the project area. Open-cut operations in the central ‘main’ zone have been removed from the current project design. The eastern ridge of the Hong Kong zone has also been excluded from the current project design. The current design, therefore, avoids direct disturbance to all stopes identified as providing potential microbat habitat. The three pits included in the current project design maintain a buffer of at least 85m to stopes currently identified as microbat habitat and a buffer of at least 130m to the stope currently identified as the main Ghost bat roost. There are two stopes located 65m from the proposed Hong Kong 1 pit (stopes 53 and 63); however, these stopes were targeted during the survey program and were not identified to be supporting a significant microbat colony. These stopes are also separated from the proposed Hong Kong 1 pit by a steep gully and, therefore, the topographical separation is substantial. The waste rock dump, haul roads, site access and other ancillary infrastructure should be located as far as possible from the microbat habitat areas identified. The maps in Appendix A show an 85m buffer zone from areas of microbat habitat identified during the field survey. It is recommended that, wherever possible, works involving machinery and vehicle movements be excluded from this buffer zone. Armstrong (2010) identified machinery movements within 50m of an adit entrance may have been responsible for lower emergence counts in that study and such actions represent potential for detrimental effects. Project designs for ancillary infrastructure that maximise the buffer between microbat habitat areas and machinery/vehicle movements will form a key part of impact management.

1.2 Timing and sequencing

Of the conservation-significant species recorded within the project area, Ghost bats are likely most sensitive to disturbance. It is recommended that, where possible, the proposed action be timed to minimise the risk of impacts to the local Ghost bat population. Optimal timing with respect to the ecology of the local Ghost bat population will need to be informed by the monitoring program, which should encompass at least one breeding season cycle prior to the commencement of the action. Sensitive periods will include gestation and when females are carrying young or leaving young in nurseries. The exact timing of these periods should be determined through the monitoring program, but Churchill (2008) identifies that females give birth in July and August after 11–12 weeks gestation, and that young can fly at 7 weeks (but are not fully weaned until March). The reproductive periods reported by Churchill (2008) indicate April through to October may represent an important period for disturbance to be minimised.

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Impact Management 30

Pit development should be sequenced to minimise disturbance to the roost habitat areas. Development of Main Pit 2 should not occur simultaneously with the Hong Kong pits, as this will result in simultaneous disturbance on multiple sides of the main roost habitat area. Sequential pit development will limit the disturbance to one side of the main roost habitat area at any given time. This will maximise the capacity for microbats to disperse, forage and return to roost sites without needing to pass through an active disturbance footprint. The sequencing of pit development could be informed by the monitoring program (see details below), and if conducted prior to and concurrent with operations, could provide relevant details on which habitats are occupied (or unoccupied) at the time of disturbance and whether immature individuals are still present within the roost. The sequencing of pit development could then be designed to minimise disturbance to sensitive areas. The timing of certain activities could be restricted to particular periods of day or night to minimise the risk of roost disturbance. Ghost bats may be vulnerable to disturbance from vehicle movements in close proximity to the day roost, whereby sudden take-offs could dislodge young or ultimately result in abandonment of the roost. Some activities could be restricted to night periods when the roosts are mostly unoccupied and, therefore, less vulnerable to disturbance. Data from this current study suggest that, during July, Ghost bats leave the day roost by 21:00 and do not return to the roost until approximately 05:00. If hauling activities and other vehicle/machinery movements are restricted to periods where the roosts are unoccupied, the risk of disturbance to the day roost may be reduced. The dusk fly-out and pre-dawn return periods would also need to be avoided to prevent impacts associated with individuals avoiding emergence or return to the roost. The exact timing of night activities may need to vary seasonally and would need to be informed by the monitoring program.

1.3 Rehabilitation

Mine closure planning should include specific approaches to protect roosts and maintain habitat stability where possible. None of the habitats identified should be scheduled for backfilling and movement of machinery in close proximity to habitat stopes should be avoided where possible. There are safety considerations with respect to the retention of open shafts; however, these features should be managed carefully to avoid impacts to roosting microbats. Public access should be restricted at the boundaries of the project area, where possible, to minimise the risk posed by open shafts and the amount of closure infrastructure required at the individual stope level. The use of fences near stopes providing microbat habitat should be avoided where possible, as Ghost bats have been identified as particularly vulnerable to new fences. Where fences are required (e.g. for public safety), the use of barbed wire should be avoided. Measures to increase the detectability of fences should also be incorporated (e.g. through the addition of broad fabric strips along the length of wires). The use of bunds may reduce the need for fencing near open shafts; however, the use of machinery for bund construction should be considered carefully with respect to disturbance of day roosts.

1.4 Education

Site inductions should include content on sensitive environmental matters and the importance of avoiding impacts to microbat species and habitat.

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Impact Management 31

2. Monitoring program

The establishment of an on-going monitoring program will form a critical mechanism to minimise impacts to conservation-significant microbat species from the proposed action. The monitoring program should incorporate all conservation-significant species recorded during the baseline and targeted surveys to date, with specific focus given to the local population of Ghost bats. Data obtained through the monitoring program will be critical for establishing the significance of this population and identifying appropriate management strategies and responses to minimise impacts. The monitoring program should be designed to establish local population dynamics and reproductive ecology prior to the commencement of the action. This will inform management strategies with respect to timing and sequencing of disturbance, as detailed above. The monitoring program should incorporate at least one full breeding season period, whereby local population dynamics and the timing of sensitive reproductive periods (e.g. females carrying young) can be identified. The frequency of monitoring events will depend on the outcomes of each site visit and whether the necessary data can be obtained. For example, the frequency might be determined by whether sensitive periods could be identified during the site visit or another site visit is required after only a short interval to capture the necessary data. However, it is suggested a minimum of four monitoring events should be conducted to establish baseline conditions prior to commencement of the action. Any impact management strategies developed should be reviewed prior to commencement of the action considering the outcomes of the monitoring program. Pre-disturbance data collected as part of the monitoring program should include the following: - Population estimates based on stope-watch counts and seasonal variation of numbers as well as expected daily variation. - Roost emergence and return periods and seasonal variation. - Data on population structure where this can be collected without significant disturbance to the colony (i.e. to confirm whether the main roost is a maternal roost site or not). - Roost utilisation data, to determine whether the same stope is continued as a maternal roost or if other stopes are used, and whether there is variation in the use of other stopes as day roosts. - Acoustic data on daylight activity within the stope. - Incidental or targeted data on foraging behaviour including hunting at stopes providing habitat for other microbats. Data collected during the pre-disturbance monitoring program will give an indication of baseline conditions to inform management strategies as detailed above. The pre-disturbance data will also provide a baseline for comparison during development of the site to determine appropriate management responses to potential changes from baseline conditions. Monitoring conducted after the commencement of the action should include the above components for comparison with baseline conditions. Roost monitoring (e.g. daylight acoustic detection and stope-watching) during activities that pose a higher risk of disturbance to roosts should be conducted to identify whether management responses are required for these

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Impact Management 32

activities. Higher risk activities include machinery movements and extraction/dumping of material in close proximity to significant roosts. Monitoring should be continued for at least one breeding cycle after the completion of the action to provide data on the population’s response to the action and whether further management is required (e.g. alternative rehabilitation measures).

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References 33

References

Armstrong, K. N. (2010). Assessing the short-term effect of minerals exploration drilling on colonies of bats of conservation significance: a case study near Marble Bar, Western Australia. Journal of the Royal Society of Western Australia, 93,165–174. Boles, W. E. (1999). Avian prey of the Australian Ghost Bat Macroderma gigas (Microchiroptera: Megadermatidae): prey characteristics and damage from predation. Australian Zoologist, 31(1), 82–91. Churchill, S. (2008). Australian Bats. Crows Nest, NSW: Allen & Unwin. Churchill, S. K. & Helman, P. M. (1990). Distribution of the Ghost Bat, Macroderma gigas, (Chiroptera: Megadermatidae) in central and South Australia. Australian Mammalogy, 13, 149– 156. Department of Environment and Heritage Protection (EHP) 2017. Macroderma gigas in Species Profile and Threats Database, Department of the Environment, Canberra. Retrieved from http://www.environment.gov.au/sprat. Grant, C., Reardon, T., & Milne, D. (2010). Ghost Bat count at Kohinoor Adit. Australasian Bat Society Newsletter, 35, 36–38. Hourigan, C. (2011). Northern leaf-nosed bat, Hipposideros stenotis. Targeted species survey guidelines. Queensland Herbarium, Department of Science, Information Technology and Innovation, Brisbane. Low Ecological Services (2013). Updated Environmental Assessment of Landscape, Flora and Fauna of Spring Hill Project Area. McKenzie, N. & Hall, L. (2008). Macroderma gigas. The IUCN Red List of Threatened Species 2008: e.T12590A3362578. Retrieved from http://dx.doi.org/10.2305/IUCN.UK.2008.RLTS.T12590A3362578.en. Milne, N. (2012). Threatened Species of the Northern Territory: Northern Leaf-nosed Bat Hipposideros stenotis. Northern Territory Government Department of Environment and Natural Resources. Milne, D.J. & Pavey, C. R. (2011). The status and conservation of bats in the Northern Territory. In B. Law, P. Eby, D. Lunney & L. Lumsden (Eds), The Biology and Conservation of Australasian Bats (208-225). Mosman: Royal Zoological Society of New South Wales. Pettigrew, J., Baker, G. B., Baker-Gabb, D., Baverstock, R., Coles, R., Conole, S., Churchill, S., Fitzherbert, K., Guppy, A., Hall, L., Helman, P., Nelson, J., Priddel, D., Pulsford, I., Richards, G., Schultz, M. & Tidemann, C. R. (1986). The Australian ghost bat, Macroderma gigas, at Pine Creek, Northern Territory. Macroderma, 2(1), 8–19 Threatened Species Scientific Committee (TSSC) 2016. Conservation Advice. Macroderma gigas, Ghost bat. 5 May 2016.

SPRING HILL – TARGETED MICROBAT SURVEY prepared by: Northern Resource Consultants Pty Ltd

References 34

Tidemann, C. R., Priddel, D. M., Nelson, J. E., & Pettigrew, J. D. (1985) Foraging behaviour of the Australian Ghost Bat, Macroderma gigas (Microchiroptera: Megadermatidae). Australian Journal of Zoology, 33, 705–713. Ward, S. & Milne, N. (2016) Threatened Species of the Northern Territory: Ghost Bat Macroderma gigas. Northern Territory Government Department of Environment and Natural Resources. Woinarski, J. C. Z., Burbidge, A. A., & Harrison, P. L. (2014). The Action Plan for Australian Mammals 2012. Collingwood: CSIRO Publishing. Worthington Wilmer J., Moritz, C., Hall, L. & Toop, J. (1994). Extreme population structuring in the threatened Ghost Bat, Macroderma gigas: evidence from mitochondrial DNA. Proceedings of the Royal Society, London, 257, 193–198. Worthington Wilmer, J., Hall, L., Barratt, E. & Moritz, C. (1999). Genetic structure and male- mediated gene flow in the ghost bat (Macroderma gigas). Evolution, 53, 1582–1591.

SPRING HILL – TARGETED MICROBAT SURVEY prepared by: Northern Resource Consultants Pty Ltd

Appendix summary

Appendix A Maps Appendix B Microbat Call Interpretation Report Appendix C Spring Hill Microbat Habitat Assessment

SPRING HILL – TARGETED MICROBAT SURVEY prepared by: Northern Resource Consultants Pty Ltd

Appendix A

Maps

SPRING HILL – TARGETED MICROBAT SURVEY prepared by: Northern Resource Consultants Pty Ltd

794000

TM GOLD PTY SPRING HILL PROJECT PROPOSED SITE Main Pit 2 INFRASTRUCTURE AND LAYOUT

Legend PAF Stockpile Hong Kong 3 Proposed bat exclusion zone (85 metres) ! Bat Adits Stage 1 - WRD extent Stage 2 - WRD extent Final Pits RoadsBuffer Proposed Site Infrastructure Mobile Crusher Offices ROM Pad ROM Dam Hong Kong 1 Sediment Dam WRD Ramp

8494000 8494000 Stockpile Area Mining Leases EarthSea Heritage Sites !P 2016

Coordinate System: GDA 1994 MGA Zone 52 Projection: Transverse Mercator Datum: GDA 1994 Date: 21-Aug-17 0 45 90 180

Metres Scale: 1:4,237 at A3 §

794000 794000

34 !

32 67 ! ! 22 ! 19 30 Main Pit 2 ! 16 ! ! 17

7 13 ! !

5 !

2 1 ! !

Hong Kong 3

! 63 ! 62

57! !! 58

Hong Kong 1 8494000 8494000

66 ! Document Path:D:\GIS Projects\Spring_Hill\NRC_Data\maps_mxd\20170822_FaunaSurveyBatHabitat.mxd

794000

Coordinate System: GDA 1994 MGA Zone 52 TM GOLD PTY LTD, SPRING HILL PROJECT - BAT HABITAT POTENTIAL Projection: Transverse Mercator Datum: GDA 1994 0 50 100 Legend Meters Bat Habitat Potential Proposed bat exclusion zone (85 metres) Mobile Crusher Sediment Dam Stage 1 - WRD extent Scale: 1:2,500 at A3 ! Ghost Bats Present Area of survey for riparian corridor Offices WRD Ramp Stage 2 - WRD extent Confirmed Bats PAF Stockpile ROM Pad Stockpile Area Final Pits Credit: ! Watercourse © Commonwealth § Moderate Potential ROM Dam Roads of Australia (Bureau of Meteorology) 2014 ! Imagery: 03/06/2016 - Mining Leases Spring Hill Birdsye ecw supplied by client ! Low Potential Map Data: 2016 CNES/Astrium, Google Earth 794000

34 !

32 67 ! !

22 19 30 Main Pit 2 ! ! ! 16 ! 17

7 13 ! !

5 !

2 1 ! !

Hong Kong 3

53 ! 63 !

62 ! 57 !! 58

Hong Kong 1 8494000 8494000

66 ! Document Path:D:\GIS Projects\Spring_Hill\NRC_Data\maps_mxd\20170822_FaunaSurveyImpactedBatAdits.mxd

794000

Coordinate System: GDA 1994 MGA Zone 52 TM GOLD PTY LTD, SPRING HILL PROJECT - IMPACTED BAT ADITS Projection: Transverse Mercator Datum: GDA 1994 0 50 100

Legend Meters Adits impacted PAF Stockpile Mobile Crusher Sediment Dam Stage 1 - WRD extent

! Impacted Offices WRD Ramp Stage 2 - WRD extent Scale: 1:2,500 at A3

! No impact detected ROM Pad Stockpile Area Final Pits Credit: Watercourse © Commonwealth § Proposed bat exclusion zone (85 metres) ROM Dam Roads of Australia (Bureau of Meteorology) 2014 Imagery: 03/06/2016 - Mining Leases Spring Hill Birdsye ecw supplied by client Map Data: 2016 CNES/Astrium, Google Earth

Appendix B

Microbat Call Interpretation Report

SPRING HILL – TARGETED MICROBAT SURVEY prepared by: Northern Resource Consultants Pty Ltd

Microbat Call Interpretation Report

Prepared for (“Client”): Northern Resource Consultants Survey location/project name: Pine Creek, NT Survey dates: 24-27 July 2017 Client project reference: Job no.: NRC-1706 Report date: 4 August 2017

DISCLAIMER:

© Copyright – Balance! Environmental, ABN 75 795 804 356. This document and its content are copyright and may not be copied, reproduced or distributed (in whole or part) without the prior written permission of Balance! Environmental other than by the Client for the purposes authorised by Balance! Environmental (“Intended Purpose”). To the extent that the Intended Purpose requires the disclosure of this document and/or its content to a third party, the Client must procure such agreements, acknowledgements and undertakings as may be necessary to ensure that the third party does not copy, reproduce, or distribute this document and its content other than for the Intended Purpose. This disclaimer does not limit any rights Balance! Environmental may have under the Copyright Act 1968 (Cth). The Client acknowledges that the Final Report is intended for the sole use of the Client, and only to be used for the Intended Purpose. Any representation or recommendation contained in the Final Report is made only to the Client. Balance! Environmental will not be liable for any loss or damage whatsoever arising from the use and/or reliance on the Final Report by any third party. Methods

Survey understanding and scope

This survey was targeted at ‘cave-dependent’ bat species utilising four old mine shafts/stopes at a site approximately 25km north of Pine Creek, Northern Territory. Song Meter detectors (Wildlife Acoustics, USA) were deployed with microphones suspended up to two metres into each stope, in an effort to restrict call-recordings to those of bats leaving and/or returning to their roost sites. Two stopes (“Stope-13” and “Stope-62”) were each sampled for one entire night (sunset to sunrise); with Stope-5 detection not commencing until about 8:45 PM (approximately 1.5 hours post-sunset); and Stope-30 detection ceasing at 8:30 PM.

Visual observations were made at each stope to determine approximate numbers of Ghost Bats (Macroderma gigas) departing in the early evening (until about 8:45 PM each night). A summary of these observations was supplied with the bat-call data to enable a comparison between observed numbers and the quantity of calls recorded during each observation period.

Data received

Bat calls were recorded in full-spectrum format (WAV files), with data from each night/stope supplied in a separate folder. The data set received for analysis included 2527 WAV files in four folders: 24_July_Stope-5 (498 files); 25_July_Stope-13 (800 files); 26_July_Stope-62 (1153 files); and 25_July_Stope-30 (76 files).

Call identification

All WAV files were analysed with Anabat Insight (Titley Scientific, Brisbane), with species identified manually by comparing the call spectrograms with those of reference calls from the Northern Territory and north Queensland and/or with published call descriptions (Milne 2002).

Samples of suspected Ghost Bat echolocation and social calls were sent to Ms Nicola Hanrahan, University of Western Sydney, for confirmation of their identity and usefulness for species diagnosis. Ghost Bat records for the entire data set were then based on the presence of either echolocation pulses or one or more of three distinct social call signals (“chirps”, “squabbles” and “trills”).

Species' identities were refined by considering probability of occurrence based on general distribution information (e.g. Churchill 2008; van Dyck & Strahan 2008) and database records in the Atlas of Living Australia (www.ala.org.au).

Reporting standard

The format and content of this report follows Australasian Bat Society standards for the interpretation and reporting of bat call data (Reardon 2003), available on-line at http://www.ausbats.org.au/.

Species nomenclature follows Reardon et al. (2015).

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Species recorded

More than 3000 bat call sequences were recognised, with many sequences containing several individual calls of the same species, especially during the early evening when multiple bats would have been emerging from the roosts simultaneously.

Six “cave-dependent” species were identified (see Table 1), with two of those (Taphozous georgianus and Miniopterus orianae) responsible for over half of all identified calls. Another four call types were attributed to species not normally associated with cave-type roost requirements (see Table 1). Most of these calls had relatively low amplitude (i.e. weaker signals than the cave-bats) and were probably all recorded from bats that happened to fly directly over the stope opening.

Two of the species recorded during these surveys are listed as threatened: Hipposideros stenotis (Vulnerable, NT Parks and Wildlife Conservation Act); and Macroderma gigas (Vulnerable, C’wealth EPBC Act).

Table 1 Microbats recorded during the Pine Creek survey, 24-27 July 2017. Number of calls attributed to each species per night/site.

Date: 24-Jul 25-Jul 26-Jul 27-Jul Location: Stope-05 Stope-13 Stope-62 Stope-30 Totals Detection start time: 20:45 19:00 19:30 18:15 Detection end time: 6:30 8:00 7:00 20:30 Total WAV files: 498 800 1153 76 2527 "Cave-dependent" species Hipposideros stenotis 0 0 0 2 2 Rhinonicteris aurantia 2 4 217 0 223 Macroderma gigas 2 271 40 22 335 Miniopterus orianae 71 32 345 47 495 Taphozous georgianus 262 66 723 2 1053 Vespadelus caurinus 0 331 18 3 352 Non-cave species Chalinolobus gouldii 0 0 1 0 1 Chalinolobus nigrogriseus/Scotorepens greyii * 192 235 3 1 431 Chaerephon jobensis 10 58 53 0 121 Saccolaimus flaviventris 0 5 0 0 5 Total calls 539 1002 1400 77 3018

* C. nigrogriseus and S. greyii calls are difficult to reliably differentiate; both potentially occur in the study area.

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The approximate species composition of each stope-roost, based on the proportion of the total call count attributed to each species (“cave-dependent” species only), is shown in Figure 1. Stope-5 appears to be inhabited mainly by M. orianae and T. georgianus; while Stope-13 calls were predominantly from M. gigas and Vespadelus caurinus. Stope 62 appears to be a significant roost for Rhinonicteris aurantia, with large numbers of M. orianae and T. georgianus also recorded here. The relatively brief recording session at Stope 30 revealed predominantly M. orianae emerging, along with a small number of M. gigas.

Figure 1 Proportion of calls attributable to each species at four Stopes in the Pine Creek study area. NB: Stope-30 was recorded only for 2 hours during evening emergence; whereas all other sites include activity during both exit and pre-dawn return periods. The data for this site is based on just 76 identified calls, cf. 498-1153 calls from the other three Stopes.

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Stope-13 appears to be an important local roost for M. gigas, with about 80% of calls detected during the present survey being recorded from this site (see table 1).

Activity patterns

The pattern of M. gigas activity at Stope-13, based on number of calls recorded per 15-minute period, shows a typical post-sunset emergence, followed by pre-dawn return-to-roost (Figure 2). Similar activity patterns were also observed at Stope-62 and Stope-30; however, the total number of calls recorded at these sites was considerably lower than that at Stope-13. Stope-5 appears to not be a M. gigas roost-site, since just two calls were recorded here at around 2:30 AM, probably from a single bat searching for prey.

Figure 2 Ghost Bat activity at four Stopes in the Pine Creek study area. Number of calls detected per 15-minute period between dusk and dawn (approximate)

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Notes on visual observations made by the client at Stope-13 indicate that 96 individual M. gigas departed the roost on the night of 25th July. Observers recorded the number of individuals seen leaving the stope in 1-minute periods; and these observations were reflected by the number of calls detected during the same periods (see Table 2). In some cases, more calls were recorded than individuals seen, perhaps because some individuals circled past the microphone more than once during the observation period, or because individuals within the stope were audible to the detector but not visible to the observers.

This count data is limited to a 2-hour period on a single night, so it cannot be used to make meaningful comparisons between call-detection and direct observation results, nor to derive a useful index of population size based on call data. Significant additional survey effort of timed observations, synchronised with call detection, would be required to obtain sufficient data for a statistically viable analysis of this kind.

Table 2 Ghost Bat counts during a 2-hour observation period at Stope-13 on 25th July 2017. Aggregated to 15-minute detection periods, as per Figure 2.

Time Calls detected Bats observed % difference 19:00:00 5 6 20.00 19:15:00 35 33 -5.71 19:30:00 39 24 -38.46 19:45:00 18 10 -44.44 20:00:00 6 3 -50.00 20:15:00 15 15 0.00 20:30:00 6 3 -50.00 20:45:00 7 2 -71.43

References

Churchill, S. (2008). Australian Bats. Jacana Books, Allen & Unwin; Sydney.

Milne, D.J. (2002). Key to the Bat Calls of the Top End of the Northern Territory. Technical Report No. 71, Parks and Wildlife Commission of the Northern Territory, Darwin.

Reardon, T.B., Armstrong, K.N. and Jackson, S.M. (2015). A current taxonomic list of Australian Chiroptera. Australasian Bat Society. Version 2015-05-15. Downloaded from: http://ausbats.org.au/taxonomic-list/4589345107

Reardon, T. (2003). Standards in bat detector based surveys. Australasian Bat Society Newsletter 20, 41-43. van Dyck, S. and Strahan, R. (ed.) (2008). The Mammals of Australia (Third Edition). New Holland; Sydney.

NRC-1706_PineCreek_Jul17_bat call analysis.docx 4/08/2017 Page 6 of 9 Glossary

Technical terms used in this report are described in the following table.

Approach phase The part of a bat call emitted as the bat starts to home in on a detected prey item; a transitional series of pulses between the search phase and feeding buzz, that become progressively steeper and shorter in duration. Call Refers to a single bat call, made up of a series of individual sound pulses in one or more phases (search, approach, feeding buzz). CF (=Constant Frequency) A type of pulse in which the dominant component consists of a more- or-less ‘pure tone’ of sound at a Constant Frequency; with shape appearing flat on the sonogram. Often also contains a brief FM component at the beginning and/or end of the CF component (viz. FM- CF-FM). Characteristic frequency (Fc) The frequency of the flattest part of a pulse; usually the lowest frequency reached in the qCF component of a pulse. This is often the primary diagnostic feature for species identification. Duration The time period from the beginning of a pulse to the end of the pulse. Feeding buzz The terminal part of a call, following the approach phase, emitted as the bat catches a prey item; a distinctive, rapid series of very steep, very short-duration pulses. FM (=Frequency Modulated) A type of pulse in which there is substantial change in frequency from beginning to end; shape ranges from almost vertical and linear through varying degrees of curvature. FC range Refers to the range of frequencies occupied by the characteristic frequency section of pulses within a call or set of calls. Frequency sweep or “band-width” The range of frequencies through which a pulse sweeps from beginning to end; Maximum frequency (Fmax) – minimum frequency (Fmin). Knee The transitional part of a pulse between the initial (usually steeper) frequency sweep and the characteristic frequency section (usually flatter); time to knee (Tk) and frequency of knee (Fk) can be diagnostic for some species. Pulse An individual pulse of sound within a bat call; the shape, duration and characteristic frequency of a pulse are the key diagnostic features used to differentiate species. Pulse body The part of the pulse between the knee and tail and containing the characteristic frequency section. Pulse shape The general appearance of a pulse on the sonogram, described using relative terms related to features such as slope and degree of curvature. See also CF, qCF and FM. qCF (=quasi Constant Frequency) A type of pulse in which there is very little change in frequency from beginning to end; shape appears to be almost flat. Some pulses also contain an FM component at the beginning and/or end of the qCF component (viz. FM-qCF). Search phase The part of a bat call generally required for reliable species diagnosis. A consistent series of pulses emitted by a bat that is searching for prey or and/or navigating through its habitat. Search phase pulses generally have longer duration, flatter slope and more consistent shape than approach phase and feeding buzz pulses. Sequence Literally, a sequence of pulses that may be from one or more bats; but generally refers to a call or part (e.g. phase) of a call. Tail The final component of a pulse, following the characteristic frequency section; may consist of a short or long sweep of frequencies either upward or downward from the Fc; or may be absent.

NRC-1706_PineCreek_Jul17_bat call analysis.docx 4/08/2017 Page 7 of 9 Appendix 1 Representative call sequences from the Pine Creek survey, July 2017. (Scale: 10msec per tick; time between pulses removed)

Macroderma gigas Hipposideros stenotis

Rhinonicteris aurantia Taphozous georgianus

Vespadelus caurinus Miniopterus orianae

NRC-1706_PineCreek_Jul17_bat call analysis.docx 4/08/2017 Page 8 of 9 Chalinolobus gouldii C. nigrogriseus or S. greyii

Saccolaimus flaviventris Chaerephon jobensis

NRC-1706_PineCreek_Jul17_bat call analysis.docx 4/08/2017 Page 9 of 9