U Appendix U – Fairy Translocation Plan

Overburden Management Project APPENDIX U – PURPLE-CROWNED FAIRYWREN TRANSLOCATION PLAN

Supplementary Environmental Impact Statement February 2018

Appendix U – Purple-crowned Fairywren Translocation Plan

Table of Contents

1 Introduction...... 1 1.1 Background ...... 1 1.2 The Company ...... 1 1.3 Objectives of the Translocation Plan ...... 2 2 Ecology of the Purple-crowned Fairywren ...... 3 2.1 Conservation Status ...... 3 2.2 Habitat ...... 3 2.3 Social Behaviour ...... 3 2.4 Home Range ...... 4 2.5 Diet ...... 4 2.6 Breeding ...... 4 2.7 Threats ...... 6 2.8 Previous Translocations ...... 6 3 The Population to be Translocated ...... 8 3.1 Population Size...... 8 3.2 Group Structure ...... 8 4 The Translocation Site ...... 10 4.1 Location ...... 10 4.2 Existing Populations of Purple-crowned Fairywrens ...... 10 4.3 Potential Impacts at the Translocation Site ...... 10 4.3.1 Competition with other Individuals ...... 11 4.3.2 Effects on other Species and Ecological Processes ...... 11 4.3.3 Establishment of Pest Populations ...... 12 4.3.4 Introduction of Pathogens ...... 12 4.3.5 Impacts on Genetic Diversity ...... 13 5 Risks Associated with Translocation ...... 14 6 Approach ...... 17 6.1 Cattle Exclusion at the Translocation Site ...... 17 6.2 Monitoring of Ecosystem Recovery from Grazing ...... 19 6.3 Monitoring of Natural Recolonisation ...... 20 6.4 Approvals and Planning ...... 21 6.5 Translocation Methodology ...... 21 6.6 Timing ...... 22 7 Post-translocation Monitoring Program ...... 24 7.1 Habitat Monitoring ...... 24

i MRM OMP Supplementary EIS

7.1.1 Methodology ...... 24 7.1.2 Triggers and Corrective Actions...... 25 7.2 Monitoring of Translocated Individuals ...... 26 7.2.1 Methodology ...... 26 7.2.2 Triggers and Corrective Actions...... 27 7.3 Monitoring of Cattle and Fences ...... 29 7.3.1 Methodology ...... 29 7.3.2 Triggers and Corrective Actions...... 29 7.4 Reporting ...... 29 8 References ...... 30

List of Figures

Figure 1-1 MRM locality map ...... 1 Figure 3-1 Location of population to be translocated and the translocation site ...... 9 Figure 6-1 Current and proposed cattle exclusion areas ...... 18 Figure 6-2 Schematic diagram of a potential Purple-crowned Fairywren vacant territory...... 20 Figure 6-3 Location of fairywren survey points (red stars) at translocation sites (orange box)...... 21 Figure 7-1 Expected trajectory of re-establishing canegrass following cattle exclusion...... 25 Figure 7-2 Scenarios that would trigger corrective action in the event that canegrass density and/or height was inadequate...... 26 Figure 7-3 A comparison between population recovery following a typical decline (a, c and d) and a severe decline (b)...... 28

List of Tables

Table 1-1 Project and company details ...... 2 Table 5-1 Translocation risk register ...... 14 Table 6-1 Schedule of actions ...... 22

ii Appendix U – Purple-crowned Fairywren Translocation Plan

1 Introduction

1.1 Background This document presents a Translocation Plan for a small population of Purple-crowned Fairywrens ( coronatus macgillivrayi ) that inhabits the McArthur River Mine (MRM), a Glencore operation. This population was geographically isolated from others following the construction of a mine levee wall in 2007-2008. Proposed expansions of the mining operations at MRM, as part of the Overburden Management Project, pose a risk to this small, isolated population. As part of the environmental impact statement submitted for the Overburden Management Project, Glencore committed to translocating the population to suitable habitat on the mining lease.

A Purple-crowned Fairywren Translocation Plan was requested by the Environment Protection Authority (NT EPA) in their comments arising from the draft environmental impact statement for the Overburden Management Project. This Translocation Plan provides a detailed approach for Glencore to undertake the translocation. 1.2 The Company MRM is owned and managed by Glencore, one of the world’s largest global diversified natural resource companies. The group’s industrial and marketing activities are supported by a global network of more than 90 offices located in over 50 countries.

MRM is located 65 km by road southwest of the township of Borroloola and 740 km southeast of Darwin, in the Gulf Region of the Northern Territory, approximately midway between Darwin and Mount Isa ( Figure 1-1).

Figure 1-1 MRM locality map

1 MRM OMP Supplementary EIS

MRM consists of the open cut mine, processing plant, associated support facilities and the Bing Bong Loading Facility in the Gulf of Carpentaria. The McArthur River Mine is the world’s largest producer of zinc in bulk concentrate form, which is used by Imperial Smelting Process smelters in Europe and Asia, and a zinc concentrate which is supplied to electrolytic smelters. Concentrate is transported from the mine to our own Bing Bong loading facility by road. From there it is loaded onto a barge and transported to waiting ships at sea in the Gulf of Carpentaria.

The mine site is contained within five contiguous mineral leases (MLN 1121, MLN 1122, MLN 1123, MLN 1124 and MLN 1125), located on the McArthur River Station. The property lease is 100% owned by Mount Isa Mines Ltd (MIM) and managed by Colinta Holdings Pty Ltd, a Glencore subsidiary.

The Project and Company details relevant to this Translocation Plan are listed in Table 1-1.

Table 1-1 Project and company details

Project title McArthur River Mine

Company name McArthur River Mining Pty Ltd ABN: 90 008 167 815 ACN: 008 167 815

Address Address: 34a Bishop Street, Winnellie, NT, 0820 Postal Address: PO Box 36821, Winnellie, NT, 0831

Contact details Gary Taylor Environmental Projects Manager McArthur River Mine Email: [email protected] Phone: 0447 041 376

Document ID and version number Purple-crowned Fairywren Translocation Plan v1

Date of the Translocation Plan February 2018

1.3 Objectives of the Translocation Plan The objective of this document is to satisfy NT EPA’s request for a Translocation Plan and to provide clear direction for the relevant Glencore employees to undertake the translocation project.

NT EPA has specified the following components of the Translocation Plan (the sections of this document that address each of these are shown in parentheses):

• the risks associated with attempting to relocate the [fairy] and how these risks will be mitigated ( Section 4.3 and Section 5); • a timeline that outlines pre- and post-translocation actions ( Section 6.6 ); • detailed description of the method to be used to relocate the [fairy]wrens ( Section 6); • how the habitat included in the expanded cattle exclusion fence will be deemed suitable for [fairy]wren relocation ( Section 6.2 and Section 6.3 ); and • how the relocated [fairy]wrens will be monitored and criteria that will be used to assess the success of the relocation ( Section 7).

2 Appendix U – Purple-crowned Fairywren Translocation Plan

2 Ecology of the Purple-crowned Fairywren

2.1 Conservation Status The eastern subspecies of the Purple-crowned Fairywren ( M. c. macgillivrayi ) is listed as a near threatened species in the Northern Territory, under the Territory Parks and Wildlife Conservation Act . It is not a nationally threatened subspecies under the Environment Protection and Biodiversity Conservation Act 1999. 2.2 Habitat Purple-crowned Fairywrens have highly specialised habitat requirements. They are restricted to narrow corridors of riparian vegetation along the rivers that dissect the vast tropical savannas of northern Australia. Purple-crowned Fairywrens are confined to low, dense vegetation close to rivers and springs. There are two habitats that are favoured by the species. In some locations, the dense vegetation is dominated by the woody, palm-like Pandanus aquaticus (Rowley and Russell 1993). Elsewhere, tall, dense stands of canegrass, Chionachne cyathopoda , are the preferred habitat (van Doorn 2007). Other tall grasses (e.g., Mnesithea rottboellioides ) are sometimes used for foraging, but alone do not provide sufficient habitat for Purple-crowned Fairywrens (van Doorn 2007).

In addition to a dense understorey, suitable habitat usually also contains a tall midstorey dominated by Barringtonia acutangula, Nauclea orientalis, Ficus coronulata and other riparian species (van Doorn 2007) . There is also usually a tall canopy of Eucalyptus and/or Melaleuca present . These trees and shrubs provide cover and a foraging substrate for Purple-crowned Fairywrens during times of flood, when their favoured canegrass habitats are inundated.

Comparative studies of riparian sites across the Kimberley region suggest that sites with a tall canopy, dense shrub layer, dense cover of Pandanus and deep water were associated with a higher probability of supporting Purple-crowned Fairywrens (Skroblin and Legge 2011). At the McArthur River study area, sites with a high probability of supporting Purple-crowned Fairywren are characterised by dense stands of Chionachne cyathopoda . 2.3 Social Behaviour Purple-crowned Fairywrens live in socially monogamous pairs; however, 20-70% of pairs are accompanied by an average of one or two (rarely up to nine) subordinate helpers (Rowley and Russell 1993; van Doorn 2007; Kingma et al. 2009, 2010). Helpers assist with feeding nestlings, but do not breed themselves. Helpers are usually male progeny from previous broods (van Doorn 2007). The dominant pair spends a high proportion of time in close proximity (75% within 5 m), and the male and female coordinate their songs to form duets (Hall and Peters 2008). Pairs also cooperate to defend the territory against intruding conspecifics (Hall and Peters 2008).

Pairs that are assisted by helpers tend to live longer than pairs that breed independently (Kingma et al. 2010).

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2.4 Home Range Along the Adcock River, , Purple-crowned Fairywrens occupied territories with an average length of 156.5 m (range 50-376: Kingma et al. 2009). Along the Drysdale River, Western Australia, territories had an average length of 296 m (Rowley and Russell 1993). Along the Gregory River, Queensland, territories had an average length of 177 m (Rowley and Russell 1993). Where the riparian zone is wide (e.g., floodplains containing canegrass), multiple territories may occur parallel to the river (van Doorn 2007). In such cases, territories are 0.26 ha to 0.55 ha in area (van Doorn 2007). Such situations appear to be rare, and most territories contain linear strips of riparian habitat along waterways. Territories usually include both banks of waterways.

Observations of home range size in the vicinity of the McArthur River Mine are consistent with other studies summarised above. Based on data generated from individual colour marking and observations over a ten-year period at the McArthur River study area, it is estimated that group territories generally cover 100 to 350 m in length (mean 220 m). Territories are smaller at locations with dense cane grass (mean length 145 m) when compared to areas that do not support dense cane grass stands (mean 277 m). Territory sizes range from a mean of 0.6 ha in cane grass areas to a mean of 1.3 ha at other locations. Most territories occur within linear areas of riparian habitat along the main river channel but can extend along minor drainage lines where suitable habitat (mainly stands of dense cane grass) is present. Most territories fall within 100 – 120 m of the centre of the main river channel, with territory areas extending further from the main channel where areas of dense cane grass are located on braided channels on the adjacent floodplain. One isolated Purple-crowned Fairywren population at McArthur River was located 2.3 km from the main river channel, in a patch of cane grass associated with a minor drainage line. Where there is suitable habitat, individual group territories can occur on opposite banks of the main channel, particularly where there are wide and deep waterbodies present, broad areas of cane grass on either bank, or on braided channels. 2.5 Diet Purple-crowned Fairywrens spend the majority of their time foraging in vegetation (especially canegrass and Barringtonia ) within 2 m of the ground (van Doorn 2007). Taller vegetation (Barringtonia, Ficus and/or Eucalyptus ) provides important foraging substrates during floods when low vegetation is inundated (van Doorn 2007). Purple-crowned Fairywrens feed on a wide range of insects, which are generally gleaned from vegetation (van Doorn 2007) or the ground beneath dense vegetation (Rowley and Russell 1993).

At the McArthur River study area, Purple-crowned Fairywrens are mainly observed foraging in Chionachne cyathopoda , Chrysopogon elongatus , regenerating Melaleuca leucadendra , Pandanus aquaticus and white currant ( Fluggea virosa ) (EMS 2017; EMS 2016), with species present in the inner riparian zone, such as Barringtonia acutangula , becoming increasingly important later in the dry season (EMS 2016). Weed species are also used as foraging substrates in the wet season and early to mid-dry season. 2.6 Breeding Breeding can take place in any month, although most nests occur from the late wet season to the mid dry season. Populations living in habitats dominated by Pandanus appear to display two peaks in breeding; Kingma et al. (2009) recorded peaks in December-April and August-September, while Rowley and Russell (1993) found peaks in January-May and July-September. Such populations appear to exhibit a possible pause in breeding for two months in mid-winter (Rowley and Russell 1993).

4 Appendix U – Purple-crowned Fairywren Translocation Plan

Populations living in a canegrass-dominated habitat do not exhibit this mid-winter pause in breeding (van Doorn 2007). Instead, breeding takes place between March and September, with most nests commencing in May-August (van Doorn 2007). At the McArthur River study area—a canegrass- dominated habitat—nesting commences in March, with most nests fledging by June (later in wetter years).

In all habitats, breeding rarely occurs during the late dry season (October-November). Breeding is also rare during the wet season (December-March), when flood waters inundate potential nest sites (Rowley and Russell 1993; van Doorn 2007).

Pairs may abstain from breeding during drought years when conditions are poor (Rowley and Russell 1993). Conversely, during favourable years, females often produce multiple broods and the breeding season may be extended. Groups often re-nest after failed attempts, with up to four nests in a single season (van Doorn 2007). Older females may also re-nest in a single season after successful first attempts (van Doorn 2007).

The dominant female in each group is responsible for nest-building (van Doorn 2007). Nests are generally constructed near the base of dense clumps of canegrass (van Doorn 2007) or Pandanus (Rowley and Russell 1993). However, nests may also be built in other low, dense vegetation, such as Mnesithea rottboellioides or Barringtonia acutangula (van Doorn 2007). At McArthur River, nesting has been infrequently recorded in the riparian grass Chrysopogon elongatus at locations where canegrass is absent. Such nests have a low fledging success, due to predation (P. Barden, unpublished data).

Rates of extra-pair paternity are unusually low in Purple-crowned Fairywrens, compared to other fairywren species (Kingma et al. 2009). Each nest usually contains three eggs, but often only two (Rowley and Russell 1993; van Doorn 2007; Kingma et al. 2009). The dominant female, alone, incubates the eggs (Rowley and Russell 1993). Incubation lasts 14 days and chicks remain in the nest for a further 10-13 days (Rowley and Russell 1993; van Doorn 2007; Kingma et al. 2010). Most members of the family group (female, male and helpers) assist with feeding the nestlings (Rowley and Russell 1993).

Fledglings behave cryptically, staying hidden in dense undergrowth; however, they can be readily detected by loud begging calls when group members approach (van Doorn 2007). Fledglings continue to be fed by group members for at least three weeks after they have left the nest (Rowley and Russell 1993).

Nest success is generally low. Only half of clutches successfully hatch, and less than half of those that hatch successfully fledge (van Doorn 2007). The mean number of fledglings produced per breeding female in a given year is 0.78 to 1.07 (Rowley and Russell 1993; van Doorn 2007). In addition, at McArthur River some Purple-crowned Fairywren nests fail each year due to parasitism by the Brush ( Cacomantis variolosus ) (P. Barden, unpublished data).

Larger family groups do not lay more eggs per clutch, but successfully rear more offspring to the fledging stage (Kingma et al. 2010).

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2.7 Threats By far the greatest threat to Purple-crowned Fairywrens across most of their distribution is loss of habitat via grazing livestock. Adult annual survivorship in ungrazed sites along the River is 83-96%, compared to 29-51% in grazed sites (van Doorn 2007). Likewise, introduction of cattle into a previously ungrazed site along the Victoria River reduced annual survivorship from 90% to 26% within one year of grazing (van Doorn 2007; van Doorn et al. 2015). A comparative study of riparian sites across the Kimberley region found that evidence of cattle at a site slightly decreased the probability that Purple-crowned Fairywrens were present (Skroblin and Legge 2011).

Grazing by cattle drastically diminishes the density and height of canegrass and other understorey vegetation important for Purple-crowned Fairywrens (van Doorn 2007; Skroblin and Legge 2011). Cattle normally congregate near water during the dry season and canegrass often remains green and palatable for a longer period than other grass species, making it an attractive food source for cattle inhabiting riparian corridors (van Doorn 2007). Where their densities are high, feral horses, donkeys and water buffalo also represent an important grazing pressure on sensitive riverside vegetation (van Doorn 2007).

Fire can also temporarily remove grassy understorey important for Purple-crowned Fairywrens. It takes approximately three months for regenerating burnt canegrass to provide foraging habitat (van Doorn 2007). Purple-crowned Fairywrens have been recorded breeding in territories that were burnt four months previously (van Doorn 2007). The temporary loss of habitat immediately after fire can lead to mortality of the occupiers of the burnt territory (van Doorn 2007), and sites newly burnt by intense fires do not support Purple-crowned Fairywrens (Skroblin and Legge 2011). Habitat burnt by fires of low intensity continues to be utilised by Purple-crowned Fairywrens if the shrubby midstorey vegetation remains intact (Skroblin and Legge 2011). Due to canegrass growing in long, connected corridors, usually without firebreaks, there is the potential for any one fire to cause extensive habitat loss over many territories. Nevertheless, fires in riparian habitats are generally scarce (Skroblin and Legge 2011) and are currently considered a relatively minor threat to the species.

Weed invasion along waterways also poses a potential but unknown threat to Purple-crowned Fairywrens. While weeds may be used by the species as a foraging substrate, they do not provide suitable nest sites (van Doorn 2007). It is unclear if weed invasion per se threatens Purple-crowned Fairywrens, or whether weeds are merely a symptom of high grazing pressure and unnaturally extensive areas of bare ground. Skroblin and Legge (2011) found that weed density and diversity was strongly correlated with presence of cattle. They also found minimal correlation between weed density and fairywren presence once grazing was accounted for.

One population of the species along the Ord River, Western Australia, went extinct following the damming and flooding of this river to create Lake Argyle (Skroblin and Legge 2010). 2.8 Previous Translocations There are no documented previous attempts to translocate Purple-crowned Fairywrens, either at McArthur River or elsewhere within the distribution of the species. However, a related species, the Black and White Fairywren ( Malurus leucopterus edouardi ), has been the subject of successful translocation efforts in Western Australia.

6 Appendix U – Purple-crowned Fairywren Translocation Plan

The Black and White Fairywren has been successfully translocated to Hermite Island from the large, stable population on Barrow Island, as part of conservation efforts by the Western Australian Department of Environment and Conservation. The species was extinct on Hermite Island following invasions by feral ( Felis catus ) and black rats ( Rattus rattus ). After the eradication of these feral predators, translocation from Barrow Island was considered appropriate to safeguard the threatened species against catastrophic fires that could eliminate the entire global population on Barrow Island.

A total of 31 individuals were transferred to Hermite Island in May 2010, followed by a further 10 individuals in July 2011 (Department of Environment and Conservation 2011). Individuals were captured using mist-nets and transported via helicopter. During transit, the fairywrens were housed in specially constructed cardboard boxes and given supplementary water and feed (live termites). All were released within 48 hours of their initial capture. Four unexpected deaths occurred during translocation, possibly brought about through stressful social interactions while in captivity (Department of Environment and Conservation 2011).

Within one year, the translocated population had expanded its range within the island. By 2014, at least 27 separate groups (average group size = 2) of fairywrens had been detected on Hermite Island (Thomas et al. 2014).

Fairywrens ( Malurus ) are a widely studied group of birds, with numerous researchers across Australia undertaking studies that involve the capture, colour-banding and release of wild individuals (e.g., : Double and Cockburn 2000; Evans and Kleindorfer 2016; Red- backed Fairywren: Baldassarre and Webster 2013; Lantz and Karubian 2016; : Webster et al. 2004; Blue-breasted Fairywren: Brooker and Brooker 2002). Their amenability to study reflects the ease of their capture and their general tolerance to handling and close observation. Like other fairywrens, the Purple-crowned Fairywren has proven to be amenable to capture and study. Research on individually banded Purple-crowned Fairywrens has been undertaken by several teams across northern Australia (Rowley and Russell 1993; van Doorn 2007; Hall and Peters 2008; Kingma et al. 2009, 2010; Skroblin 2012), including at the McArthur River Mine (EMS 2008).

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3 The Population to be Translocated

3.1 Population Size A population of approximately 20 individual fairywrens, enclosed by the mine levee wall, make up the population to be translocated (Figure 3-1).

A total of 10.6 ha of riparian forest dominated by Melaleuca leucadendra , Eucalyptus camaldulensis, Casuarina cunnighamiana and Nauclea orientalis (habitat for Purple-crowned Fairywrens), with a dense understorey of canegrass, exist along 550 m of the old McArthur River channel within the mine levee wall. Studies of colour-banded individuals indicated that approximately 20 individuals inhabit this area, representing 20% of the fairy-wren population occurring within the MRM leases (EMS 2017). These comprise three to four family groups (territories). These birds have been captured and many have been individually colour-marked and observed over a nine-year monitoring period, including prior to construction of the mine levee wall.

The high density of territories (the high end of the range reported by Kingma et al. (2009)) reflects the high quality of habitat present within the mine levee wall, due to protection from livestock and fire. The population within the mine levee wall has remained relatively stable over nine years of monitoring.

Studies of the colour-banded population enclosed by the mine levee wall have revealed that it is geographically isolated from fairywrens inhabiting the remainder of the MRM leases. The poor dispersal ability of Purple-crowned Fairywrens (Skroblin 2012) prevents offspring from leaving the enclosed habitat. This also suggests that, once translocation has occurred but prior to the area being developed for mining, Purple-crowned Fairywrens are highly unlikely to recolonise the vacant habitat within the mine levee wall. 3.2 Group Structure The average size of Purple-crowned Fairywren groups recorded within the mine levee wall is 3.64 individuals (based on 321 sightings between 2008 and 2017). The largest group, which was recorded prior to the construction of the mine levee wall, contained 10 individuals. The largest group in 2017 contained four individuals. In 2017, there were four groups inhabiting the old river channel within the mine levee wall. Of individuals present in 2017, 30% were adult males, 40% were adult females and 30% were first-year immatures. This represented a below-average number of immature birds fledged within 2017, despite relatively favourable rainfall during the year. Group size in 2017 (2.35 individuals per group) was also smaller than average. Possible reasons for the recent population decline include (a) stochastic variation in predation, (b) inbreeding depression, and/or (c) gradual deterioration of riparian habitat as a result of reduced water in the old channel.

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MRM OMP Supplementary EIS

4 The Translocation Site

4.1 Location The proposed translocation site is along the McArthur River upstream from the existing cattle exclusion fence (see Figure 3-1). The translocation area contains 2.1 km of riparian vegetation that has, until recently, been heavily grazed by cattle and feral herbivores. 4.2 Existing Populations of Purple-crowned Fairywrens The translocation site has supported lower densities of Purple-crowned Fairywren than habitats in the vicinity of the mine ever since monitoring of riparian birds along the McArthur River first began in 2007. At that time, a 1.8 km stretch of the McArthur River within the translocation site contained only 38% of the fairywren population contained in a similar length of the river now enclosed by the mine levee wall (EMS 2008). Since this time, however, there has been decreasing grazing pressure from cattle and feral herbivores within the fenced mine. This has resulted in a doubling of fairywren density within the fenced area between 2010 and 2012 (EMS 2012). Over the past three years, the population of Purple-crowned Fairywrens within the translocation area fluctuated between 2 and 18 individuals (EMS 2014; EMS 2016). Banding studies have revealed that this population within the translocation area is strongly dependent on emigration from the core breeding population within the fenced area (EMS 2016).

In October 2017, there were two groups of Purple-crowned Fairywren known to be present within the translocation area (2 adults and four first-year birds in each group, for a total of 12 birds). Another group of 6 birds is present in the fenced area to the south of the levee wall (P. Barden, unpublished data). 4.3 Potential Impacts at the Translocation Site The Commonwealth Government’s policy statement Translocation of Listed Threatened Species— Assessment under Chapter 4 of the EPBC Act lists five potential impacts of translocation at translocation sites:

• translocated individuals could compete with residents already present at the translocation site; • translocated individuals could cause a cascade of (usually unpredictable) effects in the receiving ecosystem; • translocated individuals may become a pest in the translocation site; • disease may be spread to new areas via the translocation of infected individuals; and • translocation can introduce genetic diversity not naturally occurring at the translocation site, disrupting local adaptations.

The risks associated with these potential impacts have been considered with respect to translocating Purple-crowned Fairywrens and are assessed in the following subsections.

10 Appendix U – Purple-crowned Fairywren Translocation Plan

4.3.1 Competition with other Individuals

Translocation of wildlife into habitat that already supports a population of the species is unlikely to be successful, because vacant territories are normally unavailable and translocated individuals are likely to be out-competed by the residents.

At MRM, it is expected that in the first years after habitat within the proposed translocation site has been partly restored by excluding cattle, there will be vacant territories available for translocated Purple-crowned Fairywrens, with limited competition from resident pairs.

The proposed translocation site at MRM currently experiences high grazing pressure from livestock and therefore contains suboptimal habitat for Purple-crowned Fairywrens; there are currently few areas of dense riparian grass. Two groups of Purple-crowned Fairywrens currently occupy the proposed translocation site, along with small numbers of transient individuals that disperse from nearby fenced areas. It is known from colour-banding studies that one of the resident pairs is also descended from the main population within the existing fenced area. This pair has recently bred in sub-optimal riparian grass ( Chrysopogon ), in the absence of the more favoured canegrass ( Chionachne ).

Optimal (ungrazed) habitats generally support Purple-crowned Fairywrens at densities of 10-18 birds per kilometre of river (Rowley and Russell 1993). As the proposed translocation site contains 2.1 km of the McArthur River, it is expected to contain vacant habitat that could support 21-38 Purple- crowned Fairywrens, once the habitat has been restored.

It is expected that there may be some natural recolonisation of habitat within the translocation site following the removal of livestock and the restoration of habitat. This recolonisation, however, is expected to be slow due to the following reasons:

• When territories are abandoned due to the death of one or more occupants, they often remain empty for several years before being reoccupied (Rowley and Russell 1993). • When previously grazed habitat is allowed to regenerate, Purple-crowned Fairywrens fail to recolonise if this habitat is too isolated, despite the habitat appearing optimal for the species (van Doorn 2007). • Purple-crowned Fairywrens are resident, territorial birds that rarely change the location or size of their territories between years (Rowley and Russell 1993; Hall and Peters 2008). • Due to the linear nature of their riverine habitat, dispersal of offspring is only possible in one dimension rather than two (Rowley and Russell 1993). • Purple-crowned Fairywrens are relatively long-lived birds with insufficient productivity to generate large reservoirs of surplus birds available to fill vacant territories (Rowley and Russell 1993).

4.3.2 Effects on other Species and Ecological Processes

The introduction of a new species to an area can have numerous unintended consequences on the ecology of that area. Translocated predators can influence prey populations, translocated herbivores can influence vegetation cover and composition, and any translocated species may compete with other species for resources. In general, translocating species to areas where they occurred historically (the situation proposed in this translocation plan) is less likely to have unintended deleterious consequences on other components of the ecosystem. Nevertheless, the potential for ecosystem impacts is an important consideration.

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Rowley and Russell (1993) reported Purple-crowned Fairywrens to experience only slight competition with other species, due to their highly specialised habitats and foraging habits. Red-backed Fairywrens ( M. melanocephalus ) are sometimes common in grasslands bordering rivers supporting Purple-crowned Fairywrens. The former occasionally forage into riverside vegetation where, if they meet with Purple-crowned Fairywrens, interaction is minimal and brief (Rowley and Russell 1993). The smaller Red-backed Fairywrens are generally chased away by Purple-crowned Fairywrens (Rowley and Russell 1993). Red-backed Fairywrens currently inhabit riparian environments in the translocation area (EMS 2017). However, this species is not as closely tied to the riparian zone as the Purple-crowned Fairywren, and also frequents grassy woodlands away from the McArthur River. As part of this translocation program, approximately 820 ha of remnant woodland, most of which occur away from the McArthur River, will be fenced to exclude cattle. The large-scale improvement in habitat quality for Red-backed Fairywrens as a result of reduced grazing should outweigh any loss of territories that result from displacement by translocated Purple-crowned Fairywrens along the McArthur River.

Most other insectivores that occur in habitats suitable for Purple-crowned Fairywrens are either true fly-catchers, which capture their prey by flying sorties from perches, or forage much higher in the midstorey and canopy (Rowley and Russell 1993). Translocation of Purple-crowned Fairywrens will, therefore, have a negligible impact on these other species.

Purple-crowned Fairywrens often nest in close proximity to various finches, but the nests of the former are positioned inside thickets and closer to the ground, whereas finches nest on the outside of thickets (Rowley and Russell 1993). No aggression between Purple-crowned Fairywrens and finches has been observed (Rowley and Russell 1993).

Overall, the translocation of Purple-crowned Fairywrens is highly unlikely to impact any species already inhabiting the proposed translocation site.

4.3.3 Establishment of Pest Populations

Wildlife that is translocated to novel environments can become a pest in the absence of natural predators, disease or competitors. Purple-crowned Fairywrens will be returned to locations that formerly supported them, which are immediately adjacent to areas currently supporting the species. There is, therefore, negligible risk that they will become a pest at the translocation site.

4.3.4 Introduction of Pathogens

Movement of individuals between populations risks the introduction of novel disease to the receiving population. The short period of isolation between the population enclosed in the mine levee wall and those elsewhere along the McArthur River mean that it is highly unlikely that different pathogens are present in the two populations. Furthermore, the small size and isolation of the population to be translocated makes it even less likely to contain disease that would threaten the remaining populations. The individuals to be translocated will not be held in captivity off-site (a potential source of new infections) prior to release.

12 Appendix U – Purple-crowned Fairywren Translocation Plan

4.3.5 Impacts on Genetic Diversity

Purple-crowned Fairywrens that inhabit small, isolated catchments often exhibit subtle genetic divergence from neighbouring populations, as a result of limited gene flow between the populations (Skroblin 2012). In order to not disrupt natural evolutionary processes, translocations should not occur between genetically differentiated populations. This is not a concern at the McArthur River; the population enclosed by the mine levee wall was connected to populations elsewhere along the McArthur River as recently as 2007. Translocation would actually restore natural gene flow between the enclosed population and others along the McArthur River. Furthermore, translocation would prevent inbreeding depression, which is likely to eventuate within the small, isolated population if this remains enclosed within the mine levee wall.

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5 Risks Associated with Translocation

In addition to potential impacts at the translocation site, several risks have been identified that may compromise the success of the translocation program. However with the implementation of the identified mitigation measures the risk can be actively managed to an acceptable level. These risks are discussed in Table 5-1, along with management measures proposed to mitigate these risks where practicable.

Table 5-1 Translocation risk register

Risk Description Likelihood and potential consequence Mitigation measures

1 Failure of the A previous case-study study indicated that Purple-crowned Fairywrens will be newly fenced destocking and appropriate fire management translocated when the habitat at the translocation site resulted in a 36% increase in a Purple- translocation site fulfils criteria listed in to develop crowned Fairywren population within a Section 6.2 . appropriate single year (Legge et al. 2011). habitat for Regular monitoring of the translocation Purple-crowned Partly restored riparian habitat along re- site prior to translocation will identify Fairywrens. channelled sections of the McArthur River has potential failure of habitat been colonised by Purple-crowned Fairywrens development. within five years of the construction of the diversion (EMS 2012), implying that habitat If required, active planting of canegrass restoration can occur quickly, even when the may be undertaken in areas starting quality is very low. permanently damaged by grazing.

The current cattle-exclusion zone at MRM protects high-quality habitat for, and stable populations of, the Purple-crowned Fairywren, implying that protected stretches of the McArthur River can support suitable habitat.

Following previous fencing of riparian areas along the McArthur River, Purple-crowned Fairywrens increased in density from 0.3 birds per survey to 4.1 per survey (a 13.7-fold increase) within two years (EMS 2011), implying rapid recovery of habitat values.

Following fencing of riparian areas at MRM, Purple-crowned Fairywrens are increasingly observed foraging in regenerating riparian vegetation, particularly regenerating Melaleuca (up to 18% of foraging observations in some seasons).

Translocation cannot proceed until the habitat within the translocation site has developed appropriately (see Section 6.2 ). Therefore, failure of this habitat to develop will lead to project delays while restoration works are completed.

14 Appendix U – Purple-crowned Fairywren Translocation Plan

Risk Description Likelihood and potential consequence Mitigation measures

2 Intrusion by Annual floods regularly damage fences, The existing Cattle Management Plan cattle into the allowing access for cattle to Purple-crowned will continue to be followed: fences are fenced Fairywren habitat (van Doorn 2007). checked every two weeks and translocation site intruding cattle are surveyed via might re-damage Inadequate maintenance of fences can provide helicopter at least quarterly. habitat. temporary access for cattle, inhibiting or reversing habitat restoration. The prompt removal of intruding cattle will likely prevent widespread damage Most flood damage to fences and cattle to developing canegrass. incursions occur at a time when cattle are dispersed in the landscape. Most cattle are Fence repairs and cattle removal will removed from fenced areas by the crucial be implemented as early as practical period when most damage to riparian following the wet season. vegetation occurs (mid to late dry season).

3 Failure to obtain Delays in the approval process could result in Applications for permits will be approvals to MRM missing the important window of time submitted within a suitable timeframe translocate. after suitable habitat has been restored by to allow for the translocation to take cattle exclusion, but before vacant territories place. have been naturally colonised by emigrants from neighbouring populations.

Delays could increase competition between translocated individuals and residents, resulting in a higher risk of failure.

4 Failure to Purple-crowned Fairywrens respond Netting will not take place when capture the vigorously to playback (Rowley and Russell fledglings are present. target population 1993) and are readily captured using mist nets within the mine as they respond to territorial incursions Group composition will be identified levee wall. simulated by call broadcast (van Doorn 2007). prior to netting, so that uncaptured individuals are not overlooked. Fledglings and some adults are wary and difficult to catch (van Doorn 2007). Failure to Pre-existing individual colour bands capture some individuals, especially one of and territory locations will used a the dominant birds of the group, may disrupt guide to identify members of groups. the group dynamics and lead to increased stress among the translocated birds. Every attempt will be made to translocate entire family groups concurrently.

The capture and translocation will be undertaken outside of the breeding season when it has been determined that there is no chance of eggs or young remaining at nest sites.

A final inspection of the habitat within the mine levee wall will be undertaken one month after translocation has been completed, to determine whether any individuals remain present. Any individuals that remain will be netted and transferred to the release site.

15 MRM OMP Supplementary EIS

Risk Description Likelihood and potential consequence Mitigation measures

5 Mortality/injury There was no mortality among 177 Purple- All handling of Purple-crowned during capture crowned Fairywrens captured/handled by van Fairywrens will be undertaken by and/or transport Doorn (2007). Of 319 individuals previously trained -banders possessing caught and banded at MRM, there have been appropriate licences from the no deaths or other incidents. Australian Bat and Bat Banding Scheme. Four deaths occurred during the translocation project for the Black and White Fairywren, Captured fairywrens will be possibly due to aggression between captive immediately transferred to the birds (Department of Environment and translocation site, rather than being Conservation 2011). This former project held held in captivity. individuals for up to 48 hours in captivity. The close proximity of the release location to Fairywrens will be stored in individual the capture location would preclude extended bags during transport, to avoid the holding times. potential for non-group members to be accidentally housed together. There is a small risk that Collared Sparrowhawks ( Accipiter cirrocephalus ) could Mist nets will be monitored at all times, kill Purple-crowned Fairywrens while they and captured birds will be removed are caught in mist nets (van Doorn 2007). immediately, to reduce the risk of depredation. The capture session will be suspended if any other risks to the welfare of the birds are detected.

Capture and movement will only be undertaken during the morning and during suitable seasonal conditions.

6 Disruption of the Purple-crowned Fairywrens are long-lived, All individuals belonging to a single social structure have long-lasting partnerships, and benefit social group will be captured and then of the from the help of offspring. Therefore, any released simultaneously at a single translocation disruption to the structure of social groups is location within the translocation site. group. likely to induce stress and reduce the success of subsequent breeding attempts.

16 Appendix U – Purple-crowned Fairywren Translocation Plan

6 Approach

6.1 Cattle Exclusion at the Translocation Site MRM currently manages a 3,391 ha livestock-free fenced area (containing 1,698 ha of remnant vegetation) surrounding active operations in accordance with a Cattle Management Plan. Fences are checked every two weeks and intruding cattle are surveyed via helicopter at least quarterly.

The current cattle-free area will be expanded to approximately 4,810 ha (containing 2,694 ha of remnant vegetation) to accommodate the McArthur River Mine Overburden Management Project (Figure 6-1). This will result in an additional 2.1 kilometres of the McArthur River that will be cattle- free. Once habitat has been restored along this fenced section of the river, there is the potential to support approximately 13 territories of Purple-crowned Fairywrens (assuming an average of one territory per 150 m of river: Kingma et al. 2009).

The fences around the cattle exclusion area will comprise an approximately 120 cm high four-strand barbed wire fences. Where the fence crosses the McArthur River, strainer assemblies will be installed on either side of the principal flood zone. This ensures that fences at high risk of damage by floodwaters are isolated from the main fence. The fence that crosses the McArthur River will have a minimal number of in-line wires, to reduce the amount of flood debris caught by the fence. The fence that crosses the McArthur River will be positioned in a straight section of the river, so that the fence itself does not lead to erosion.

17

Appendix U – Purple-crowned Fairywren Translocation Plan

6.2 Monitoring of Ecosystem Recovery from Grazing Prior to translocation, the translocation site should demonstrate recovery from the impacts of grazing. The key habitat attributes that are affected by grazing cattle are primarily components of the understorey (van Doorn 2007; Skroblin and Legge 2011). Prolonged grazing can also reduce canopy cover by inhibiting the regeneration of seedlings and saplings.

A comparison of the habitat attributes of 30 sites along the McArthur River with and without Purple- crowned Fairywrens revealed three habitat variables that were most correlated with fairywren presence: percentage canopy cover, percentage canegrass cover and percentage cover of ‘rainforest’ species (P. Barden, unpublished data, 2017). Sites supporting Purple-crowned Fairywrens tended to have: • ≥5% cover of cane grass and ≥20% canopy cover; or • 2-5% cover of cane grass and ≥30% canopy cover; or • ≥40% canopy cover and ≥30% cover of ‘rainforest’ species. These criteria predicted 10/12 sites where Purple-crowned Fairywrens were present, and 13/17 sites where Purple-crowned Fairywrens were absent. They, therefore, constitute useful preliminary benchmarks for determining suitability of habitat as a translocation site. Sites that fulfil one of the three criteria will be considered suitable as translocation sites. These criteria may be refined as more habitat data becomes available and the minimum requirements for a ‘vacant territory’ become better understood. Monitoring of habitat within potential translocation sites is to be undertaken in May-June, to correspond with the timing of the surveys on which the success criteria are based. Identifying potential translocation sites is to be a four-step process: Step 1: The entire length of the McArthur River within the translocation area will be traversed, and the most-suitable translocation sites (those with the most canegrass and/or canopy cover) will be identified through rapid visual assessment. Step 2: Any sites found to be most suitable in step 1 will be checked to ensure they are not already occupied by Purple-crowned Fairywrens. Step 3: In most-suitable sites identified in step 1 that lack Purple-crowned Fairywrens, the locations and approximate area (in m 2) of each canegrass patch will be recorded, using GPS and tape measures, respectively. Lengths of the river that support at least 300 m 2 of canegrass within a 1.5 ha stretch of riparian habitat (equivalent to 2% cover) qualify for Step 4. Step 4: Percentage cover of canopy and rainforest species is to be assessed in each 1.5 ha plot that supports ≥2% cover of canegrass. Percentage cover is to be estimated using a 150 m long transect, which runs perpendicular to the river through the middle of the 1.5 ha plot ( Figure 6-2). Foliage cover is to be assessed with a forestry densitometer at 150 one-metre intervals along the 150 m tape measure. The number of readings that intersect the foliage is to be multiplied by 2/3 to derive an estimate of percentage cover. Foliage is to be categorised into ‘rainforest’ and ‘sclerophyll’ species. The latter includes the following genera: Casuarina, Corymbia, Eucalyptus, Lophostemon and Melaleuca. Any genera not classified as sclerophyllous fall into the ‘rainforest’ category.

19 MRM OMP Supplementary EIS

150 m long transect to assess canopy cover

150 m 2 2 110 m 90 m

2 2 Upper bank zone, 2 70 m 120 m containing canegrass 5 m 2 5 m 100 m 100

Lower bank zone, containing Barringtonia

Figure 6-2 Schematic diagram of a potential Purple-crowned Fairywren vacant territory. Pale green polygons indicate canegrass clumps, the area of which (shown in green text) is measured in step 3 of the monitoring procedure. The boundary of the vacant territory (shown as an orange box) is determined by placing a 1.5 ha rectangle around ≥300 m2 of canegrass. In the above hypothetical example, there is only one location of this territory that meets the requisite cover of canegrass. Canopy cover is then assessed by running a 150 m transect (shown as a red dotted line) from the centre of the river channel through both the lower and upper bank zones. This transect is to pass through the centre of the vacant territory.

If the four monitoring steps reveal the potential territory to be vacant and fulfilling at least one of the three suitability criteria, the territory will be considered to be an appropriate translocation site for one family group. 6.3 Monitoring of Natural Recolonisation For translocation to be successful, not only should habitat at a translocation site be suitable for Purple- crowned Fairywrens, but the territory must be vacant (other Purple-crowned Fairywrens are absent). There is a period of time between the habitat assessments (in May-June) and the proposed translocations (in August-October), during which formerly vacant territories may be colonised.

To determine whether this is the case, fairywren surveys will be undertaken at 50 m intervals through each translocation site within the week prior to translocation. Surveys will also be undertaken at points 50 m upstream and downstream of the translocation site ( Figure 6-3), to allow for the detection of fairywrens that only partially overlap in range with the translocation site.

Fairywren surveys entail broadcasting a recording of a 1.5 minute long series of Purple-crowned Fairywren territorial duets, and listening and watching for responding individuals. This method is known to be highly effective for detecting occupied territories of Purple-crowned Fairywrens (Skroblin and Legge 2010). Translocation sites that are within 50 m of a positive record of a Purple- crowned Fairywren are considered to contain occupied territories and are not to be used for translocation.

20 Appendix U – Purple-crowned Fairywren Translocation Plan

150 m

100 m 100

Figure 6-3 Location of fairywren survey points (red stars) at translocation sites (orange box). 6.4 Approvals and Planning Prior to undertaking the translocation project, the following approvals and permits must be obtained:

• approval for MRM to undertake the Overburden Management Project must be obtained from the Northern Territory and Commonwealth Governments; • the Northern Territory Government must approve this Translocation Plan; • a Permit to Take or Interfere with Wildlife must be obtained from the Parks and Wildlife Commission of the Northern Territory; • a licence to undertake research involving under the Northern Territory Welfare Act; • approval to capture birds for research purposes by an approved animal ethics committee; and • the person(s) undertaking the capture and banding of Purple-crowned Fairywrens must have a current project approval and an A-class authority with mist net endorsement from the Australian Bird and Bat banding Scheme to capture and band birds. 6.5 Translocation Methodology Once monitoring of ecosystem recovery reveals the presence of suitable, vacant territories within the translocation area, translocation can occur.

Where possible, family groups will be captured simultaneously using mist nets. The number of nets employed per territory will depend on the density of vegetation within each territory, which limits the potential locations to install nets. Nets will be placed within known territories, rather than at the boundary between territories, to avoid capturing multiple groups simultaneously or disturbing neighbouring groups. Where passive capture cannot be undertaken, limited call playback will be used to lure the family group into the net(s). Nets will never be left unattended, and birds will be removed from the nets within five minutes of capture.

Once captured, birds will be removed from the nets and placed into individual cotton holding bags. Each bird will be banded with a numbered aluminium ring (13 mm, size 02) and an individual combination of split enamel metal colour bands or anodised (coloured) metal bands. Plastic colour bands may be used in some combinations but not in contact with the foot. The sex and approximate age of each bird will be recorded, along with its weight and tarsus length. The captured group will be immediately taken to the translocation site (20 min drive) and released.

21 MRM OMP Supplementary EIS

The aim of the translocation is to capture the entire group on a single morning, and translocate each group as a single unit. Groups with active nests will not be captured until nesting has been completed. Groups with young and dependent fledglings will also not be captured, as fledglings typically don’t approach mist nets (van Doorn 2007).

Translocations are to be undertaken in August to October, the period of the year in which breeding is unlikely, and temperatures and road conditions will facilitate safe capture and movement of the birds. 6.6 Timing Disturbance to Purple-crowned Fairywren habitat within the mine levee wall is scheduled to commence in 2021. The schedule of actions to be undertaken before this time is listed in Table 6-1.

Table 6-1 Schedule of actions

Date* Action*

May-Jun 2018 Monitor baseline ecosystem condition in the future translocation site prior to cattle removal.

Sep-Oct 2018 Construct cattle fence extension around the future translocation site †.

Oct-Nov 2018 Muster and remove any cattle within the exclusion area.

Feb 2019 Survey for intruding cattle and remove intruders.

May 2019 Survey for intruding cattle and remove intruders.

May-Jun 2019 Monitor ecosystem recovery after the first wet season, and determine whether supplementary planting of canegrass is required during the second wet season.

Aug 2019 Survey for intruding cattle and remove intruders.

Aug-Oct 2019 If ecosystem monitoring reveals that habitats are likely to be suitable for Purple-crowned Fairywrens in 2020, apply for permits to undertake the translocation in 2020.

Nov 2019 Survey for intruding cattle and remove intruders.

Jan-Apr 2020 If there was insufficient natural recruitment detected by the 2019 monitoring of ecosystem recovery, undertake planting of canegrass within the future translocation site.

Feb 2020 Survey for intruding cattle and remove intruders.

May 2020 Survey for intruding cattle and remove intruders.

May-Jun 2020 Monitor ecosystem recovery after the second wet season.

Aug 2020 Survey for intruding cattle and remove intruders.

22 Appendix U – Purple-crowned Fairywren Translocation Plan

Date* Action*

Aug-Oct 2020 If the 2020 ecosystem monitoring reveals that ecosystem recovery is adequate and territories are vacant, undertake translocation.

If the 2020 ecosystem monitoring reveals that ecosystems are likely to have recovered by 2021, apply for permits to undertake the translocation in 2021.

Nov 2020 Survey for intruding cattle and remove intruders.

Jan-Apr 2021 If there was insufficient recruitment of canegrass detected by the 2020 monitoring of ecosystem recovery, undertake supplementary planting of canegrass.

Feb 2021 Survey for intruding cattle and remove intruders.

May 2021 Survey for intruding cattle and remove intruders.

May-Jun 2021 Monitor ecosystem recovery after the third wet season.

Aug 2021 Survey for intruding cattle and remove intruders.

Aug-Oct 2021 If the 2021 ecosystem monitoring reveals that ecosystem recovery is adequate and territories are vacant, undertake translocation.

Nov 2021 Survey for intruding cattle and remove intruders.

Jan 2022+ Implement long-term monitoring program of the translocated population ( Section 7).

*This schedule is indicative, and is dependent on the success of habitat restoration and changes to the mining schedule. †Perimeter fences around the cattle exclusion area will be checked weekly (when weather permits) from November 2018. Damaged fences will be repaired immediately.

23 MRM OMP Supplementary EIS

7 Post-translocation Monitoring Program

Following translocation, the translocation site will be monitored in order to assess the success of the project. The monitoring programs to take place are described in the following subsections. 7.1 Habitat Monitoring 7.1.1 Methodology

Ecosystem recovery will continue to be monitored annually following the procedure described in steps 3 and 4 within Section 6.2. Once there has been no significant change in habitat quality over three successive years, habitat monitoring will reduce in frequency to once every three years.

The objectives of this monitoring are:

1) to determine the length of time for canegrass to fully recover from the removal of grazing pressure (i.e., habitat stabilisation in Figure 7-1), in order to inform other initiatives to restore habitat for Purple-crowned Fairywrens; 2) to characterise natural variation in habitat quality resulting from rainfall fluctuations (the size of fluctuations after habitat stabilisation in Figure 7-1); 3) to detect any long-term decline in habitat quality following habitat stabilisation, as might be expected from ongoing weed invasion, erosion, and/or other pressures external to grazing; and 4) to determine whether habitat quality (canegrass cover, canopy cover, rainforest cover) is maintained above the threshold considered to reflect habitat suitability for Purple-crowned Fairywrens (i.e., fluctuations after habitat stabilisation do not drop below the threshold shown in Figure 7-1).

24 Appendix U – Purple-crowned Fairywren Translocation Plan

ation

abitat abitat

Translocation can occur H stabilis

Threshold for habitat suitable for Purple-crowned Fai rywrens Canegrass cover canopy and

Time since cattle have been excluded

Figure 7-1 Expected trajectory of re-establishing canegrass following cattle exclusion. The light-shaded period is prior to translocation and the dark-shaded period follows translocation.

7.1.2 Triggers and Corrective Actions

In the event that natural fluctuations in habitat condition cause this habitat to be temporarily unsuitable for Purple-crowned Fairywrens in poor years (panel A in Figure 7-2), the following studies will be undertaken:

• Habitat condition within the long-fenced section of the McArthur River (known to contain a productive, stable population of Purple-crowned Fairywrens) will be assessed to determine whether the benchmarks currently used for habitat suitability (based on limited data) are appropriate. • Habitat data will be compared to fairywren population data within the translocation site (Section 7.2 ) to determine whether fluctuations in habitat quality below the suitability threshold are associated with severe mortality. Mortality is defined as severe when it takes more than one good breeding season for the population to recover to original densities (described further in Figure 7-3).

If the above studies suggest that the canegrass suitability thresholds are overly strict (i.e., similar habitats occur in nearby areas supporting stable fairywren populations, and fairywren populations within the translocation site do not severely decline when habitat falls in quality below the suitability threshold), the suitability thresholds will be adjusted accordingly.

25 MRM OMP Supplementary EIS

If the above studies suggest that fluctuations lead to frequent, severe declines in fairywren populations, and that such declines are not observed in nearby long-protected habitat, the causes for these fluctuations will be investigated. If necessary, additional restoration works may be undertaken at the site to increase the density of canegrass and other riparian vegetation. Such works may include planting and weed control.

[A] [B]

Figure 7-2 Scenarios that would trigger corrective action in the event that canegrass density and/or height was inadequate. Panel A shows high annual variation in canegrass that leads to regular temporary habitat deficiency. Panel B shows a gradual decline in habitat condition. Axes and thresholds marked on the charts are as for Figure 7-1.

In the event that a gradual, long-term decline in habitat suitability is observed (panel B in Figure 7-2), the potential causes of this decline will be investigated:

• Long-term trends in rainfall and erosion pressure will be investigated by comparing changes in habitat quality with weather patterns over the same period. • Weed data collected as part of the habitat monitoring (the density of all plant species, including weeds, is recorded in each transect) will be compared to data on canegrass, riparian grasses and native shrub density to determine whether competition with expanding weed populations is a potential cause of decline of native riparian vegetation. • Fire records will be consulted to ascertain whether increased fire frequencies could have caused long-term declines in canegrass. Further fire control measures (e.g., fire breaks) could be implemented if fire is determined to be a cause of the decline. 7.2 Monitoring of Translocated Individuals 7.2.1 Methodology

The population of Purple-crowned Fairywrens living within the translocation area will be surveyed twice annually, by broadcasting recordings of a 1.5 minute long series of Purple-crowned Fairywren territorial duets, and listening and watching for responding individuals. This will be done at 50 m intervals along the entire 2.1 km of the McArthur River contained within the translocation area.

The number of family groups, number of individuals per group, and the colour combinations of banded individuals will be recorded in each survey. Surveys will be undertaken at the start and end of the main breeding period (March-April and September-October, respectively) over the three years following translocation. Thereafter, surveys will be undertaken annually in September-October.

26 Appendix U – Purple-crowned Fairywren Translocation Plan

The aims of the monitoring program are:

1) to determine the success of translocation; 2) to monitor how the number of individuals and family groups change over time; and 3) to determine whether potential territories remain vacant over extended periods of time. 7.2.2 Triggers and Corrective Actions

The current project is the first known attempt at translocating Purple-crowned Fairywrens. With increasing fragmentation of the species’ habitat across its distribution, translocations are likely to be the only means of re-establishing the species in catchments where it has gone extinct. As such, it is important to quantify the success of the current translocation, to inform future efforts.

Translocation will be considered successful if:

• the translocation area ultimately supports a similar number of Purple-crowned Fairywrens as, or more than, the sum of the source population (~20 individuals) and the pre-existing population within the translocation area (~15 individuals); and • translocated individuals (identified from their bands) constitute at least 50% of the territory holders within the first breeding season at the translocation site. A failure of Purple-crowned Fairywrens to establish territories, or a predominance of unbanded territory-owners (which naturally colonised the site) would suggest that translocation has not been successful. The potential causes of failure would need to be addressed in future translocation attempts. For example, a failure of translocated individuals to establish territories, but successful natural colonisation, indicates that habitat restoration was successful but that translocation itself led to high mortality among moved individuals. Conversely, a small number of established territories dominated by translocated individuals might suggest that habitat restoration was only partly successful but translocation itself may be worthwhile in better habitats.

In addition to assessing the success of the translocation program, ongoing monitoring of the population at the translocation site will serve to track population size over time. Such data will be used to identify severe declines in response to annual environmental variation (see Section 7.1.2 ), as well as to detect long-term declines that may be driven by factors other than grazing (erosion, too frequent fire, weeds, etc). Figure 7-3 shows the expected population patterns indicative of the former, while the latter would appear as a pattern resembling panel B of Figure 7-2.

In the event of regular, temporary, severe declines, measures will be taken to improve the overall condition of riparian habitat, such that sufficient habitat is maintained even in years of poor rainfall. This may be achieved by weed control, and supplementary planting of canegrass and other riparian vegetation.

27 MRM OMP Supplementary EIS

Translocation

a d Threshold for habitat suitable for Purple-crowned c Fairywrens Canegrass (green) and density

fairywren (purple) size population b

Time since cattle have been excluded

Figure 7-3 A comparison between population recovery following a typical decline (a, c and d) and a severe decline (b). Severe declines, by definition, take more than one good breeding season for the population to recover to its original size. Severe declines are associated with a drop in habitat quality below a threshold value suitable for supporting Purple-crowned Fairywrens.

In the event of long-term population declines, the potential causes of this decline will be investigated:

• Long-term trends in rainfall and erosion pressure will be investigated by comparing changes in habitat quality with weather patterns over the same period, to assess if climatic variation is a potential cause of the long-term decline. • Weed data collected as part of the habitat monitoring (the density of all plant species, including weeds, is recorded in each transect) will be compared to data on canegrass density to determine whether competition with expanding weed populations is a potential cause of canegrass decline. • Fire records will be consulted to ascertain whether increased fire frequencies could have caused long-term declines in canegrass. Further fire control measures (e.g., fire breaks) could be implemented if fire is determined to be a cause of the decline.

28 Appendix U – Purple-crowned Fairywren Translocation Plan

7.3 Monitoring of Cattle and Fences 7.3.1 Methodology

Cattle and fence monitoring is described in the Cattle Management Plan. Fences are to be monitored weekly (where access is possible) and cattle are to be monitored via helicopter at least quarterly.

7.3.2 Triggers and Corrective Actions

Damaged fences are to be repaired, where practicable, within one week of detection. Intruding cattle are to be mustered and removed from the exclusion area. 7.4 Reporting The results of monitoring will be recorded in the following ways:

• Results of fortnightly fence inspections and quarterly surveys of cattle within the exclusion area will be recorded in a log maintained by the MRM Superintendent – Environment and Community. • An annual report will present and discuss the results of annual habitat and population assessments within the translocation area. • The success of the translocation project will be assessed in a final report, to be completed once habitat quality has stabilised in the translocation area.

29 MRM OMP Supplementary EIS

8 References

Baldassarre, D.T. and M.S. Webster. (2013) Experimental evidence that extra-pair mating drives asymmetrical introgression of a sexual trait. Proceedings of the Royal Society B: Biological Sciences 280 , 20132175-20132175. Brooker, L.C. and M.G. Brooker (2002). Dispersal and population dynamics of the blue-breasted fairy- wren, Malurus pulcherrimus , in fragmented habitat in the Western Australian wheatbelt. Wildlife Research 29, 225-233. Department of Environment and Conservation (2011). Gorgon Gas Development: Threatened and Priority Species Translocation and Reintroduction Program Annual Report 2010/2011. Annual report for the Threatened and Priority Species Translocation and Reintroduction Program Account. Double, M. and A. Cockburn (2000). Pre-dawn infidelity: females control extra-pair mating in superb fairy-wrens. Proceedings of the Royal Society of London B: Biological Sciences 267, 465-470. EMS (2008). McArthur River riparian bird colour banding project: August & November 2007. Report prepared for McArthur River Mining/Xstrata by Ecological Management Services Pty Ltd, Coolum Beach. EMS (2011). McArthur River riparian bird monitoring: October 2010. Report prepared for McArthur River Mining/Xstrata by Ecological Management Services Pty Ltd, Coolum Beach. EMS (2012). McArthur River riparian bird monitoring: November 2012. Report prepared for McArthur River Mining/Xstrata by Ecological Management Services Pty Ltd, Coolum Beach. EMS (2014). McArthur River riparian bird monitoring: Late Dry Season September 2014. Report prepared for McArthur River Mining by Ecological Management Services Pty Ltd, Coolum Beach. EMS (2016). McArthur River riparian bird monitoring: July 2016. Report prepared for McArthur River Mining by Ecological Management Services Pty Ltd, Coolum Beach. EMS (2017). ). McArthur River riparian bird monitoring: October-November 2016. Report prepared for McArthur River Mining by Ecological Management Services Pty Ltd, Coolum Beach. Evans, C. and S. Kleindorfer (2016). Superb Fairy-wren ( Malurus cyaneus ) sons and daughters acquire song elements of mothers and social fathers. Frontiers in Ecology and Evolution 4:9. doi: 10.3389/fevo.2016.00009 Hall, M. and A. Peters (2008). Coordination between the sexes for territorial defence in a duetting fairy-wren. Animal Behaviour 76, 65-73. Kingma, S.A., M.L. Hall, G. Segelbacher and A. Peters (2009). Radical loss of an extreme extra-pair mating system. BMC Ecology 9, 5. Kingma, S.A., M.L. Hall, E. Arriero and A. Peters (2010). Multiple benefits of cooperative breeding in purple-crowned fairy-wrens: a consequence of fidelity? Journal of Animal Ecology 79, 757-768. Lantz, S.M. and J. Karubian (2016) Male Red-backed Fairywrens appear to enhance a -based signal via adventitious molt. The Auk 133 :3, 338-346. Legge, S., S. Murphy, R. Kingswood, B. Maher and D. Swan (2011). EcoFire: restoring the biodiversity values of the Kimberley region by managing fire. Ecological Management and Restoration 12, 84-92. Rowley, I. and E. Russell (1993). The Purple-crowned Fairy-wren Malurus coronatus. II. Breeding Biology, Social Organisation, Demography and Management. 93, 235-250.

30 Appendix U – Purple-crowned Fairywren Translocation Plan

Skroblin, A. (2012). Phylogeography and Conservation Biology of the Purple-crowned Fairy-wren, Malurus coronatus . Ph.D. thesis, the Australian National University, . Skroblin, A. and S. Legge (2010). The distribution and status of the western subspecies of the Purple- crowned Fairy-wren ( Malurus coronatus coronatus ). Emu 110, 339-347. Skroblin, A. and S. Legge (2011). The influence of fine-scale habitat requirements and riparian degradation on the distribution of the purple-crowned fairy-wren ( Malurus coronatus coronatus ) in northern Australia. Austral Ecology 37, 874-884. Thomas, N., A. Burbidge and S. Garretson (2014). Hermite Island Fauna Reconstruction. Information Sheet 76/2014, Science and Conservation Division, Department of Parks and Wildlife, Western Australia. van Doorn, A. (2007). Ecology and conservation of the purple-crowned fairy-wren ( Malurus coronatus coronatus ) in the Northern Territory, Australia. Ph.D. Thesis, University of Florida. van Doorn, A., J.C.Z. Woinarski and P.A. Werner (2015). Livestock grazing affects habitat quality and persistence of the threatened Purple-crowned Fairy-wren Malurus coronatus in the Victoria River District, Northern Territory, Australia. Emu 115, 302-308. Webster, M.S., K.A. Tarvin, E.M. Tuttle and S. Pruett-Jones (2004). Reproductive promiscuity in the splendid fairy-wren: effects of group size and auxiliary reproduction. Behavioral Ecology 15, 907- 915.

31