Assessment of the Potential Effects of the Proposed Waitaha Hydro Scheme on Vertebrate Fauna ( and Bats).

Report for Westpower Ltd by Wildlife Surveys Ltd

June 2014

Rhys Buckingham 42 Aranui Road Mapua [email protected] 03 540 2365

Wildlife Surveys 2014 Terrestrial fauna Waitaha Hydro Scheme

Table of Contents

Executive Summary ...... i 1. Introduction ...... 1 2. Proposed Development Plan (as at November 2013) ...... 2 3. Field Survey for Terrestrial Fauna, November and December 2012 ...... 5 3.1. Objectives ...... 5 3.2. Description of Survey Area and its surroundings ...... 5 3.3. Survey Methodology ...... 9 3.3.1. Bats ...... 9 3.3.2. Fernbirds ...... 11 3.3.3. Other birds ...... 14 3.3.4. Powelliphanta land snails ...... 14 3.4. Results ...... 14 3.4.1. Summary ...... 14 3.4.2. Bats ...... 15 3.4.3. Fernbirds ...... 20 3.4.4. Other birds ...... 21 3.4.5. Audio Recordings ...... 27 3.4.6. Powelliphanta snails ...... 28 4. General Discussion ...... 29 4.1. Short-tailed bats ...... 29 4.2. Long-tailed bats ...... 29 4.3. Birds ...... 30 4.3.1. Fernbirds ...... 30 4.3.2. Comparison with 2006-2007 baseline survey ...... 31 4.4. Powelliphanta snails ...... 31 5. Significance and Natural Values of Terrestrial Fauna within the Survey Area ...... 32 5.1. Summary of Significance ...... 38 6. Predicted Effects of the Scheme on Bats, Birds and Powelliphanta Snails ...... 39 6.1. Bats ...... 40 6.1.1. Bat roosts ...... 40 6.1.2. Bat foraging behaviour ...... 41 6.1.3. Bat commuting routes ...... 42 6.1.4. Summary of effects on bats ...... 42

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6.2. Birds ...... 43 6.2.1. Fernbirds ...... 43 6.2.2. Hole-nesting birds ...... 43 6.2.3. Other forest or non-riverine birds ...... 43 6.2.4. Riverine birds ...... 44 6.2.5. Summary of effects on birds ...... 46 6.3. Miscellaneous potential effects on terrestrial fauna by the Scheme ...... 47 7. Mitigation ...... 48 8. Monitoring ...... 51 9. Conclusion...... 52 Acknowledgements ...... 53 References ...... 54 Appendices ...... 59 Appendix 1. Birds referred to in report (in checklist order after Gill et al. 2010) ...... 59 Appendix 2. Bat Detector Sites and Records ...... 61 Appendix 3. Audio Recorder sites and results ...... 62 Appendix 4. Threatened, At Risk and infrequent records (2006-07 and 2012) ...... 63 Appendix 5. Results of bat surveys 2006/2007 ...... 65 Appendix 6. Distribution maps of Threatened, At Risk and selected Not Threatened indigenous bird in Waitaha fauna survey area, 2006-2007...... 66

List of Figures Figure 1. Survey Area and proposed Scheme footprint as at 14 November 2013 ...... 2 Figure 2. Location of bat detectors within the survey area ...... 11 Figure 3. Fernbird transects and call playback sites ...... 12 Figure 4. Acoustic recorder sites for bird survey ...... 13 Figure 5. Bat survey results in 2012 ...... 16 Figure 6. Bat pass activity rates in the lower Waitaha Valley ...... 18 Figure 7. Comparisons of mean bat pass rates at three sites downriver of Macgregor Creek (Macgregor Junction, 'Scrub bank' and High bank') and the Flat Site ...... 18

Figure 8. Mean bat pass rates in various habitats ...... 19 Figure 9. Bat activity throughout the night at various locations ...... 19 Figure 10. Bat activity during November and December 2012 at various locations within the survey area ...... 20

Figure 11. Records of , kaka, and in 2012 ...... 23

Figure 12. Records of long-tailed cuckoo and shining cuckoo in 2012 ...... 25

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Figure 13. Records of kereru and in 2012 ...... 26 Figure 14. Records of brown creeper, and robin in 2012 ...... 27

List of Tables Table 1. Indicative areas (in hectares) of vegetation potentially affected by each of the Scheme's components (after TACCRA 2013) ...... 4

Table 2. Mean bat pass rate/night at different locations on the West Coast ...... 17 Table 3. Threat status and abundance of Threatened and At Risk species recorded in the Scheme area (Threat status for birds from Robertson et al. (2013) and for bats from O’Donnell et al (2010)) ...... 22

Table 4. Criteria for determining significance for the purposes of Section 6(c) of the RMA, RPS, WDP and Natural Heritage Values of the CMS ...... 33

Table 5. Summary of significance (RPS and WDP) and natural heritage values (CMS) ...... 38 Table 6. Riverine birds recorded in the Waitaha Valley and level of potential effect from the Scheme (information after Heather & Robertson 1996) ...... 45

List of Plates Plate 1a. Low stature shrub hardwood on alluvial terrace extending to mature podocarp hill forest on the true right of the Waitaha River above Morgan Gorge ...... 6

Plate 1b: Looking up valley toward Morgan Gorge………………………………………………………………..7

Plate 1c: Mosaic of different habitat types within the survey area above the junction of Macgregor Creek and Morgan Gorge …………………………………………………………………….………………7

Plate 1d: Abrupt forest edge with foreground rank grasses and tree fern on the true left of Macgregor Creek not far from its confluence with the Waitaha River ……………………………..8

Plate 1e: Backwater of the lower Waitaha River near ‘Doughboy Hill’ showing disturbed vegetation (gorse common) and regenerating podocarp/hardwood forest on the hill slopes……………………………………………………………………………………………………………………………………8

Plate 2a & b. Digital bat detectors used in survey ...... 10

Plate 3. Fernbird habitat upper Kiwi Flat...... 21

Plate 4. Kea at Robinson Slip ...... 24

Report Version Status: Final.

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Executive Summary

Overview Westpower Ltd via ElectroNet Services Ltd commissioned Wildlife Surveys Ltd to undertake a baseline fauna survey for bats, fernbirds and Powelliphanta snails, mainly in the lower part of the Waitaha River below Morgan Gorge, but also at Kiwi Flat. The survey undertaken in November and December 2012 was part of an assessment of environmental effects for Westpower Ltd’s proposed Waitaha Hydro Scheme (the Scheme). This report includes:  the proposed development plan (as at November 2013);  description of the survey area, objectives, methods and results of the 2012 survey;  a discussion of 2012 survey results in context with past fauna surveys in the Waitaha Valley;  a discussion of the significance of fauna in terms of the West Coast Regional Policy Statement 2000 (the RPS) and the Westland District Plan 2002 (the WDP);  an assessment of natural values in terms of the West Coast Conservation Management Strategy 2010-2020 (the CMS);  a description of potential effects of the Scheme on fauna; and  suggestions for mitigation and monitoring potential effects of the Scheme on fauna.

The proposed development plan (as at November 2013) Westpower Ltd is proposing the development of a run-of-river hydroelectricity generation scheme on the Waitaha River, South Westland. The Scheme involves diverting water from the Waitaha River above Morgan Gorge through a tunnel to a powerhouse located on the true right flats below Morgan Gorge. Preliminary design concepts have been prepared. The headworks located just above Morgan Gorge on the true right of Kiwi Flat include a low weir, intake channel and associated structures, an intake access road and temporary contractor facilities. The lower valley infrastructure includes a tunnel portal exit, an access road and parallel transmission line leading from the powerhouse and switchyard, a tailrace to convey water from the powerhouse back to the river, and stopbank and flood protection where required.

Field survey area and objectives (2012) A field survey was carried out in early summer 2012 to extend knowledge of terrestrial fauna (bats, birds and Powelliphanta snails) obtained on earlier surveys (Overmars & Buckingham 2007) and address information gaps that were discussed at an Options Selection workshop held in Christchurch on 11 October 2012 (Westpower 2012). The survey area included lowland hillside forest, valley floor and riverine habitats below Morgan Gorge, and forest and scrub habitats surrounding Kiwi Flat.

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The objectives (listed below) were selected to obtain additional information required for bats, fernbirds and Powelliphanta land snails.  To determine whether bats are present below Morgan Gorge, and if so what species are present;  to evaluate the extent of bat activity (if any) below Morgan Gorge and at a site near the proposed tunnel portal entrance above Morgan Gorge;  to evaluate the presence/absence, distribution and relative abundance of fernbirds (and other birds) within the survey area; and  to evaluate the presence/absence of Powelliphanta land snails by searching for shells on the ground surface, particularly at Kiwi Flat where shells were found in 2007 and 2011.

Survey methods (2012) Field survey methods were chosen to provide robust baseline data that could be compared to the results of previous surveys (Overmars and Buckingham 2007). High sampling intensities were required to detect bats and fernbirds, which were expected to be in relatively low densities within the survey area. The survey for bats involved using 20 digital bat detectors widely spaced in a range of habitats from Kiwi Flat to Doughboy Hill (near the end of Waitaha Road on the east bank). These were left in the field to automatically record bats over a 45-night period from 12 November to 27 December 2012. The survey for fernbirds involved playback of recorded fernbird calls in suitable habitat (e.g. scrubland, wetland, forest edge) below Morgan Gorge and at Kiwi Flat. Acoustic recorders were also used for automatic surveillance in suitable fernbird habitat areas below Morgan Gorge. These recordings were reviewed for all birdcalls using Song Scope™ software. All birds encountered during the field survey, or detected on acoustic recording devices were listed. Species were ranked using the Department of Conservation (DOC) threat classification list (Robertson et al. 2013) and comparisons were made with previous surveys in the lower/mid Waitaha Valley (Overmars and Buckingham 2007). A search was made for Powelliphanta snails in scrub habitat at Kiwi Flat and other potentially suitable habitat for snails below Morgan Gorge in 2012. This involved searching for Powelliphanta shells on the ground surface during walkthrough surveys using standard methodology (after Walker 1997).

Survey results (2012) Long-tailed bats (Nationally Critical) were found throughout the survey area from Doughboy Hill in the lower valley to Kiwi Flat. This was an extension of the known long-tailed bat range, as they were not detected below Morgan Gorge in 2007 (Overmars & Buckingham 2007) and I know of no earlier records at that location. While very low long-tailed bat activity was recorded between Macgregor Creek and Morgan Gorge, moderate bat activity occurred near the river terrace downriver of Macgregor Creek confluence. Highest bat activity was recorded at the single surveillance site located close to the proposed tunnel portal intake above Morgan

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Gorge. There was no indication from activity data that detectors were deployed close to a bat roost at any site (none of the detectors recorded the high levels of bat activity in the early evening and morning that are typically associated with bats leaving and returning to a nearby active colonial roost). No short-tailed bats were detected. No fernbirds (At Risk: Declining) were detected, even in habitats that seemed ideal for fernbirds (notably a wetland in the upper part of Kiwi Flat where fernbirds were recorded in September 2006). A total of 38 bird species (26 indigenous/endemic and 12 introduced) were recorded during November and December 2012. This compared to 35 bird species (27 indigenous and 8 introduced) recorded during combined 2006 and 2007 surveys (Overmars & Buckingham 2007). In total, five Threatened and five At Risk bird species were recorded in the survey area (2006/2007 & 2012). Threatened bird species included blue (Nationally Vulnerable), grey duck (Nationally Critical), falcon (Nationally Vulnerable1), kaka (Nationally Vulnerable) and kea (Nationally Endangered). At Risk species included black shag (Naturally Uncommon), South Island pied oystercatcher (Declining), long-tailed cuckoo (Naturally Uncommon), South Island fernbird (Declining) and New Zealand pipit (Declining). Threatened and At Risk species were generally recorded infrequently and had localised distributions. Exceptions were falcon, kea and long-tailed cuckoo, which were all encountered more frequently than expected on both surveys. Blue and grey ducks were not encountered during the terrestrial fauna surveys in 2012, however they were not specifically surveyed then. Western weka (Not Threatened) had a localised distribution, being most conspicuous near the scrub edges surrounding Robinson Slip and also present at Kiwi Flat. No sign of kiwi was found during either survey. Moreporks (Not Threatened) were not recorded in 2012 and their scarcity was noted during 2006/2007 surveys. Small indigenous Not Threatened birds such as bellbird, and were common throughout relatively unmodified habitats. and robins were not encountered in modified scrubby habitat downriver of Robinson Slip in 2012. No Powelliphanta snails or empty shells were found during the 2006/2007 and 2012 fauna surveys. One empty shell, presumably washed downriver, was found near the confluence of Whirling Water and the Waitaha River in May 2007 (McLennan 2007a) while another shell was found at a similar site (true right, Whirling Water about 100m from its confluence) in June 2011 (F. Overmars, pers. comm.).

General discussion of baseline survey results (2006/2007 and 2012)

Bats Combined survey results suggest that short-tailed bats are unlikely to be present within the lower Waitaha Valley. Introduced mammalian predators are assumed to

1 Currently listed as Taxonomically Indeterminate (Robertson et al 2013)

iii Wildlife Surveys 2014 Terrestrial fauna Waitaha Hydro Scheme be the most likely reason for the disappearance of short-tailed bats and the shrinkage of long-tailed bat populations in remote forest locations in the South Island. Results from a number of bat surveys in the West Coast region indicate that there is a regionally significant long-tailed bat population in the survey area, with a core population at Kiwi Flat. Bat activity data within the survey area indicated two preferred areas for foraging (above Morgan Gorge and downriver of Macgregor Creek). While there was ample roosting habitat for bats near where detectors were placed at Kiwi Flat (2006/2007 and 2012), there was sparse or no roosting habitat for bats in the lower part of the valley (below the confluence of Macgregor Creek) where moderate activity of bats was recorded. It is possible that long-tailed bats fly between Kiwi Flat and the lower valley for foraging.

Fernbirds The absence of fernbird records in the survey area during November and December 2012 does not necessarily mean they are absent, but suggests very low numbers if they are present. Fernbirds can be cryptic at certain times of the year, but they tend to be most conspicuous during their peak-breeding season (November and December) when the 2012 survey was undertaken. Fernbirds are good dispersers and thus might frequent the Waitaha Valley from time to time.

Other birds Terrestrial bird distributions and relative abundances were similar in 2012 to those recorded in 2006-2007 (Overmars & Buckingham 2007). For example, species such as kaka, kakariki, weka, kereru, rifleman and robin were recorded in low numbers on both surveys with more or less the same patchy distribution patterns. As in 2006-07, the indigenous : tomtits, grey warblers, bellbirds and were common throughout. The differences in bird species and relative abundances between survey years are probably related to differences in survey coverage as well as seasonal influences. The 2006-2007 survey largely focused at more unmodified forest ecosystems surrounding Kiwi Flat and the high terraces in the lower valley, while the 2012 survey focused on valley floor ecosystems in the lower valley, which were variably modified. The western weka population at the Waitaha is of special note, as it appears that it is a remnant population, isolated from the population further north on the West Coast. If weka have been separated from other populations for some time, the population may display unique genetic characters. The threat status of Western weka has recently been changed from ‘At Risk’ to ‘Not Threatened’ (Robertson et al 2013).

Powelliphanta snails Living populations of Powelliphanta are unlikely to be present in the survey area given the search effort to date. It is considered most likely that the shells found at Kiwi Flat in 2007 and 2011 were washed downstream in a flood, rather than representing snails living in the vicinity. The only known Powelliphanta snail species present in the general area is restricted to alpine habitats, very likely including the headwater catchments of the Waitaha River.

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Significance (RPS & WDP) and Natural Values (CMS) of terrestrial fauna The survey area contains areas of significant habitat for indigenous fauna based on assessment of guidelines/criteria for significance set out in the RPS (Policy 9.2 (a)-(p)) and the WDP (Policy 4.9D(i)-(viii)), and accordingly have high natural heritage values based on assessment criteria in the CMS (Policy 3.3.2.3(1)). The area’s significance is largely defined by the relative intactness of the proposed footprint, the presence and representativeness of Threatened and At Risk species, and the potential distinctiveness of at least one species (western weka). The small scale of the Scheme and its minimal effect on significant habitats and natural heritage values greatly reduces the level of potential effects in terms of the RPS, WDP and CMS. All species and their habitats found within the Scheme footprint are well represented elsewhere.

Assessed potential effects on terrestrial fauna caused by the Scheme Loss of faunal habitat and potential direct loss of fauna during the construction phase (particularly during breeding) are the main adverse effects on terrestrial fauna caused by the Scheme. However, overall effects are considered negligible, given the small size of the Scheme’s construction footprint (c. 4.53 ha of vegetation affected) and that it largely avoids significant terrestrial faunal habitat such as mature forest. The project design has aimed at minimising where possible effects on terrestrial fauna. Key elements of the design that make this feasible are:  decision not to build a road into Kiwi Flat;  using underground tunnels for transporting water from the intake (just above Morgan Gorge) to the powerhouse (below Morgan Gorge);  selecting an option of tunnel and intake (known as Option B) where overall effects on fauna were considered by experts to be minimal;  low weir design to minimise the area of backwater effect above the weir;  minimising the areas of construction and mature forest removal at the tunnel portal entrance and exit, and other components of the footprint;  reducing the length of the abstraction reach by locating the powerhouse closer to Morgan Gorge;  avoiding or minimising disturbance to stable tributaries as these have particular importance for aquatic fauna;  designing structures that minimise effects of sedimentation and consequent habitat effects;  positioning the access road to the powerhouse along valley flats that comprise least important habitat for terrestrial fauna;  aligning the power transmission line along the access road from the powerhouse to reduce habitat clearance; and  eliminating or reducing the risk of birds getting electrocuted by transmission wires. Although riverine birds and bats may be indirectly affected (positive or adverse) by any change to their food source or breeding habitat caused by changes in river flows or sedimentation, I consider that these effects are likely to be negligible given that:

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 Scheme design and proposed mitigation aim to avoid or minimise potential effects;  Threatened or At Risk birds are relatively scarce within the abstraction reach;  the abstraction reach is only 2.6 km;  productivity of aquatic fauna is relatively low in the main stem compared to stable tributaries that are either not affected, or minimally affected by the Scheme (McMurtrie & Suren 2014); and  sediment accumulation is unlikely given the frequent flooding events (Allen & Hay 2013; Doyle 2013; Hicks 2013). Other potential effects of the Scheme on terrestrial fauna include:  improving access to predators (such as dogs) by construction of new roads (but only in the lower valley from Macgregor Creek to the proposed powerhouse);  increased risk of road kills, especially during the construction period;  noise and disturbance caused by humans and machinery (also mainly during the construction phase); and  lighting from the powerhouse and intake (very localised and intermittent) this may be a positive effect for bats and moreporks, while an adverse effect for their prey: i.e. flying (McMurtrie & Suren 2014). Minor positive effects other than from lighting might include power poles being used as perches or roosts for some birds, and road access routes being used by bats for navigation. Based on reasons discussed above and mitigation proposed, overall effects of the Scheme on terrestrial fauna (i.e. bats and birds except , which are covered elsewhere) are negligible in my opinion, especially in context with the ongoing current threat of predators on indigenous fauna within the Waitaha Valley.

Mitigation The Scheme design has largely avoided adverse effects on terrestrial fauna (bats and birds) within the Waitaha Valley. Other recommended mitigation to further reduce effects on terrestrial fauna includes:  minimising where possible the effects of construction activities within the main breeding season for bats and birds (spring and early summer) at particularly sensitive areas (e.g. tunnel portal entrance and other headworks sites where large-diameter trees are to be removed);  a survey for potential and occupied bat roost trees within the proposed construction sites immediately prior to construction;  a survey to detect nesting kaka within the proposed construction sites (carried out at the same time as the bat roost survey);  reducing road speeds to minimise road deaths of birds such as weka and kereru (use of road signs and staff induction);  ensuring all food and rubbish is collected and removed from the site promptly to avoid local pest problems, or encourage scavenging behaviour from kea or weka; and

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 implementing measures to reduce dog access to the Waitaha Valley (signage, and advocacy).

Monitoring Given the assessed negligible effects of the Scheme on terrestrial fauna, I see no particular benefit in carrying out specific monitoring on any terrestrial fauna covered in this report, although bats should be monitored if they are to be managed by predator control. Notwithstanding, monitoring would need to be carried out for pest and weed control management, and for physical effects (e.g. changes in river flow, sedimentation, streamside erosion) that might affect fauna and faunal habitat. Details of this monitoring are outside the scope of this report and would be covered as part of relevant concession and resource consent conditions, and management plans.

Conclusion  The November–December 2012 survey extended the known range of long- tailed bats from Morgan Gorge to the lower valley downriver of Macgregor Creek. Short-tailed bats were not detected and are very unlikely to be present.  The abundance and distribution of bird species including Threatened and At Risk species were found to be similar to that recorded in 2006/2007. The combined baseline surveys provide a comprehensive knowledge of terrestrial fauna within the mid to lower Waitaha Valley.  The Scheme location and surrounding areas are considered significant in terms of the RPS and WDP, and of high natural value in terms of the CMS. This is mainly due to the presence of several Threatened and At Risk fauna, high representative values for long-tailed bat and blue duck, and the potential distinctiveness of at least one species (western weka).  Notwithstanding these overall level of significance and natural heritage values, all species recorded have a wide distribution range, and similar habitats are found widely throughout the West Coast.  Given the small and linear footprint of the Scheme, its design and the proposed mitigation, the Scheme is predicted to have negligible effect on terrestrial fauna values currently present in the Waitaha Valley.  Predators are considered to be a far greater threat to terrestrial fauna in the Waitaha Valley than any adverse effects caused by the Scheme. The absence of short-tailed bats, kiwi and relatively low numbers of Threatened bird species and individuals are indications of high predation levels in the Waitaha Valley.  While the design of the Scheme has largely contributed to the assessed negligible adverse effects on terrestrial fauna (bats and birds), in my opinion effects will be further reduced if mitigation and associated monitoring as described in this report are followed.

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1. Introduction Westpower Ltd (Westpower) via ElectroNet Services Ltd commissioned Wildlife Surveys Ltd to undertake a baseline fauna survey for bats, fernbirds and Powelliphanta snails mainly in the lower part of the Waitaha River below Morgan Gorge, but also at Kiwi Flat. The survey was undertaken in an area proposed to be part of the Waitaha Hydro Scheme (the Scheme) (Figure 1). This survey was carried out in November and December 2012 and involved three separate trips. The survey aimed to increase knowledge of terrestrial fauna values, building on information obtained in comprehensive fauna surveys carried out in 2006 and 2007 (Overmars & Buckingham 2007). In particular, the 2012 survey aimed to verify the presence/absence of bats and fernbirds below Morgan Gorge. The decision to carry out these further surveys resulted from recommendations given at an Options Selection workshop held in Christchurch on 11 October 2012 (Westpower 2012). Comprehensive terrestrial fauna surveys carried out in 2006 and 2007 in the central and lower part of the Waitaha Valley (Overmars & Buckingham 2007) recorded a number of threatened species (after Hitchmough et al. 2007). Significant regional populations of long-tailed bat (Chalinolobus tuberculatus) and blue duck2, as well as lower-density populations of other threatened fauna such as kaka and western weka were found during these surveys. Highest faunal values were found at Kiwi Flat, and surrounding forest and riverine habitats. No bats were recorded below Morgan Gorge then. Scant records of blue ducks were obtained below the gorge, including sightings and faecal sign (Overmars 2013; Overmars & McLennan 2010). Fernbirds were recorded at only one locality on one occasion: in scrub on the north side of Kiwi Flat in September 2006 (Fred Overmars, pers. comm.). Bat records from the 2006/2007 fauna survey (Overmars & Buckingham 2007) are found in Appendix 5 and records for Threatened, At Risk and other birds from this survey are found in Appendix 6. Small introduced mammals: possums (Trichosurus vulpecula), (Mustela erminea), ship (Rattus rattus) and mice (Mus musculus) were common throughout, at abundance levels that would threaten many indigenous fauna including , lizards and forest birds (MacLennan 2007a & b). Comparative analyses indicated that the mouse and populations at the Waitaha Valley were behaving in much the same way as those in a botanically similar forest at Sanctuary, 40 km away. This report describes and discusses the results of the 2012 survey in comparison with earlier surveys. The report also outlines the significance of terrestrial fauna in the Scheme and surrounds, discusses potential adverse (and positive) effects, and suggests various options for mitigating adverse effects.

2 Scientific names of birds given in Appendix 1

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Figure 1. Survey Area and proposed Scheme footprint as at November 2013

2. Proposed Development Plan (as at November 2013) Westpower is proposing the development of a run-of-river hydroelectricity generation project on the Waitaha River, South Westland. The Scheme proposal involves diverting water from the Waitaha River above Morgan Gorge through a tunnel to a powerhouse located on the true right flats below Morgan Gorge.

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Preliminary design concepts have been prepared. The headworks, which are located just above Morgan Gorge on the true right of Kiwi Flat include a low weir, intake channel and intake portal entrance and associated structures, an intake access road and temporary contractor’s facilities. The lower valley infrastructure includes a tunnel portal exit, an access road and parallel transmission line leading from the powerhouse and switchyard, a tailrace to convey water from the powerhouse back to the river, and stopbank protection where required. The tunnel is approximately 1.5 km long, while the abstraction reach (section of river between the weir and where water returns to main river from the tailrace) is approximately 2.6 km. The total vegetated footprint has been calculated as c. 4.53 ha affected by construction and c. 3.69 ha of permanent disturbance. Table 1 provides a more detailed description of the Scheme’s components. Physical effects of this construction are:  The section of weir across the river channel is likely to be 4-5m high at which level there will be no storage.  After construction of the weir, at baseflows there will be a temporary backwater effect that might initially extend some 250-300 m upstream but no permanent formation of a lake, or submergence of vegetation.  Disturbance of c. 4.53 ha of various vegetated habitats by various components of construction (Table 1).  Overall, only a very small area of large trees (hardwood >60 cm dbh and podocarp >30 cm dbh) will be affected (TACCRA 2013).

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Table 1. Indicative areas (in hectares) of vegetation potentially affected by each of the Scheme's components (after TACCRA 2013)

Scheme Component(s) Construction Permanent Riparian (Construction)

Area 1: Headworks and Associated Infrastructure Item(s)

Weir. 0.0050 0.0010 0.0

Intake Channel. 0.0325 0.0163 0.0

Intake Structure and Intake Portal. 0.0478 0.0278 0.0294

Tunnel Portal Entrance. 0.0187 0.0187 0.0

Tunnel Portal Entrance Apron, Intake Access Road 0.1370 0.0790 0.0410 and River Protection at Road Toe.

Road to Contractor’s Facilities Area. 0.1040 0.0 0.0300

Contractor’s Facilities Area. 0.2200 0.0 0.0

Flushing Tunnel Outlet. 0.0100 0.0100 0.0100

Area 1 Subtotals 0.5750 0.1528 0.1104

Area 1 Subtotals Rounded Up 0.58 0.16 0.12

Area 2: Infrastructure Item(s)

Tunnel Portal Exit and Construction Apron. 0.2480 0.1800 0.0

Access Road and Transmission Line Parallel. 2.5470 2.4198 0.0450

Waterway Training and Flood Protection at Alpha 0.3375 0.1688 0.1750 Creek.

Powerhouse, Switchyard and Hard-fill Area. 0.3150 0.3150 0.0

Powerhouse to Tunnel Portal Exit Access Road and 0.1275 0.1275 0.0 Penstock.

Tailrace. 0.2000 0.2000 0.0250*

Stopbank as River Protection for Powerhouse, 0.1755 0.1169 0.1755 Switchyard, Tailrace, Penstock and Access Road.

Area 2 Subtotals 3.9505 3.5280 0.4205

Area 2 Subtotals Rounded Up 3.96 3.53 0.43

Scheme Totals 4.5255 3.6808 0.5309

Scheme Totals Rounded Up 4.53 3.69 0.54 Note: Areas do not include non-vegetated zones affected by work components or parts thereof, e.g. where these are on exposed bedrock, in active riverbed, or other barren land prior to construction (TACCRA 2013).

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3. Field Survey for Terrestrial Fauna, November and December 2012 A field survey was carried out in early summer 2012 to extend knowledge of terrestrial fauna obtained on earlier surveys (Overmars & Buckingham 2007) and address information gaps that were discussed at an Options Selection workshop held in Christchurch on 11 October 2012 (Westpower 2012). The 2012 Survey Area (Figure 1) included lowland hillside forest, valley floor and riverine habitats below Morgan Gorge, and forest and scrub habitats surrounding Kiwi Flat. The survey involved an acoustic survey for bats below Morgan Gorge (with one detector placed near the proposed tunnel portal entrance above the gorge), a focused survey for fernbirds using playback of their calls at Kiwi Flat and below Morgan Gorge, and a walkthrough survey for Powelliphanta land snails at Kiwi Flat and forest flats below Morgan Gorge. The objectives (as below) were selected to best evaluate additional information sought for bats, fernbirds and Powelliphanta land snails. 3.1. Objectives The objectives of the field survey in 2012 were:  To determine whether bats are present below Morgan Gorge, and if so what species are present;  to evalulate the extent of bat activity (if any) below Morgan Gorge and at a site near the proposed tunnel portal entrance above Morgan Gorge;  to evaluate the presence/absence, distribution and relative abundance of fernbirds (and other birds) within the survey area; and  to evaluate the presence/absence of Powelliphanta land snails by searching for shells on the ground surface, particularly at Kiwi Flat where shells were found in 2007 and 2011. 3.2. Description of Survey Area and its surroundings The terrestrial fauna survey was carried out in the lower Waitaha Valley, which lies approximately 44 km south of Hokitika and c. 16 km northeast of Hari Hari. The area is predominantly public conservation land, part of the Waitaha Forest Conservation Unit administered by the Department of Conservation (DOC). The area lies within the Wilberg Ecological District (WED), which contains two other major West Coast catchments: the Wanganui and Whataroa/Perth Valleys. The lower part of the valley downriver of Robinson Slip is partly privately owned. The Waitaha River descends through a glaciated valley with almost vertical escarpment walls rising from the valley floor on the true right below Morgan Gorge and very steep forested slopes within Morgan Gorge itself. The lower valley forms a braided flood plain, reaching nearly 1 km wide opposite Doughboy Hill. Kiwi Flat is approximately 2 km long and 500m wide at its widest point. The flat comprises river gravels, dense scrub patches and scattered low scrub and grasses. The vegetation cover in the lower Waitaha Valley (Kiwi Flat and below) is varied, and broadly comprises:  podocarp/hardwood forest above the high terraces in the lower valley extending close to Kiwi Flat above Morgan Gorge;

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 hardwood dominated forest (with low or no podocarp element) on faces, gully sides, foot slopes and other localised areas;  dense mixed scrub 1-2 m high on terraces at Kiwi Flat;  patchy scrub and regenerating trees on low river terraces throughout;  patchy scrub and grassy clearings on low river terraces and flood channels below Morgan Gorge, and  disturbed areas of scrub near stream and river terraces with a high component of weeds (notably gorse), downriver of Macgregor Creek. Refer to TACCRA (2013) for a detailed description of vegetation in the Scheme. Plates 1a–e show various typical terrestrial fauna habitats surveyed in 2012.

Plate 1a. Low stature shrub hardwood on alluvial terrace extending to mature podocarp hill forest on the true right of the Waitaha River above Morgan Gorge The proposed contractor’s facilities will affect some low-stature vegetation as in the foreground.

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Plate 1b. Looking up valley toward Morgan Gorge. While this stretch of river is within the abstraction reach, vegetated habitat here is not affected by the Scheme. Long-tailed bat activity was low and infrequent here (see Figure 5).

Plate 1c. Mosaic of different habitat types within the survey area, above the junction of Macgregor Creek and below Morgan Gorge. Vegetation types comprise narrow grassy clearings with patchy shrub land on the valley flat (foreground), lower stature forest on steep slopes (middle background) and mature podocarp/hardwood forest on the high terrace (upper background below distant hills). Occasional long-tailed bat activity was recorded within tall forest on the high terrace (see Figure 5).

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Plate 1d. Abrupt forest edge with foreground rank grasses and tree fern on the true left of Macgregor Creek not far from its confluence with the Waitaha River. Occasional long-tailed bat activity recorded here (see Figure 5).

Plate 1e. Backwater of the lower Waitaha River near ‘Doughboy Hill’ showing disturbed vegetation (gorse common) and regenerating podocarp/hardwood forest on the hill slopes. Whereas low long-tailed bat activity was recorded here, moderate activity was recorded about 500 m upriver toward the confluence of Macgregor Creek (see Figure 5).

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The survey area was chosen to include all lowland habitats that would possibly be affected by the Scheme. At the time of the survey the design plans were not finalised, therefore the survey area was extended beyond the then defined footprint options. Consequently, the area of survey was considerably broader than the final Scheme footprint (Figure 1). The broader area also enabled an evaluation of habitats adjacent to the Scheme to provide some context of distribution/abundance of bats and different species of birds, and provide more confidence in determining the presence or absence of Powelliphanta snails. The survey largely focused on bats and fernbirds below Morgan Gorge, although fernbird habitat surrounding Kiwi Flat was also surveyed. A thorough search for Powelliphanta was undertaken in low-stature vegetation on terraces at Kiwi Flat near where empty shells were previously found, and one bat detector was deployed just above the swing bridge (true right), near the proposed tunnel portal entrance above Morgan Gorge. While the survey area comprised mainly natural vegetated habitat, it also included farmland edges, modified scrubland downriver of the Robinson Slip, and riverbed. 3.3. Survey Methodology

3.3.1. Bats The main method for evaluating the presence of bats within the survey area involved establishing 20 digital bat recorders (Plate 2) at various locations below Morgan Gorge and one detector at or near the proposed headworks at Kiwi Flat (Figure 2). These detectors were deployed to automatically record bats at night over a 45-day period between 12 November and 27 December 2012. In addition, one walkthrough survey using a hand held heterodyne bat detector was carried out along the true right river terrace below Macgregor Creek on 8 December 2012. Bat detectors were spaced about 300 m apart at quieter locations along the lower river terrace and backwaters extending from the river below Morgan Gorge (east bank) to Doughboy Hill and near the end of Waitaha North Bank Road. Some detectors were positioned in forest well away from the river, along tributary streams, terrace slopes and high terraces. One detector was deployed in forest about 50 m above the proposed weir near the swing bridge at the top of Morgan Gorge. This was the sole bat surveillance site in the Kiwi Flat area above Morgan Gorge in 2012. The recorders were deployed at sites where bats are likely to be detected if present: along river/stream terraces and forest edges for long-tailed bats, and within forest for short-tailed bats (Mystacina tuberculata). The recorders were left in place to monitor bat echolocation calls continuously overnight for periods of about 20 nights, after which batteries and SD cards were replaced and monitoring resumed. Some detectors were then moved to different sites to ensure wide surveillance coverage. Bat detectors were deployed at a total of 31 sites (discounting site changes of <50 m) (Figure 2).

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Plate 2a.

Plate 2b. Plate 2a & b. Digital bat detectors used in survey

Bat detector units are waterproof and can withstand most situations except being submerged in water. Thus detectors were placed above maximum high river levels when deployed alongside rivers at locations where river noise was minimal (noise switch tends to turn off on the later model detectors at noisy sites). They were removed prior to the record flood conditions during the New Year. The digital bat recorders (Plate 2) are heterodyne ultrasound detectors designed to monitor and record simultaneously the optimum ultrasound frequencies (28 and 40 kHz) for detecting echolocation calls from short-tailed bat and long-tailed bat respectively (Lloyd & Cockburn 2009). A ‘call’ or ‘pass’ is defined as an unbroken sequence of echolocation calls. The recorders have an effective acoustic range of about 50 m for long-tailed bats and about 30 m for short-tailed bats, and have a 120° surveillance arc in front of the detector. Recordings can be reviewed rapidly to identify bat echolocation calls using custom made software (BatSearch).

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Figure 2. Location of bat detectors within the survey area

3.3.2. Fernbirds A walkthrough transect survey using fernbird call playback was carried out in areas offering suitable fernbird habitat (i.e. low scattered shrubs, tall grass and wetland) in the survey area (Figure 3). Typical areas searched are shown in Plates 1a, c & d (foreground in each photo) and Plate 3. Recording equipment was carried to record local fernbird dialect if fernbirds were located, as most birds respond best to locally recorded calls. Surveys along these transects were carried out during early morning

11 Wildlife Surveys 2014 Terrestrial fauna Waitaha Hydro Scheme or later afternoon when fernbirds tend to be most vocal. Counts were replicated on three consecutive days in November (12-14 November), while a more general search using tape playback was carried out over the same locations in December.

Figure 3. Fernbird transects and call playback sites

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Transects followed the true right side of the Waitaha Valley below Morgan Gorge to ‘Doughboy Hill’ downriver of the Robinson Slip (Figure 3). Other transects followed the true right side of Macgregor Creek. A more intensive playback survey was carried out at Kiwi Flat (Figure 3), as fernbirds had been recorded on the north side of Kiwi Flat in September 2006 (Overmars & Buckingham 2007).

Figure 4. Acoustic recorder sites for bird survey

In addition to playback surveys, digital programmable acoustic recorders were established at sites offering suitable habitat for fernbirds (Figure 4). These recorders

13 Wildlife Surveys 2014 Terrestrial fauna Waitaha Hydro Scheme were programmed to record from 5 am to 10 am and from 5 pm to 10 pm. Data review focused on times when fernbirds were most likely to be vocal (early morning and around sunset). Recordings were reviewed using Song Scope™ software, by scanning spectrograms or listening to .wav files.

3.3.3. Other birds All other birds encountered during the survey were noted. Automatic acoustic recordings were also reviewed and any species of bird identified were listed. The review included listening for moreporks between 9 and 10pm (approximately an hour after sunset) when they are typically vocal.

3.3.4. Powelliphanta land snails A search for Powelliphanta was carried out at Kiwi Flat and the lower Waitaha Valley in November and December 2012. This involved searching for Powelliphanta shells on the ground surface during walkthrough surveys using standard methodology (after Walker 1997). Potential snail habitat such as terrace scrub on Kiwi Flat and forest flats below Morgan Gorge was searched more thoroughly than other areas. Only the alpine snail Powelliphanta rossiana rossiana is known to be present in the surrounding area. This species is restricted to isolated alpine sites between Ross and Harihari, such as at Mt Bonar, some 8 km to the west of the lower Waitaha Valley (Walker 2003) and is unlikely to be present in the Scheme footprint. 3.4. Results

3.4.1. Summary Long-tailed bats were recorded from above Morgan Gorge to the lower Waitaha Valley in 2012 (they were not detected below Morgan Gorge on earlier surveys). Bats were most active (highest call rates) at the single surveillance site located close to the proposed tunnel portal entrance above Morgan Gorge. Moderate bat activity occurred near the river terrace downriver of Macgregor Creek confluence, while low activity of bats was recorded between Macgregor Creek and Morgan Gorge, (Figure 5). No short-tailed bats were detected. Similar bird assemblages (species, distributions and relative numbers) were recorded during the 2012 and 2006/2007 surveys. Although there were differences in numbers of species recorded on each survey, distributions and observed densities were similar for a range of species including western weka, , native (kea, kaka and kakariki), robin and rifleman (Appendix 6). Some species recorded were likely to be seasonal visitors (e.g. Canada , South Island pied oystercatcher and shining cuckoo in early summer 2012). Fernbirds, blue ducks and moreporks were recorded during 2006/2007 in low-moderate numbers, but were not encountered in the 2012 survey. A separate survey for blue duck was undertaken in December 2012 (Overmars, 2013). No sign of Powelliphanta land snails was found in the lower Waitaha Valley below Morgan Gorge, or at Kiwi Flat during the 2006/2007 and 2012 surveys. However there are two independent incidental records of Powelliphanta found at Kiwi Flat. A damaged empty shell was found on a strandline of leaves and twigs near the confluence of Whirling Water in 2007 (McLennan 2007a) and another shell was

14 Wildlife Surveys 2014 Terrestrial fauna Waitaha Hydro Scheme found nearby on the true right bank of Whirling Water in June 2011 (F. Overmars, pers. comm.). In both cases the shells had probably been washed downstream during a flood.

3.4.2. Bats All bat calls recorded during the acoustic survey were identified as being from long- tailed bats, an endemic New Zealand insectivorous bat ranked as Nationally Critical in DOC’s threat classification list (O'Donnell et al. 2010). No short-tailed bats were recorded at the ten forest sites considered suitable short-tailed bat habitat monitored for 287 bat-detector nights. Although this negative result does not rule out the presence of short-tailed bats, they are probably absent given their rarity in the South Island (Lloyd 2001, 2005 & 2009). Long-tailed bats were relatively active in some parts of the Waitaha Valley (Figure 5). They were frequently recorded at Kiwi Flat and other sites above Morgan Gorge during 2006-2007 (Overmars & Buckingham 2007) (Appendix 5), but none were recorded below Morgan Gorge during a survey in January 2007. When the results of all surveys are combined, long-tailed bats were recorded at 7 out of 15 survey sites above Morgan Gorge, and 10 out of 38 sites below Morgan Gorge (zero out of eight sites in January 2007; 10 out of 30 sites in 2012). The bat pass rate at Kiwi Flat was high compared to most other areas where bats have been detected on the West Coast (Table 2). During January 2007, when the old style automated bat monitoring systems (Batbox III™ bat detector wired to a tape recorder) were deployed along the Waitaha River terraces on the east bank between Macgregor Creek and Morgan Gorge, no bats were detected on either the terraces close to the river or the higher forested terraces. Very few bats were detected at similar sites during surveys in November and December 2012 using the newer more effective digital bat detectors (Plate 2) and higher sampling intensities. However, when the surveillance area was increased, moderate bat activity levels were detected on river terraces below Macgregor Creek (Figures 5 & 6). The bat pass rate recorded on a single detector deployed at Kiwi Flat above Morgan Gorge (in forest above the swing bridge, on the true right) was notably higher than recorded on any other detectors; 8.83 calls/night compared to 4.35 calls/night, the highest mean pass rate at any other site (Figure 7). The detector at Kiwi Flat was located in the general area of the proposed tunnel portal entrance within the headworks.

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Figure 5. Bat survey results in 2012

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Table 2. Mean bat pass rate/night at different locations on the West Coast (after Buckingham 2002, Lloyd 2011, and Overmars & Buckingham 2007) Location Date Bat- Mean detector pass/night nights Waitaha River: Kiwi Flat 2006-07 23 2.57 Waitaha River: Kiwi Flat 2012 35 8.83 Waitaha River below Macgregor Ck 2012 129 2.12 Waitaha River between Macgregor 2012 246 0.02 Ck and Morgan Gorge Lake Ianthe Forest 2001 22 0.18 Wanganui Forest 2001 19 0.16 Mahinapua Forest 2001 12 2.0 Kaniere Forest 2001 20 1.0 Craigieburn Forest (Paparoa) 2001 11 0.73 Mokihinui River (above Mokihinui 2010-11 307 12.07 forks) Mokihinui River (below Mokihinui 2010-11 833 0–0.65 forks)

Long-tailed bat activity was notably higher in riverine habitats (river terrace, flats, or over water) than other habitats sampled (Figure 8). Few bat calls were recorded in forest habitat remote from the river except at Kiwi Flat (though this site was within 100 m of the river above Morgan Gorge). Bats were recorded at only one of five detector sites below Morgan Gorge along the forest edge >100 m away from the river (near Macgregor Creek: NZTM 1415433 5225119). Another detector located at the forest edge about 50 m from the river (NZTM 1415257 5223401) recorded only two bat calls in 37 bat-detector nights. These results were surprising given that other studies have found that long-tailed bats favour forest edge (e.g. O’Donnell 2000, 2001).

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Locations 12

10

8

6

4 Mean Mean Bat Pass 2

0 River below River above Forest above Kiwi Flat Macgregor Ck Macgregor Ck Macgregor Ck

Figure 6. Bat pass activity rates in the lower Waitaha Valley (bars represent standard error on all charts)

High Pass Locations 12

10

8

6

4 Mean Mean Bat Pass

2

0 Macgregor junct Scrub bank High bank Kiwi Flat

Figure 7. Comparisons of mean bat pass rates at three sites downriver of Macgregor Creek (Macgregor Junction, 'Scrub bank' and High bank') and the Kiwi Flat Site

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Habitats 1 0.9 0.8

0.7 0.6 0.5 0.4

Mean Mean Bat Passes 0.3 0.2 0.1 0 Riverine Non-River Forest Edge Interior Forest Figure 8. Mean bat pass rates in various habitats (data from bat detectors at forest edge >100m from river used for Forest Edge value) Note: Standard Error bars

Bat activity data indicate that bats were using riverine habitats for foraging and probably commuting, but not roosting or breeding. Feeding buzzes were recorded on a few occasions in the area downriver of Macgregor Creek. At most sites, bat activity typically began soon after 22:00 hrs with activity peaking during the following hour. However, at the Kiwi Flat site there was a second smaller peak of activity between 1 am and 3 am (Figure 9). None of the detectors recorded the high levels of bat activity in the early evening and morning that are typically associated with bats leaving and returning to a nearby active colonial roost. Although there was ample roosting habitat for bats near the Kiwi Flat detector site, there was sparse or no roosting habitat close to the detector sites in the lower part of the valley, downriver of Macgregor Creek where moderate activity levels were recorded.

6

5

4 Kiwi Flat 3 Macgregor Ck to 2 Morgan Gorge

Mean Mean Pass Hour per Below Macgregor Ck 1

0 21 22 23 0 1 2 3 4 Hour intervals

Figure 9. Bat activity throughout the night at various locations

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Nighttime temperatures were relatively low at the beginning of survey in November (8 °C at dusk, 3–5 °C minimum), but became warmer by early December (10–13 °C at dusk, 10 °C minimum). Weather records from the closest weather recording station (at Hokitika Airport) showed mean daily maximum temperatures of 16.57 °C in November and 18.55 °C in December 2012 during the survey period (calculated from data provided by http://freemeteo.com). Mean daily minimum temperatures each month were 7.29 °C and 10.09 °C respectively. Wind speeds were similar in the two months, but rainfall was higher in December (220.9 mm in December cf. 128.9 mm in November). Bat activity below Morgan Gorge appeared to be higher in December than November, whereas the reverse pattern was observed at Kiwi Flat. One explanation for this could be that the bats extended their range downriver from their core home range at Kiwi Flat as summer progressed, however the differences are probably not significant (Figure 10). Locations and Seasons: Riverine Habitat

16 14 12 10 8 6 4 2 0

Mean Mean Bat Pass per Night Nov Dec Nov Dec Nov Dec Kiwi Flat Morgan Gorge to Below Macgregor Macgregor Ck

Figure 10. Bat activity during November and December 2012 at various locations within the survey area Note: Chart uses data from detectors located within c. 100m of the main river

3.4.3. Fernbirds No fernbirds were encountered during November and December 2012 and they did not respond to playbacks of recorded fernbird calls. Some fernbird-like calls were heard, but these were all tracked to song thrush or yellowhammer (background river noise often make initial identification of calls difficult). Automatic audio recorders did not record fernbirds. The most typical fernbird habitat (Plate 3) surveyed (patchy scrub and wetland) was on the northern side of Kiwi Flat (outside the proposed Scheme footprint). Fernbirds were recorded there in 2006 (Overmars & Buckingham 2007), but they were not encountered throughout Kiwi Flat after an exhaustive playback search in November 2012.

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Plate 3. Fernbird habitat upper Kiwi Flat. Fernbird were recorded here in 2006, but there was no response to playback in 2012. The site is well outside of the Scheme’s footprint.

Fernbirds may occasionally visit the area and even establish in small colonies in the area, as there is suitable habitat on many river terraces, and along the true right of Macgregor Creek. Suitable habitat includes scattered scrub near the forest edge, and tall grasses and patchy scrub on the river flats upriver from Macgregor Creek.

3.4.4. Other birds A total of 38 bird species (26 indigenous and 12 introduced) were recorded during November and December 2012. This compared to 35 bird species (27 indigenous and 8 introduced) recorded during the 2006 and 2007 surveys (Overmars & Buckingham 2007). Species not observed in 2012, but recorded in 2006/2007 were grey duck (Nationally Critical), blue duck (Nationally Vulnerable), fernbird (At Risk), morepork (Not Threatened) and goldfinch (Introduced). Species recorded in 2012, but not in 2006/2007 included white-faced heron (Not Threatened), South Island pied oystercatcher (At Risk), shining cuckoo (Not Threatened, one record) and : Canada goose, little owl (one record), greenfinch and magpie (one record). Of the indigenous birds recorded in 2012, three (falcon, kaka and kea) are ‘Threatened’ and four are ‘At Risk’ (Robertson et al 2013). Including grey duck and blue duck (recorded in 2006/2007), five threatened bird species are known to be present in the Waitaha Valley. The inclusion of the 2006 fernbird record at Kiwi Flat gives a total of five At Risk bird species. The threat classification list for birds used in Overmars & Buckingham (2007) was Hitchmough et al. (2007), whereas this report uses the most recent list (Robertson et al 2013). The main threat classification changes since Miskelly et al (2008) include the elevation of kea from ‘At Risk’ to ‘Nationally Endangered’ and both western weka and South Island rifleman from ‘At Risk’ to ‘Not Threatened’. Table 3 lists Threatened and At Risk fauna recorded while Figures 11-14 show the distribution of Threatened and At Risk birds, and/or infrequently encountered birds. A complete bird list is given in Appendix 1.

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Table 3. Threat status and abundance of Threatened and At Risk species recorded in the Scheme area (Threat status for birds from Robertson et al. (2013) and for bats from O’Donnell et al (2010)) Common Name Scientific Name Threat Status 2006-07 2012 Long-tailed bat Chalinolobus Nationally Present at Kiwi Present tuberculatus Critical Flat throughout Blue duck Hymenolaimus Nationally Mod numbers Refer Overmars malacorhynchos Vulnerable above Morgan (2013) Gorge Grey Duck Anas superciliosa Nationally Recorded at Not recorded Critical Kiwi Flat Black shag Phalacrocorax At risk: Rarely recorded Occasionally carbo Naturally recorded flying novaehollandiae Uncommon up or down river NZ (Bush) falcon Falco Taxonomically Occasional Occasional novaeseelandiae Indeterminate: Nationally Vulnerable Western weka Gallirallus a Not Patchy Patchy australis Threatened** distribution distribution S.I. pied Haematopus At risk: Not recorded Frequent in oystercatcher finschi Declining lower valley Kereru (NZ Hemiphaga Not Infrequent Occasional pigeon) novaeseelandiae Threatened* South Island kaka m. Nationally Infrequent Infrequent meridionalis Vulnerable Kea Nestor notabilis Nationally Frequent at Frequent in Endangered** Kiwi Flat lower valley Yellow-crowned Not Infrequent Infrequent parakeet auriceps Threatened* Long-tailed Eudynamys At risk: Relatively Relatively cuckoo taitensis Naturally frequent frequent uncommon South Island Acanthisitta c. Not Infrequent Infrequent rifleman chloris Threatened** South Island Bowdleria p. At risk: One record Kiwi Not recorded fernbird punctata Declining Flat NZ pipit Anthus n. At risk: Infrequent: Infrequent: novaeseelandiae Declining Kiwi Flat Kiwi Flat * Listed as ‘Threatened’ in 2006-2007 (Hitchmough et al. 2007); ** Listed as ‘At Risk’ in Miskelly et al (2008). New Zealand falcon, kea (Plate 4) and long-tailed cuckoo were widely distributed and relatively often encountered in both 2006/2007 and 2012 (Figures 11 & 12), whereas kaka and kakariki were infrequently recorded (Figure 11). A falcon was occasionally heard or seen around the Robinson Slip area where groups of up to three kea were regularly seen or heard. Long-tailed cuckoos were heard quite often

22 Wildlife Surveys 2014 Terrestrial fauna Waitaha Hydro Scheme throughout and one was seen near the confluence of Alpha Creek (Figure 12). Shining cuckoos (Figure 12) were not encountered, however an automatic recorder recorded a single call. Western weka (cover photo) were localised in distribution, being most conspicuous near the farm edge near Robinson Slip (Figure 13).

Figure 11. Records of falcon, kaka, kakariki and kea in 2012

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A family of weka was observed in patchy scrub and grassland just upriver of the slip between the forest edge and the river. Weka are also present at Kiwi Flat. The occasional kereru was seen mainly in regenerating forest along the river terrace upriver of Macgregor Creek (Figure 13). Rifleman were present in taller podocarp forest toward Kiwi Flat but were infrequently encountered (Figure 14).

Plate 4. Kea at Robinson Slip

No sign of kiwi was found during either survey (including during a focused survey for kiwi undertaken in 2006-2007). No blue ducks were recorded during the 2012 terrestrial fauna survey. Grey ducks have only been reported above Morgan Gorge, though it is probable that small numbers frequent the lower river and tributaries. Single black shags were occasionally seen flying up or down the river below Morgan Gorge in 2012. South Island pied oystercatchers were frequently seen and heard around Robinson Slip and adjacent farmland and river flats. Other indigenous birds associated with the river or river flats included white-faced heron (infrequent), paradise duck (frequent), spur-winged plover (occasional) and southern black- backed gull (occasional). While Threatened or At Risk bird species were generally localised or infrequently recorded in the lower Waitaha Valley, many Not Threatened small passerines were conspicuous. Upriver from Robinson Slip, bellbirds, tomtits, grey warblers and silvereyes were very conspicuous, while fantails were occasionally observed, particularly near the forest edge. Robins and brown creeper were less often encountered (Figure 14). Tomtits and robins were not recorded downriver of Robinson Slip, presumably because the habitat was more modified and patchy. were observed occasionally throughout, but rarely recorded on automatic recorders. Moreporks were not recorded in 2012 and their scarcity was noted during 2006/2007 surveys (Overmars & Buckingham 2007). The habitat upriver from Robinson Slip is less modified, with larger patches of scrub and nearby contiguous forest. Downriver of the slip, most of the forest has been cleared and converted to farmland, with patches or strips of second-growth scrub along the river and stream margins. Therefore, it is not surprising that a greater range of indigenous birds are more abundant upriver of Macgregor Creek.

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A higher ratio of introduced birds was found in 2012, presumably because this survey focused more on modified habitat in the lower Waitaha Valley than 2006-

Figure 12. Records of long-tailed cuckoo and shining cuckoo in 2012

2007 surveys. Introduced birds were most abundant downriver of Robinson Slip where the habitat is most modified (see above). In this area, blackbirds, redpolls, song thrushes and chaffinches dominated calls on automatic recording devices. Canada geese were reported as seasonal visitors in Overmars & Buckingham (2007) and this was confirmed both in November and December 2012 surveys. While a

25 Wildlife Surveys 2014 Terrestrial fauna Waitaha Hydro Scheme single Canada goose was repeatedly seen in the main river near the Douglas Creek confluence in November, twenty were seen together on the riverbed downriver of Macgregor Creek on 27 December 2012. There was one recording of two little owls calling to each other on an automatic acoustic recorder deployed near a backwater approximately opposite Douglas Creek (NZTM 1415374 5224522). This was a new bird record for the valley.

Figure 13. Records of kereru and weka in 2012

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Figure 14. Records of brown creeper, rifleman and robin in 2012

3.4.5. Acoustic Recordings Reviewing acoustic recordings involved both listening to .wav files in real time and scanning spectrograms using Song Scope™ software. A total of 111.25 hours of recordings were reviewed (five recorders in use 12-15th November and two recorders 7-9th December 2012). This included 90.75 hours of recordings from south of Macgregor Creek and 20.50 hours from downriver of Macgregor Creek.

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A total of 17 indigenous and 9 introduced bird species were identified during the audio review. A higher proportion of introduced bird species were recorded downriver of Macgregor Creek than upriver of this creek (37% cf. 32% respectively of total bird species), consistent with general observations as described above. Two species identified from acoustic recordings were not observed in the field: the indigenous shining cuckoo (one occasion south of Macgregor Creek: NZTM 1415374 5224522) and the introduced little owl (same recorder location). No calls of moreporks or kaka were noted, though occasional falcon, kea and long-tailed cuckoo were recorded.

3.4.6. Powelliphanta snails No sign of Powelliphanta land snails was found during a casual search for empty shells on the ground surface. Most search effort was undertaken in dense low- canopy shrub hardwood vegetation covering low terraces at Kiwi Flat, and forest flats upriver of Robinson Slip. These were considered the most likely habitats for Powelliphanta. Similarly, no sign of Powelliphanta was found during specific searches for them in 2006-2007 (Overmars & Buckingham 2007).

A damaged, empty Powelliphanta shell was found on a sand bank just downstream from the confluence of Whirling Water and the Waitaha River in May 2007 (McLennan 2007a). Another shell was found in the same general area in June 2011 (F. Overmars, pers. comm.). The locations of both these shells indicated that they were washed downstream in floods. Failure to find Powelliphanta snails or shells in nearby habitats after a reasonable search effort further suggests that these shells were not from local Powelliphanta populations.

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4. General Discussion

4.1. Short-tailed bats The combined results of bat surveys in the Waitaha Valley during 2006/2007 and 2012 suggest that short-tailed bats are probably absent in this area. No records of short-tailed bats were obtained in 64 hours of surveillance at four survey sites above Morgan Gorge in 2006, in 38.5 hours at five survey sites and one transect throughout the survey area in 2007 (Overmars & Buckingham 2007), and in 287 bat- detector nights during November and December 2012 (only forest sites suitable for short-tailed bats are included in these statistics). Short-tailed bats are now rare and localised in mainland South Island, the only known population being in (Lloyd 2001, 2005, 2009; O’Donnell et al. 1999). A population found in the Oparara Valley near in the 1990s is now believed to be locally extinct (Lloyd 2009). Predation and possibly competition by introduced fauna are the most likely reasons for the disappearance of short-tailed bats (and decline of long-tailed bats) in forest locations in the South Island. Recent studies have shown that predators are impacting on populations of New Zealand endemic bats (Elliott & Suggate 2007; Pryde et al. 2005). Densities of small, introduced mammalian predators are high in the Waitaha Valley (McLennan 2007a & b). The absence of kiwi and the rarity of other predator-vulnerable species such as kaka, kakariki and rifleman suggest that introduced mammalian predators have had a significant impact on predator- sensitive species (including bats) in the Waitaha Valley. 4.2. Long-tailed bats The survey results indicate that there is a regionally significant long-tailed bat population in the lower Waitaha Valley, with apparently a core activity range at Kiwi Flat (Overmars & Buckingham 2007). Based on pass-rate data, the Waitaha bat population is denser than populations in many other parts of the West Coast (Table 2). The known range of long-tailed bats in the Waitaha Valley was extended in 2012 by increasing survey coverage and sampling intensity. Bats might also be present in the upper valley above Kiwi Flat, but this part of the valley has not been surveyed. The reason for the apparent patchiness of bat activity below Morgan Gorge is not known. The 2007 and 2012 surveys both found nil to very low bat activity between Robinson Slip and Morgan Gorge. The occasional pass in November and December 2012 in that stretch of valley might have been bats flying over (perhaps between Kiwi Flat and the lower river) or foraging. Higher bat activity was recorded immediately downriver of Robinson Slip, close to the Waitaha River flats. The recordings of feeding buzzes in this area indicate that bats were foraging. The river forms a wide flood plain below Robinson Slip (Plate 2b), perhaps providing a greater food supply for bats than upriver where the river narrows (Plate 1b). Long-tailed bats are also known to be present in coastal forests near the Waitaha River (Lake Ianthe Forest to the south and Kakapotahi Forest to the north)

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(Buckingham 2002; pers. obs.). Individuals from these populations could fly to the lower Waitaha River to feed, as the distances (<19 km) are within bat flight range (O’Donnell 2001). It would require radio-tagging bats to determine bat movement patterns in this area. Although long-tailed bats are known to have large home ranges, core activity areas are much smaller (Griffiths 2007; O’Donnell 2001). For example, the home ranges of long-tailed bats in Fiordland, calculated by median minimum convex polygons, were 1,589 ha for adult males, 1,361 ha for post-lactating females, 657 ha for non- reproductive females and 330 ha for lactating females (O’Donnell 2001), whereas the core activity areas averaged only 5.7% of the home ranges and the ranges of roosting sites was 9.4% of home range. In South Canterbury, the mean home range size for long-tailed bats was 471.4 ± 50.9 ha while the core areas of activity were 54.4 ± 5.4 ha (Griffiths 2007). Relatively little is known about seasonal movements and habitat use of long-tailed bats (Griffiths 2007; O’Donnell 2000). Studies indicate that patterns of activity vary between populations. Both Griffiths (2007) and O’Donnell (2000) have shown a strong correlation between intensities of bat activity, dusk and minimum temperatures, and invertebrate activity. It is unlikely that bats roost or breed on the river flats below Morgan Gorge given the general absence of suitable roosting trees in the immediate vicinity. The vegetation in this part of the valley is low-stature forest and scrub that becomes more fragmented and weed-infested (e.g. gorse and exotic grasses) downriver of Robinson Slip. Taller forest is present at Doughboy Hill, and on forest slopes generally >200m asl on each side of the valley below Morgan Gorge. Suitable roost trees are abundant surrounding Kiwi Flat, including some quite close to the proposed headworks. The absence of bat passes in the first hour after sunset at Kiwi Flat (and most other sites) suggests that detector sites were not close to bat roosts. Long-tailed bats typically leave roosts soon after sunset (average c. 17 minutes after) though emergence time varies considerably with different locations (O’Donnell 2001). Typically, detectors placed near roosts show peak bat activity soon after sunset, but this was only noted at detectors along the river terrace downriver of Macgregor Creek in November and December 2012. As none of these detectors was close to suitable bat roost habitat it was assumed that bats flew rapidly to this area immediately after emerging from their roosts. Long-tailed bats are capable of flying large distances (c. 3-11 km) at speeds of up to 60 kmph (O’Donnell 2001). This would mean that bats leaving roosts at Kiwi Flat, some 4-5 km away, could reach the area downriver of Macgregor Creek in as little as 4 minutes. 4.3. Birds

4.3.1. Fernbirds The absence of fernbird records from the lower Waitaha Valley in November and December 2012 does not necessarily imply that fernbird are absent, but if they are present they are in very low numbers, or only occasional colonisers. Fernbirds can be notoriously cryptic at certain times of the year, but they tend to be most conspicuous during their peak-breeding season (November and December) when the

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2012 survey was undertaken. Fernbirds were easily detected using call playback in a wetland area at Kakapotahi Forest in December 2012. Therefore, response would also have been expected had fernbirds been present in the Waitaha survey area. Because fernbirds appear to be good dispersers, they might frequent the Waitaha Valley from time to time. For example, fernbirds have occasionally been recorded in suboptimal fernbird habitat (e.g. roadside scrub at Granville Forest (Grey Valley) or scrub below power pylons at Orikaka Forest (lower Buller Valley)) several kilometres from stronghold habitat areas (pers. obs.). The fernbird record at the northeast corner of Kiwi Flat in 2006 is from the best fernbird habitat surveyed during 2012: an area of wetland with patchy cover of shrubs and tall grasses (Plate 3). The area is well outside the area affected by the Scheme.

4.3.2. Comparison with 2006-2007 baseline survey Terrestrial bird distributions and relative abundances recorded in 2012 were similar to those recorded in 2006-2007 (Overmars & Buckingham 2007) (Appendix 6). Species such as falcon, kaka, kakariki, weka, kereru, rifleman and robin were recorded in low numbers on both surveys and with more or less the same distribution patterns. Weka were commonly encountered along the farm edge in the lower valley, but rarely further up the valley until Kiwi Flat where a small population is present. Kaka and riflemen were only encountered in taller forest between Morgan Gorge and Kiwi Flat. Kea were as conspicuous in 2012 as on earlier surveys, with groups of at least three birds seen in the lower valley near Robinson Slip in 2012. Both robins and rifleman tended to have a very patchy distribution within forest habitat. Long-tailed cuckoos were relatively conspicuous both summers (2006-07 and 2012), while moreporks were rare in 2006-07 and not recorded in 2012. Common indigenous passerines (e.g. tomtits, grey warblers, bellbirds and silvereyes) showed similar levels of abundance and distribution during each survey. Additional species recorded in 2012 include Canada goose (introduced), which were previously reported as seasonal visitors to the area, and shining cuckoo (indigenous), which was expected to be present seasonally (Overmars & Buckingham 2007). The presence of little owl was perhaps more surprising, although they are occasionally recorded on the West Coast (Robertson et al. 2007; M. Charteris, pers. comm.; pers. obs). The differences in bird species and relative abundances recorded between the survey years are probably related to differences in survey coverage as well as seasonal influences. The 2006-2007 survey largely focused at more unmodified forest ecosystems surrounding Kiwi Flat and the high terraces in the lower valley, while the 2012 survey focused on valley floor ecosystems in the lower valley that were variably modified, or in stages of regeneration. 4.4. Powelliphanta snails The failure to find Powelliphanta was not surprising, as they are not known to be present in lowland forest habitat in this locality (Walker 2003). The only known Powelliphanta species present in the area is the alpine snail Powelliphanta rossiana rossiana. This Nationally Endangered snail is known to be present on Mt Bonar,

31 Wildlife Surveys 2014 Terrestrial fauna Waitaha Hydro Scheme some eight kilometers to the west, and elsewhere at isolated alpine sites between Ross and Harihari (Walker 2003). Although a population of lowland Powelliphanta may have been missed during the surveys, this is probably unlikely. From the site descriptions where shells were found at Kiwi Flat in 2007 and 2011 (McLennan 2007a; Overmars, pers. comm.), it is most likely that they were washed downstream in a flood. A relatively intensive search for shells in scrub habitat at Kiwi Flat including an area close to where the shell was found failed to find any sign of Powelliphanta.

5. Significance and Natural Values of Terrestrial Fauna within the Survey Area The survey area is considered to contain areas of significant habitat for indigenous fauna based on assessment of guidelines/criteria for significance set out in the West Coast Regional Policy Statement 2000 (the RPS) (West Coast Regional Council 2000) and the Westland District Plan 2002 (the WDP) (Westland District Council 2002). The survey area has high natural heritage values based on assessment criteria in the West Coast Conservation Management Strategy 2010-2020 (the CMS) (Department of Conservation 2010). The RPS and WDP criteria are for the purposes of Section 6(c) of the Resource Management Act 1991 (RMA), whilst the CMS criteria are for the purposes of integrated conservation management of natural and historic resources under the Conservation Act 1987. Table 4 outlines guidelines/criteria set out in the RPS (Policy 9.2), the WDP (Policy 4.9D) for assessing significance in terms of the RMA and criteria in the CMS (Policy 3.3.2.3(1)) for assessing natural heritage values. The relative intactness of terrestrial fauna habitats within the Scheme’s footprint, the presence and representativeness of Threatened and At Risk species, and the potential distinctiveness of at least one species (weka) in the area largely define the level of significance and natural heritage values in this location (Table 5). The main fauna (bats, birds and Powelliphanta snails) of national significance within the survey area (2006/2007 and 2012) and to some extent affected by the Scheme are long-tailed bats and blue ducks. These species are present in relatively high numbers compared to many other parts of the region and therefore should be regarded as regionally significant. The presence of an isolated population of western weka in the Waitaha Valley is also of note, as this population may be genetically distinct from other populations further north. Threatened fauna include grey duck, New Zealand falcon, kea and kaka, and several At Risk birds are also present in the Scheme’s footprint and vicinity.

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Table 4. Criteria for determining significance for the purposes of Section 6(c) of the RMA, RPS, WDP and Natural Heritage Values of the CMS

RPS WDP CMS Policy 9.2 (Policy 4.9D) (Policy 3.3.2.3(1)) a) The desirability for their protection by statute or covenant; b) Protection status, including reserves created under the (iv) Protected Status West Coast Accord; c) The degree to which the area is representative of an (ii) Representativeness Representativeness, association of species or an ecosystem that is typical of Diversity the region; d) The likelihood of the area retaining its viability, quality (i) Intactness and Size Viability, Intactness and integrity of processes over a long time period; e) The presence or absence of an indigenous species or (vi) Threat Threatened Species community of indigenous species that is rare or and Habitat threatened regionally or nationally; f) The degree to which the area is distinctive in terms of (iii) Distinctiveness Diversity indigenous species that are unusual, endemic, or that reach a distribution limit in the region; g) The extent to which the area has been modified from a (i) Intactness and Size Viability, Intactness natural state or affected by weeds or pest species; h) Its connection with other areas of significant (v) Connectivity indigenous vegetation or significant habitats of indigenous fauna; i) Its contribution to the avoidance or mitigation of natural hazards; j) Its use or value on a local, regional or national scale for (viii) Scientific or Other Natural Landscape public access, recreation, amenity and heritage Cultural Values Character purposes; k) The relationship of Poutini Ngai Tahu and their culture (viii) Scientific or Other Taonga Species and and traditions with their ancestral lands, water, sites, Cultural Values Habitat waahi tapu, mahinga kai and other taonga; l) The contribution of the area or habitat to maintenance (v) Connectivity Diversity and enhancement of ecological and reproductive processes water quality, water flow and soil conservation; m) The relationship of the area or habitat to any water body included in a water conservation order; n) Whether they occur near wetlands and estuaries; o) The importance to migratory species, including (vii) Migratory Species whitebait; p) The relevance of ecological districts in relation to matters (c), (e) and (f).

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The relevance of criteria listed in Table 4 to the RPS, WDP and CMS in terms of terrestrial fauna (bats, birds and Powelliphanta snails) is described in detail below. Criteria are listed in italics. The significance of blue ducks is discussed in more detail by Overmars (2014). RPS 9.2(a). The desirability for their protection by statue or covenant; The area is largely located within fully protected public conservation land administered by DOC. The remainder, being the downriver part is mostly farmland that has no values for conservation protection. RPS 9.2(b) Protection status, including reserves created under the West Coast Accord; WDP 4.9D(iv) Protected Status; The Scheme’s footprint is largely located within fully protected public conservation land administered by DOC. However, it is my understanding that this criteria alone does not signify that an area has significant or high values. RPS 9.2(c) The degree to which the area is representative of an association of species or an ecosystem that is typical of the region; WDP 4.9D(ii) Representativeness CMS 3.3.2.3(1) Representativeness, Diversity Three species found within the Scheme’s footprint have a relatively high degree of representativeness relative to the region. These species are the long-tailed bat, blue duck, and western weka. Densities of long-tailed bat and blue duck are relatively high compared with other areas surveyed in the region and the West Coast generally, whereas the western weka appears to be an isolated population with potential genetic significance (discussed in more detail below under criterion “f”). Several surveys for bats in the Buller Region mostly have failed to find bats in lower valley catchments or coastal foothills (Buckingham 1998, 1999, 2002; Lloyd 2011). In South Westland, records indicated small populations of bats in lowland forest and swampland areas (Buckingham 2002; DOC bat data base). Therefore, the moderate- high activity of long-tailed bats in the Waitaha Valley is of importance. On the other hand, no species of terrestrial fauna (bats and birds) found in the survey area is restricted to this area, and all species detected have relatively wide distributions regionally or nationally. No particularly representative habitat or ecosystem was identified in the Scheme’s footprint or surrounding area. Similarly, the vegetation assessment for the Options Selection workshop found no unique vegetation communities that were not represented at other similar sites throughout the central West Coast (TACCRA 2013). RPS 9.2(d) The likelihood of the area retaining its viability, quality and integrity of processes over a long time period; WDP 4.9D(i) Intactness and Size CMS 3.3.2.3(1) Viability, Intactness The Waitaha Valley is subject to the usual variability of natural processes found in other wild river valleys on the West Coast, and this is not likely to change in the long

34 Wildlife Surveys 2014 Terrestrial fauna Waitaha Hydro Scheme term unless subject to a catastrophic event such as a major earthquake or flood. On the other hand, the effects of introduced fauna on indigenous ecosystems are likely to exacerbate over time, leading to a reduction of fauna populations including possibly local , as well as impacting on the quality of their habitats. Overall, the Scheme is unlikely to significantly change the viability, quality and integrity of processes due to its relatively small footprint, its avoidance of significant habitats and habitat components, the short length of the abstraction reach, and prioritised use of already modified areas in the lower valley. The construction footprint is relatively small, occupying an estimated 4.54 ha as compared to surrounding areas of similar vegetation types e.g. within the Waitaha Catchment c. 15,988.8 ha, and the Wilberg Ecological District c. 84,113.8 ha (refer TACCRA 2013). Indeed, any potential effects caused by the Scheme are negligible compared to the serious ongoing threat of introduced mammalian predators. RPS 9.2(e) The presence or absence of an indigenous species or community of indigenous species that is rare or threatened regionally or nationally; WDP 4.9D (vi) Threat CMS 3.3.2.3(1) Threatened Species and Habitat Surveys for bats and birds have found five Threatened and five At Risk species present within the survey area (Table 3). These include two Nationally Critical species (long-tailed bat and grey duck), one Nationally (kea) and three Nationally Vulnerable species (blue duck, falcon and kaka). Therefore, this criterion has a high value of significance for the Scheme. RPS 9.2(f) The degree to which the area is distinctive in terms of indigenous species that are unusual, endemic, or that reach a distribution limit in the region; WDP 4.9D(iii) Distinctiveness CMS 3.3.2.3(1) Diversity The area is considered potentially distinctive for at least one species, the western weka. The population of western weka in the Waitaha Valley appears to be an isolated population known to be present at least as early as 1892 (Douglas 1936 as quoted in Overmars & Buckingham 2007). The population of weka south of Hokitika is gradually expanding after a population crash in South Westland in the 1930s and 1940s (Beauchamp 1999; Beauchamp et al. 1999; Eastwood 1998) with a notable increase of records south of Ross extending to near Lake Ianthe (pers. obs and anecdotal records). It is likely that the Waitaha weka population is isolated from the expanding northern population, and survived the 1930–40 population crash, similar to populations in the Copland Valley and at Karangarua. Assuming that the Waitaha weka population is remnant, individuals may have distinctive genetic or behavioural attributes that differ from other weka populations on the West Coast.

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RPS 9.2(g) The extent to which the area has been modified from natural state or affected by weeds or pest species; WDP 4.9D(i) Intactness and Size CMS 3.3.2.3(1) Viability, Intactness The larger part of the proposed Scheme lies within relatively unmodified vegetation and therefore rates significantly in this regard. While introduced browsers (particularly goats and deer) have localised effects on the quality of these habitats, TACCRA (2013) observed browse effect on indigenous vegetation to be very low. The area has relatively high densities of introduced mammalian predators (McLennan 2007a & b) that have ongoing impacts on indigenous fauna, as indicated in the relatively low numbers of predator sensitive species (e.g. blue duck in the lower catchment, kaka, kakariki, etc.). The part of the Scheme’s footprint downriver of Macgregor Creek is highly modified and has relatively low values for many fauna (but not bats). Weeds have spread up the Valley as far at least as Kiwi Flat, but they have little influence on the faunal values described in this report. RPS 9.2(h). Its connection with other areas of significant indigenous vegetation or significant habitats of indigenous fauna; WDP 4.9D(v) Connectivity The Scheme’s footprint is contiguous with a large area of similar indigenous habitats, though the river valley itself represents significant habitat for blue duck, western weka and long-tailed bats. The Scheme is not considered to significantly influence connectivity due to its small linear footprint and use of underground tunnels and access. RPS 9.2 (i). Its contribution to the avoidance or mitigation of natural hazards; This criterion has no direct relevance to terrestrial fauna or its habitat. RPS 9.2(j). Its use or value on a local, regional or national scale for public access, recreation, amenity and heritage purposes; WDP 4.9D(viii) Scientific or Other Cultural Values CMS 3.3.2.3(1) Natural Landscape Character This criterion is not applicable to terrestrial fauna. RPS 9.2(k) The relationship of Poutini Ngai Tahu and their culture and traditions with their ancestral lands, water, sites, waahi tapu, mahinga kai and other taonga; WDP 4.9D(viii) Scientific or Other Cultural Values CMS 3.3.2.3(1) Taonga Species and Habitat I am not aware that the Waitaha Valley has particular values (regarding fauna covered in this report) for Ngai Tahu that are different from other wild rivers on the West Coast, although I understand a cultural impact assessment will be undertaken which may provide further information.

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RPS 9.2(l) The contribution of the area or habitat to maintenance and enhancement of ecological and reproductive processes, water quality, water flow and soil conservation; WDP 4.9D(v) Connectivity CMS 3.3.2.3(1) Diversity For a number of species (particularly long-tailed bat, blue duck, grey duck and black shag) this criterion scores potential significance in terms of the importance of riverine and associated faunal habitats. Water quality and flow reflects the abundance of invertebrates, which in turn influences the abundance and distribution of bats, blue ducks and other fauna that feed on freshwater invertebrates, or otherwise use the riverine habitat. The Scheme has less significance in this regard for non-riverine species or fauna not reliant on riverine habitat, except perhaps for Western weka that are assumed to be an isolated population with possibly unique genetic characteristics (see also Criterion “f” above). Faunal diversity within the study area is probably similar elsewhere in the South Westland beech gap area though few formal surveys can confirm this. RPS 9.2(m). The relationship of the area or habitat to any water body included in a water conservation order; Not applicable: The Waitaha River is not currently listed as a Water Conservation Order (WCO). The closest river with WCO status is the Ahaura River, more than 100 km north of the Scheme project locality (National Water Conservation [Grey River] Order 1991). RPS 9.2 (n). Whether they occur near wetlands and estuaries; Apart from the river itself and associated tributaries, only small areas of flat water and wetland (mostly temporary) occur within the Scheme. The river habitat clearly has high significance for species such as long-tailed bat (for foraging and commuting), blue duck (for feeding, roosting and nesting), and black shag (for feeding and commuting). There is little to no significance of the area for wetland fauna such as bittern, crake spp. and fernbirds, which were not recorded, and are unlikely to be present. There are unlikely to be any effects on estuarine habitats, given the Scheme’s overall design (Hicks 2013). RPS 9.2(o) The importance to migratory species, including whitebait; WDP 4.9D(vii) Migratory Species Several migratory species of birds are present, or likely to be present, within the Scheme Area. Not all are of positive conservation importance (e.g. the introduced Canada goose). Long-tailed cuckoo (At Risk) appear to be regular summer migrants recorded in relatively good numbers both in 2006-2007 and 2012 surveys. Kereru (Not Threatened) are likely to use different habitats within the Scheme area at different times of the year (forest habitat in winter and scrub and regenerating forest in spring through to autumn). The Scheme is expected to have little influence on migratory species: therefore this criterion has relatively low significance for terrestrial fauna.

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RPS 9.2 (p). The relevance of ecological districts in relation to matters (c), (e) and (f). The relative densities and distributions of at least three species: long-tailed bat, blue duck and western weka have potential significance in terms of the Wilberg Ecological District. The WED contains three major West Coast catchments: the Whataroa/Perth Valley, The Wanganui Valley and the Waitaha Valley, but comparative data between these catchments is scant or not available. Therefore, the relevance of fauna under this criterion is uncertain. 5.1. Summary of Significance The Scheme lies within an area that is rated moderately to highly significant based on several criteria provided by the RPS and WDP and contains high natural heritage values based on assessment criteria in the CMS. The main values of significance are summarized in Table 5.

Table 5. Summary of significance (RPS and WDP) and natural heritage values (CMS)

Regional Policy Statement West Coast District Policy CMS Policy 9.2 (Policy 4.9D) (Policies 3.3.2.3 (1) c) The degree to which ii) Representativeness Representativeness, Diversity the area is representative of an association of species or an ecosystem that is typical of the region; d) The likelihood of the (i) Intactness and Size Viability, Intactness area retaining its viability, quality and integrity of processes over a long time period; e) The presence or (vi) Threat Threatened species and habitat absence of an indigenous species or community of indigenous species that is rare or threatened regionally or nationally; f) The degree to which (iii) Distinctiveness Distinctiveness and Diversity the area is distinctive in terms of indigenous species that are unusual, endemic, or that reach a distribution limit in the region; g) The extent to which (i) Intactness and Size Viability, Intactness the area has been modified from a natural state or affected by weeds or pest species;

The presence and population status of long-tailed bat, blue duck and western weka are of particular importance. The area as a whole is regionally significant for long- tailed bats. The Waitaha Valley appears to be a stronghold for these species. The

38 Wildlife Surveys 2014 Terrestrial fauna Waitaha Hydro Scheme significance of weka in the area relates to its isolated population status with potential genetic distinctiveness. Notwithstanding this overall level of significance and natural heritage values, no bat or bird species was found to be endemic to the Waitaha Valley. In fact, all species recorded have a wide distribution range, and similar habitats are found widely throughout the West Coast. The ecological baseline surveys carried out for Westpower since 2006 have significantly contributed to the knowledge of ecosystem components and processes within the Waitaha Valley. This is consistent with some of the objectives and policies in the CMS (3.3.2.1: Knowledge and information needs, Objective 1, Policies 3 and 4). Critical gaps of knowledge (CMS Policy 3.3.2.1 [3]) have been identified from these surveys allowing a more robust evaluation of significances and values.

6. Predicted Effects of the Scheme on Bats, Birds and Powelliphanta Snails Loss of faunal habitat and potential direct loss of fauna during the construction phase (particularly during breeding) are the main predicted adverse effects on terrestrial fauna caused by the Scheme. Lesser potential effects are discussed in Section 6.3. Overall predicted effects are considered negligible, given the small size of the Scheme’s footprint (c. 4.53 ha of vegetation affected) that largely avoids significant terrestrial faunal habitat such as mature forest. The project design has aimed at minimising, where possible, effects on terrestrial fauna. Key elements of the design to achieve this are:  decision not to build a road into Kiwi Flat;  using underground tunnels for transporting water from the intake (just above Morgan Gorge) to the powerhouse (below Morgan Gorge);  selecting an option of tunnel and intake (known as Option B) where overall effects on fauna were considered by experts to be minimal (Westpower 2012);  low weir design minimising area of backwater effect above the weir;  minimising area of construction and mature forest removal at the tunnel portal sites (entrance and exit) and other components of the footprint;  reducing the length of the abstraction reach by locating the powerhouse closer to Morgan Gorge;  avoiding or minimising disturbance to stable tributaries as these have particular importance for aquatic fauna (McMurtrie & Suren 2014);  designing structures that minimise effects of sedimentation and consequent habitat effects (McCahon 2013);  positioning the access road to the powerhouse along valley flats that comprise least important habitat for terrestrial fauna;  aligning the power transmission line along the access road from the powerhouse to reduce habitat clearance; and

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 eliminating or reducing the risk of birds getting electrocuted by transmission wires. Indirect potential effects (adverse or positive) on bats and riverine birds3 caused by potential change in riverine habitat are also considered to be negligible, though these effects are harder to predict. These effects include (1) riverside or streamside habitat loss caused by construction or changes to river flow and sedimentation and (2) changes in the fish and invertebrate resource for birds that largely feed on aquatic fauna (e.g. shags, ducks and waders). Other technical reports (Allen & Hay 2013; Doyle 2013; Hicks 2013; McMurtrie & Suren 2014) discuss the likelihood and extent of these effects. I consider these effects negligible because:  Threatened or At Risk birds are relatively scarce within the abstraction reach;  the abstraction reach is relatively short (2.6 km), approximately 6.5% of the overall length of the 40 km river;  aquatic fauna values of the main stem (Waitaha River) are much less than stable tributaries that remain largely unaffected by the Scheme (McMurtrie & Suren 2014)  frequent flooding events would likely prevent sediment accumulation that might otherwise result from the Scheme (Allen & Hay 2013; Doyle 2013; Hicks 2013);  headworks design further reduces the likelihood of sediment accumulation (McCahon 2013);  other construction design can adequately mitigate any potential effects (refer other technical reports); and  it is unlikely that effects of the Scheme on riverine fauna (e.g. disturbing nests during the breeding season) would be any greater than natural effects from floods or slips. A description of potential effects on a range of fauna (bats, birds and Powelliphanta snails) and individual species is given below. 6.1. Bats There are three main types of effects the Scheme will potentially have on bats. These are:  removal or disturbance of roosting or breeding habitat;  reduction in food supply or foraging habitat; and  affecting commuting routes. I discuss each of these types of effects in detail below.

6.1.1. Bat roosts Long-tailed bats are colonial species that largely roost and breed in tree cavities (O’Donnell 2001). Occasionally solitary bats (usually males) are found in roosts. A characteristic of long-tailed bat roosting behaviour is the regularity they change

3 except blue duck that is covered in a separate report: Overmars, 2014.

40 Wildlife Surveys 2014 Terrestrial fauna Waitaha Hydro Scheme roosts and the short roost occupancy time (typically one or two days for reproductive females). This behaviour has important management implications, especially for developers who propose to modify or remove tall forest habitat. Bats might be roosting or breeding in affected trees that have not shown bat activity on surveys prior to development. This means that to be sure bats are not occupying an area at the time of forest removal, appropriate surveys (radio-tag monitoring or acoustic surveys) need to be undertaken up to the night prior to tree removal. Long-tailed bats actively select roosts on the basis of topography, forest composition and tree characteristics (O’Donnell 2001; Sedgeley & O’Donnell 1999a&b). In the Eglinton Valley, Fiordland, 95 % of roost trees were in open-structured, mature, lowland forest within 500 m of the forest edge, on relatively flat valley floor. 74 % of roosting trees were >80 cm in diameter (dbh) and were 100–600 years old. Older and larger trees have more cavities, thus are favoured for roosting. Occasionally long-tailed bats roost in caves, limestone fissures or even man-made structures. Little if anything appears to be known of roost selection by long-tailed bats in podocarp forests on the West Coast, but similar habits as described above for Fiordland beech forests are probably likely. In the North Island (e.g. Hawkes Bay) long-tailed bats roost in various podocarps such as rimu (), kahikatea () and miro (Prumnopitys ferruginea), with trunk girths of 50–140 cm dbh (O’Donnell 2001). The tunnel portal exit and associated construction area, powerhouse and switchyard, tailrace, road access and transmission route will all be located on the river flats below Morgan Gorge. Vegetation cover in this area largely comprises scattered scrub, grassland and regenerating forest, with very few potential roosting trees for bats. Small areas with very occasional emergent rimu and kahikatea occur on the proposed access road upstream of Macgregor Creek (TACCRA 2013). Providing pre-construction surveys are undertaken for bat roosts (see Section 7), bats are unlikely to be affected in this part of the Scheme’s footprint. Large trees suitable for bat roosts are located within, or quite close to (probably within 50 m), the tunnel portal entrance and access road immediately above Morgan Gorge. The proposed contractor’s facilities on a terrace on the true right of Kiwi Flat are mainly vegetated in low-stature forest not suitable for bat roosts (Plate 1a). Construction, or consequential effects such as slips, might affect potential roost habitat in the headworks area where suitable bat roost trees were identified. However, a pre-construction bat roost survey at sites where large-diameter trees are to be cleared (if any) will ensure that any roost trees are vacated prior to felling. At the time of survey (November-December 2012), bat acoustic activity did not indicate that this area was being used for bat roosts.

6.1.2. Bat foraging behaviour Long-tailed bats are exclusively insectivorous, taking prey on the wing from dusk through the night (O’Donnell 2001). They are often seen flying or foraging before dark. Studies have shown that long-tailed bats eat a large variety of aquatic and terrestrial flying invertebrates, particularly dipterans, coleopterans, and lepidopterans (Gillingham 1996).

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Any effects on bat’s insectivorous prey species caused by the Scheme might indirectly affect bats, although effects on bats are considered negligible and in any case difficult to measure given other ongoing threats to invertebrates and bats by introduced mammalian predators and vespulid wasps. Direct effects on bat foraging habitat by the Scheme are unlikely, as most bat foraging activity is over the river or river margins well downstream of the abstraction reach. The exception might be above Morgan Gorge where high bat activity was recorded in the forest, albeit forest relatively close to the river. The relatively small footprint (c. 0.58 ha during construction and 0.16 ha permanent) at the headworks above Morgan Gorge (Table 1) is expected to have negligible effects on bat foraging behaviour. Bats have efficient sonar echolocation navigating abilities and are unlikely to inadvertently collide with solid objects such as power poles or buildings. There may be minor positive effects for bats where outside lights may be installed e.g. at the powerhouse and intake although this will be limited and will be operated on a sensor or remote and intermittent basis. It is known that bats forage on insects attracted to street lights at Pelorus Bridge, Marlborough (Lloyd 2010). Similarly, initial backwaters created by the weir may have some positive effects for long-tailed bats, as they tend to favour areas of slow moving or still water for foraging (Lloyd 2011; Buckingham & Charteris 2008).

6.1.3. Bat commuting routes Long-tailed bats typically use forest edges, or roads cut through forest for foraging and commuting (O’Donnell 2001). Surprisingly, there was no correlation between bat activity and forest edge habitat on surveys in 2012 in the Waitaha Valley (Figure 8), as was recorded in the Eglinton Valley, Fiordland (O’Donnell 2001) or elsewhere (B. Lloyd, pers. comm.). However, survey sampling was not designed to measure long-tailed bat’s comparative use of different habitat components during different seasons in the Waitaha Valley. Within the Waitaha Valley, bats can choose the river, terrace or cliff edges above the river, or low points in the ridge separating Kiwi Flat from the lower valley for commuting along. The proposed access road and tailrace from the powerhouse may potentially benefit bats for commuting or foraging, though any benefit is likely to be very minor. Overall it is unlikely that the Scheme would have much effect on bat commuting routes.

6.1.4. Summary of effects on bats Given the latest Scheme development plans (November 2013), including a tunnel to transport water from the top of Morgan Gorge and tunnel portal exit with powerhouse and road access along the low river terrace, potential adverse effects on bats are considered to be negligible. Bat roost sites are potentially affected by the Scheme, but can be avoided with mitigation (see Section 7). Foraging opportunities and bat commuting routes are unlikely to be affected. Minor positive effects may also occur such as feeding opportunities for bats around outside lights, and using tailrace and roadways for commuting.

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6.2. Birds

6.2.1. Fernbirds Given the absence or extreme rarity of fernbirds, effects on fernbird are not considered other than effects on potential fernbird habitat. The proportion of potential habitat affected is extremely small, and the quality of habitat poor compared to fernbird habitat in the wider area such as large wetland pakihi areas at Ianthe and Kakapotahai Forests toward the coast. Fernbirds may occasionally disperse from these wetland areas into valleys such as the Waitaha Valley. Unlike many other At Risk (and Threatened) endemic birds, fernbirds can adapt to modified habitat such as scrub beneath power pylon routes (Orikaka Valley: pers. obs.), roadside verges (Granville Forest: pers. obs.), or pine plantations (Craigieburn Forest, east Paparoa: pers. obs.).

6.2.2. Hole-nesting birds Hole-nesting birds such as kaka, kakariki, rifleman and morepork might be affected if cavity-providing trees including dead trees were removed. The large-diameter, senescent, or dead-standing trees found in mature indigenous forest are critically important for these species (as well as for bats as discussed in the previous section). These forest components are also favoured as feeding, roosting or sheltering habitat for other fauna such as lizards and insects. The current development plan (November 2013) indicates very little mature indigenous forest will be affected. Most of the forest habitat along the lower river terrace below the tunnel exit is low-stature mixed scrub typified by a range of Coprosma spp., Carmichaelia grandiflora, Pseudopanax crassifolius, Carpodetus serratus, Myrsine divaricata, etc., tree ferns and occasional regenerating forest trees (TACCRA 2013) that would provide very little roosting/breeding opportunity for hole- nesting birds (or bats). The proposed headworks including the intake access road above Morgan Gorge is within, or relatively close to, potential roost and nesting sites for hole-nesting birds though the tunnel construction itself may not directly affect this habitat. Consideration would need to be given to any potential effects of slumping or washout indirectly caused by construction that might affect this habitat (as discussed earlier). The proposed intake access road and the access to the powerhouse in the lower valley may affect a low number of larger-diameter trees. The vegetation in the proposed contractor’s yard on an alluvial terrace on the true right of the Waitaha River at Kiwi Flat is composed of dense hardwood scrub only 3-5 m high and therefore not suitable roosting or breeding habitat for hole-nesting birds. It should be noted that hole-nesting species are particularly prone to predation, and are often the first species to disappear in unprotected ecosystems (Elliott & O’Donnell 1988; Innes & Hay 1991; Innes et al. 2010; Moorhouse et al. 2003; O’Donnell 1996). Therefore any effects on birds due to minor habitat disturbance are considered negligible compared to ongoing effects of predators.

6.2.3. Other forest or non-riverine birds Effects of the Scheme on falcon, kea, western weka, and common forest birds are considered to be negligible based on:

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 the small proportion of bird habitat affected by the proposal;  the type of habitat affected (the Scheme mostly avoids taller forest habitat, which is disproportionately more important for most indigenous birds);  the relatively low numbers of Threatened or At Risk bird species present in the footprint area; and  the large territories of some Threatened or At Risk species (e.g. falcon, kea) in relation to the relatively small Scheme’s footprint area. At least one falcon occupies the area around Robinson Slip, and another is known from Kiwi Flat (Overmars & Buckingham 2007). have large territories, typically feed in open areas or around forest edges, and are very unlikely to be affected by the Scheme. Similarly, kea that were recorded frequently in the lower valley below Morgan Gorge and at Kiwi Flat in 2006/2007, and kaka recorded infrequently, have large territories. None of these species are likely to nest within the Scheme’s footprint, but it is recommended that a nest survey be carried out for kaka during the bat surveys, since kaka, if present, are likely to be in the same large trees that will be examined for bat presence. Weka tend to be present around forest margins or in scrub thickets and may be affected by the Scheme. Potential effects on weka include disturbance or destruction of nests (weka can nest over several months from early spring through to late autumn), removal of cover or feeding habitat, and being run over on access roads. Increased access for dogs will also need to be considered, though it is acknowledged that the core weka population appears to be around the periphery of farmland downriver of Robinson Slip where there is currently good access for dogs. Effects on species such as long-tailed cuckoo (At Risk), shining cuckoo and kereru (Non Threatened) are considered negligible, but could involve loss of nests and minor reductions in food resource through loss of habitat. Seasonal migration patterns for these and other species are unlikely to be affected by the Scheme. Non- threatened small birds such as tomtits, robins and grey warblers are present widely outside the Scheme’s footprint and effects on them are considered negligible due to the small scale and narrow linear shape of the Scheme’s footprint.

6.2.4. Riverine birds Several bird species associated, or partly associated, with river and riverbed habitats were recorded in the Waitaha Valley. These included Threatened species such as blue duck and grey duck, At Risk species such as black shag and South Island pied oystercatcher, and Not Threatened species such as white-faced heron, paradise , spur-winged plover, and southern black-backed gull. Adverse effects on riverine birds by the Scheme will vary according to the species (Table 6). Effects are likely to be greater for those species that nest close to the river (e.g. , and spur-winged plover), or species that are specialist river feeders (e.g. blue duck, grey duck and black shag). Fluctuation in river levels such as an initial backwater effect above the weir may cause loss of breeding and feeding habitat for some of these species. Similarly, building up of silt may restrict breeding and feeding opportunities for these birds. However, similar losses would be expected from normal flood events especially those occurring during the breeding season. Adverse effects of silting are considered unlikely (Hicks 2013).

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Table 6. Riverine birds recorded in the Waitaha Valley and level of potential effect from the Scheme (information after Heather & Robertson 1996)

Species Nesting habitat Feeding habit Level of potential effect Black shag Usually in trees or Mainly small and Negligible (nest high cliffs near water medium-sized fish, above river and food but koura and supply not affected) invertebrates also taken White-faced Usually high up trees Typically fish, frogs, Negligible (nest high heron not necessarily near tadpoles, above river and food water invertebrates: supply not affected) generalist not necessarily aquatic food Paradise Riverbed, farm pond Aquatic vegetation. Negligible (generalist shelduck etc with open view Pasture grass and feeders) clover etc. Blue duck Hollow log, cavity or Almost entirely (refer Overmars dense vegetation aquatic insects: 2014) near stream or river predominantly caddis fly larvae Grey duck A bowl of grass Mainly seeds sieved Negligible (nesting generally away from from the water and and food supply water and up to 10m aquatic vegetation. unlikely affected at above ground Ducklings and least after temporary nesting females take backwater effect) aquatic invertebrates South Is pied Territorial nesters: Mainly molluscs, Negligible oystercatcher on riverbeds or worms and (distribution mainly farmland larvae outside affected area) Spur-winged Generally rough Generalists: Negligible (generalist plover open pasture or wet earthworms, insects feeders and area but also and their larvae but distribution mainly riverbed also seeds and leaves outside affected area) Black-backed Usually colonial Generalists and Negligible (generalist gull nesters: gravel opportunists taking a feeders and beaches, coastal, wide variety of food: distribution mainly riverbeds offal, refuse, carrion, outside affected invertebrates, fish, area) lizards, even birds

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Any changes in river flow, sedimentation, or other causes of water quality loss will affect riverine birds to some extent. These changes might affect nesting habitat, feeding habitat or the food source itself. Adverse effects are potentially greater for river specialists such as blue duck, grey duck and black shag than other species such as spur-winged plover, white-faced heron and southern black-backed gull that have a more generalist diet and habitat use. Other technical reports discuss the potential effects of river flow changes, sedimentation and land stability caused by the Scheme (Allen & Hay 2013; Doyle 2013, Hicks 2013), and freshwater ecology that might affect some terrestrial fauna (McMurtrie & Suren 2014). From my understanding, effects of the Scheme on riverine birds4 will be negligible, given the design of the scheme, the short abstraction reach (2.6 km), the relative rarity of sensitive riverine fauna within that reach, the relatively low aquatic faunal productivity in the main stem, the frequent flooding that naturally affect these fauna, and the mitigation proposed. Effects on specific riverine bird species are discussed below. Adverse effects on the Nationally Critical grey duck are considered negligible given the relatively small proportion (6.5%) of river permanently affected. Grey ducks are ranked Nationally Critical because the species freely hybridise with the introduced mallard (Williams & Basse 2006). Purebred grey ducks are becoming very rare and may now be restricted to remote forest areas, but this is not known. The Scheme is not expected to increase the chance of mallard invasion given the small area of vegetation clearance (c. 4.53 ha during construction) and use of a tunnel that would deny access of mallards from the lower valley to Kiwi Flat. Similarly, adverse effects on the riverine At Risk species (black shag and South Island pied oystercatcher) are expected to be negligible. Black shags are rarely seen: there are only occasional observations of single birds flying up or down river below Morgan Gorge in 2012. No black shags were observed at Kiwi Flat or the abstraction reach over an extended period of observation between 2006-2012 (F. Overmars, pers. comm.). No black shag roosts or nests were identified during the survey, therefore it is unlikely that their breeding habitat would be affected by the Scheme. South Island pied oystercatchers are found in the lower floodplain of the Waitaha River and it is unlikely that their range extends into the proposed abstraction reach. The proposed access road may affect oystercatchers and other riverine birds such as paradise shelduck and spur-winged plover, if they choose to breed along it during the construction period (overall negligible effect).

6.2.5. Summary of effects on birds Overall potential adverse effects on non-riverine birds are considered to be negligible given the low extent of critical habitat (large-diameter trees and podocarp trees) affected, and the scheme’s relatively small footprint. This would mean little adverse effect on forest-specialist species such as kaka and rifleman that are sensitive to habitat modification. Species such as weka and kereru that are found within the proposed footprint tend to adapt to changes in natural habitats over time.

4 Effects on blue duck covered in Overmars 2014)

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However, some birds could be prone to road kills and increased predation as a result of the proposed access road up the lower valley. These effects are also considered negligible providing mitigation is in place (see Section 7). Similarly, effects (direct, indirect; positive, adverse) on riverine birds by the Scheme are considered to be negligible, because:  threatened or At Risk riverine birds are relatively scarce within the abstraction reach;  the abstraction reach is relatively short (2.6 km), only 6.5% of the length of the river;  aquatic invertebrate productivity in the main stem (Waitaha River) is less than that found in the more stable tributaries (McMurtrie & Suren 2014) that remain largely unaffected by the Scheme;  frequent flooding events will probably prevent sediment accumulation that might otherwise result from the Scheme (Allen & Hay 2013; Doyle 2013; Hicks 2013);  headworks design further reduces the likelihood of sediment accumulation (McCahon 2013); and  other construction design and mitigation will reduce adverse effects (refer Allen & Hay 2013; Doyle 2013; Drinan & McMurtrie 2014; Hicks 2013; McCahon 2013; McMurtrie & Suren 2014; Overmars 2014). Predators are considered to be a far greater threat to terrestrial fauna in the Waitaha Valley than any potential adverse effects from the Scheme. 6.3. Miscellaneous potential effects on terrestrial fauna by the Scheme While the main predicted or potential effects on fauna have been discussed previously, lesser potential effects include noise (mainly during construction), increased risk of road kills (particularly for weka), disturbance caused by humans or their machinery, bright light (e.g. during construction) and dust (presumably a very minor effect in this area, mainly during construction). Anthropogenic noise pollution is known to affect birds living near construction areas, or in roadside habitats (e.g. Ortega 2012; Parris & Schneider 2008). Bird response to noise tends to focus on avoidance of noise, changes in foraging and other behaviour including vocal communication, changes in reproductive success, and stress responses. There is considerable international literature on the effects of anthropogenic noise on birds, conveniently reviewed by Ortega (2012). Noise effects from the Scheme are quite localised and mainly temporary (i.e. during the construction phase). In addition, birds (and possibly bats) habituate to regular or constant noise to some extent (e.g. Brown 1990; Manci et al. 1998; Pater et al. 1999). Roads have a broad range of adverse effects on terrestrial fauna: e.g. direct mortality from road construction and vehicle collision, creating physical barriers, fragmenting habitats, and altering behaviour such as from vehicle noise (Trombulak & Frissell 2000). Weka are particularly vulnerable to being run over by vehicles (e.g. Freeman 2010) and kereru can swoop low and be hit by vehicles (e.g. Clout et al. 1995). Although overall road effects by the Scheme are considered

47 Wildlife Surveys 2014 Terrestrial fauna Waitaha Hydro Scheme negligible, they are greatest during the construction period when traffic is heavier, noisier, and more frequent. Effects from roads on birds are likely to be greatest during the breeding season. Another potential effect is an increase in predation as a result of increases in predator numbers due to establishment of road access. However, I consider this very unlikely because the area is probably now at carrying capacity for most mammalian predators, and predators currently have easy access along the riverbed and low river terraces. Road access could increase the risk of dogs roaming upriver of Macgregor Creek, but I consider this a negligible risk providing mitigation is in place (see Section 7). Local predator problems could occur if food and other scraps are not stored properly and carried out of the area promptly. In addition, problems associated with food could occur if indigenous species such kea and weka get access to it. The power transmission line has potential effects on bats and birds. These include loss of habitat, death or disturbance of fauna during construction, and electrocution. New Zealand studies have shown that falcons and other birds are vulnerable to electrocution on power transmission lines (Fox & Wynn 2010; Gaze & Fox 2010). Overseas studies on bird deaths through electrocution are more extensive (e.g. Ferrer & Janss 1999; Lehman et al. 2007). However, power poles can provide some benefit to birds in providing perching and nesting sites (Potapov et al. 2001). It is my understanding that a 2½ m spacing between conductors is proposed, which should negate any risk of electrocution to birds (greater width than wingspan). In a radio tracking study of 55 falcons on the Wairau Plain, Marlborough, 47% of 21 falcons whose cause of death was known were electrocuted (Fox & Wynn 2010). These included seven juvenile females, one juvenile male, one adult female, and one adult male. These studies suggest that electrocution might be the single greatest cause of mortality for the New Zealand falcon. Effects on Powelliphanta snails are not discussed because: 1. There is no evidence of any populations in the Scheme or surrounding areas, and 2. Potential Powelliphanta habitat (i.e.. river terraces with shrub hardwood cover at Kiwi Flat; and forest cover below Morgan Gorge) is largely outside the proposed footprint.

7. Mitigation As discussed in Section 6 above, overall effects by the Scheme on terrestrial fauna (bats and birds, excluding blue duck, which are discussed elsewhere) are considered to be negligible. However, because of the ecological and RMA significance of many fauna and faunal communities within the area, any actual or potential adverse effects should be avoided, remedied or mitigated. To a large extent this has been accomplished in the Scheme’s design (refer Section 6). Other mitigation recommended to further reduce effects on terrestrial fauna includes:  Where possible, minimising the effects of construction activities during the main breeding season for bats and birds (spring and early summer) at

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particularly sensitive areas (e.g. tunnel portal entrance and other headworks sites where large-diameter trees are to be removed);  a survey for potential bat roost trees and occupied roosts within proposed construction sites immediately prior to construction;  a survey to detect nesting kaka within the proposed construction sites (carried out at the same time as the bat roost survey);  reducing road speeds to minimise road deaths of birds such as weka and kereru (use of road signs and staff induction);  ensuring all food and rubbish is collected and removed from the site promptly to avoid local pest problems and scavenging behaviour by kea or weka; and  implementing measures to reduce dog access to the Waitaha Valley (signage and advocacy). Mitigation from both the Scheme design and additional recommendations are discussed in more detail below.

Minimise loss or modification of key habitats The current footprint plan largely avoids critical and favoured habitats for birds and bats. However, there are small areas within the footprint that contain large trees or podocarps (which area important for bats and several indigenous birds, such as kaka, kakariki, kereru and tui). Where possible, these habitat components should be avoided during construction. Similarly, dead standing trees are important for some birds and should be left unless they pose a hazard or obstruction. The decision to establish the powerhouse and access roads along the low river terrace rather than the high terrace as considered earlier, minimises the Scheme’s impact on mature forest ecosystems. TACCRA (2013) also notes the importance of minimising the removal of large hardwood trees (>60 cm dbh) and podocarp trees (≥30 cm dbh) in the construction of the proposed access road to the powerhouse and tunnel portal exit. Interference to side creeks and stable tributaries will be avoided or minimised by the Scheme’s design. McMurtrie & Suren (2014) have shown significantly higher aquatic invertebrate density and diversity in stable tributaries than the main stem of the river, or other tributaries. Existing habitats downriver of Robinson Slip are very modified and mitigation is not required, other than ensuring a stable riverbank. Care should to be taken to ensure construction does not erode river terraces, or any part of the footprint. Mitigation should include weed control and planting appropriate locally sourced endemic plants to stabilize riverbanks as part of a rehabilitation plan/construction management plan.

Preventing or minimising electrocution of birds Section 6.3 discusses the risk of transmission lines to birds, especially falcons. However, it is my understanding that a 2½ m spacing between conductors is proposed, which should negate the risk of electrocution to birds as the gap is wider than any bird’s wingspan.

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Bat roost tree and roost activity surveys Survey for potential bat roost trees within the proposed construction sites are recommended prior to construction (as part of a rehabilitation plan/construction management plan). Any potential bat roost trees found in construction sites should be checked for nighttime bat activity immediately before construction begins and if any bats are present construction should be delayed until the bats abandon the roost. Typically, long-tailed bats roost in cavities in trees >80 cm diameter at breast height (dbh) within, or close to, areas of old-growth forest. Although potential roost cavities are often not easily visible, a tree’s suitability for roosting can be predicted from the tree’s characteristics (e.g. species, size, growth-form, presence of visible cavities, age and condition) and the surrounding forest structure (Sedgeley & O’Donnell 1999a&b; Sedgeley 2003, 2006). Usually roost cavities are in the largest and oldest trees available. Potential roost tree sites will be identified from vegetation descriptions (TACCRA 2013) and aerial photographs incorporating the Scheme’s footprint that from latest plans (November 2013) indicate relatively few potential roost trees affected. Each potential roost tree (or groups of trees) within or very close to the footprint will be checked for bat activity. Bat activity will be monitored using acoustic bat recorders at night, immediately before construction begins at each potential bat roost site. If any occupied roosts (or indications of them) are detected, construction will be postponed until the bats move to another roost outside the immediate construction area (expected to be only a few day’s delay). Surveys will be undertaken using these methods at all areas of construction where potential bat roost trees are identified. It should be noted that long-tailed bats frequently move their roosts, with adults moving their young during the breeding season (late spring/early summer) (see Section 6.1.1). Therefore, it is important that surveys for occupied bat roosts are carried out immediately prior to construction to avoid the risk of felling trees containing bat roosts and consequently killing the occupants.

Minimising construction during breeding season The best time to carry out construction to minimise effects on breeding bats and birds is late summer/autumn through to early spring when most species have finished breeding. Although the range of birds found in the Waitaha Valley nest over different seasonal periods, the overall peak-breeding season is usually spring (late September through to late December). The main breeding season for bats is November and December. This is also often the best time for construction activities, being generally the most settled weather on the West Coast. Construction during settled weather reduces other undesirable effects such as washouts and slumping. While it is suggested that construction within the most sensitive habitat areas (i.e. around the headworks and intake access road) should be carried out during late summer to early spring, it is not always practical to undertake construction at optimal times to reduce effects on terrestrial fauna. Ceases to construction could

50 Wildlife Surveys 2014 Terrestrial fauna Waitaha Hydro Scheme prolong the overall period for construction which in itself creates further effects. Rather than prolong the duration of construction works it is preferable to minimise the numbers of days that bird species are exposed to construction disturbance. An acoustic survey for bats is proposed in areas where tall forest is present (as described above). A survey to detect nesting kaka at similar sites can be undertaken at the same time as the bat roost survey. If bats and or breeding kaka are found within the proposed construction area, activities such as tree felling will be temporarily halted or alternative routes found to avoid disturbance.

Reducing road speeds An access road will be constructed to the powerhouse from Waitaha Road. Existing farm tracks will be widened and built for construction requirements. Higher traffic use along existing or new roads will increase the risk of road kills, especially weka and possibly kereru in this area (see Section 6.3). Weka are most common along the farmland, scrubby river terrace edges, and forest edges where access roads are likely to be established. Kereru are seasonally abundant in the mixed scrubland on the low river terrace upriver of Macgregor Creek. Restricting traffic speed will help to reduce road kills. Illustrated explanatory signs are also recommended.

Preventing access to dogs and other predators Because dogs are a potential threat to ground birds such as weka and blue duck, they should be prevented from entering the valley. Currently there are no indications that dogs are a problem, as there is a healthy weka population around the farm edge. Signs encouraging people not to bring dogs into the valley (with reasons) would help prevent any potential future problems. All food scraps and other rubbish should be contained and promptly removed from the site to reduce the risk of attracting rodents or other pests. Predator control should be carried out on all access routes to reduce predator numbers. Predator control should target possums, feral cats, mustelids and rodents. Goat and hare control should also be undertaken. These matters will be covered in relevant management plans.

8. Monitoring Given the assessed negligible effects of the Scheme on terrestrial fauna, I see no particular benefit in carrying out specific monitoring on any terrestrial fauna covered in this report other than bats, if predator control is undertaken. However, there would need to be monitoring for pest and weed control management and physical effects (e.g. changes in river flow, sedimentation, streamside erosion, etc) that might affect fauna and faunal habitat. Details of this monitoring are outside the scope of this report and will be covered as part of relevant concession and resource consent conditions and management plans.

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9. Conclusion The November–December 2012 survey extended the known range of long-tailed bats in the Waitaha valley from Kiwi Flat to below the Morgan Gorge. Although Kiwi Flat appears to be the core area for these bats, moderate bat activity was recorded on the river terrace immediately downriver of the Macgregor Creek confluence. Short-tailed bats were not detected and are very unlikely to be present. The abundance and distribution of birds (including Threatened and At Risk species) were generally similar to that recorded during 2006–2007 (Overmars & Buckingham 2007). No fernbirds or Powelliphanta snails were found in 2012. Specialised surveys for blue ducks are reported elsewhere (Overmars & McLennan 2010; Overmars 2013). The use of automatic acoustic recorders in 2012 increased the knowledge of birds occupying river terraces and other areas below Morgan Gorge. The combined baseline surveys provide a comprehensive knowledge of terrestrial fauna within the mid to lower Waitaha Valley (from Kiwi Flat to Doughboy Hill). The Scheme and surrounding area is considered significant in terms of the assessment of guidelines/criteria for significance set out in the RPS and WDP because of the presence of several Threatened and At Risk fauna, high representative values for long-tailed bat and blue duck, and the potential distinctiveness of at least one species (western weka) present in the area. The Scheme footprint contains high natural heritage values based on assessment criteria in the CMS. Notwithstanding this overall level of significance, all species recorded have a wide distribution range, and similar habitats are found widely throughout the West Coast. Given the small linear footprint of the scheme, its design and the mitigation proposed, it is predicted that the Scheme will have a negligible effect on terrestrial fauna values currently present in the Waitaha Valley. Construction of the various components of the Scheme largely avoids the tall podocarp/hardwood forest that is considered most important for bats and forest birds (especially kaka, kea and rifleman). The powerhouse and associated infrastructure will be located on the lower river terrace, thereby mainly avoiding the loss of large forest trees. The access road to the powerhouse and the transmission line route will either go through already disturbed areas (i.e. below Macgregor Creek), or be cleared carefully to reduce loss of mature and large-diameter trees (i.e. above Macgregor Creek). Large trees might be removed in the headworks’ footprint (tunnel portal entrance and associated structures, access road and contractor’s facilities), but overall the headworks’ effects on non-riverine fauna are considered negligible, because the total footprint of the headworks is only 0.58 ha during construction and 0.16 ha when completed (TACCRA 2013). Although riverine birds may be indirectly affected (positively or adversely) by any change to their food source or breeding habitat caused by changes in river flows or sedimentation, I consider that these effects are likely to be negligible because:

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 threatened or At Risk birds are relatively scarce within the abstraction reach;  the abstraction reach is relatively short (c. 2.6 km), only c. 6.5% of the length of the river;  aquatic invertebrate fauna values of the river’s main stem (Waitaha River) are much lower than in the stable tributaries (McMurtrie & Suren 2014) that are largely unaffected by the Scheme;  frequent flooding events will probably prevent sediment accumulation that might otherwise result from the Scheme (Allen & Hay 2013; Doyle 2013; Hicks 2013);  headworks’ design further reduces the likelihood of sediment accumulation (McCahon 2013); and  other construction design features and mitigation should also reduce adverse effects (refer Allen & Hay 2013; Doyle 2013; Drinan & McMurtrie 2014; Hicks 2013; McCahon 2013; McMurtrie & Suren 2014; Overmars 2014). In my opinion, predators are a far greater threat to terrestrial fauna in the Waitaha Valley than any possible adverse effects from the Scheme. The absence of kiwi and short-tailed bats, and relatively low numbers of Threatened bird species and individuals are indications of high predation levels in the Waitaha Valley. In my assessment, while the overall design of the Scheme means that there will be negligible adverse effects on terrestrial fauna (bats and birds), any remaining adverse effects will be further reduced by the mitigation and associated monitoring proposed in this report.

Acknowledgements I thank Sue Cotton and Rodger Griffiths (ElectroNet Ltd) for information and updates on the development plan. Matt Charteris (Waybacks Ltd) assisted on the first field survey (November 2012). I am indebted to Dr Brian Lloyd (Lloyds Ecological Consulting Ltd) for critically reviewing a draft of this report, and Martin Kennedy (West Coast Planning Ltd) for his review and advice on relevant parts of the draft report. I also thank Fred Overmars (Sustainability Solutions Ltd), Shelley McMurtrie (EOS Ecology Ltd), Jan Derks (TACCRA Ltd), Dr John MacLennan (Environmental Services), and Martin Doyle for providing important information in their respective fields. Mark Hamilton (MBC Ltd) provided the maps.

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Elliott, G.; Suggate, R. 2007. Operation Ark: Three year progress report. Department of Conservation, Christchurch. 83 pp. Ferrer, M.; Janss, G.F.E (Eds) 1999. Birds and powerlines: collision, electrocution and breeding. Quercus Press. 239 pp. Fox, N.C.; Wynn, C. 2010. The impact of electrocution on the New Zealand falcon (Falco novaeseelandiae). Notornis 57: 71–74. Freeman, S. 2010. Western weka road-kill at Cape Foulwind, Buller, New Zealand. New Zealand journal of zoology 37: 131–146. Gaze, P.; Fox, N.C. 2010. The electrocution of falcons in Marlborough and implications for birdlife elsewhere. Abstracts of papers presented at the Ornithological Society of New Zealand AGM and conference, 2 June 2010, Nelson, New Zealand. Notornis 57: 106. Gillingham, N. J. 1996. The behaviour and ecology of long-tailed bats (Chalinolobus tuberculatus Gray) in the central North Island. Unpublished MSc thesis, Massey University, Palmerston North, New Zealand. Griffiths, R. W. 2007. Activity patterns of long-tailed bats (Chalinolobus tuberculatus in a rural landscape, South Canterbury, New Zealand. New Zealand journal of zoology 34: 247–258. Heather, B.D.; Robertson, H.A. 1996. ‘The field guide to the ’ Penguin Books (NZ) Ltd, Auckland. 432 pp. Hicks, D. M. 2013. Sediment investigations relating to a proposed HEP scheme on the Waitaha River. Contract report prepared for Westpower Ltd. 25 pp. Hitchmough, R.; Bull, L; Cromarty, P. (compilers) 2007. New Zealand threat classification system lists—2005. Department of Conservation, Wellington. Innes, J.G.; Hay, J.R. 1991. The interactions of New Zealand forest birds with introduced fauna. Pp 2523-2533 in J.L. Craig; G.S. Dumbell (Conveners) Integrating New Zealand Conservation. Acta XX Congressus Internationalis Ornithologici. Symposium No. 48. Innes, J.; Kelly, D.; Overton, J. M.; Gillies, C. 2010. Predation and other factors currently limiting New Zealand forest birds. New Zealand journal of ecology 34 (1): 86–114. Lehman, R.N.; Kennedy, P.L.; Savidge, J.A. 2007. The state of the art in raptor electrocution research: a global review. Biological Conservation 136: 159-174. Lloyd, B.D. 2001. Advances in New Zealand mammalogy 1990-2000: Short-tailed bats. Journal of the Royal Society of New Zealand 31 (1): 59-81. Lloyd, B. D. 2005. Lesser short-tailed bat. ‘The handbook of New Zealand mammals’. C. King. Melbourne, Oxford University Press: 110-126. Lloyd, B.D. 2009. Acoustic survey of the for lesser short-tailed bats Mystacina tuberculata: October 2009. Lloyds Ecological Consulting. For: Department of Conservation Buller Kawatiri Area Office. 11 pp. Lloyd, B.D. 2010. Top of the South Bat Conservation Programme: Royal Forest and Bird Protection Society annual report 2009-2010. Unpublished contract report for Royal Forest and Bird Protection Society. 24 pp. Lloyd, B.D. 2011. Evidence in-chief in the matter of Appeals pursuant to Section 120 of the Resource Management Act 1991 for Meridian Energy Limited regarding the Mokihinui Hydro Project. 102 pp.

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Lloyd, B.; Cockburn, S. 2009. Introduction to the Department of Conservation’s Digital Bat Detector and BatSearch software. Unpublished report for the Department of Conservation. 29 pp. Manci et al. 1988. Effects of Aircraft Noise and Sonic Booms on Domestic and Wildlife: A Literature Synthesis. U.S. Fish and Wildlife Service National Ecology Research Centre. McCahon, I. 2013. Waitaha Hydro Scheme: Morgan Gorge intake: Preliminary headworks concept. Contract report for Westpower Ltd prepared by Geotech Consulting Ltd. 13 pp including plans. McLennan, J.A. 2007a. Small mammal survey, lower Waitaha catchment, May 2007. Environmental Services Ltd, Havelock North. McLennan, J.A. 2007b. Small mammal survey, lower Waitaha catchment, January 2007. Environmental Services Ltd, Havelock North. McMurtrie, S. & Suren, A. 2014. Proposed Waitaha Hydro Scheme: Assessment of Environmental Effects: Benthic Ecology of the Waitaha Catchment. EOS Ecology report No. 06003-ELE01-02, contract report prepared for Westpower Ltd. EOS Ecology, Christchurch. 151pp Miskelly, C.M.; Dowding, J.E.; Elliott, G.P.; Hitchmough, R.A.; Powlesland, R.G.; Robertson, H.A.; Sagar, P.M.; Scofield, R.P.; Taylor, G.A. 2008. of New Zealand birds, 2008. Notornis 55: 117–135. Moorhouse, R; Greene, T.; Dilks, P.; Powlesland, R.; Moran, L; Taylor, G.; Jones, A.; Knegtmans, J.; Wills, D.; Pryde, M.; Fraser, I.; August, A.; August, C. 2003. Control of introduced mammalian predators improves kaka Nestor meriodionalis breeding success: Reversing the decline of a threatened New Zealand . Biological Conservation 110(1): 33–44. O’Donnell, C.F.J. 1996. Predators and the decline of New Zealand forest birds: an introduction to the hole-nesting bird and predator programme. New Zealand journal of zoology 23: 213–219. O’Donnell, C.F.J. 2000. Influence of season, habitat, temperature, and invertebrate availability on nocturnal activity by the New Zealand long-tailed bat (Chalinolobus tuberculatus). New Zealand journal of zoology 27: 207–221. O’Donnell, C.F.J. 2001. Advances in New Zealand mammalogy 1990–2000: Long-tailed bat. Journal of the Royal Society of New Zealand 31 (1): 43–57. O’Donnell, C.F.J.; Christie, J.; Corben, C.; Sedgeley, J.A.; Simpson, W. 1999. Rediscovery of short-tailed bats (Mystacina sp.) in Fiordland, New Zealand: preliminary observations of , echolocation calls, population size, home range, and habitat use. New Zealand journal of ecology 23(1): 21–30. O'Donnell, C.F.J.; Christie, J.E.; Hitchmough, R.; Lloyd, B.D.; Parsons, S. 2010. The conservation status of New Zealand bats, 2009. New Zealand Journal of Zoology 37: 297-311. Ortega, C.P. 2012. Effects of noise pollution on birds: A brief review of our knowledge. Ornithological Monographs No. 74: 6-22. Overmars, F. 2013. Proposed Waitaha Hydro Scheme. Blue duck surveys, Kiwi Flat to Douglas Creek, December 2012 (Draft). Contract report prepared for Westpower Ltd, Greymouth by Sustainability Solutions Ltd. 20pp.

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Overmars, F. 2014. An assessment of environmental effects of the proposed Waitaha Hydroelectricity Scheme on whio/blue duck (Hymenolaimus malacorhynchos). Prepared for Westpower Ltd, Greymouth, by Sustainability Solutions Ltd. 102pp. Overmars, F.B.; Buckingham, R.P. 2007. Baseline fauna survey of proposed Waitaha Hydro Scheme Area. Contract report prepared for ElectroNet Services Ltd, Greymouth. 42 pp. Overmars, F.; McLennan, J. 2010. Blue duck (whio) population, habitat use and predators, Waitaha River (year 1 report). Proposed Waitaha Hydro-electricity Scheme. Contract report prepared for Mitton Electronet Ltd, Christchurch. 118 pp. Parris, K. M., and A. Schneider 2008. Impacts of traffic noise and traffic volume on birds of roadside habitats. Ecology and Society 14(1): 29. Pater et al. 1999. Assessment of Training Noise Impacts on the Red-cockaded Woodpeacker: 1999 Results. US Army Corps of Engineers. Potapov, E.; Fox, N.; Gombobaatar, S.; Sumya, D.; Shagdarsuren, O. 2001. Mongolian sakers benefit from electrical installations. Abstracts of 4th Eurasian congress on raptors. Seville, Spain 25-29 September 2001. Estacion Biologica Donana, RRF. 145. Pryde, M.A.; O’Donnell, C.F.J.; Barker, R.J. 2005. Factors influencing survival and long-term population viability of New Zealand long-tailed bats (Chalinolobus tuberculatus): Implications for conservation. Biological conservation 126: 175–185. Robertson, C.J.R.; Hyvönen, P.; Fraser, M.J.; Pickard, C.R. 2007. “Atlas of bird distribution in New Zealand: 1999–2004”. The Ornithological Society of New Zealand, INC. 533 pp. Robertson, H.A.; Dowding, J.E.; Elliott, G.P.; Hitchmough, R.A.; Miskelly, C.M.; O’Donnell, C.F.J.; Powlesland, R.G.; Sagar, P.M.; Scofield, P.; Taylor, G.A. 2013. Conservation status of New Zealand birds, 2012. New Zealand threat classification series 4. Department of Conservation, Wellington. 22 pp. Sedgeley, J.A., 2003. Roost site selection and roosting behaviour in lesser short-tailed bats (Mystacina tuberculata) in comparison with long-tailed bats (Chalinolobus tuberculatus) in forest, Fiordland. New Zealand Journal of Zoology 30, 227-241. Sedgeley, J.A., 2006. Roost site selection by lesser short-tailed bats (Mystacina tuberculata) in mixed podocarp-hardwood forest, Whenua Hou/Codfish Island, New Zealand. New Zealand Journal of Zoology 33, 97-111. Sedgeley, J; O’Donnell, C.F.J. 1999a. Roost selection by the long-tailed bat, Chalinolobus tuberculatus, in temperate New Zealand rainforest and its implications for the conservation of bats in managed forests. Biological conservation 88: 261–276. Sedgeley, J.A., O'Donnell, C.F.J., 1999b. Factors influencing the selection of roost cavities by a temperate rainforest bat (Vespertilionidae: Chalinolobus tuberculatus) in New Zealand. journal of zoology (London) 249: 437-446. TACCRA 2013. Waitaha Hydro Scheme Terrestrial Flora Description and Assessment of Effects. Contract report for ElectroNet Ltd prepared by TACCRA Ltd. 96 pp. Trombulak, S.C.; Frissell, C.A. 2000. Review of ecological effects of roads on terrestrial and aquatic communities. Conservation biology 14 (1): 18-30. Walker, K. 1997. Techniques for monitoring populations of Powelliphanta land snails. Ecological management No. 5: 53-63. Department of Conservation, Wellington.

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Walker, K. J. 2003. Recovery plans for Powelliphanta land snails. Threatened Species Recovery Plan 49. Department of Conservation, Wellington. x+208 pp+64 plates. West Coast Regional Council 2000. West Coast regional policy statement. 147 pp. Westland District Council 2002. Westland District Plan. Westland District Council, Hokitika. Westpower 2012. Westpower: Proposed Waitaha Hydro Scheme options selection workshop 11th October 2012. Option selection assessment papers. Westpower Ltd, Greymouth. Williams, M.; Basse, B. 2006. Indigenous gray ducks, Anas superciliosa, and introduced mallards, A. platyrhynchos, in New Zealand: processes and outcome of a deliberate encounter. Acta Zoologica Sinica 52 (supplement): 579–582.

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Appendices

Appendix 1. Birds referred to in report (in checklist order after Gill et al. 2010)

Asterisk denotes recorded on 2012 survey

Great spotted kiwi Apteryx haastii Canada goose* Branta Canadensis maxima Paradise shelduck* Tadorna variegata Blue duck Hymenolaimus malacorhynchos Mallard* Anas platyrhynchos platyrhynchos Grey duck Anas superciliosa Black shag* Phalacrocorax carbo novaehollandiae White-faced heron* Egretta novaehollandiae novaehollandiae Australasian bittern Botaurus poiciloptilus * Circus approximans New Zealand falcon* Falco novaeseelandiae Western weka* Gallirallus australis australis South Island pied oystercatcher* Haematopus finschi Spur-winged plover* Vanellus miles novaehollandiae Southern black-backed gull* Larus dominicanus dominicanus New Zealand pigeon (kereru)* Hemiphaga novaeseelandiae South Island kaka* Nestor meridionalis meridionalis Kea* Nestor notabilis Yellow-crowned parakeet* Cyanoramphus auriceps Shining cuckoo* Chrysococcyx lucidus lucidus Long-tailed cuckoo* Eudynamys taitensis Morepork Ninox novaeseelandiae novaeseelandiae Little owl* Athene noctua New Zealand kingfisher Todiramphus sanctus vagans South Island rifleman* Acanthisitta chloris chloris Grey warbler* Gerygone igata Bellbird* Anthornis melanura melanura Tui* Prosthemadera n. novaeseelandiae

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Brown creeper* Mohoua novaeseelandiae Australian magpie* Gymnorhina tibicen South Island fantail* Rhipidura fuliginosa fuliginosa South Island tomtit* Petroica macrocephala macrocephala * Petroica australis australis South Island fernbird Bowdleria punctata punctata * Zosterops lateralis lateralis Welcome swallow* Hirundo neoxena neoxena Skylark* Alauda arvensis Eurasian blackbird* Turdus merula merula Song thrush* Turdus philomelos New Zealand pipit* Anthus novaeseelandiae novaeseelandiae Dunnock* Prunella modularis Chaffinch* Fringilla coelebs European greenfinch* Carduelis chloris European goldfinch Carduelis carduelis britannica Common redpoll* Carduelis flammea Yellowhammer* Emberiza citrinella

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Appendix 2. Bat Detector Sites and Records

Location Easting Northing No bat Mean Feeding nights pass buzz Quarry 1415725 5227977 41 0 Doughboy East 1416032 5227514 17 0 Doughboy West 1415497 5227513 39 0.08 Lower River 1 1415351 5226999 3 0 Lower River 2 1415326 5226859 40 4.35 Lower River 3 1415285 5226569 3 2.0 Lower river 4 1415263 5226041 24 2.96 Nth Macgregor 1415317 5225758 20 1.0 Yes Robinson Slip (tin hut 1) 1416326 5225799 23 0 Robinson Slip (tin hut 2) 1416300 5225801 21 0 Robinson Slip (upper) 1416901 5225922 45 0 Sth Macgregor 1 1415362 5225138 3 0 Sth Macgregor 2 1415431 5225114 40 0.1 Sth Macgregor 3 1415761 5225307 43 0.16 Granite Creek 1415550 5224880 24 0 Granite Ck forest 1415549 5224774 42 0 Lower backwater 1415318 5224586 3 0 Op. Douglas Ck 1415244 5224538 40 0 Op. Douglas Ck 2 1415190 5224308 3 0 Op. Douglas Ck 3 1415189 5224338 22 0 Upper backwater 1415288 5224188 27 0 Alpha Creek 1415349 5223759 23 0 Alpha Creek knoll 1415388 5223685 15 0 Alpha Creek bluff 1415489 5223778 43 0 Alpha top terrace 1415579 5223687 43 0.23 Lower gorge 1 1415256 5223397 37 2 Lower gorge 2 1415142 5222932 18 0 Lower gorge 3 1415162 5223065 15 0 Lower gorge forest 1 1415181 5222870 18 0 Lower gorge forest 2 1415182 5222891 15 0.07 Kiwi Flat 1415844 5222216 35 8.83

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Appendix 3. Audio Recorder sites and results (NR = Not Recorded)

Site location Easting Northing Date No. nights Threatened, At Risk and uncommon indigenous bird species recorded installed NZ Falcon Weka Kea Long-tailed Shining Robin cuckoo cuckoo Alpha Creek flat 1415355 5223655 12. Nov. 3 NR* NR NR NR* NR NR Upper backwater 1415295 5224106 12. Nov. 3 NR NR Recorded NR NR NR Lower backwater 1415372 5224518 12. Nov. 3 Recorded NR Recorded NR Recorded NR South Macgregor 1415427 5225110 12. Nov. 3 Recorded Recorded Recorded Recorded NR Recorded North Macgregor 1415718 5225756 13. Nov. 2 NR* Recorded Recorded NR* NR NR South Macgregor 1415381 5225146 08.Dec. 1 NR NR* Recorded NR NR NR* North Macgregor 1416111 5225858 07. Dec. 2 NR* Recorded NR* Recorded NR NR

* Also confirmed present in the area during daytime surveys

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Appendix 4. Threatened, At Risk and infrequent bird records (2006-07 and 2012)

Species Threat Status Abundance Distribution Comments Black Shag At Risk Infrequent River throughout Only one seen at a time flying up/down river in 2012 Blue Duck Nationally Vulnerable Infrequent Above Morgan Gorge Not observed in 2012 Grey duck Nationally Critical Infrequent Kiwi Flat Not observed in 2012 Western weka Not Threatened Occasional Farm edge, near Pair and family seen on terrace south of Macgregor Creek Macgregor Creek, Kiwi confluence in December 2012 Flat NZ falcon Nationally Vulnerable Occasional Robinson Slip, below Two-three territories suspected (Taxonomically Indeterminate) Morgan Gorge, Kiwi Flat South Is kaka Nationally Vulnerable Infrequent Forest areas Morgan One sighting of two birds below Morgan Gorge in 2012 Gorge Kea Nationally Endangered Occasional Throughout Three seen in group at Robinson Slip. Not uncommon Kakariki Not Threatened Infrequent Forest areas throughout Only one record near Morgan Gorge in 2012 Kereru Not Threatened Occasional Near Macgregor Creek Feeding in patchy scrub south of Macgregor Creek & elsewhere Long-tailed At Risk Occasional Throughout One seen near confluence of Alpha Creek cuckoo Shining cuckoo Not Threatened One record Below Morgan Gorge One call recorded on automatic audio recorder. Not confirmed. Morepork Not Threatened Infrequent Patchy throughout Not recorded in 2012 Little owl Introduced One record Below Morgan Gorge One record of two individuals calling on 13 Nov 2012

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South Is rifleman Not Threatened Infrequent Tall forest near Morgan Also occasionally found at Kiwi Flat in 2006-2007 Gorge (Overmars & Buckingham 2007) South Is robin Not Threatened Infrequent Patchy distribution Forest edge and tall forest Fernbird At Risk One record Kiwi Flat, true right September 2006 in scrub on north bank of Waitaha River Pipit At Risk Infrequent Kiwi Flat Recorded on all surveys at Kiwi Flat

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Appendix 5. Results of bat surveys 2006/2007 (from Overmars & Buckingham 2007)

Note: 1. LTB: Long-tailed bat 2. Three sites close to others are not visible at this scale.

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Appendix 6. Distribution maps of Threatened, At Risk and selected Not Threatened indigenous bird species in Waitaha fauna survey area, 2006-2007 (from Overmars & Buckingham 2007). Note: threat rankings updated after Robertson et al. 2013.

Threatened Species: Grey duck NZ falcon (Taxonomically Indeterminate) SI kaka Kea

At Risk Species: Long-tailed cuckoo

Not Threatened: Western weka Kereru Kakariki Morepork SI rifleman SI tomtit and grey warbler SI robin Brown creeper

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