Assessment of the Potential Effects of the Proposed Waitaha Hydro Scheme on Vertebrate Fauna (Birds 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 i Wildlife Surveys 2014 Terrestrial fauna Waitaha Hydro Scheme 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 bird 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 species 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 Kiwi 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 falcon, kaka, kakariki and kea in 2012 .................................................. 23 Figure 12. Records of long-tailed cuckoo and shining cuckoo in 2012 ................................... 25 ii Wildlife Surveys 2014 Terrestrial fauna Waitaha Hydro Scheme Figure 13. Records of kereru and weka in 2012 ...................................................................... 26 Figure 14. Records of brown creeper, rifleman 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 .........................................................................