Draft Lizard Management Plan for the Sumner Road Reopening Project

DRAFT LIZARD MANAGEMENT PLAN FOR THE SUMNER ROAD REOPENING PROJECT

Prepared for the Christchurch City Council by:

Marieke Lettink Fauna Finders 176 Mt Pleasant Road Christchurch 8081

January 2014

Summary

The Canterbury earthquakes that occurred in 2010 and 2011 caused significant rockfall damage to the 2.6 km-section of Sumner Road between Evans Pass and Lyttleton, Christchuch, leading to its closure. The Sumner Road Reopening Project, under development by the Christchurch City Council, will require substantial rock remediation, including benching of the Crater Rim Bluffs and extensive scaling elsewhere (Aurecon 2013). The proposed construction activities will have severe adverse effects (significant mortality and permanent habitat loss) on the Canterbury gecko (Woodworthia cf. brunnea), one of four lizard species known from the area. This nocturnal species occupies rock outcrops and bluffs, and has a conservation status of ‘Declining’ (Hitchmough et al. 2013). This Draft Lizard Management Plan provides recommendations for undertaking limited salvage and transfer of a minimum of 200 Canterbury geckos from affected and accessible parts of the consent area to a predator-free location. The long-term aim of this undertaking is the establishment of a viable population of Canterbury geckos at a secure site, thereby in part making up for losses incurred during construction. Salvage is a difficult and expensive undertaking that will at best recover only a small portion (most likely <5%) of the affected populations and should only be implemented once other options (e.g. reducing the amount of rock removed and compensation) have been exhausted. Details of the process and an indicative time line are provided.

This report may be cited as: Lettink, M. 2014. Draft Lizard Management Plan for the Sumner Road Reopening Project. Unpublished Report prepared for the Christchurch City Council, Christchurch. 7 pp. Front cover photograph: Crater Rim Bluffs and Sumner Road near Evans Pass (photo: Aurecon) Insert: Canterbury gecko (Woodworthia cf. brunnea)

1. Introduction

1.1. Context and scope

This is a living document that should be read in conjunction with other relevant documents relating to the Sumner Road Road Reopening Project, particularly the Sumner Road Stage 3 A&B Concept Design Report (Aurecon 2013), the Assessment of Environmental Effects (AEE; Davis et al. 2014) and the Ecology Management Plan (EMP; Davis et al. in prep.). This draft Lizard Management Plan (LMP) provides specific recommendations for undertaking limited salvage and transfer of Canterbury gecko (Woodworthia cf. brunnea) from affected and accessible parts of the consent area to a secure, predator-free location. The long-term aim of this undertaking is the establishment of a viable gecko population at a secure site, thereby in part making up for losses incurred during construction. The Canterbury gecko inhabits rock outcrops and bluffs, and has a conservation status of ‘Declining’ (Hitchmough et al. 2013). Rock remediation (benching and scaling) and the construction of haul roads required for the reopening of the 2.6-km section of Sumner Road between Evans Pass and Lyttleton will have severe adverse effects on this species, with significant mortality (likely loss of hundreds or several thousand individuals) and permanent habitat loss expected during construction (see AEE for further details). The most effective mitigation method available for Canterbury gecko is reducing habitat loss (i.e. the amount of rock removed). Compensation is recommended if this cannot be achieved for safety or other reasons. Salvage and transfer of lizards is considered a last resort that should that only be implemented once other options (in this case, mitigation or compensation) have been exhausted (Draft key principles for lizard salvage and transfer in New Zealand; Department of Conservation Lizard Technical Advisory Group Report, in prep.1).

1.2 Lizard values of the consent area

Four species of lizard (Table 1) were found during a 3-day survey of accessible parts of the consent area and similar habitats in its immediate vicinity, conducted in November 2013 (Davis et al. 2014). Three of the lizard species found are of conservation concern (as indicated by a conservation status of ‘Declining’ under the New Zealand Threat Classification System; Hitchmough et al. 2013). A total of 65 individual lizards were found during the survey, consisting of 60 Canterbury geckos, one jewelled gecko, one common skink clade 5, one McCann’s skink and two unidentified skinks (glimpsed too briefly to permit identification but would have been McCann’s and/or common skink).

Table 1. Lizard species found in the consent area and their conservation status (from Davis et al. 2014). Common name Scientific name Conservation status Common skink clade 5 Oligosoma aff. polychroma Clade 5 Declining Canterbury gecko Woodworthia cf. brunnea Declining Jewelled gecko1 Naultinus gemmeus Declining McCann's skink Oligosoma maccanni Not Threatened 1This species was recorded in an adjacent catchment several hundred meters from the consent area. It is also likely to be present in the consent area (based on the presence of similar shrubland and forest habitat).

The lizard assemblage found in the consent area represents four of the five lizard species known from Banks Peninsula (Lettink & Whitaker 2004). The fifth species, Central Canterbury spotted skink (O. aff. lineoocellatum ‘Central Canterbury’), has not been recorded from the Port Hills since the 1950s and is now very rare on Banks Peninsula (DOC Herpetofauna Database; Lettink et al. 2008).

1 This report is not yet available for public release. It was available to the author because she is a member of the Department of Conservation (DOC) Lizard Technical Advisory Group (TAG). The DOC Lizard TAG provides nationwide advice on issues relating to lizards, including RMA matters.

2. Methods

2.1 Definition of lizard salvage and transfer

Lizard salvage and transfer has been defined as an entire process that includes “… exploration of alternatives (e.g. avoidance of lizard habitat), the capture of lizards at the impact site, temporary captive care, data collection, transport to a receiving site, release at a receiving site, post-release monitoring, contingency implementation as appropriate, and reporting back to the Department of Conservation and/or consent authorities to close the loop” (Draft key principles for lizard salvage and transfer in New Zealand; DOC Lizard TAG Report, in prep.). It is a last resort mitigation activity that should only be considered if other options have been fully exhausted. This is because salvage and transfer is typically difficult and expensive to impliment, can delay development projects by weeks or months, and does not in itself achieve no-net-loss of local lizard values.

2.2 General requirements for lizard salvage and transfer

Lizard salvage and transfer requires:  Wildlife Act Authority and/or a translocation permit from DOC. Wildlife Act Authority is required for any development that will destroy native lizard species and cause deliberate disturbance to their habitats. A translocation permit is a specialised Wildlife Act permit required for threatened species and for any transfer where lizards are moved over distances exceeding 500 m. All translocation permit applications require consultation with iwi. Several months may be required for the preparation and processing of Wildlife Act permits.  A Lizard Management Plan prepared by a suitably-qualified ecologist or herpetologist. This Plan should outline salvage methods to be used, identify suitable release site(s) and provide specific recommendations for post-release monitoring, habitat enhancement and/or predator control.  A suitable release site(s). Salvaged lizards should ideally be released in an area that contains suitable habitat for the affected species, does not already have a resident population (or very few individuals), and is subject to effective predator control (Draft key principles for lizard salvage and transfer in New Zealand; DOC Lizard TAG Report, in prep.).  Suitable weather conditions. Lizard salvage and transfer can only be undertaken when lizards are active (from c. October to April, excluding any period of very cold, wet or hot weather).

2.3 Salvage of Canterbury geckos from the consent area

Salvage of Canterbury geckos from the consent area is considered a difficult undertaking that will at best recover only a small portion (most likely <5%) of the affected populations (Davis et al. 2014). This is because most of the site cannot be accessed due to the steep and unstable terrain. In addition, it can be difficult to trap or extract the noctural geckos from the typically deep and narrow crevices they occupy by day. However, in accessible areas, animals and/or their sign (faecal pellets outside crevices and sloughed skinks) are easily detected by crevice inspections and the careful lifting of surface rocks (Figure 1). Reasonable efforts should be made to salvage geckos from affected and accessible areas of the consent area. The peripheral margins (top, sides and bottom) of the Crater Rim Bluffs are a priority due to the extensive benching proposed for this area. Advice received to date suggests it would be relatively straight-forward to access the top of the Crater Rim Bluffs by rope access, using rock anchors installed during previous roped geotechnical inspections (Leon Gerrard, Engineering Geologist, Aurecon, pers. comm.; Gareth Hallan, Abseil Access, Christchurch, pers. comm.).

Figure 1. Crevice (left) and surface rock (right) occupied by Canterbury geckos. Geckos have distinctive white uric acid caps on their faeces (see remnant white splotching below the crack pictured on the left) and such sign can be used to confirm gecko presence, even when animals are not visible in the crevice. A gecko captured from under a surface rock was released (inside red circle on right) once the rock had been carefully replaced.

2.4 Capture methods

Geckos should be captured by hand following manual crevice extraction and careful lifting of loose surface rocks. Live trapping using secured funnel traps (“Gee minnows”) should also be undertaken if salvage coincides with a period of warm weather (Canterbury geckos emerge from their crevices on warm nights to forage). Safe access to the top of the Crater Rim Bluffs will require a minimum of two Rope Access Technicians (two people are required for safety reasons). The daily rate for a team of two Rope Access Technicians is approximately $1500, covering 10 h of labour and the use of climbing gear and hand tools (Martin Wilson, Managing Director, Abseil Access Limited, Wellington). Rope Access Technicians would initially need to work closely with a herpetologist (ideally one with some climbing experience) to be trained in gecko extraction and capture methods. It is impractical for a herpetologist to accompany Rope Access teams during the scaling proposed for Zone 3A because of the large area to be covered, use of multiple teams and lengthy time-frame required for completion of the work (an estimated 500 team days or 38–48 weeks, depending on whether three or four Rope Access teams are used, with each team consisting of three workers; Aurecon 2013). However, with minimal training from a herpetologist, Rope Access Technicians could salvage geckos incidentally encountered during light scaling with hand-held tools. Geckos living in crevices targetted for light scaling have several possible fates: (1) being injured or killed when hand- held tools are inserted in their crevices; (2) being dislodged and falling to the ground along with the displaced rock they were clinging to, resulting in injury or mortality on impact; or (3) remaining uninjured and clinging to the newly-exposed, remaining rock surface. It is recommended that animals in the third category be captured by Rope Access Technicians for subsequent release in secure habitat. This is the only opportunity to recover animals present in crevices ear-marked for scaling: more intensive methods (e.g. use of airbags, drill and blast boulder popping using a generator, tools and explosives) will almost certainly kill any geckos that are present outright. Storage and temporary care of animals should follow the procedures described in the Draft New Zealand guidelines for conservation-related lizard translocations (DOC Lizard TAG in prep.).

2.5 Release site Canterbury geckos should be released in the 7.8-ha predator-fenced sanctuary at Riccarton Bush, Christchurch. This site meets the criteria for an ideal release site: it is surrounded by a pest-mammal exclusion fence, has on-going pest surveillance and a track record of effectively managing occasional rat incursions, and the capacity to receive many hundreds of animals. The habitat (mature podocarp

5 forest) is vastly different to that used by geckos at the salvage site, but is suitable for the species. In the absence of mammalian predators (cats, mustelids, hedgehogs and rodents; all of which prey on lizards), Canterbury geckos will occupy all available habitat, from the ground to the forest canopy. Riccarton Bush has previously been used to release small numbers of Canterbury geckos (DOC Herpetofauna Database; John Moore, Ranger, Riccarton Bush, Christchurch, pers. comm.). Any resident population is unlikely to be abundant, as indicated by a lack of encounters during routine management operations of park staff and regular inspection of wooden weta boxes (these typically attract geckos). There is only one record of a gecko found by the park ranger in 2006 (a dead animal found by a walking track; DOC Herpetofauna Database). Initial consultation over the potential release of Canterbury geckos at Riccarton Bush has been positive (John Moore; pers. comm.). To maximise the chances of the transfer leading to the establishment of a viable population, it is recommended that a minimum of 200 individuals be released. Release of 30–40 animals, as has been common in many New Zealand past translocations of reptiles and birds (reviewed by Sherley et al. 2010) is not recommended because of the low probability that released animals will be able to find each other, reproduce and establish a viable population. Even 200 Canterbury geckos released in a predator-free environment will likely take years to become a growing (or in the very least, self- sustaining) population due to the species’ ‘slow’ life-history traits (delayed maturation, slow growth, low reproductive output, with females producing a maximum of two offspring per year; Cree 1994).

2.6 Post-release monitoring

In general, post-release monitoring is recommended where the outcome (i.e. success or failure of lizards to establish a viable population at the release site) is not guaranteed and where there is a need for data to inform future translocations (Draft key principles for lizard salvage and transfer in New Zealand; DOC Lizard Technical Advisory Group Report, in prep.). Canterbury geckos released at Riccarton Bush would be given the best possible chance of survival (by virtue of being released in a predator-free environment) but population establishment and growth is not guaranteed due to uncertainties over post-release behaviour, particularly dispersal. Post-release monitoring is not recommended at this stage because there is currently no effective method for monitoring geckos living in tall forest2. However, the opportunity to learn from this translocation should be pursued. This is best achieved through a well-designed telemetry study (e.g. fitting geckos with small transmitters and radio-tracking to determine daily movements following release). Such a study would be ideal for a university student completing a post-graduate qualification in Ecology (e.g. the research component of an Honours or Masters Degree).

3. Time line

Specific dates cannot be given until the Project has been finalised and consented, and a firm commitment is made towards undertaking salvage and transfer. An indicative time line for potential salvage and transfer of Canterbury geckos is provided below. It should be kept in mind that salvage can only be undertaken when animals are active (from c. October to April).

Week 1 Herpetologist to prepare and submit a Translocation Permit application to DOC.

Weeks 2–8 Processing of the applications by DOC, including iwi consultation (note: this could take longer due to a change in the permitting structure within the Department).

2 Methods for detecting (cf. monitoring) geckos living in tall forest include spotlighting and artificial retreats. A discussion on the limitations of such methods for monitoring is provided in the DOC Herpetofauna Toolbox.

Week 9 Conduct salvage of Canterbury geckos from along the top of the Crater Rim Bluffs (assumes approval is granted and time-of-year and weather conditions are suitable). Requires a team of two Rope Access Technicians working closely with a herpetologist for an initial period of 3-4 days. All salvaged geckos to be held in temporary care and released at Riccarton Bush at the end of the week.

Week 10-12+ Herpetologist to review process and make amendments as required (e.g. decide whether the Rope Access Team is required for additional work). Continue salvage until a minimum of 200 geckos are salvaged and/or no further geckos are captured with reasonable effort expended. Rope Access Teams working in Zone 3A to salvage geckos incidentally encountered during light scaling for release at Riccarton Bush.

4. Acknowledgments

The following people provided useful comments and information that aided the development of this Draft Plan: Gareth Hallan and Martin Wilson (Abseil Access), Markus Davis, John Moore (Riccarton Bush), Leon Gerrard (Aurecon) and Lynn Adams (DOC Lizard Technical Advisory Group leader).

5. References

Aurecon 2013. Sumner Road Stage 3 A&B Concept Design Report. Unpublished Report prepared for Christchurch City Council by Aurecon, Christchurch. Cree A. 1994. Low annual reproductive output in female reptiles from New Zealand. New Zealand Journal of Zoology 21: 351–372. Davis M, Lettink M & Patrick B. 2014. Sumner Road Reopening Project Assessment of Environmental Effects – Ecology. Unpublished Report prepared for Christchurch City Council. Davis M, Lettink M & Patrick B. In prep. Draft Sumner Road Reopening Project Ecology Management Plan. Unpublished Report prepared for Christchurch City Council. DOC Herpetofauna Database (www.doc.govt.nz/nzherpatlas). DOC Lizard Technical Advisory Group. In prep. Key principles for lizard salvage and transfer in New Zealand. Unpublished Report, Department of Conservation, Wellington. DOC Lizard Technical Advisory Group. In prep. New Zealand guidelines for conservation-related lizard translocations. Unpublished Report, Department of Conservation, Wellington. Hitchmough R, Anderson P, Barr B, Monks J, Lettink M, Reardon J, Tocher M & Whitaker T. 2013. Conservation status of New Zealand reptiles, 2012. New Zealand Threat Classification System Series 2, Department of Conservation, Wellington. Lettink M & Whitaker T. 2004. Lizards of Banks Peninsula. Department of Conservation, Christchurch. Lettink M, Cree A, Norbury G & Seddon PJ. 2008. Monitoring and restoration options for lizards on Kaitorete Spit, Canterbury. DOC Research & Development Series 301, Department of Conservation, Wellington. Sherley GH, Stringer IAN & Parrish GR. 2010. Summary of native bat, reptile, amphibian and terrestrial invertebrate translocations in New Zealand. Science for Conservation 203.