Technical ReportPDF Available

Paekakariki-Pukerua Bay Escarpment Lizard Protection Trial

  • Callister & Associates

Abstract and Figures

The first aim of this project is to gain an understanding of lizard diversity and abundance on a small site on New Zealand’s Paekakariki-Pukerua Bay escarpment through lizard surveys and monitoring programmes. On this small site, an aim is then to improve animal pest control regimes so they protect existing lizard populations and allow these populations to recover over a five to ten year period. If pest control is successful, the project will explore options for translocation from local lizard breeding programmes. Other aims are to develop a template to guide other community groups and to help increase community awareness of the key role lizards can play in New Zealand’s ecosystems.
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Paekakariki-Pukerua Bay Escarpment
Lizard Protection Trial
Lizard on the escarpment: Peter Kentish
Prepared by Paul Callister
April 2017
By 2030 lizards will become abundant on the Paekakariki-Pukerua Bay escarpment.
To gain an understanding of lizard diversity and abundance on a small site on the Paekakariki-
Pukerua Bay escarpment through lizard surveys and monitoring programmes.
On this small site to improve animal pest control regimes so they protect existing lizard
populations and allow these populations to recover over a five to ten year period.
If pest control is successful, to explore options for translocation from local lizard breeding
To develop a template to guide other community groups.
To help increase community awareness of the key role lizards can play in New Zealand’s
Many people contributed to this draft and most are mentioned in the body of the report. However, I
would like to particularly thank a number of people. Angus Hulme-Moir first suggested setting up
the lizard protection trial and then provided ongoing support and feedback as the plan was
developed. Trent Bell and Murray Williams also provided useful comment on early drafts. Dalice
Sim offered helpful statistical advice in the early planning stages. Working in the field with Sarah
Herbert helped me gain some confidence in surveying lizard populations. Many people volunteered
in setting up the trial and the success of it will depend on a continuing high level of support over its
lifetime. The project would not have been possible with the support of the Ministry of the
Environment funded Kapiti Biodiversity project, a range of specialists within the Department of
Conservation and Nga Uruora.
Introduction .................................................................................................................................... 4
Mice control as a key element of lizard protection ........................................................................... 6
The site and the trial design ............................................................................................................. 8
A control site ................................................................................................................................ 15
Setting up the trial area.................................................................................................................. 16
Pest monitoring and trap management on the trial site ................................................................... 18
The wider pest control regime ....................................................................................................... 19
Lizard monitoring ......................................................................................................................... 21
Analysing the data......................................................................................................................... 23
Risks including health and safety .................................................................................................. 23
Publicity for the project ................................................................................................................. 24
Timeline........................................................................................................................................ 25
Options if the trial is not successful ............................................................................................... 26
References .................................................................................................................................... 26
Appendix 1 Data sheets (based on an Ecogecko template) .......................................................... 27
Appendix 2 Lizard monitoring H & S plan ................................................................................. 29
Lizards are New Zealand’s largest terrestrial vertebrate group with more than 100 species.
Historically, they would have occupied almost all available ecosystems from coastal shores to
mountain peaks. Lizards play an important role in ecosystem processes and function as predators,
pollinators, frugivores and seed dispersers. Lizards are emerging as iconic flagship and indicator
species in conservation and ecological restoration. Despite 85 percent of this fauna being threatened
or at-risk, lizards can be exceptionally abundant when released from mammalian predation pressure.
Nga Uruora began animal pest control in 1997. In the early days of pest control on the Paekakariki-
Pukerua Bay escarpment most attention focussed on making the area stock proof and targeting
possums in our Kohekohe remnants.
A key aim was to protect the existing forest and assist in
natural revegetation.
Over time, the pest control effort changed. The area trapped has expanded. Mustelids and, to a
lesser degree, rats have been targeted. The aims were to protect both forest areas and to support bird
populations. Nga Uruora has a vision to ‘bring the birdsong back from Kapiti Island’ and the
protection of birds has been a key driver in pest control efforts. In this early phase of pest control,
mice were not seen as a key threat to birdlife.
In 2012 the Wellington Regional Lizard Network published a lizard strategy for the Wellington region
(Romijn et al. 2012). This document brought together the views of lizard experts (Herpetologists)
along with a variety of other stakeholders, including the Department of Conservation and local
This report painted a picture of significant lizard diversity in the Wellington region. However, it
also identified a range of threats to these populations. Balancing these factors, the study also
identified opportunities to support gecko and skink populations in the Wellington region. Lizards
should be abundant in our area. But through predation and habitat change they are under extreme
pressure. Predators include rats, mice, hedgehogs and mustelids. Habitat change can include areas
of former scree grassing over.
Macrons are not used in this report.
In June 2015, it was announced that the government was providing a $294,000 Community
Environment Fund grant for a project aimed at protecting and restoring biodiversity on the southern
part of the Kapiti Coast. The funding has been aimed at helping local communities to support bird
populations, improve habitats for lizards and weta, propagate and plant rare dune plants, increase
fish and insect populations in streams, and facilitate an increase in local pest control.
Aside from the fact that there have historically been few sightings of lizards on the escarpment,
little was known about the local lizard populations.
The MfE project gave not only Nga Uruora a
chance to study lizard abundance but also allowed our neighbours at Queen Elizabeth Park and
Whareroa Farm Reserve to explore their own lizard populations. It was also hoped the research
would give Nga Uruora and the other groups some guidance as to how to improve pest control to
support lizard populations.
In 2015, at the start of the MfE project, two pest control reports were prepared to guide the
increased pest control on the Paekakariki-Pukerua Bay escarpment. There was a report setting out
how there would be the creation of a wider ‘Kapiti Mainland Island’
. This was followed by a more
detailed operational report for Nga Uruora.
A lizard strategy report was also prepared to help guide
the lizard research.
At this point there was a lack of information on the best ways to support local
lizard populations aside from the standard ideas of increasing overall predator control.
In summer 2016, Ecogecko and volunteers undertook surveys at both Queen Elizabeth Park and
Whareroa farm. Ecogecko also undertook two small surveys on the Paekakariki escarpment. A
report summarising the findings was then prepared. This set out a list of lizards that might be
expected to be found in the area, what was found and some recommendations for further study.
also gave some ideas for enhancing pest control, especially in relation to mice on the escarpment. In
both Queen Elizabeth Park and Whareroa farm very few lizards were found. While more lizards
were found on the escarpment, it was clear from the survey work mice were common and likely to
In the summer of 2016/2017 lizards were starting to be seen regularly at the site known at the ‘quarry’.
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be impacting lizard populations. It has also become clear from autopsy work carried out by Sue
Blaikie on locally trapped rats and mustelids that lizards formed part of their diet.
In mid-2016 a pest control workshop was held bringing together the local pest control community.
A key theme was how to support lizard populations with a particular emphasis on controlling mice.
At this workshop, Ecogecko set out their ideas for mice control.
In addition, Angus Hulme-Moir
explained what the Friends of Whitireia Park were doing with their lizard protection trial.
Following the workshop, Nga Uruora began exploring setting up a lizard protection trial on the
escarpment. There were a number of reasons for choosing the escarpment. These were that it had
suitable habitat to support lizard populations, that survey lizard populations were higher than in
neighbouring areas, that existing non-mouse predator control was well developed and that toxins
were able to be used on the site.
Angus Hulme-Moir helped facilitate this process both as a volunteer at Whitireia Park and as an
employee of the Department of Conservation. The Department of Conservation provided advice on
both pest control and lizard monitoring. Assistance was also provided by researchers from Victoria
University (Nicola Nelson and Sarah Herbert) and Otago University (Dalice Sim). As a result of
this advice, but also consideration of what work volunteers could undertake, a lizard protection the
trial plan was devised for the escarpment. The idea was to set up some demonstration projects
which would provide guidelines for community groups to support lizard populations on small sites.
This project is led by the Kapiti Biodiversity project (represented by Nga Uruora). The Department
of Conservation has provided, and will continue to provide, technical support facilitated by a
Memorandum of Understanding with Nga Uruora (signed in April 2017). The project has the
support of Ngati Toa. Ecogecko has also provided technical and practical support.
Mice control as a key element of lizard protection
This section draws heavily on a 2016 paper prepared by James Reardon of the Department of
Conservation. There has only been minor editing to make it more relevant to the Paekakariki-
Pukerua Bay escarpment.
It has long been known that mice are a direct predator and competitor of lizards in New Zealand
(Newman 1993). More recently, researchers have observed their predatory behaviour during post
release monitoring of some of our largest lizard species suggesting their impacts are not limited to
small lizard species (Norbury et al. 2014). Therefore a key aim of a lizard protection trial is to
maintain mice to sustainably low indexes of abundance throughout all seasons.
The most cost effective control of mice has traditionally involved toxins, notably the second
generation anticoagulant brodifacoum. However many scientists suggest that due to the bio-
accumulative and persistent nature of this toxicant that strategy is not viable long-term. Ideally,
other methods of mouse control will be found. To date there is no evidence of trapping programmes
achieving sustained suppression to appropriate levels. Recent results from community conservation
efforts to suppress mice at Whitireia Park using the A24 self-resetting trap demonstrated good
levels of suppression at high density deployment but unfortunately these outcomes reversed as
productivity increased mouse populations which then quickly overwhelmed the trapping effort.
The strategy in the lizard protection trial will be to supplement a trapping network with triggered
poisoning of mice to maintain indexed abundance of mice to below 5%. Given the promising
results from the Whitireia Park management areas (Angus Hulme-Moir pers comm.), together with
strong pressure to employ self-resetting traps, the trial will follow recommendations of employing a
network of A24s at 20m spacings supplemented by bait stations. As well as covering the area
intended for lizard recovery the grids will extend to buffer lines surrounding this area. According to
the Department of Conservation, the Saddle island study has provided much information about
mouse home range changes with density and their initial estimations Densities on the island ranged
from 8.8-19.2 mice/ha, with home ranges varying from 0.15-0.48 ha (MacKay et al. 2011). Taking
a mid-point of that range would require a buffer of at least 40m to account for extrapolated home
range diameter. Therefore, to protect 1ha of habitat would require an area of 180m x 180m filled
with traps and bait stations at 20m spacings.
The Department of Conservation note that it is vital
that close scrutiny of detection and bait take data is maintained to help adaptively manage an
expansion of this buffer if data suggests it is inadequate.
For the first phase of this management (year 1 &2) it has been recommended that the project record
tracking rates (using tracking tunnels) monthly as standard procedure and the frequency is elevated
to fortnightly when tracking is rebounding between 3-5%. Once tracking rates hit 3%, fortnightly
For the mouse eradication program on nearby Mana Island the spacings of bait stations was 50 metres
filling of bait stations it is recommended begin filling bait stations. For practical reasons (number of
tracking tunnels) only 5% tracking bands are able to be used in this trial.
The most effective toxicant, brodifacoum, will initially be used in the trial. Due to concerns about
its long life in the environment those running the trial will continue to seek safer toxins. In terms of
safety of brodifacoum for lizards, a 2016 study gives some comfort (Weir, et al. 2016).
The Department of Conservation note that the rebaiting strategy is critical to maintain lethal dose
availability at all times during the toxin knockdown. The duration of the toxicant application will be
informed by peripheral and control rodent abundance indexing. As soon as tracking rates in the
core area decline to acceptable levels the toxicant can be withdrawn and the hope is that the A24
self-resetting traps can maintain suppression. A risk in this design is that the toxicant dominates the
suppression mechanism and the expensive investment in A24 traps plays a negligible role in
suppression. This risk further emphasises the need to maintain monitoring data and to adaptively
review the programme.
The site and the trial design
The lizard protection site is located on the Paekakariki-Pukerua Bay escarpment. The Department of
Conservation recommended an overall site 180 by 180 metres for pest control. Within this was
recommended a 100 x 100 lizard monitoring area.
Finding the best site on the escarpment has its challenges. Ideally the site would have easy access, be
either fully above or below Te Araroa trail, be surrounded by intensive pest control, have suitable
lizard habitat plus not be directly above the railway tracks as there is a need to keep away from this
area with a danger of debris falling on tracks. Trevor Thompson, Field Officer for the QE2 Trust, has
noted that the best sites for lizards in the Wellington Region are those without long grass and also
very dry (personal communication, 2017). This site does have long grass but is dry with no visible
watercourses in the area.
After a number of investigations, including a visit from Les Moran and Lynn Adams from the
Department of Conservation Technical Advisory Group, it was decided to use an open site at the
centre of the escarpment.
While it does not fully meet the ideal site criteria it seems the best option.
There is regenerating forests on the margins of this site, but the central part is mainly covered in grass
The site chosen is directly below a memorial seat for ecologist Geoff Park. This seems very appropriate as it was Geoff’s book Nga Uruora that
the group looking after the escarpment is named after.
and muehlenbekia with occasional propinqua and flax plants. This area is adjacent to an area known
as the ‘Ecosite’ which contains mature Kohekohe forest. This site has had some form of pest control
since 1997 and in 2015 became one of Nga Uruora’s two ‘rat free’ sites. The Ecosite has an extensive
network or traps and bait stations and has a set of tracking tunnels within it. In the first tracking tunnel
exercise carried out in November 2015 before the expanded pest control network was put in tracking
tunnel rates for rats were 33%. In May 2016 there were 5% and in November 2016 a zero result was
achieved. There was only a small amount of mice and hedgehog presence recorded.
To reach both the Ecosite and the proposed lizard protection site, a zig zag track from the current
State Highway 1 (known as Bob’s track) can be utilised.
Bob’s track was the site of one of
Ecogecko’s surveys in summer 2016 and a small number of Northern grass skinks and Raukawa
geckos were detected. But the survey also showed the area had a high number of mice at that time of
the year.
Figure 1 shows Bob’s track, a 180 by 180 metre square (yellow) and the 100 by 100 metre square
Figure 1
While both the 180 metre square and the 100 metre are mostly below Te Araroa some parts are above
the track. However, all of the 50 metre square is below it. In addition, almost all the 50 metre square
This track was built by Nga Uruora to allow easy access to the Ecosite before Te Araroa was built.
contains mainly grass and muehlenbekia whereas outside this there are forested areas. There are also
some small areas of flax.
The site is very steep especially below the 50 metre square. There is also some weed invasion starting
to occur within the 50 metre square, primarily fennel. It is proposed the fennel would be controlled.
The steep exposed nature of the site provides a risk to the success of the project as there will be
challenges accessing parts of it, especially in poor weather conditions.
Figure 2
The Department of Conservation recommended a 180 metre square with a 100 metre square within it
(Figure 3). Within this 180 metre square would be traps and/or bait stations at 20 metre intervals.
Figure 3
In the Paekakariki-Pukerua Bay site it was decided to put in 40 Goodnature A24 traps with 75 bait
stations to cover the full 180 x 180 metre grid. The traps/bait stations are 20 metres apart in the core
area and, initially in the first year, in a 30 x 20 metre grid outside of this.
The bait stations are
Philproof economy rodent bait stations.
While it was recommended that the lizard monitoring area be 100 x 100 metres, site considerations
as well as concerns about finding enough long term volunteer input meant that initially it was decided
to initially focus on a 50 x 50 metre lizard monitoring site. However, during the installation phase in
late December 2016 it was decided to increase this to 60 x 50 metres.
Within this 60 x 50 metre lizard monitoring site, onduline and pitfall traps (4 litre) were installed in
December 2016at 10 metre spacings. This provides 42 sites for monitoring lizards. Within this
monitoring area and slightly beyond tracking tunnels were installed in late December 2016/early
January 2017 at 20 metre spacings. There are 20 tracking tunnels. This means tracking indexes have
to be calculated in 5% bands so the trigger of 3% for putting out poison bait cannot be used. Thus if
any one (or more) of the tracking tunnels shows mice activity it will trigger a need to fill the bait
In this core site 20 Goodnature traps were installed in April 2017. These also have a bait station
attached. Ten of the Goodnature traps have counters attached to give another monitor of catch activity.
In addition, a further ten A24s will have remote sensors attached.
If a 20 x 20 metre spacing is needed across to whole site to keep mouse numbers down to acceptable levels then additional bai t stations will be
Figure 4
Surrounding the core of the lizard monitoring site out to the full 180 metres either way are another
20 Goodnature traps with bait stations and then bait stations only around the edge (a total of 40
Goodnature traps).
On the outer edge the traps/bait stations are at 30 metre spacings across the slope
by 20 metres down. If this proves inadequate to control mice then this will be reduced to 20 x 20
metre spacings.
The additional 20 A24s have been lent to the project by Friends of Whitireia Park.
Figure 5
In addition, included within the lizard site trap network as well as nearby to it will be up to 13
remote sensed traps. Nine of these traps will be placed within the 180 x 180 metre lizard control
trial at approximately 90 metre spacings.
These will be placed on site in April 2017. These will be targeting primarily mustelids, but also
potentially catch any hedgehogs or rats that have avoided the A24s and, in the case of rats, the bait
stations. There are two reasons including the remote sensed traps. First, the remote sensing allows a
quicker response to keeping the network fully covering the area. But more importantly in relation to
the lizard trial it will allow fresh specimens to be quickly collected and autopsied to assess what
they are eating.
This will be another way of monitoring lizard populations.
To date only rats and mustelids have been autopsied but not hedgehogs.
Figure 6
The remote sensing experiment is a collaboration between Econode, Nga Uruora (on behalf of the
Kapiti Biodiversity Project) and Groundtruth.
In the first stage of the trial, the setup the aerial for
radio coverage did not cover the lizard protection site. As a result an additional aerial was set up on
Tokomapuna/Airplane Island on the east side of Kapiti Island in April 2017.
A control site
It was discussed in early stages of planning that it would be ideal to have a control site on the
escarpment for lizard monitoring. For a variety of reasons it was decided this was impractical. As a
rough guide to what would be happening without pest control two similar sites on the escarpment
were chosen and a small network of 12 onduline squares set up at 10 metre distances. These will be
checked at the same time as the main monitoring. It is understood that while this will not provide
valid scientific data it may some idea of how background conditions (season etc) might be affecting
lizard numbers. In the first lizard monitoring this site will not have pitfalls but these will be installed
for further monitoring.
The edge of the ‘control’ sites are at least 75 metres away from the edge of the intense mouse control,
well outside of mice home ranges. They are also at the top of Bob’s track to allow easy checking.
Figure 7
Potentially Mana Island, given its proximity to the trial area and that it is a pest free environment,
should provide some measure of expected lizard abundance in a low pest environment. It may be that
if regular surveys were carried out at Mana then seasonal variations in lizard abundance could be
assessed giving some idea of whether changes in lizard numbers on the escarpment were due to pest
control or other factors such as weather conditions. This will need to be explored further.
Setting up the trial area
As discussed, the onduline, pitfalls and tracking tunnels were laid out in later December 2016/early
January 2017. A number of working bees were held and following people assisted: Jim Hammond,
Chris Keating, Jean Fleming, Tony Older, Sue Boyde, Glenda Robb, Liz Johns, Andy McKay, Paul
Callister, Peter McLaughlin, David McKay, Michael Bennett and Vicky Griffin.
Figure 8
Much of the work setting ups the pest control network has been carried out by Peter McLaughlin as
a contractor to the Kapiti Biodiversity Project.
Pest monitoring and trap management on the trial site
Pest numbers within the trial area will be monitored in a number of ways. These are:
Tracking tunnels
Catch data from the remote sensed DOC200s
Catch data from 10 remote sensed A24s.
Data recorded on ten of the A24s with counters.
Motion cameras placed in and around the area from time to time
Tracking tunnels will be the main tool used to determine how the pest control regime is working and
what responses are needed. However, the other tools will give us some additional information.
The first full tracking tunnel monitor will be carried out in mid-April 2017. This will determine mice
presence just after the first lizard monitor is carried out. Tracking tunnel monitors will then be carried
out monthly until May. While the recommendation is two weekly monitors in peak mouse season are
recommended it is considered not possible using volunteer labour. Monitors will then be carried out
every two months. Monthly tracking tunnel monitors will resume again in spring (September) and
the same regime will be carried out each year.
Once the first lizard monitor is carried out, the 35 outer bait stations without A24s will be filled with
brodificoum blocks. Throughout the year, these will be checked once a month and filled when empty.
The bait stations with the A24s will only be filled when the A24s no longer keep mice numbers down
to 5% or less on tracking cards (ie having mouse footprints on just one of the 20 tracking cards).
The wider pest control regime
The lizard trial is embedded within the wider pest control on the escarpment. The Department of
Conservation provides an ideal of how this wider pest control would operate (see earlier Figure 4).
On the escarpment such a broad pattern of pest control does occur in a North and South direction.
However, topography and other factors mean the spacing is not as exact as the diagram. On the site
chosen for the lizard protection trial directly above it is an area with intensive pest control. Next to
this in farmland. Below the trial is State Highway 1 then the sea.
Figure 9
Figure 10 uses December 2016 data to show bait stations and traps surrounding the lizard
protection trial.
Figure 10
Currently the traps used around the lizard protection site are DOC200s with a small number of
Goodnature A24s. The bait stations are Philproof minis. There are also a small number of Timms
traps deployed targeting possums and cats depending on what bait is used.
This existing trap network relies volunteers checking them at least monthly. The bait stations are
filled twice a year, in spring with brodificoum and in autumn with diphacinone.
The success (or otherwise) of this wider trapping effort is measured in a number of ways. First,
there is the data on catch rates. However, this does not indicate what is left in the environment only
what is caught. Nga Uruora has also begun using motion cameras to help assess pest numbers. In
addition, tracking tunnels are monitored on two sites on the escarpment twice a year, once in spring
and once in autumn. One of the monitoring sites is directly above the trial site with 12 tracking
tunnels deployed at approximately 120 metre spacing (Figure 11). These are mostly in the forest
area but some are near to open grassland. Therefore there are a total of 32 tracking tunnels either
within or next to the lizard protection trial.
Figure 11
Lizard monitoring
Ecogecko suggests that the escarpment should support populations of Ngahere gecko, Northern
grass skinks, Barking geckos, Ornate skinks, Copper skinks, Brown skinks, Spotted skinks and
Raukawa gecko. Not long ago, there were probably Whitakers skinks. A key goal of this experiment
is to see lizard numbers, and hopefully variety of lizards, increase over the trial period. However,
given the slow rate of breeding the change in numbers over five years is not likely to be dramatic.
For example for geckos the rate of increase is intrinsically very low (3-4 years to reach maturity, 2
offspring per year). Copper skinks also have only 2-3 offspring per year, but they do mature in 2
years. Given changes are likely to be small, it is particularly important to collect high quality
reliable data. Expert statistical assistance will also be needed in interpreting lizard data collected.
The Department of Conservation advise that there is no magic number or configuration of pitfalls or
days checked. However, they stress that there is a need to do exactly the same thing consistently
over the duration of the study. They note that the number of checks per year can vary somewhat
because they will be converted to captures per trap per day. However, if a check is carried out, all
the pitfalls must be checked that day, and the lay-out, set-up, baiting etc. of traps cannot change
over the course of the study.
The Department of Conservation recommend only checking during mild weather thus avoiding
extremes of cold, heat and heavy rain. On such an exposed site checking in poor weather conditions
would be difficult anyway. They also recommend avoiding checking during prolonged droughts
when animals may be stressed by water loss and water provided in pitfalls may evaporate quickly.
While the volunteers involved in monitoring will have all been trained in lizard handling there is no
provision for on-going expert support of monitoring. Therefore only basic data will be collected.
This will be species (if known) and size (an estimate if they are a juvenile or adult). The
identification guides produced by Greater Wellington Regional Council will be made available to
those carrying out the surveys.
If expert help does become available during any of the monitors then additional data can be
collected. Some additional background data, including weather conditions, will be collected during
each monitor. The project will use datasheets provided by Ecogecko (see appendix 1)
The first lizard monitor will be carried out in late March/early April 2017. By this time the onduline
squares and pitfalls will have been in place for three months. The monitor will take place over four
days over two weekends (a total of 8 days). The pitfalls will be opened on Thursday evening and
baited with tinned pear. The control onduline site will also be baited with pears. The pitfalls and
onduline will then be checked on Friday, Saturday and Sunday. The pitfalls will be closed after
checking on the Sunday. In the first monitor, Trent Bell from Ecogecko has agreed to help on the
first few days.
This pattern of checking will be repeated each year.
The tracking tunnels will be also used from time to time to see if lizards are present on the site.
Instead of being baited with peanut butter honey and/or pear will be used. Tracking tunnels
deployed elsewhere on the escarpment have proved useful in demonstrating lizard presence.
Figure 12
Analysing the data
We will seek professional advice with regards to analysing the data being produced by the trial.
Risks including health and safety
There are a number of risks within this project. One is a financial risk. It may not be able to attract
sufficient funding to allow the project to continue over its expected life of 5-10 years.
Another risk relates to volunteer input. There will need to be two teams of volunteers. One team will
be responsible for predator control and tracking tunnel monitoring the other team for lizard
monitoring. Both teams need to be able to work on steep terrain often in strong winds. It may not be
able to attract sufficient volunteers to allow the project to continue over its expected life of 5-10 years.
Given the steep nature of the site there is a potential that volunteers may be injured in their work. The
Health and Safety protocols used on the Whitireia lizard monitoring site have been adapted for use
on the escarpment (Appendix 2)
Handling of toxins will be required in this work. All Nga Uruora pest control volunteers work under
GWRC Health and Safety protocols so this will help minimise risk. Toxin warning signs are already
on entrances to the escarpment given the current use of toxins.
If few lizards are found in initial years volunteers can lose interest and forget skills. As this project is
reliant on volunteers, ways need to be found to keep them interested
Wasps are a risk on the escarpment. If wasps are detected, it is proposed to deploy Vespex on this
site to protect it. Nga Uruora has a licensed Vespex operator as part of its committee.
There is a potential for extreme weather events or an earthquake to damage the area.
There is a small risk that boulders dislodged could reach State Highway 1. As the area is above rail
tunnels there is little risk to the railway.
There is some small potential for vandalism in relation to the project.
There is an overall risk that the project might not be successful and that lizard numbers may not
Publicity for the project
Publicity would be given to the project through the use of various social media including newsletters.
Given the popularity of Te Araroa (with potentially over 20,000 walkers per year), a sign providing
information about lizards will be placed above the trial site. This will have general information about
lizards and some information about the trial. It will be of the same style of other signs on the
escarpment designed by Isobel Gabites. These are high quality vandal proof signs based on Izone
panels. Help will be sought from lizard specialists in designing this sign.
Figure 12
There is also the potential to create short low cost publicity video.
It is proposed that this project will run for at least five years and hopefully ten. The first stage of the
project began in December 2016/January 2017 with the laying out of the onduline, pitfalls and
tracking tunnels. This does not make a commitment to continue the project.
The following will take place in the first six months.
1. The 42 onduline and pitfall sites have installed by the end of December 2016. The small
comparison sites of 12 ondulines was installed at the same time.
2. The 20 tracking tunnels have been installed by the end of January 2017. The first monitor
will take place in mid-April 2017.
3. The first lizard monitor is scheduled to place in late March/early April 2017 (three months
after the onduline squares have been installed). Ecogecko will lead this first monitor.
As an example see
4. The main pest control network will be installed between December and April and will ‘go
live’ in April 2017.
Options if the trial is not successful
If there is a lack of long term support for the project, or very few lizards are found, this site could
simply be used as a way of setting up lizard surveys for a couple of years and then project
abandoned. However, if this occurred an option is to proceed with revegetating the site while
leaving the onduline and pitfalls in place. Once the long grass was replaced new surveys could be
carried to see the effect of habitat change.
Romijn, R., Adams, L., Hitchmough, R. 2012. Lizard strategy for the Wellington region 2012-20,
Wellington Regional Lizard Network.
MacKay, J.W.B. et al. 2011. A successful mouse eradication explained by site-specific population
data. pp. 198203 in Veitch, C.R.; Clout, M.N.; Towns, D.R. (Eds): Island invasives: eradication and
management. IUCN (International Union for Conservation of Nature), Gland, Switzerland.
Newman, D.G. 1994. Effects of a mouse, Mus musculus, eradication programme and habitat change
on lizard populations of Mana Island, New Zealand, with special reference to McGregors skink,
Cyclodina macgregori. New Zealand Journal of Zoology 21(4): 443-456.
Norbury G, et al. 2014. Impacts of invasive house mice on post-release survival of translocated
lizards. New Zealand Journal of Ecology 38: 322-327.
Weir, S.M. et al. 2016. Acute toxicity and risk to lizards of rodenticides and herbicides commonly
used in New Zealand. New Zealand Journal of Ecology 40(3): 342-350
Appendix 1 Data sheets (based on an Ecogecko template)
Escarpment lizard monitoring data collection sheet:
NB: Use one row for each animal caught (e.g. use 2 rows for 2 lizards caught in the same pitfall)
Team leader’s name:
Site name:
Start time:
Finish time:
Temperature (°C):
Rain past 24 hrs?:
Wind (Beaufort scale):
Cloud cover (in eighths):
Whose camera:
Location (trap
Trap type
SVL (mm)
(length from
snout to vent)
TL/BL (mm)
Photo number and/or
photo of site tag
e.g Trap 1.1
e.g. pitfall or under
e.g. OP
e.g. 5024 - 5028
Scar on right side
Trap #
Maintenance needed
(cross out when fixed)
Appendix 2 Lizard monitoring H & S plan
Slips, Trips & Falls
Significant Hazards
Isolate or
Hazard Controls
Uneven tracks and
surfaces on the
escarpment, steep site
with chance of falls,
and chances of falling
rocks from above
Stout footwear with good grip required.
Recommend walking stick for those with weak ankles
Induction for new participants identifies particular
hazardous areas such as areas with steep drops, slippery
grass and sharp rocks. Take care with dislodging rocks if
working above others.
Group support while working on the lizard protection site.
The area to be checked preferably in pairs to ensure group
First aid to be carried for each separate group
Cell phone carried for each separate group
Personal locator beacon to be carried for each separate
Carrying loads, tools
etc increases the risk
of taking a fall.
Minimise carrying loads to bare essentials (notebook, cell
phone, camera, food, water, essential clothes & first aid)
Organise additional volunteer help to minimise need to
carry heavy loads
Significant Hazards
Isolate or
Hazard Controls
Distance from help
and poor
communications in
Checks to be carried out preferably in pairs
First aid carried between pairs
Cell phone carried
Personal locator beacon carried if working alone.
Bright clothing or hi viz jackets to be worn to assist with a
rescue if needed.
If a person works alone they either a) register this with a
contact person who will report them missing if they do not
return home b) they check in and out via txt with project
coordinator (Paul Callister 0220862405)
Significant Hazards
Isolate or
Hazard Controls
Cold windy conditions
Check forecast before leaving to survey
Clothes appropriate for the conditions windjacket and jersey
Carry water and snacks
Hot sunny conditions
Check forecast before leaving to survey
Sun hat and sunscreen
Carry water and snacks
Wet conditions
Check forecast before leaving to survey
Clothes appropriate for the conditions raincoat
Consider abandoning survey as conditions are not ideal for
lizard survey and grass becomes slippery.
In relation to all weather hazards, decision to go ahead to be
made by project co-ordinator (Paul Callister) or, if unavailable,
Peter McLaughlin.
Significant Hazards
Isolate or
Hazard Controls
Salmonella poisoning
from lizards
Each group to carry hand sanitizer as well as hand
washing water and soap. Either is to be used at the end
of the checks
Do not eat food during checks
Wasp stings
M & E
Take care if seeing wasps flying
Specific prescribed anti-histamines to be carried by
individuals with a known history of allergic reaction
When concentrations of wasps are detected install
Vespex bait stations at appropriate time
Significant Hazards
Isolate or
Hazard Controls
Parking next to SH1
Be aware when entering and exiting vehicles at the
bottom of Bob's Track on SH1 and be careful pulling out
onto the road
Reviewed by Peter Kentish, Nga Uruora Health & Safety co-ordinator
ResearchGate has not been able to resolve any citations for this publication.
Full-text available
Invasive species can have negative consequences on native reptile populations, especially on island systems. Chemical control can be a cost-effective way to control or eradicate invasive species. Chemical control is currently in use in New Zealand to limit impacts of non-native mammals and plants on a range of native biodiversity. However, it is important to consider the potential non-target risks of chemical control to native species that are likely already significantly reduced in number. We aimed to characterise the toxicity of several rodenticides and herbicides to reptiles and to provide a screening-level risk assessment of these chemicals applicable to native reptiles of New Zealand using the western fence lizard, Sceloporus occidentalis, as a surrogate organism. We used the Up-and-Down testing procedure to estimate oral toxicity for all compounds. We tested five rodenticides (brodifacoum, coumatetralyl, pindone, diphacinone and cholecalciferol). Only pindone was toxic to fence lizards at concentrations below 1750 μg g–1 (LD50 = 550 μg g–1). We tested five herbicides (glyphosate, clopyralid, triclopyr, metsulfuron-methyl and haloxyfop-methyl) and one common adjuvant in glyphosate formulations (polyethoxylated tallowamine or POEA). Only triclopyr was toxic to fence lizards below 1750 μg g–1 (LD50 = 550 μg g–1). Toxicity does not necessarily imply risk. Using the pindone concentrations in accepted bait formulations in New Zealand, a 10 g lizard would need to ingest 4.7 g of pindone bait in a single day in order to achieve toxic levels, which is extremely unlikely. We used the highest acceptable application rate for triclopyr to estimate risk for reptiles and found minimal risk of acute toxicity from triclopyr applications. Taken together, our data suggest little risk of reptile acute toxicity from the tested rodenticides or herbicides in New Zealand, but research into sub-lethal effects is also required in order to make informed decisions about the ecological impacts of chemically controlling invasive species.
Full-text available
Invasive house mice (Mus musculus) have detrimental effects on biodiversity, but their impacts can be difficult to detect and are often unquantified. We measured their effects on survival of a translocated population of an endangered lizard in New Zealand. Twelve captive-reared Otago skinks (Oligosoma otagense) were translocated to a 0.3-ha area of grassland/shrubland cleared of invasive mammals and surrounded by a mammal-resistant fence. Sixteen more skinks were released 2 years later but this was followed by an incursion of mice for c. 160 days. Peak mouse density was at least 63 per hectare, and they were seen attacking adult skinks (> 25 cm in length), which is previously undocumented for this lizard species. Using photo/re-sight methods and Program MARK, we estimated skink survival (phi) and detectability (p) in the presence of mice (second cohort: phi = 0.15 per annum, 95% Confidence Interval (CI) 0.01 – 0.48; p = 0.28, 0.20 – 0.38) and in their absence (first cohort: phi = 0.44 p.a., 95% CI 0.03 – 0.82; p = 0.29, 0.22 – 0.39). Survival of skinks from the first cohort during the mouse incursion was unaffected, presumably because they were already established and had access to familiar or more optimal refugia. Their survival over the entire 3 years of monitoring (0.83, 95% CI 0.60 – 0.93) compared favourably with published estimates for viable populations in the wild, protected from all invasive mammals. This suggests it may be feasible to re-establish captive-reared lizards in the wild, but mice should be considered a limiting factor, at least during the initial translocation phase.
During 1984 an unsanctioned farm road was constructed through the known range of McGregor's skink (Cyclodina macgregori) on Mana Island (217 ha). Monitoring of the island's lizard populations commenced in 1986 to assess the effects of habitat changes caused by the construction of the road. Between 1987/88 and 1988/89 the capture rate (pitfall traps) for McGregor's skink declined significantly. This decline is attributed to increased predation by mice (Mus musculus) following a buildup of mouse numbers after cattle (the only stock then present) were removed from the island in 1986. In August 1989 a successful programme to eradicate mice was implemented, and no mice or their sign have been seen since February 1990. Since then, the capture rates have increased significantly for C. macgregori, the gecko (Hoplodactylus maculatus), and the Cook Strait giant weta (Deinacrida rugosa) (Orthoptera). Even though individual C. macgregori show strong site fidelity and are potentially long‐lived (10+ years), only three of 64 caught to April 1988 have been recaptured since the last mouse was trapped. Adults appeared more vulnerable to predation than juveniles. All captures of McGregor's skink on Mana Island were made within a small area (
Lizard strategy for the Wellington region
  • R Romijn
  • L Adams
  • R Hitchmough
Romijn, R., Adams, L., Hitchmough, R. 2012. Lizard strategy for the Wellington region 2012-20, Wellington Regional Lizard Network.
A successful mouse eradication explained by site-specific population data. pp. 198–203 in Veitch
  • J W B Mackay
MacKay, J.W.B. et al. 2011. A successful mouse eradication explained by site-specific population data. pp. 198–203 in Veitch, C.R.; Clout, M.N.; Towns, D.R. (Eds): Island invasives: eradication and management. IUCN (International Union for Conservation of Nature), Gland, Switzerland.
Island invasives: eradication and management. IUCN (International Union for Conservation of Nature
  • J W B Mackay
MacKay, J.W.B. et al. 2011. A successful mouse eradication explained by site-specific population data. pp. 198-203 in Veitch, C.R.; Clout, M.N.; Towns, D.R. (Eds): Island invasives: eradication and management. IUCN (International Union for Conservation of Nature), Gland, Switzerland.