Nga Uruora animal pest control operational plan 2015-2018 December 2015 1
Nga Uruora animal pest control operational plan 2015-2018 Our area Our core area for animal pest control is the Paekakariki-Pukerua escarpment, 1 including parts of Perkins farm/middle Run, and Ames Street Reserve. 2 Our vision To reduce key introduced mammal pests in our core areas to levels that support expanding native bird, lizard and invertebrate populations. Our goals 1. To reduce mustelid, possum, feral cats, rat and hedgehog populations on the Paekakariki- Pukerua Bay escarpment, including parts of Perkins farm/middle Run, to levels sufficient to support expanding native bird populations, including creating a suitable environment for the expected arrival of kaka and kakariki. 2. To reduce mustelid, possum, feral cats, rat and hedgehog populations in Ames Street Reserve to support the nesting of blue penguins. 3. To create 30 hectares of rat free sanctuaries within key native forest areas on the Paekakariki-Pukerua Bay escarpment. A main aim is to create safe nesting sites within these prime forest areas. 4. Based on recommendations arising from lizard surveys, to create pest control hot spots on the Paekakariki-Pukerua Bay escarpment that reduce predators to abundance levels sufficient for lizard populations to persist and expand. 5. To work with neighbouring pest control groups, including the Paekakariki Rat Pack and Friends of Paekakariki Streams, to create a halo effect for the pest control work. 1 The escarpment begins near Muri Station and finishes at Paekakariki. It excludes the escarpment above Pukerua Bay beach. 2 The official name for Perkins farm was Middle Run. However, the farm is now commonly referred to as Perkins farm after the last owner. In the report the area is referred to as Perkins farm/middle Run. 2
6. To create a sustainable trapping labour force through attracting and supporting volunteers and through raising funds to pay for on-going pest contract support. Contents Introduction... 4 Our location... 5 What we are trying to achieve... 6 Regenerating forest... 6 Our birds... 7 Lizards... 8 Expanded animal pest control plans... 8 Ames Street Reserve... 9 Perkins farm/middle Run... 9 Kohekohe Loop Track... 10 Betty Perkins Reserve... 10 AT Clark rat free sanctuary... 10 Te Araroa track... 11 Quarry... 12 Ecosite rat free sanctuary... 12 Bob s track... 13 Other isolated patches of forest... 13 Lizard hot spots... 14 Ferrets and feral cats... 14 Pest control targets... 14 Possums... 14 Rats... 14 Mice... 14 Mustelids... 15 Hedgehogs... 15 Feral cats... 15 Monitoring... 15 Rodent tracking tunnels... 16 The Trap.org.nz recording system... 18 Bird counts... 19 Motion cameras... 19 Our workforce... 19 Health and Safety... 20 References... 20 Appendix 2: The use of Brodificoum... 21 3
Introduction Nga Uruora began animal pest control in 1997. Over time this effect has expanded. In the NUKP 2011 Strategic Plan, statements included to remove and permanently exclude large browsing mammals from conservation areas and to restrict all other pest animals (possums, rats, rabbits, stoats) to low levels indefinitely. The report noted that: Nga Uruora has been trapping and poisoning pest animals on the escarpment for over 10 years. To begin with, an effort was made to record kills and the amount of bait used but few Kill Crew volunteers are diligent record keepers. This is still the case but it is improving. Two new lines of DOC 200 traps were added early in 2010 and the kills in these have been recorded in Google Docs ever since. 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, channelled through the Friends of Queen Elizabeth Park (Kapiti) Trust, is to be used to restore local biodiversity. As part of the project, the Trust will work with the local community 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. Nga Uruora is using some of the money to expand animal pest control and this report is the operational plan for this work on the Nga Uruora site. It covers the period June 2015, when some of the initial expanded pest control work commenced, through to June 2018 when the MfE project is completed. A copy of wider Kapiti Mainland Island report is available on the Nature Space website. 3 This includes a description of pest control being undertaken in neighbouring areas including that undertaken by Greater Wellington Regional Council. 3 http://www.naturespace.org.nz/documents/project-reports 4
Our location Figure 1 shows the location of the wider Kapiti Mainland Island project site. To the West, the area is bordered by the sea. Just offshore, and within flying distance for some bird species, are two significant nature reserves, Kapiti Island and Mana Island. To the East is the Akatarawa range, an area controlled by GWRC and classified as a Key Native Ecosystem (KNE). 4 The main Nga Uruora area is the KiwiRail owned land from Paekakariki to Pukerua Bay. Additional areas where Nga Uruora has, or will, undertake pest control are part of Perkins farm/middle Run, AT Clark Reserve and Ames Street Reserve. While there are areas such as the Akatarawas nearby it is not clear whether the forest corridors are sufficient to allow an inward migration of some bird species. Figure 1: The animal pest control area Source: Greater Wellington Regional Council 4 http://www.gw.govt.nz/kne/ 5
What we are trying to achieve The aims of pest control vary between projects and will vary over time. In the early days of pest control on the Paekakariki-Pukerua Bay escarpment most attentions focussed on making the area stock proof and targeting possums in our key Kohekohe forests. A key aim was to protect the existing forest and assist in natural revegetation. Over time, the pest control effort has changed. The area trapped has expanded and mustelids and, to a lesser degree, rats have been targeted. The aims have been to protect both forest areas and to support bird populations. As we further expand our pest control we need to define what we are trying to protect as that strongly influenced our trapping layout and practices. There are three main areas of flora and fauna we are primary wishing to protect, regenerating forests, birds and lizards. Protecting invertebrates is also important but is currently not part of a specific strategy. Regenerating forest Our core forests are kohekohe dominated. Possums control is needed to protect canopies, flowering and seed formation as well as understory browsing. Rats are also a major problem in terms of eating seeds and preventing regeneration. Possums also browse a wide range of other plants and will especially target some plants such as the Northern Rata Nga Uruora is trying to re-establish on the escarpment. For Kohekohe, seeding occurs in winter so rat control is needed in winter and spring. But a range of other trees seed throughout the year so ideally rat control within forests and on their margins for regeneration reasons should be year round. 6
Our birds A core vision of Nga Nga Uruora since its beginnings has been to bring the dawn chorus back to the Kapiti Coast. Despite a major effort in planting and pest control since 1997, we still only have a very limited range of native birds. The following is a list of birds seen or heard during formal five minute birds counts at the Paekakariki escarpment Ho Chi Minh and Loop tracks between August and November 2015. Bellbird, Blackbacked gull, Blackbird, Chaffinch, Dunnock, Fantail, Goldfinch, Greenfinch, Greywarbler, Harrier, Kereru, Kingfisher, Rock pigeon, Silvereye, Shining cuckoo, Sparrow, Starling, Swallow, Thrush, Tui and Yellowhammer It is known that Little Blue Penguins nest in Ames street reserve and our pest control in this area is designed to protect them. It has been suggested a range of other native birds may already live permanently on the escarpment, may be passing through or may arrive soon. Examples include: Pipit (probably present or passing through), Morepork (probably present), Red-billed Gull (likely to pass through), Shag spp (may use the escarpment and could nest in this area over time), Tomtit (present through Akatarawa forests), Whitehead (present through Akatarawa forests), Kakariki (may arrive soon), Kaka (may arrive soon). 5 As yet we do not have any of the rarer New Zealand birds including Tomtit, Saddleback, Stichbird, North Island Robin and Kiwi. It is unlikely these will become part of the escarpment bird populations in the medium term. Strategies for supporting bird populations depends on their lifestyle such as whether they are tree or ground nesting, how fast they breed and what their food sources are. 5 This list was suggested in correspondence with Ian Flux. 7
To date we have not had a clear strategy for supporting birds. Our aim has been to reduce predators year round where possible. As we expand our pest control we will need to refine our strategies. For example, do we concentrate our rat control just at prime nesting periods? Lizards 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. Little is known about the lizard populations on the escarpment. The MfE project will give us a much better idea of lizard abundance. It will also give us guidance as to how to improve our pest control to support lizard populations. Expanded animal pest control plans Nga Uruora began pest control on the Paekakariki-Pukerua Bay escarpment in 1997. Early pest control mainly focussed on setting out bait stations on key areas of mature kohekohe forest on the escarpment to target possums. From the beginnings of its pest control effort, Nga Uruora has relied heavily on the use of Brodificoum (for a discussion of the use of Brodificoum see Appendix 1). The baits and the plastic hockey stick bait stations have been supplied by Greater Wellington Regional Council. While these bait stations have targeted possums, rats have always been a by-kill. Timms traps have also been used to target possums. Over time, Nga Uruora has been adding DOC200 traps, targeting mustelids. Again rats have been a by-kill. The main areas with the DOC200 traps were along the Ho Chi Minh trail and the ecosite. In the early days, members also undertook pest control of areas of bush on the Carrad farm at Pukerua Bay and also in QE covenants on Pamela Meeking-Stewart s farm. However, this work is no longer part of Nga Uruora s pest control activities. Supported by a grant from GWRC and supplemented by spending from membership fees, in 2014 Nga Uruora purchased 45 DOC200 traps. These have been primarily laid out along Te 8
Araroa trail up to the lookout. The new traps allowed us to extend our mustelid and rat control along the escarpment. In 2014, Nga Uruora began to trial 5 Goodnature rat traps. The MFE project provides addition pest control funding for three years beginning June 2015. Funding available for pest control totals $37,900 for new trapping hardware and $39,000 for a paid contractor to help set out traps and support the trapping effort (gamekeeper). This funding covers a number of groups and areas. As at August 2015 the budget allocated for Nga Uruora was just under $11,000 for hardware and $18,000 for paid contract support. The following sets out 1) trapping arrangements in each area, 2) how these will be expanded and 3) a proposed regime for checking/replenishing baits and 4) an indication of who will undertake the work in each area. The numbers of traps in each area and their location is not set out in the text. This information is all recorded on Trap.org.nz. Ames Street Reserve A network of DOC200 traps are serviced in Ames Street. These are checked three weekly. The traps help protect nesting penguins in spring. Perkins farm/middle Run Using Doc200 traps, limited mustelid control will also commence on part of Perkins farm/middle Run. These will be located at the base of Waikakariki Stream and in gullies above the Paekakariki Hill Road. These will be initially checked every 2-3 weeks, then at least monthly. NUKP has also commenced possum and rat control within the key forest remnants on Perkins farm/middle Run. This has involved placing at least one Philproof bait station, a Goodnature possum trap, a Goodnature rat trap and a DOC200 trap in each significant patch of forest at the base of Waikakariki Stream and in gullies above the Paekakariki Hill Road. The bait stations will be refilled 3-4 times in the first season, then move refills in spring and autumn. Depending on catch rates, the layout of other traps will be reviewed at the end of the first year. The coverage of Perkin s farm/middle Run will be reviewed at the end of year one. 9
In the first year the layout of traps and the re-setting/replenishing for baits will be carried out solely by the pest contractor under the terms and conditions laid out in our Right to Occupy agreement with NZTA. Kohekohe Loop Track A network of DOC200 traps are maintained. These are checked three weekly. Betty Perkins Reserve A network of bait stations and DOC200 traps have been maintained in this area. The DOC200 traps are checked monthly. Three extra bait stations have been added to this area and the old hockey sticks replaced by philproof bait stations making a total of 6 bait stations, 3 Timms and 1 Doc 200. Four or five Doc 200's around the southern perimeter will also be added. This area will also have coverage from the Doc 200's below on the Paekakariki Hill Road. This area will initially need 2 to 3 week checking of the Doc 200's and Timms. The bait could be checked every 3 or 4 months, eventually getting down to twice a year (Spring and Autumn). AT Clark rat free sanctuary Intensive rat control will commence on this site in late 2015/early 2016. The area is centred on the KCDC AT Clark Reserve. A 21.5 hectare site containing a mix of mature kohekohe forest and regenerating bush will be protected by a grid of 100 metre by 50 metre traps (DoC200) and bait stations (Philproof mini). This is an expansion of rat control already undertaken in the area. This area now has full coverage of bait stations with DOC200's to be added round the perimeter via Paekakariki Hill Road. The bait stations will need initial checking every 3 to 4 months and then reduced to twice yearly as pest numbers are reduced. The Docs 200s will 10
need to be checked every 3-4 weeks. A tracking tunnel exercise for rats was carried out in November 2015 and showed a tracking index of 33.3%. No lizards were detected on the cards. The 33% is well above our target rate of 5%. Figure 2: Sites of Rat free sanctuaries on the Paekakariki-Pukerua Bay escarpment Te Araroa track Te Araroa trail provided a spine along the whole escarpment. The trail will be completed in early 2016. Our aim is to have DOC200s every 100 metres along the length of this track. In late 2014 the traps reached from the beginning of the track at Paekakariki end through to the Lookout. These traps have been checked monthly. New traps will be laid out from the Lookout through to Pukerua Bay from December 2015 through to March 2016. Some of this will involve shifting existing traps at the base of the Ecosite. As this section of the trail remain a construction site until the track opening, the layout of the traps and initial checking will be carried out by the pest contractor. While these DOC200s are primarily targeting mustelids they also catch rats. 11
Quarry The quarry will be an extension of the AT Clark rat free sanctuary. DOC200 traps are on the track running through the quarry. An aim is to have a grid of 100 metre by 50 metre traps which will be achieved by a mix of the DOC200 traps, bait stations and an experimental use of Victor traps. Bait stations will fill gaps between other traps and will form a barrier next to the railway line. The traps will initially be checked weekly and then when catch rates reduce they will be checked monthly. This area will also have protection from the line of bait stations to be installed above Te Araroa track and below the Paekakariki Hill Road. Ecosite rat free sanctuary The second rat free sanctuary is the Ecosite. Again, existing pest control will be supplemented by adding new traps and bait stations. This area is approximately 7.2 hectares. A tracking tunnel exercise for rats was carried out in November 2015 and show a tracking index of 24%. This is well above our target rate of 5%.24% The current hockey stick bait stations will be replaced and new Philproof bait stations added to form a 100 by 50 metre grid. New Timms will be used to replace old corroded ones. DOC200s to be installed around the perimeter of this area - mainly the farm land. Goodnature possum and/or rat traps could be installed in various areas. The mix of input from the pest contractor will be determined by discussions with the current trapping team in this area. It is aimed to have the bait stations checked every three months. 12
Bob s track Bob s track allows easy access to the ecosite. DOC200 traps will be placed at 100 metre spacings on this track and checked monthly. Other isolated patches of forest There are a number of isolated patches of regenerating forest along the escarpment away from current tracks. These seem ideal places to put Goodnature possum/rat traps and a bait station which could be filled twice a year. This will be determined in the next 6 months so the traps/bait stations are in place for the 2016 spring nesting season. Figure 3: Examples of isolated patches of forest 13
Lizard hot spots Based on recommendations arising from lizard surveys, pest control hot spots on the Paekakariki-Pukerua Bay escarpment will be created that reduce predators to abundance levels sufficient for lizard and weta populations to persist and expand. As yet, it has not been determined what sort of traps or bait stations would be used. It is likely this work will commence in 2016/2017. Ferrets and feral cats Two DOC250 traps will be placed along the escarpment well away from housing areas and from time to time baited with meat. This will target any feral cats living on the escarpment and if there are ferrets in the area these traps are capable of catching them. Pest control targets Possums For possums pest control targets are based primarily around a Residual trap catch (RTC) index. Our target is 5% RTC by December 2016. As yet, we have no plans to carry out formal RTC monitoring. Rats A Tracking Tunnel Index (TTI) will be used for rodent monitoring and setting targets. In the rat free sanctuaries the target is to reduce rat numbers to under a 5% TTI over the period September to February. Outside the rat free sanctuaries no specific target for rats will be set, but with an aim to keep levels as low as possible within available resources. Mice 14
It is accepted that it is extremely difficult to control mice. While the use of Brodificoum will control some mice. However, control of rats and mustelids has the potential to lift the mice population. Mustelids While a formal target for mustelids will not be set, the aim is to keep them at very low levels across the whole escarpment. Hedgehogs Hedgehogs are a by kill from using DOC200 traps. No specific targets are being set. Feral cats No specific target is set but an aim is to keep numbers as low as possible. Monitoring There are a number of ways animal pests can be monitored: These include: Tracking tunnels before and after the control program. Leg hold traps for possums. For kill traps, counts of animals. For bait stations, the amount of bait taken. Counters on self-setting traps. Regular bird counts help to monitor bird populations. Lizard surveys. Field based motion triggered cameras Observations of rat browse on native fruits such as kohekohe and tawa will help to determine if the native forest is recovering. 15
No one monitoring method provides an ideal way of measuring the success of animal pest control. For Nga Uruora, trap data (including counters on Goodnature traps) will be heavily relied on to indicate abundance of rodents and mustelids. Other monitoring such as bird counts and use of motion cameras will also help with monitoring. However, tracking tunnels have been set up for rodent monitoring. Rodent tracking tunnels According to the Department of Conservation, using tracking tunnels as a method for monitoring small mammal abundance in New Zealand was first described by King and Edgar (1977). Much of the tracking tunnel advice is based around areas significantly larger than our pest control areas (Gillies and Williams, 2013). DOC note that for most study sites (300 to 10 000 ha), 6 to 20 tunnel lines in the treatment area (and a similar number set in the nontreatment area if applicable) should be sufficient for surveying rodents, and anywhere between 4 and 15 lines should be sufficient for surveying mustelids. Clearly, our monitoring is on a much smaller scale and data collected will reflect the much smaller sampling frames. Tunnel tracking for rodent abundance were set up in Nga Uruora s two rat free sanctuaries in October 2015. There is sufficient space to have 20 tunnels on the larger site (Figure 4) and 12 tunnels on the smaller Ecosite (Figure 5). With 20 tunnels we will be able to monitor in 5% bands (ie if one trap records a rat the TTI is 5%). For the site with 12 tunnels we can only monitor in 8.3% bands. The layout for the tracking tunnels was designed by Sara Moylan, Senior Environmental Monitoring Officer, GWRC. These will be monitored yearly in spring. We will aim to do this a week or two after putting out our spring bait in the bait stations. 16
Figure 4: Tracking tunnel locations at AT Clark reserve 17
Figure 5: Tracking tunnel locations at the ecosite Rodent tracking tunnel exercises were carried out on both sites in November 2015. On site 1 (Ecosite) a TTI of 33% for rats and 33% for mice was recorded. On site 2 (AT Clark) a TTI of 25% for rats and 25% for mice was recorded. The aim is to get the TTI down to 5% in both sites. The Trap.org.nz recording system At mid-2015 Nga Uruora began its transition across to using the web based trap data collection system Trap.org.nz. This combined mapping and data recording system was already used by QE Park and the Paekakariki Rat Pack. 18
Kill traps such as DOC200 traps provide useful data. The amount of bait taken from bait stations also provides some data but target animals and kill rates cannot be identified. Some self-setting traps, notably Goodnature, are not designed to provide an accurate record of kills. However, for our trial of five rat traps counters will be used to record how many times each trap has been set off. Bird counts Five minute bird counts have also been carried on one site for Nga Uruora in 2007/2008 and again 2010-2011. Counts began again in mid-2015 on a nearby site due to plant growth making the original site unsuitable. Motion cameras Motion triggered cameras can provide a useful picture of animal activity and behaviour in the bush including around trap sites. In October 2015, NUKP obtained a motion activated camera to assist us in understanding animal behaviour. Cameras will not be used as a formal monitoring tool but will help refine other ways of monitoring. Our workforce From late 2015 until mid 2018, Nga Ururoa will be able to utilize a mix of paid contractors and volunteers for pest control. Ensuring on-going funding for a paid contractor to undertake some of the pest control work post the MfE project is an important issue. Finding people to look after the traps at the southern end of the escarpment once TA opens will also be important. Overall, it is important we continue to attract volunteers as people drop out or need a break - for various reasons. Finally, over the next three years we will explore labour saving devices. This could include electronic notifications of traps being triggered. 19
Health and Safety The trappers on the Paekakarki-Pukerua Bay escarpment work under GWRC guidelines. The right to occupy agreement Nga Uruora has with NZTA regarding Perkins farm/middle Run has additional health and safety requirements. In the immediate future only the paid pest contractor will work on Perkins farm/ Middle Run. In terms of the use of Brodificoum in rodent control by Nga Uruora, the practices of the Auckland group Ark in the Park will be drawn upon. Ark in the Park have their rodent baits in sealed plastic bags in bait stations. This reduces bait spread and bait becoming mouldy and unpalatable to rats in damp forests. Plastic bags will be filled by the paid pest contractor and distributed when needed. This will save volunteers dealing with bulk supplies of Brodificoum. The bulk supplies of Brodificoum are stored in secure lockers at Whareroa farm shed. Suitable warning signs are at this shed. In addition, Brodificoum warning signs will be placed at all walking entrances to the escarpment. References Department of Conservation (2007) Fact sheet: Key facts about Brodifacoum, Department of Coservation,http://www.doc.govt.nz/documents/conservation/threats-and-impacts/animalpests/northland/brodifacoum-factsheet.pdf Gillies, C. (2013) Animal pests: tracking tunnel indices of small mammal abundance: Version 1.0, Department of Conservation. Gillies, C and Williams, D. (2013): DOC tracking tunnel guide v2.5.2: Using tracking tunnels to monitor rodents and mustelids. Department of Conservation, Science & Capability Group, Hamilton, New Zealand. www.doc.govt.nz Greater Wellington Regional Council (2014) Key Native Ecosystem Plan for Queen Elizabeth Park 2014-17 20
Ministry of Primary Industries (undated) Brodifacoum, http://www.foodsmart.govt.nz/whats-in-our-food/chemicals-nutrients-additivestoxins/poison-residues/brodifacoum/ Ritchie, J. (2005) Brodifacoum - risky for rats, safe for the environment, Great Barrier Island Charitable Trust, http://www.gbict.co.nz/newsletters/issue15/brodifacoum.htm Appendix 2: The use of Brodificoum Brodifacoum is a poison used in New Zealand primarily for control of possums and rodents. It is a second-generation anticoagulant. It is bothused in conservation projects and is contained in rodent control products available to the public. Its usefulness in killing rodents was first noted in the 1970s, and it was first registered in New Zealand in the early 1980s. Brodificoum has been used successfully in rodent eradication programmes on New Zealand s offshore islands and is still used by the Department of Conservation in control of rodents in offshore islands in Kapiti Coast (Department of Conservation, 2015). It is however not used by the Department of Conservation on departmental land on mainland New Zealand. Hence it cannot be used on Whareroa farm. Brodificoum is a key tool in TB related possum control and is used on the Kapiti Coast by GWRC for this purpose. Various New Zealand agencies put out guides for the use of brodificoum and this includes discussions of its benefits and risks to the wider environment (for example MPI undated; Department of Conservation, 2007). Community groups using brodificoum have also attempted to summarise its benefits and risks. An example is an on line article with the title Brodifacoum - risky for rats, safe for the environment (Ritchie, 2005). Based on the current advice, Nga Uruora will continue to use brodificoum as a key tool in its animal pest control. It is likely to be continue to be used on QE Park for possum control. However, it will not be used on Whareroa farm. 21