Latest Updates
You will be part of a team based in either Twizel (TMAP) or Franz Josef (PFSW) tasked with protecting native taonga and restoring te taiao (nature) by removing invasive predators across mainland Aotearoa. You will undertake field-based conservation work in alpine and remote terrain.
If you’ve ever hugged a tree, maybe you felt like you didn’t get much back. Trees are strong, silent types—but there’s a lot going on behind that bark.
This trial evaluated the effectiveness of using a thermal-imaging drone to detect target invasive predators – specifically ship rats (Rattus rattus) – in coastal and intertidal environments in South Westland.
Made of melted snow, the Callery River tumbles cold and cobalt from the ramparts of South Westland’s Main Divide. There’s no such thing as easy country here: the river squirms between flanks so steep that the contour lines on a topomap form solid blocks of orange. You might call it ‘tiger country’. It used to be rat, stoat and possum country too. But no longer.
It’s the most abundant element in the universe, but just a tiny breath of hydrogen is a tailwind driving Predator Free 2050.
Suddenly, carbon’s a thing. Everyone wants to know how much we’re sitting on. But how do you measure something you can’t see?
Next time you’re stacking firewood, take a moment to read the stories that tree rings tell...
Without trees, your world would be a much hotter place already…
Trees are factories. They’re laboratories. They’re air conditioners. They’re brokers and traders. They are, in short, living marvels.
What is carbon, anyway? And why does it matter in the context of Aotearoa New Zealand’s environment?
Zero Invasive Predators (ZIP) established a pair of study sites in native forest in South Westland to compare the impact of introduced wild animals—and their control—on the structure of those sites, and their current carbon stocks.
The control of forest browsers can deliver benefits for both the climate and biodiversity. However, the present carbon accounting framework needs revision before those benefits can be monetised through the voluntary carbon market and counted towards Aotearoa’s national emissions reduction commitments.
Carbon in our native forests looks steady at first glance, but the way that carbon is stored is shifting. That could mean more emissions ahead.
Updated: September 2025
Phase 1: first applications for eradication trial delivered
Alongside the operation to protect pukunui, ZIP is delivering a small-scale eradication trial across 6,500 hectares within the operational area. The aim is to test tools and techniques for completely removing target predators, and the knowledge gained will inform the design of future eradication operations.
The trial consists of an additional application of non-toxic prefeed and toxic bait, followed by intensive predator detection. These additional applications of bait formed Phase 1 of the operation and were delivered over June and July. The area was then treated again in Phase 2 to complete the trial.
Samples from several animal carcasses found in the operational area immediately after Phase 1 have been analysed by Manaaki Whenua—Landcare Research. The Predator Free Rakiura Engagement and Advisory Group had several questions about the resulting toxicology report, which have been answered by DOC’s technical experts.
Phase 2 now complete
Phase 2 – the suppression operation across the entire treatment area – was completed on Friday 22 August (see more information below). This phase consisted of one application of non-toxic pre-feed, followed by an application of toxic bait.
Pukunui/Southern NZ dotterel is one of the most threatened birds in New Zealand with just 105 remaining, largely because of predation by feral cats and other predators. The population has declined from 176 since 2020. The Pukunui Recovery Project aims to rebuild the pukunui population to at least 300 birds by 2035.
To help achieve this, trapping efforts need to be supplemented with aerial predator control this year. We are aiming to control more than 95% of predators in the operational area. This will give pukunui the best chance at having a more successful breeding season in spring.
The safest and most effective way to control introduced predators over large areas is to use biodegradable bait pellets containing 1080. The bait targets rodents and possums. Feral cats are also controlled through secondary poisoning as they feed on the carcasses of the dead rodents and possums.
Helicopters accurately distributed bait across 43,000 hectares of Rakiura National Park along pre-determined and monitored flight paths. The treatment area included a variety of terrain in and around the Tin Range, including alpine shrublands where pukunui breed and lower-lying kamahi/podocarp forest. The area was also extended to cover the large home ranges of feral cats where possible.
Map 1 (below) shows the area of approximately 43,000 hectares for predator control, and the eradication trial site within this area (approximately 7,000 hectares). Given the large scale of the operational area, multiple helicopters will be used to distribute bait.
Map 2 (below) shows where bookable hunting blocks intersected with the operational area, as well as the areas where deer repellent was applied
Map 1
Map 2
ZIP delivered a small-scale eradication trial across approximately 7,000 hectares within the pukunui operational area. The aim was to test tools and techniques for completely removing target predators. Now that the trial has been completed, predators will not be prevented from reinvading the area.
The trial consisted of an additional application of nontoxic prefeed and toxic bait, followed by intensive predator detection. ZIP has used this method to successfully eradicate predators from large areas in South Westland and Te Manahuna Aoraki.
The trial is helping us to learn about the effectiveness of using 1080 to eradicate three types of rats – kiore, ship rats and Norway rats - on Rakiura. This will inform the design of future eradication operations.
DOC is delegated authority by the Environmental Protection Agency to consider applications for permission to use 1080 on land administered or managed by DOC. Permission has been granted for this operation. ZIP has also received the required permission from Te Whatu Ora – Health New Zealand.
The operation was carried out between June and September this year. This timing was chosen with the aim to give pukunui the best possible protection for their spring/summer breeding season.
The operation was carried out in two phases. Each phase began with the distribution of pre-feed nontoxic bait to prepare predator species to eat the toxic bait that was applied afterwards.
Phase 1: From June – Two applications of pre-feed non-toxic bait within the smaller 1080 to Zero trial block no earlier than June 5, followed by toxic bait no earlier than June 12. Repeated in phase two.
Phase 1 was completed on 7 July 2025
For the first phase, bait was only applied within the smaller trial area of approximately 6,500 hectares.
The phase began with two applications of non-toxic pre-feed cereal bait pellets, which are an undyed brown colour.
Non-toxic pre-feed was followed by one application of toxic bait at a target rate of 4 kilograms of cereal bait pellets per hectare.
The cereal bait pellets used in this eradication trial are dyed green and contain 1.5 grams of 1080 per kilogram of bait. At an application rate of 4 kilograms per hectare, that’s the equivalent of less than two teaspoons of 1080 spread across an area the size of a rugby field.
Phase 2: From August – One application of pre-feed non-toxic bait no earlier than 27 July 2025, across the entire operational area of approximately 43,000 hectares, followed by one application of toxic bait no earlier than 1 August 2025.
Phase 2 was completed on 22 August 2025
The phase began with one application of non-toxic pre-feed cereal bait pellets.
Non-toxic pre-feed was followed by one application of toxic bait at a target rate of 2 kilograms of cereal bait pellets per hectare.
The eradication trial area was treated a second time in Phase 2, at a target rate of 2 kilograms per hectare.
Brodifacoum was not used as part of this operation.
DOC has recently completed its annual pukunui flock count. The pukunui population has increased from 101 to 105. As part of the flock count, juveniles were banded so their survival rates can be monitored. The flock count will be repeated next year.
Trail cameras have been set up to monitor the impacts on predators. The cameras will also capture native species including Rakiura tokoeka kiwi. Harlequin gecko, small-eared skink and southern skink are also being monitored before and after the operation.
Kiwi/Tokoeka in Broad Bay, Stewart Island. Credit: Bradley Shields.
Camera networks have been set up to monitor predators, particularly feral cats, rats and possums, before and after the operation. The cameras won't be able to differentiate between the three rat species, so traps are also being used to ensure we measure the impact on kiore.
1080 bait pellets containing deer repellent will be distributed across bookable hunting blocks within the operational area. White-tailed deer will be monitored by trail camera grids in the deer repellent and non-deer repellent areas, and also in a non-treatment area.
The aim is to better understand whether using deer repellent reduces the impact of 1080 on the white-tailed deer population on Rakiura. We also want to know whether deer repellent reduces the effectiveness of the bait on the three target rat species. This will be valuable research for Predator Free Rakiura.
Prior to the operation, DOC and ZIP consulted with partners, key stakeholders and potentially affected parties.
This includes Te Rūnanga o Ngāi Tahu and its respective Papatipu Rūnaka, Rakiura residents, landowners adjacent to the operational area including the Rakiura Māori Lands Trust, the local marine farming and fishing industry, Rakiura National Park concessionaries, and commercial operators such as hunting groups and tourism businesses.
As a result of this consultation, the following decisions were made in the operational plan:
Hunting blocks stayed open for bookings throughout operations, with appropriate communication with hunting parties and recommendations in place not to consume meat until caution periods are lifted.
Deer repellent was used within bookable hunting blocks only. This aims to mitigate the impact on white-tailed deer hunting opportunities in areas where hunters are most likely to be. Non-deer repellent bait was used in the open hunting zone, including across pukunui breeding grounds.
Deer repellent was also used in buffer zones around certain higher value hunting blocks, recognising that deer home ranges may extend beyond the hunting blocks.
The deer monitoring areas have moved to the Doughboy Bay area and are being used to understand the impact of a standard predator control operation on white-tailed deer with and without deer repellent. This changed the location of the 1080 to Zero trial area.
The treatment area boundaries were changed on the eastern side of the original operational area to completely avoid some of the bookable hunting blocks.
Waterways were tested within the operational area for sodium fluoroacetate. Samples were taken at various locations from source to confluence to give an accurate representation of entire water catchments. These locations included South West Arm where the Rakeahua River meets the ocean environment and Doughboy Creek where the creek meets the sea.
Bait was not sown directly into the ocean. By using a 'safeline' approach, all bait was applied above the mean high water springs (MHWS) tidal level to prevent bait from entering the marine coastal environment.
Loading site: The operation was carried out from a land-based loading site in the Mason Bay area. No bait loading or helicopter refuelling took place on vessels at sea.
1080 is a manufactured, biodegradable toxin. Its active ingredient, fluoroacetate, is found in some poisonous plants in Australia, Africa and Brazil. It is also found at lower levels in a few of our native plants. Bait pellets are made up of sodium fluoroacetate (0.15% of each pellet), cereal, cinnamon lure, sugar, and green dye.
1080 bait is broken down naturally in the environment by micro-organisms, fungi and plants into harmless compounds and does not leave permanent residues in soil, water, plants or animals. 1080 dissolves to harmless levels very quickly when exposed to water and is almost always undetectable in waterways after 24 hours. 1080 operations have never contaminated drinking water in New Zealand. There are regulations and practices to prevent this.
Research studies show that the use of 1080 increases the breeding success of many native species including kiwi and kākā. 1080 does not negatively impact populations of invertebrates including kōura or insects such as caddisflies, mayflies and midges. Fresh water fish including eels/tuna and trout are also unaffected
1080 is poisonous to humans, domestic and game animals. In areas where the toxin has been applied, dogs are at high risk until poisoned carcasses have disintegrated. This takes four to eight months. During this time, people can still hunt game animals however it is advisable not to take meat from within the operational areas. Once carcasses have decomposed, the caution period will be lifted, and normal hunting activities can resume. Unpermitted dogs are not allowed at any time in Rakiura National Park.
Risks can be eliminated by following these rules:
DO NOT touch bait
WATCH children at all times
DO NOT EAT animals from this area or within the buffer zone outside the treatment boundary. The standard buffer zone is 2 km for deer.
Poison baits or carcasses are DEADLY to DOGS
Observe these rules whenever you see warning signs about pesticides. These signs indicate pesticide residues may be still present in baits and poisoned carcasses. When signs are removed this means you can resume normal activities in the area. Always report suspected vandalism or unauthorised removal of signs.
If you suspect poisoning, please contact:
Your local doctor or hospital
The National Poisons Centre: 0800 764 766 (urgent calls) or 03 479 7248 or dial 111
Seek veterinary advice for suspected poisoning of domestic animals
Stakeholders have been notified and public notices were published in local newspapers.
There will be warning signs placed at public entrances to the treatment area and in huts within or adjacent to the treatment area immediately prior to the operation.
After the operation, DOC will contact stakeholders about the results. We will continue to share insights about the outcomes for pukunui and other native species over time.
Contact DOC and ZIP by emailing: pukunui@doc.govt.nz
Learn more about why 1080 is used to control introduced predators
See operational updates and detailed maps of predator control on public conservation land
See updates about track access and safety on public conservation land
An ArcGIS StoryMap
An ArcGIS StoryMap
From Friday 1 July, the Te Manahuna Aoraki Project Board engaged ZIP to lead the development and implementation components of Te Manahuna Aoraki Project.
This is a significant milestone for all of our team, but especially for our newest members who have joined us from previous roles with our partner, the Department of Conservation (DOC). We are excited to welcome Adriana Theobald, Chloe Underwood, Doug Rands, Jolene O’Connor, Julia Gibson, Simone Smits, Tom Smits, and Geoff ‘Woody’ Woodhouse to ZIP.
Te Manahuna Aoraki Project is a partnership between mana whenua, the Department of Conservation, NEXT Foundation, Toitū te Whenua Land Information New Zealand, high country landowners, and other philanthropists and government agencies.
The project launched in 2018, with the vision to protect and revitalise the upper Mackenzie Basin and Aoraki Mount Cook National Park so native animals and plants can thrive. The 310,000 hectare project area includes mountain ranges, dryland tussock grasslands, Lake Pūkaki, Lake Takapō/Tekapo and the extensive braided river systems that feed them. The area is home to an extraordinary range of native birds, plants, reptiles and invertebrates – from New Zealand’s rarest wading bird, the kakī, to the endangered robust grasshopper.
This is an exciting time for ZIP, and we are thrilled by the opportunity to take on new skills, experience and pest elimination challenges across this diverse and spectacular landscape.
Over the next year, we will work to expand the alpine predator elimination in the Malte Brun Range, and turn our attention to eliminating other key threats to native species.
Keep an eye out for updates here, and on the Te Manahuna Aoraki Project website, Facebook and Instagram.
ZIP’s predator elimination model involves removing predators from a specific area and then protecting it from reinvasion. After the elimination operation, we intensely monitor the area and quickly respond to any predator detections using a range of techniques, one of which is the targeted application of aerial 1080 around the detection site.
Native birds in the Perth River Valley are recovering just as well in areas that have had one or more of these localised aerial treatments, when compared to surrounding areas that were only treated during the main elimination operation.
Earlier this year we reported positive signs of bird recovery in the Perth River Valley following our operation to eliminate possums, rats and stoats. In this update, we take a closer look at how this recovery looks in areas of the valley that have received different numbers of toxin applications. This work is part of the Predator Free South Westland project.
Setting up a trail camera. A MotoLure that dispenses mayonnaise is placed in the camera’s field of view to attract predators. Photo by Chad Cottle.
In 2019 we removed over 99% of predators in the Perth River Valley by applying aerial 1080 bait to all potential habitat in an elimination operation. We always anticipated that some predators might survive the operation or could reinvade the area over time; after all, an elimination approach requires us to protect the conservation gains we make. Our network of 142 lured trail cameras helps us detect these individuals so we can respond quickly to remove them.
Possums sneaking a snack of mayonnaise are caught in the act by a trail camera.
Usually, our first response to a predator detection is a ground-based operation using bait stations, traps and detection dogs. In some cases, however, the terrain makes this approach impractical and/or a ground-based response is not enough to prevent the emergent predators from spreading. When this happens, we use an aerial treatment of 1080 bait precisely targeted to the localised area where predators have been detected. The confluence of the Perth and Barlow Rivers seems to be particularly prone to reinvasion of rats from across the Barlow River, and has been treated on numerous occasions over the past three years (shaded dark grey in the map below).
Perth River Valley predator elimination project area. Grey shading shows the frequency of localised aerial treatments since 2019. Each dot represents a trail camera set up in front of a lure dispenser.
We sometimes get asked if this use of localised aerial treatments is slowing the recovery of native birds present in the Perth River Valley site. There is plenty of scientific evidence that native bird populations do better when predators are controlled (see references, below). Here, we investigated our camera network to see if there was any difference in native bird recovery between areas that had been treated multiple times and areas that only received the initial elimination treatment. Although trail cameras are primarily used to detect predators, they also detect native birds that happen to pass by. When we compare the proportion of cameras that detect birds, at the same sites, over time, we can get an indication of the relative size of these populations.
We looked at three species— kea, kakaruai/South Island robin, and ngirungiru/South Island tomtit. These species are known to be vulnerable to predation and we therefore expect their populations to recover when predators are removed. They are also the species that spend a lot of time on the forest floor and, because the cameras are low to the ground, are detected most consistently. We know that detections fluctuate over the year, peaking in summer with new fledglings. By comparing two late summer months, these seasonal variations are minimised.
We compared the number of cameras that detected birds in January 2020 (one month before any localised treatments took place) with February 2022 (one month after the most recent treatment for which we have analysed data) in areas that had received either none, between one and two, and three or more localised treatments.
Trail camera detections in January 2020 and February 2022 of kea, kakaruai/South Island robin, and ngirungiru /South Island tomtit in areas of the Perth River Valley that have received different numbers of aerial treatments. Numbers of cameras in each area ranged: 0 treatments, n=25; 1-2 treatments, n=54; and 3+ treatments, n=42
In areas that have received localised aerial treatments, more cameras are detecting kea and ngirungiru than two years ago. Kakaruai detections have remained reasonably stable, which is not surprising given the relatively low number of detections. The very low numbers (or lack) of species detections in areas that have not been treated beyond the initial elimination operation was surprising. However, this result may be explained in part by the habitat type most of these cameras were in (higher altitude in some cases, and the narrow, colder Upper Perth River Valley) where we would expect to find fewer native birds. Across the whole Valley, predator numbers are close to zero, so predation is unlikely to be a factor.
These camera detection results support the increase in birdlife that our field team are seeing and experiencing first-hand. Native bird populations continue to recover in the Perth River Valley, and the localised treatments to maintain predator freedom are not hindering that recovery.
A pair of kea show off in front of a lured trail camera, June 2022
Thank you to Matt Hickson of the Department of Conservation for a review of an earlier draft of this update.
Kemp, J. R., Mosen, C. C., Elliott, G. P., & Hunter, C. M. (2018). Effects of the aerial application of 1080 to control pest mammals on kea reproductive success. New Zealand Journal of Ecology, 42(2), 158–168.
Miskelly, C. M., Greene, T. C., McMurtrie, P. G., Morrison, K., Taylor, G. A., Tennyson, A. J. D., & Thomas, B. W. (2021). Species turnover in forest bird communities on Fiordland islands following predator eradications. New Zealand Journal of Ecology, 45(2), 1–15.
Schadewinkel, R. B., Senior, A. M., Wilson, D. J., & Jamieson, I. G. (2014). Effects on South Island robins (Petroica australis) from pest control using aerially applied 1080 poison. New Zealand Journal of Ecology, 315–321.
van Heezik, Y., Ray, S. M., Jamieson, I. G., Allen, O., & Schadewinkel, R. (2020). Impacts of aerial 1080 predator control on nest success and adult survival of South Island robins. New Zealand Journal of Ecology, 44(2), 1–11.
On Thursday 28 April, ZIP field rangers returned to their tent in the Perth River Valley to find that kea had reduced it to shreds. The Perth River Valley is a remote and rugged 12,000 hectare site within the footprint of the Predator Free South Westland project area. ZIP has been working to eliminate possums, rats and stoats from the site since 2018, and the area is now effectively predator-free.
The large tent, located at the confluence of the Perth and Barlow Rivers and affectionately referred to by the team as the ‘Content’, has been a permanent fixture in the Perth River Valley field site since late 2020. While the field team have enjoyed frequent encounters with kea at the Content, this was the first encounter in which kea in this part of the field site had lived up to their reputation for mischief and destruction – and they certainly made up for lost time!
During the weekend of Saturday 30 April, the team returned to remove the damaged tent, and found a mob of eight unbanded juvenile kea on, and around, it. As gear was removed from the tent, the birds amused themselves by climbing over the neatly stacked equipment, undoing packages and opening boxes.
The tent, wooden base and all, was removed from the site and returned to the ZIP field base in Franz Josef, where it will undergo some sorely-needed repairs and maintenance. Fortunately for the team, the tent fly appears to have sustained most of the damage, so with the purchase of a new fly the Content should live to fight another day – perhaps at another location within the Predator Free South Westland project area.
ZIP Chief Executive Al Bramley says, “While certainly inconvenient for our rangers, this encounter is another positive sign that kea in the area are continuing to do very well in the absence of possums, rats and stoats. The team is thrilled to be seeing the results of our work with Predator Free South Westland to protect these charismatic, cheeky birds, and we look forward to seeing what hijinks they get up to next!”
Predator Free South Westland has now completed the second phase of a predator elimination operation in South Ōkārito Forest. This is a major milestone for the project, which seeks to protect and restore nature by eliminating possums, rats and stoats from 100,000 hectares across South Westland. Now, the work to protect the forest against predator re-establishment begins.
Predator Free South Westland Board Chair Katie Milne says, “The elimination of invasive predators from the forest of South Ōkārito will have significant benefits for the last remaining population of New Zealand’s rarest kiwi, the rowi, along with the many other native taonga that call this area home.”
The first phase of the operation was completed in November 2021, and achieved a substantial reduction of possums, rats and stoats. However, a small number of rats survived, and went on to breed in the site. To remove this emerging population, the second phase was initiated on 23 March.
Due to the nature of the South Ōkārito site, this predator elimination operation was particularly complex, and required a combination of aerial broadcast, ‘trickle sowing’, hand- and drone-laying techniques to complete. This complexity was further compounded by a highly unusual turn of events for the West Coast: low rainfall! To ensure that target predators interact with the toxic baits, it is important that no non-toxic prefeed baits remain in the environment when toxin is applied. In South Westland, this would typically occur within 1-2 weeks. In this instance, the prefeed application was followed by 23 fine nights before sufficient rainfall occurred to degrade the bait. Toxic bait was applied between 10-13 April.
The operation appears to have been a success. Pleasingly, no rats have been detected since the operation. If any rats are detected in the coming weeks, they will be removed using targeted ground-based techniques.
A small number of stoats, and an estimated two possums, have been detected in the site since the operation was completed. The team is now working to remove these using targeted ground-based techniques before they are able to re-establish a population.
The measures taken to minimise the risk of karoro (black-backed gulls) eating bait appear to have also been largely successful, and substantially reduced the impact on the karoro population. Pleasingly, there have been no reports of affected dogs or livestock.
The field team has been pleased to report many kea sightings since the operation, and surveys of popular kea sites are also encouraging. A group of kea (including this season’s fledglings) were recently seen at the Pakihi Walk carpark, and local helicopter pilot Gus Gordon reported seeing a flock of kea over the Waiho Loop.
ZIP Operations Director Duncan Kay, who oversees the predator elimination work on the ground, says, “The Predator Free South Westland team has greatly appreciated the ongoing support and patience of the local community during our work to eliminate invasive predators from South Ōkārito. We are now looking forward to protecting the site and watching the native taonga respond!”
