A rat in Fiordland surrounded by measuring tools.

Study reveals surprising insights on rat behaviour in NZ forests

If we can understand how invasive species use different habitats, we can better predict how their populations might change due to climate change. In a published paper in Biological Invasions, Joanna Carpenter and colleagues looked at how food availability and temperature affected the distribution and density of ship rats in Aotearoa New Zealand forests.  Spoiler … Continue reading Study reveals surprising insights on rat behaviour in NZ forests

Little spotted kiwi

Unseen threat: sanctuary kiwi exposed to parasitic disease from cat scat

A recent study has found high exposure rates of toxoplasmosis in a kiwi population that does not share its habitat with cats. Toxoplasma gondii (T. gondii or toxo), a parasite found primarily in cat poop, is a cause of sickness and even death in native wildlife. We’re talking kiwi, kākā, kererū and even Māui and … Continue reading Unseen threat: sanctuary kiwi exposed to parasitic disease from cat scat

Weasel with a blackbird.

Bird count not body count: weasel study suggests recovery of native species more important than predator kill count

Described as “murderous saveloys with legs”, new research reveals weasels cannot be underestimated as a threat to native wildlife. It is suggested we pay closer attention to the recovery of native species rather than simply counting the number of predators killed. The impact of stoats is well documented, but DOC ranger Jamie McAulay and wildlife … Continue reading Bird count not body count: weasel study suggests recovery of native species more important than predator kill count

A black cat on a dirt road.

Cat catastrophe: The final frontier – managing feral cats

Part 3 of our series Cat catastrophe: Why are we behind Australia in managing cats? Cats are the eighth-most populous species in the world and are found on every continent except Antarctica. But, as invasive species across many of these continents, their popularity comes at a tremendous cost. Despite Australia’s differences in land size and … Continue reading Cat catastrophe: The final frontier – managing feral cats

A collage of stoat images

It’s business time: stoat mating mania and what you can do about it

Spring has sprung and the stoat mating frenzy has begun. From the moment they open their eyes as babies, female stoats are almost certainly already pregnant. It might be jarring to our human sensitivities but stoat reproduction is undeniably impressive. Clever copulation Each spring, pregnant female stoats find a cosy den to hunker down and … Continue reading It’s business time: stoat mating mania and what you can do about it

A cat roaming in the grass

The feral factor – new research into roaming feral cats

Feral cats live on every continent except Antarctica – surviving in deserts, forests, farms, and cities. But even though they can live almost anywhere, some habitats are more appealing than others.  New research published in the New Zealand Journal of Ecology found that landscape type might play a role in how far feral cats wander. … Continue reading The feral factor – new research into roaming feral cats

A cat playing with a spring

Cat catastrophe: Why are we behind Australia in managing cats?

Part 1: One massive problem, two different approaches As Kiwis, we pride ourselves on leading the world when it comes to protecting our native species. Our ambitious and ground-breaking Predator Free 2050 goal – and the investment and ingenuity behind it – is unlike anything seen elsewhere on the global stage. Why, then, are we quickly … Continue reading Cat catastrophe: Why are we behind Australia in managing cats?

A kea perched on a rock

Flying at half-mast: connecting kea decline to mast years

New research published in the New Zealand Journal of Zoology shows that mast years are bad news for kea. Native beech trees produce millions of tasty seeds in a mast year, which rodents love. The rodent populations explode, setting in motion a devastating cascade of events. But it’s when the masting stops that taonga species … Continue reading Flying at half-mast: connecting kea decline to mast years

A rat caught on camera sniffing an A24 trap.

Self-resetting traps useful for rat control, not eradication

Good for rat population control, but not a stand-alone tool – that’s how two scientists have described the success of self-resetting traps on Goat Island. In a recent study, Auckland University biologists Dr Markus Gronwald and Dr James Russell tested 10 Goodnature A24 self-resetting traps on Goat Island (Te Hāwere-a-Maki).   They found that while the … Continue reading Self-resetting traps useful for rat control, not eradication

Rat-trapping has a long history in Aotearoa

Rat-trapping started early in Aotearoa’s history. The Polynesian ancestors of Māori brought the kiore across the Pacific in their voyaging waka, probably around the 13th Century AD and early Māori developed several types of ingenious rat traps to catch them. Aotea, Horouta and Māmari waka traditions mention that kiore were passengers on their voyages to … Continue reading Rat-trapping has a long history in Aotearoa

Image of rolling Waikato hills

Waikato pest distribution, detectability studied

A recent study by Brandon Breedt and Carolyn King provides the first estimates of the proportion of the Waikato Region occupied by each of the target introduced mammal predator species. The results offer a warning to pest managers that pests are more widespread and harder to remove than is commonly assumed, and that the absence … Continue reading Waikato pest distribution, detectability studied

River tested as reinvasion obstacle to possums

Reinvasion by predators, of previously cleared areas, is one of the many challenges of becoming predator free. We can’t fence huge tracts of wilderness – but we can potentially make use of natural barriers. Possums, for example, may be reluctant to cross rivers. Anecdotal reports that rivers are an obstacle to possum expansion have been … Continue reading River tested as reinvasion obstacle to possums

Rats, mice and 264,457 tracking records shed light on rodent dynamics

Researchers Susan Walker, Joshua Kemp, Graeme Elliott, Corey Mosen and John Innes used 264,457 rodent tracking records collected quarterly from 23,709 tracking tunnel stations in forests across the length and breadth of New Zealand over an 18 year period from late 1999 to late 2016 to get a clearer picture of how ship rat and … Continue reading Rats, mice and 264,457 tracking records shed light on rodent dynamics

Tūī numbers treble in predator control study

When you remove predators from islands and restore forest habitat, the expectation is that native forest birds will flourish and that the new ‘improved’ conditions may favour native birds over introduced species. But is that what happens? Researchers John Ralph, Carol Ralph and Linda Long looked at how bird populations on the seven islands and … Continue reading Tūī numbers treble in predator control study

A close up of beech trees

Blue Mountains study shows 1080 effective – even for hedgehogs, mice

In the past there’s been some uncertainty over the effectiveness of large-scale aerial 1080 operations to control mice and little is known about its effect on hedgehogs. Recent trail camera monitoring of mammal predators before and after a control operation in the Blue Mountains, West Otago, suggests the operation not only controlled rats, stoats and … Continue reading Blue Mountains study shows 1080 effective – even for hedgehogs, mice

NZ brushtail possum. Image credit: Nga Manu.

Dual 1080 bait switch solves bait-shy possum issues

When researchers tested a dual baiting regime on ship rats back in 2016-2017, they also made some interesting observations about possum behaviour in their study area. Could dual baiting be adapted to overcome the bait-shy behaviour of possum survivors too? Department of Conservation and Landcare Research scientists, Graham Nugent, Richard Clayton, Bruce Warburton and Tim … Continue reading Dual 1080 bait switch solves bait-shy possum issues

A rat eating a snail

Rats on the move – how far do they disperse?

How far might young rats disperse if they find themselves in a place with few other rat competitors? It’s an important question, with implications for deciding what surveillance is needed to detect invasions in predator-free islands, sanctuaries and ultimately, large predator-free mainland areas. But to find out how far rats disperse you need to release … Continue reading Rats on the move – how far do they disperse?

Map of Auckland Island

Auckland Islands introductions included horses, possums, chickens

Did you know there were once horses on the Auckland Islands? Possums were deliberately introduced too but didn’t last long. Hardly surprising. It’s a harsh environment and not remotely like their warm Australian homeland. Scientists investigating mammal predators in the Auckland Islands group have switched to studying history recently, looking at the very early records … Continue reading Auckland Islands introductions included horses, possums, chickens

A close up of a rabbit

Identifying impediments to PF goals

Achieving Predator Free 2050 goals will take more than just a scaling-up of eradication efforts according to researchers Duane Peltzer et al from Landcare Research (Lincoln) and the University of Canterbury. They look beyond economic and technological feasibility to identify the key impediments we need to overcome, in a paper recently published in the Journal … Continue reading Identifying impediments to PF goals

A group of volunteers

Latest ‘Public Perceptions’ survey gives insight into predator control views

The results of the latest Public Perceptions of New Zealand’s Environment have just been released and, as with the previous survey in 2016, the research includes a section produced in collaboration with Predator Free New Zealand Trust and the BioHeritage Challenge, Ngā Koiora Tuku Iko, investigating public perceptions and opinions relating to predator control. “The … Continue reading Latest ‘Public Perceptions’ survey gives insight into predator control views

Hauraki Gulf islanders surveyed on pest control attitudes

Now that an increasing number of our wildlife-rich – but uninhabited by humans – offshore islands are becoming predator free, the conservation spotlight is turning to some of New Zealand’s inhabited islands. But predator eradication becomes more complicated when people are living onsite. Its not just about what’s technically possible. It’s also about what people … Continue reading Hauraki Gulf islanders surveyed on pest control attitudes

A mottled petrel bird sitting

Researchers surprised by petrel numbers on ‘refuge’ islands

A survey of 71 islands in southern Fiordland in the summer of 2017, by researchers from Museum of New Zealand Te Papa Tongarewa and the Department of Conservation, found forty breeding colonies of three petrel species spread across 35 of those 71 islands, according to a report just published in Notornis, the scientific journal published … Continue reading Researchers surprised by petrel numbers on ‘refuge’ islands

A tutu bush

Native plants show potential as future rat toxins

Tuhoe researchers recently joined other scientists in evaluating naturally occurring toxins in native plants. Could one of those toxins provide a culturally acceptable alternative to existing rodenticides? The results of their study have just been published in the New Zealand Journal of Ecology. Anticoagulant poisons have been used to kill rats and mice for decades, … Continue reading Native plants show potential as future rat toxins

two rūrū sit on a branch

Video camera study reveals rare birds in ruru diet

The ruru (morepork) is a predator – but it’s certainly not on the ‘predator-free’ hit list. Those slots are just for introduced mammal predators which haven’t co-evolved with our vulnerable native species. Ruru do prey on other native wildlife however, including endangered species, as a recent study carried out on Tiritiri Matangi Island reveals. Sarah … Continue reading Video camera study reveals rare birds in ruru diet

Kaikoura red-billed gull study reveals predator impacts over 52 years

If you park up at the beach with a feed of fish and chips it can seem like red-billed gulls are common and thriving. But 52 years’ worth of observations and monitoring data from New Zealand’s biggest gull breeding colony on the Kaikoura Peninsula tells a somewhat different story. Mammal predators are part of that … Continue reading Kaikoura red-billed gull study reveals predator impacts over 52 years

Image of cliffs and the water below

Would summer eradication of rodents work for Auckland Island?

Approximately one-third of New Zealand’s islands are now free of all invasive mammals. Could Auckland Island be next? Predator control and eradication operations are often carried out in winter – when predators are hungry and uptake of bait likely to be greater. But when it comes to eradications of sub-Antarctic islands, like Auckland Island, the … Continue reading Would summer eradication of rodents work for Auckland Island?

Dual 1080 application could be key to possum and rat eradication

Dual 1080 operations – would two toxin applications a few weeks apart work better than one? Possibly, if a few other conditions are also met. Currently, aerial 1080 drops are used to control introduced predators, but not expected to totally eliminate them. Aerial 1080 application is used to knock predator numbers right down and give … Continue reading Dual 1080 application could be key to possum and rat eradication

A rat eating a snail

New toxin combination tested for rats and possums

Up until the 1950s, most pest control toxins for vertebrates, including rats, were fast-acting. While a quick death for pests is a good thing humane-wise, the issue was, rats didn’t necessarily die. They’d try a little toxin, quickly feel the effects and sensibly refuse to have anything more to do with it, before they’d consumed … Continue reading New toxin combination tested for rats and possums

Kākā on a branch

Thermal squeeze could put pressure on native wildlife

Thermal squeeze: it’s what happens when temperatures rise, predators spread out to higher altitudes and their vulnerable prey species are squeezed into less-than-ideal pocket habitats at the outside edges of their range. Like most predicted consequences of climate change, it’s not good news. So will it happen to New Zealand species? If so, what species … Continue reading Thermal squeeze could put pressure on native wildlife

A kiwi being held

Long-range study follows kiwi for 22 years

A 22-year study in Tongariro Forest has followed 142 radio-tagged North Island brown kiwi through 4 landscape-scale aerial 1080 operations, covering an area of 20,000 hectares. Not only did all 142 kiwi survive the 1080 drops, but the long-term study reveals a swag of other interesting information on kiwi chick survival and fantail nesting success … Continue reading Long-range study follows kiwi for 22 years

A rat eating a snail

New clues in the search for synthetic lures

Peanut butter is the standard rat attractant – and apparently, they’re pretty keen on chocolate and Nutella too. But researchers at Victoria University of Wellington’s ‘Centre for Biodiversity and Restoration Ecology’ have come up with some chemical compounds that wild rats seem to rate even better than peanut butter. The quest for an irresistible rat … Continue reading New clues in the search for synthetic lures

A close up of a rock wren

Latest research from Otago University and DOC investigates rock wren and 1080

Recently there have been several research projects looking at predators in the alpine environments of the South Island. It’s a completely different ecosystem to the much-studied lowland forest systems and there’s still a lot to be learnt about the key predator threats to our alpine species and how best to address those threats. In his … Continue reading Latest research from Otago University and DOC investigates rock wren and 1080

More than ten lizard feet displayed on someones gloved hands

Jamie’s thesis reveals diet preferences of alpine stoats

Back in 2017, PFNZ Trust talked to Otago Zoology student Jamie McAulay about his Masters research on the diet of stoats. Well the Masters is done and dusted and Jamie’s thesis is now available online through the University’s ‘OUR Archive’ site. So what has Jamie found out? The research project looked specifically at the diet … Continue reading Jamie’s thesis reveals diet preferences of alpine stoats

Craig Gillies holds a ferret

Monitoring methods trialled in Whangamarino wetland

Monitoring is an essential part of measuring the success of a predator control programme, but monitoring methods used in forests may not be directly applicable to wetlands. Tracking tunnels may not work, for example, where water levels fluctuate significantly. It was an issue that faced Department of Conservation researchers Craig Gillies and Matthew Brady at … Continue reading Monitoring methods trialled in Whangamarino wetland

A native grasshopper amongst large stones

Insects get eaten too – so does predator control help grasshoppers?

Insects get eaten too. Scientists have reported that invertebrates have been found in 10-30% of cat guts and scats in the Mackenzie Basin, suggesting high country invertebrates, including some rare endemic grasshoppers, could be vulnerable to introduced mammal predators. Christchurch-based researchers, Jennifer Schori, Richard Maloney, Tammy Steeves and Tara Murray investigate whether reducing mammal predators … Continue reading Insects get eaten too – so does predator control help grasshoppers?

Image of a kiore rat in some dry grass or hay

Rat genetics tracks invasion back through time

New Zealand researchers have been taking a closer look at the family histories of Man’s long-time travelling companion – the rat. Genealogy meets gene analysis in this study, carried out by Auckland University researchers James Russell, Judith Robins and Rachel Fewster and published this month in the international journal Frontiers in Ecology and Evolution. Kiore … Continue reading Rat genetics tracks invasion back through time

Image of of a mouse eating a leaf

Tree-climbing habits of predators studied

Many of NZ’s introduced mammal predators – including house mice – are good at climbing trees. To understand the impact they have on tree-nesting birds and other tree-living wildlife, we need to learn more about how predators use vegetation compared with the ground. Mice aren’t commonly found in trees, for example, but that changes in … Continue reading Tree-climbing habits of predators studied

A black fronted tern in flight

Clearing river islands may help nesting terns

Researchers from the University of Otago and Department of Conservation have been investigating how to improve the plight of our endangered black-fronted terns in research recently published in the New Zealand Journal of Ecology. Traps, bait stations and a Komatsu bulldozer can all help make riverbed nest-sites safer. But one key predator was still undeterred … Continue reading Clearing river islands may help nesting terns

Workers place chew cards in bush

Regional Councils tackle biodiversity challenge

New Zealand’s regional councils have just released a ‘think piece’ on the future of biodiversity management in New Zealand. “Our native flora and fauna is a taonga that does much to define us as a nation. It’s also under threat, and we are losing ground in many cases. This timely thinkpiece suggests how we could … Continue reading Regional Councils tackle biodiversity challenge

Someone checking a trap in a field

Hawke’s Bay study shows predator control contributes to farmland biodiversity

Predator control for conservation purposes tends to focus on reserves, sanctuaries and remnants of native habitat rather than open pastures. When researchers publish articles on pastural predator control, they’re generally focused on possums and TB eradication. But landscape scale predator control on multi-tenure farmland is increasingly playing a part in Predator Free 2050 goals and … Continue reading Hawke’s Bay study shows predator control contributes to farmland biodiversity

A mouse burrowing

Researchers study new ways to stop bait going mouldy

It’s not quite a sugar-coated pill, but the principle is similar – a nice flavoured coating that not only encourages rodents to take the bait, but also protects the toxic cereal bait within from deteriorating over time and going mouldy. Norway rats, in particular, have been found to avoid mouldy bait. Research recently published in … Continue reading Researchers study new ways to stop bait going mouldy

A view of Quail Island

Lessons learned in combating mice on Quail Island

Canterbury’s Quail Island Ecological Restoration Trust has been working with Department of Conservation staff and researchers from Lincoln and other universities to eradicate introduced mammals from the island and document their processes, successes and learning outcomes in an article recently published in the New Zealand Journal of Zoology. “Ōtamahua/Quail Island is an 85 ha Recreation … Continue reading Lessons learned in combating mice on Quail Island

A close up of a mouse

Mice numbers in the absence of mammal predators

House mice are the smallest mammal predators to have been introduced to Aotearoa/New Zealand since humans first arrived here around 1280AD. The mice arrived on European ships by the 1820s and nowadays they are present in most habitats throughout the country. Worldwide they are among the world’s most prevalent invasive mammals due to their rapid … Continue reading Mice numbers in the absence of mammal predators

Norway rat. Image credit Ngā Manu.

Bait consumption study shows what appeals to rats

D-Block bait and DITRAC All-Weather BLOX are two commonly used, long-life rodent baits with the same active ingredient, the anticoagulant Diphacinone. Rats and mice need to consume bait over several days to get a lethal dose, so it’s important to keep them coming back for more. Although the toxin is the same, the two bait … Continue reading Bait consumption study shows what appeals to rats

Side on of a rock wren showing it's feathers and colouring

Stoats and mice top rockwren predator list

In research just published in international ornithology journal Ibis, Department of Conservation scientist Kerry Anne Weston, Colin O’Donnell, Paul van Dam-Bates and Joanne Monks investigated the impact of introduced mammalian predators in our little-studied alpine region. Their study revealed that stoats and house mice are the 2 introduced predators having the most impact on New … Continue reading Stoats and mice top rockwren predator list

A person sets up a camera trap

Detecting predators in the city – what works best?

Tracking tunnels, chew cards and WaxTags© are commonly used to detect predator presence and monitor abundance, but in recent years there’s been a new tool in the conservation kit – the remote camera. Evaluations of its use are showing that it is a tool with a lot of promise and some significant advantages over traditional … Continue reading Detecting predators in the city – what works best?

A close up of a stoat

Capturing the cryptic – finding better ways to detect stoats

When stoats were recently captured on video raiding the spring nests of rock wren, yet tracking tunnels failed to detect their presence, scientists became concerned about the effectiveness of tracking tunnels as a monitoring method in alpine regions. Was there a better way to detect stoats? How did other monitoring techniques compare with tracking tunnels … Continue reading Capturing the cryptic – finding better ways to detect stoats

Alpine stoats caught on camera raiding rock wren nests

Stoats are emerging as a key threat to our alpine wildlife as scientists learn more about predator/prey relationships in this less-studied habitat. Remote alpine zones are home to unique skinks and geckos, some of which have only recently been discovered, along with insects such as alpine weta which can survive being frozen and the tiny … Continue reading Alpine stoats caught on camera raiding rock wren nests

A stoat perched on a rock

A24 vs Stoats – island experiment deemed a success

The A24 self-resetting trap has been around for a year or two now, but development of the product and testing of its capabilities continues, along with evaluations of how best to utilise the traps in ‘real world’ predator eradications. Darren Peters from DOC, along with the team from Goodnature have recently been putting A24s to … Continue reading A24 vs Stoats – island experiment deemed a success

Three women stand infront of trapping tunnels

Survey investigates huge volunteer contribution

It has been estimated that between 25,000 and 45,000 people belong to community-based environmental groups in New Zealand. That’s a lot of volunteer work and, as the estimate was made in 2011, numbers since then are likely to have grown. There’s also a pretty wide range of uncertainty in those estimated numbers – 25,000 to … Continue reading Survey investigates huge volunteer contribution

A close up of the ferret's face

Predator scent may be key to developing long-life lures

When scientists Patrick Garvey (University of Auckland), Alistair Glen and Roger Pech (Landcare Research, Lincoln) tested the response of 18 wild-caught stoats to the scents of bigger, dominant predators, the response of the stoats was the opposite of what they expected. The researchers used towels from the bedding of ferrets and cats (familiar top-order predators) … Continue reading Predator scent may be key to developing long-life lures

A bundle of rat babies

Canadian researchers come up with innovative rat-luring techniques

Rats are a uniquely serious problem on islands such as New Zealand where there has been a rodent-free evolution of our wildlife and plantlife, but scientists around the world are also looking for better ways to control rats because of their disease-carrying and food-spoilage attributes. Black (ship) rats with their tree-climbing abilities are New Zealand’s … Continue reading Canadian researchers come up with innovative rat-luring techniques

A group of people walking on a field

Survey reveals public predator control efforts

Rats are the introduced predator that homeowners are most likely to combat, according to the results just out from the 2016 ‘Public Perceptions of New Zealand’s Environment’ survey, with almost all respondents who had rats present, reporting that they attempted to control the rats near their home. Poison was the most frequently reported method of … Continue reading Survey reveals public predator control efforts

A falcon perched on a branch

Raptors vs aliens – might it work?

‘Raptors vs aliens’ – it sounds like the latest Hollywood blockbuster, but it’s actually the title of a paper published in the NZ Journal of Zoology at the end of last year. Written by NZ Landcare Research scientists A.S. Glen and R.P. Pech, along with two Australian authors, the research investigates the complex relationship between … Continue reading Raptors vs aliens – might it work?

Landscape shot of Cape Kidnappers

Landholders and landscape scale predator control

We can do island eradications. We’re the world’s best at it. Mainland, regional-scale predator control is one of the next big predator-free challenges and a key part of that challenge is getting every landholder behind the project. What happens if some landholders don’t want to be involved? Will their inaction jeopardise the project? Just how … Continue reading Landholders and landscape scale predator control

Wren on a branch

Alpine predator impacts little understood

What do we know about the effects of introduced mammalian predators in the alpine environment? The short answer is probably ‘not much’. DOC scientists Colin O’Donnell, Kerry Weston and Joanne Monks review the little that we do know in the latest volume of the NZ Journal of Ecology. They identify important gaps in our knowledge and … Continue reading Alpine predator impacts little understood

A black and orange cat lying down

Tracking cats on Rakiura/Stewart Island

While PFNZ Trust focuses on 5 key introduced predator species (possums, rats, ferrets, stoats and weasels), we acknowledge that domestic pets – both cats and dogs – are also introduced predators and are potential killers of native wildlife if allowed to stray. Wandering dogs can and do kill kiwi and penguins when they encounter them. … Continue reading Tracking cats on Rakiura/Stewart Island

Wrybill sitting on eggs

Rivercare group shares predator control outcomes

Eric Spurr and Nicholas Ledguard from the Ashley-Rakahuri Rivercare Group share the results of their group’s extensive predator control and bird monitoring work from 2000-2015 in a recently published issue of Notornis, the journal of the Ornithological Society of New Zealand. The Ashley River is a braided river in North Canterbury (near Rangiora) where eight … Continue reading Rivercare group shares predator control outcomes

A rat eating a snail

When rats come back…

Predator control operations are just that – they control mammal predators but do not completely or permanently remove them. Survivors breed and slowly rebuild the population numbers, aided by invasion of outsiders from neighbouring, uncontrolled areas taking advantage of an opportunity to upgrade to some better real estate: competition is less because the population is … Continue reading When rats come back…

Stoat on leaf litter. Image credit: Nga Manu.

Genetic profiling reveals source of invaders

Genetic profiling sounds like something from a crime thriller, but it is a modern scientific technique that can be used to better understand the dispersal behaviour of animals and relationships between various populations. Auckland’s various stoat population were recently the subject of a genetic profiling study which revealed intriguing information about connectivity and migration. Female … Continue reading Genetic profiling reveals source of invaders