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To bait, or not to bait…: wētā foraging and brodifacoum

I am lucky that my parents live right down the road from the Brook Waimārama Sanctuary. This 690 hectare fenced sanctuary is home to many native species and is about to be home to 40 spotted kiwis (Exciting!!!!). Within this Sanctuary there are “wētā hotels” that offers a haven for wētā, although I have also seen a giant leopard slug in there as well. I often visit the Sanctuary, it has a lot of history and diversity. Sanctuaries offer a safe space for vulnerable native species away from large predators. The surrounding predator-proof fence keeps the bad things out and the good things in. Unfortunately, the rest of New Zealand isn’t exactly pest free, with a lot of our native species being hunted down every day by introduced pests.

Predator Free 2050 is an exciting goal that is only 25 years away. With our unique flora and fauna, why wouldn’t we want our beautiful country to be predator free? Predator Free 2050 has a focus on removing several pest species (rats, mustelids and possums). Pest Free Banks Peninsula (PFBP) is a local project focused on protecting our beautiful coast, islands and land within Banks Peninsula. PFBP has several methods and tools to eradicate and monitor pests. A common toxin used by PFBP is brodifacoum.

A Tree Weta (Image from Avenue , 2010, CC BY S.A 3.0)

There are concerns about whether toxins, specifically brodifacoum, is killing our native species. These tasty but deadly treats are targeted at mammalian pests, but native invertebrates have also been munching away at the cereal baits that contain the toxin when they come across it. Brodifacoum-laced baits became a popular pest control toxin in the 1990s.

Quail Island is an island found near Lyttelton. The original vegetation was believed to be a broadleaf-podocarp forest, a rare forest type seen only in small areas around New Zealand. Since 1998 volunteers have been working at restoring the native ecology of the island by regularly planting native trees and targeting pests with toxins. Evidence of native birds breeding would be a good indication that restoration efforts are working and that pest control can make Quail Island a place where native species can flourish.

Two tree wētā spotted in a wētā hotel at the Brook Waimārama Sanctuary (Photo taken by Author: Kayla Valentine)

Brodifacoum bait has been used on Quail Island. It is highly effective at reducing mammalian pests. Its purpose on Quail Island was to stop reintroduction of rodents. Due to Quail Island being close to the mainland, mammalian pest are able to cross over at low tide. This slow invasion prevents Quail Island from being completely predator free.

On Quail Island the brodifacoum baits were found to have been nibbled by wētā and other invertebrates! This discovery flustered scientists. How many other native invertebrates have yet to be identified for consuming the bait?

This discovery led to increasing concern for our wētā species, many endangered or threatened. How many have died due to our toxic baits?

A monitoring tool showing possible wētā trails within the Brook Waimārama Sanctuary (Photo taken by Author: Kayla Valentine)

Studies focused on invertebrate consumption of baits have primarily used baits containing 1080. The studies that involve brodifacoum have also only focused on short-term effects (14-21 days) and one-off consumption of the bait. These hungry invertebrates are likely going for more than one course of their bait snack.

Mike Bowie and James Ross wanted to determine whether wētā were regularly consuming these forbidden snacks and whether they would survive when they did. They tested in the field and did a laboratory experiment too. The laboratory experiment consisted of wētā being fed either baits with or without brodifacoum and then monitored for 60 days for insect mortality. The field test involved monitoring traps around Quail Island for invertebrate activity.

Unfortunately, the wētā were hungry. For the field test they found that wētā and invertebrates would line up and wait their turn to eat! The wētā had distinct bite patterns when eating the bait, compared to pests such as mice. Wētā bite marks were easy to identify. In the laboratory test there was no significant difference in mortality of wētā (50% survived that were fed bait, 71% survived that were fed the control ). Mike and James determined more research was needed to be done in order for results to be more conclusive.

Quail Island from the Peninsula at low tide. (Image from Greg Hewgill, 2006, CC BY 2.0, Flickr)

So, what does that tell us exactly? The baiting methods we use to get rid of the bad things are also attracting the good things! Our native species are eating the toxins we are using to remove the pests that are eating our native species! We need to find a compromise, a less risky option for our often overlooked native invertebrates.

Brodifacoum is also a risk to birds’ species! If a bird eats an invertebrate that has eaten brodifacoum, they will be affected by the poison as well. Joanne Hoare and Kelly Hare agree with this and suggest using non-toxic or less toxic methods for pests to protect native species. There seems to be a common theme with studies done on brodifacoum… its toxic for every species! There are several concerns, not just about birds and wētā consuming the bait but many other invertebrates and species consuming it as well.

So, to bait or not to bait? Mike Bowie and James Ross showed that although there were no significant differences in mortality through the laboratory test, the wētā were eating the bait in the field test and laboratory test. I believe that in order to protect our native species, a less toxic baiting method should be considered. This will reduce long-term harm to species such as wētā. All though brodifacoum is highly successful at getting rid of pests, it can also harm other species. If there are other methods that reduce that risk, we should start with those methods then move to toxic baits as a last resort option on ecologically sensitive areas, such as Quail Island.

The author, Kayla Valentine, is a postgraduate student in the Postgraduate Diploma of Science at Te Whare Wānaka o Aoraki Lincoln University. This article was written as an assessment for ECOL 608 Research Methods in Ecology.

September 17, 2025
Wings of change: Protecting parrots where they belong

I had always wanted a parrot as a kid.

My obsession was inspired by Meena, a Bangladeshi animated TV series created by UNICEF, where the protagonist, Meena, had a clever parrot named Mithu who could speak and even help with homework from school. In the very first episode, Meena wishes to go to school, but her parents don’t think it is worth educating a female, a sad reality in many Asian countries, even now.

Determined to learn, Meena finds a creative solution: Mithu goes to class for her, memorising the lessons and teaching her later. Having grown up with this story and often seeing parrots caged in people’s houses, I had subconsciously believed that parrots were meant to be pets, friends to humans rather than untamed animals.

That belief was shattered the first time I saw a flock of parrots flying freely in the jungle. As I saw them calling to one another, I came to see that they were more than simply colourful birds living in cages; they had families, friendships, and a world of their own.

And then another surprising revelation struck me: Mithu wasn’t even a parrot; he was a parakeet! I discovered the distinction during my first birdwatching trip as an undergraduate. In that moment, I realised how early influences, particularly those from television, can shape, and sometimes mislead our views of the natural world.

A caged rose-ringed parakeet © Geoff McKay / Flickr

This memory came flooding back as I read about kea (Nestor notabilis), a playful and highly intelligent alpine parrot of New Zealand. Unlike the caged parakeets of Nepal, kea are renowned for their curious nature, a trait that has both fascinated and frustrated humans. Kea are unique among parrots. Their sharp intelligence and flexibility have allowed them to survive in the harsh alpine conditions of the South Island of New Zealand.

Using observations in a plantation-native forest matrix, a team of researchers led by Aitken in 2023 conducted a study in the Whakatipu Kā Tuka (Dart-Rees Watershed) area and discovered that kea were commonly seen in plantation forests. These birds, although strongly associated with alpine and native forest habitats, spent a surprising amount of time in exotic plantation woods, probably because these managed landscapes offered new foraging options.

Aitken also tracked individual kea and mapped their home range and habitat use using VHF (Very High Frequency) radio transmitters that were attached to three individuals as lightweight backpacks. This method confirmed the keas’ active usage of plantation forests, not only for foraging but also as part of their usual range, and helped to better understand how they navigate various settings over time.

This kind of fine-scale tracking is relatively new for kea and adds an important layer to our understanding of their behaviour in human-modified landscapes. However, it is worth noting that catching wild kea for such work is not a small feat – thanks to their sharp beaks and mischievous personalities!

A kea in its natural habitat CC BY-NC-SA 2.0 fremat/Flickr

Kea are opportunistic omnivores that consume a wide variety of foods, ranging from seeds, native fruits, nectar, to even meat from dead animals. Jodanne Aitken, a PhD student at Lincoln University, found that although kea frequently fed on seeds from Pinus radiata trees in plantation forests, their poop told a fuller story. The faeces was full of insects and other invertebrates, showing just how flexible and opportunistic their diet really is. In plantation forests, they take advantage of exotic tree species and the insects that come with them.

In contrast to many birds that avoid human-dominated landscapes, kea seem to do OK in them; curious and always eager to explore.The study also found that kea were more active in the morning and that their behavior changes with seasons, possibly linked to food availability or breeding. What’s truly fascinating is how their sharp intelligence allows them to survive not just in harsh alpine conditions, but also learn how to make the most out of new environments, like the pine plantations.

Jodanne in action detecting kea. Image by Adrian Paterson

Just like Mithu, the parakeet from my childhood who memorized lessons for Meena, kea are constantly learning from their surroundings. It is this intelligence, combined with their bold and exploratory nature that makes them such incredible survivors.

While plantation forests provide new foraging grounds, they may also expose kea to new threats. This raises a vital question: are we simply giving kea new places to forage, or are we asking them to survive in habitats that may not fully meet their needs? Human-modified landscapes, while rich in opportunity, also bring risks such as increased exposure to toxins like lead or conflict with people. These findings offer hope for kea resilience in human-altered habitats, while also informing future forest management practices.

On the other hand, the parakeets of Nepal, such as the Alexandrine and Rose-ringed parakeets, are often kept as pets, and their social skills and intellect are used for human entertainment rather than for their survival. The thought of birds with such intricate habits and close social ties being denied their natural life saddens me.

Wild parakeets form large flocks, communicating and interacting in their own ways across wide-ranging Himalayan landscapes. Unfortunately, they face growing threats from habitat loss due to urban expansion, deforestation and especially the illegal pet trade. In fact, both Alexandrine and Rose-ringed parakeets are among the most commonly trapped and sold birds in south Asia. Without stronger awareness and conservation action, their role as seed dispersers and forest connectors may be lost.

While it is heartbreaking to see parakeets in cages, it is crucial to remember that simply releasing pet birds into the wild isn’t the solution. Doing so can introduce diseases to native bird populations or create invasive species that disrupt ecosystems, as has happened in parts of the world where feral parrot colonies now compete with native wildlife. The real solution is prevention: parrots should never be taken from the wild in the first place. Instead, our focus should be on protecting their habitats and fostering respect for their role in nature.

What if we saw Nepal’s parakeets not as possessions but as individuals with a right to freedom? Kea, despite facing habitat loss and human-wildlife conflicts, still roam wild, adapting to changing landscapes. Their ability to explore, learn, and interact with their environment is a reminder of what many of Nepal’s parakeets have lost.

An AI generated image of Nepal’s parakeet and New Zealand’s kea in their natural habitat © OpenAI

Kea’s willingness to venture into plantation forests for sustenance demonstrates their adaptability, but they are not immune to human pressures. Habitat changes, exposure to toxins, and climate change are pushing their predators higher into alpine zones, creating new challenges for their survival.

Meanwhile parakeets in Nepal often face shrinking natural habitats with fewer options for survival. While kea find new ways to navigate a changing world, Nepal’s parakeets are being held back by cages or by degraded ecosystems. If we could foster the same appreciation for the natural behaviors of our own native birds, perhaps we could shift away from the practice of caging them and towards efforts that protect their wild populations.

Kea are naughty, sometimes destructive, but ultimately, they are wild; free to roam and explore. Nepal’s parakeets deserve the same fate. Instead of keeping them as pets, we should prioritize protecting their habitats, enabling them to play and be curious in the Himalayan forests of Nepal. The lesson is clear: birds, whether in Nepal or New Zealand, belong in the sky, not behind bars.

This article was prepared by Master of Science student Naresh Shrestha as part of the ECOL608 Research Methods in Ecology course.

Read full research article here:
Aitken, J., Paterson, A., Ross, J., Orr-Walker, T., & Young, L. (2023). A preliminary study of kea (Nestor notabilis) habitat use and diet in plantation forests of Nelson, New Zealand. New Zealand Journal of Zoology. https://doi.org/10.1080/03014223.2023.2251904

September 12, 2025
Keeping up with the Kiwis: Translocations and their forever holiday homes
New Zealanders, also known as the ‘kiwis’, are known for tramping up great mountains, and travelling around the globe. For the actual kiwi bird, their adventures are limited to islands and protected environments. Even our New Zealand mascot, Goldie the kiwi, manages to ‘fly’ all around the world, which I’m sure would make the national birds jealous.

That’s not to say that actual kiwi don’t get around. Our national icon is the most translocated bird in New Zealand. We have been translocating kiwi since not long after the Treaty of Waitangi (1840) due to predation and habitat loss, often with limited success. When we try our hardest to save populations through transfers, most or all birds die. So, we created protected (fenced) sanctuaries that allow a safe environment for kiwi and other native species to thrive. But after decades of conservation work and relocating kiwis out of their homes to a safer habitat, are they truly happy in their new homes?

Fenced Sanctuary – Zealandia. Image by Russellstreet

Methods for successful translocations have been developed. Methods, including the introduction of Operation Nest Egg (ONE), allows the hatching chicks to become mature before releasing into the wild. These methods has required the involvement of community groups, iwi and hapū. However… there are no resources that include information from past kiwi translocations, so we don’t know the past outcomes, whether they were effective, or how to improve them — which is wild!

Researchers at Lincoln University, Peter Jahn and James Ross, and other colleagues reviewed 102 kiwi translocation projects (mainly from the last four decades — older information having been lost or ‘poorly documented’), and they examined the mitigation translocations and rehabilitation releases. But how do you define a ‘successful’ translocation?

We can’t assume that if we release birds into a new environment that everything will magically lead to success. We must investigate if the kiwi population can settle in, grow in numbers and maintain a healthy balance on their own for it to succeed long-term. The primary goal of translocations is to “establish or restore a population with a high probability of persistence”. Unfortunately, kiwi behaviours have made it hard to grow a population, as they are irregular breeders and take several years to reach sexual maturity.

To address this, objectives were set for releases:
- To grow all kiwi populations by at least 2% per year.
- To sustain genetic diversity, each translocation will have at least 40 unrelated individuals released (a ‘founder population’).
- A minimum timeframe of 15 years is required for the population to grow (and adapt to its new environment).
By collecting data and analysing the translocation trends over the decades, we can better understand how different projects affect the survival of kiwi taxa.

Stewart Island Brown Kiwi (Tokoeka). Image by Jake Osborne

Since 1863, there have been 102 translocations, with an impressive 76 kiwi translocations just in the last 20 years. Translocated kiwi species included: Rowi, Great Spotted Kiwi, Little Spotted Kiwi, Tokoeka, and Brown Kiwi. Most of the release sites (63% since the 1860s) were in the North Island or on offshore islands (sorry Lincoln — too much farmland). However, 20 of these projects’ reports do not exist or are unavailable. But here’s what is fascinating… just over half of the translocations (58%) introduced kiwi taxa where they were not seen before (a giant leap of ‘kiwi-kind’)!

In the past, effects to reduce harm for the kiwi were deemed as an ‘emergency’ to secure populations. Recent translocations cited ecological restoration and supporting kiwi taxa across different areas as a priority (which supports natural differences, and resilience – perfect for long-term conservation outcomes)!

Unfortunately, not all kiwi species have received the same level of attention. Those with more attention are spoilt with support (more management) and obtain an improvement in their conservation status. Other kiwi species are not as lucky, such as the Great Spotted Kiwi, Fiordland Tokoeka and Rakiura Tokoeka, as their conservation status has worsened. So even though translocation effort aims for an improvement in kiwi populations, other factors, such as population sizes and lack of predator control, make this already difficult job… even more challenging.

If you look at past scientific literature on initial survival of released birds, these translocations will be reported as ‘successful’, which seems good, right? But are they ‘self-sustaining populations’? Only one project (Zealandia) has been considered as ‘successful’ due to having an increased population. Even worse…. there is little information on the genetic make-up of the new population (which defeats the purpose of becoming a long-term project).

Little Spotted kiwi at Zealandia. Image by Kimberley Collins

For future translocations, the number of releases should be adjusted (by changing the total number kiwi released in a specific area) depending on the situation — for example, when there is a low founder population, or a high mortality rate. If a population is not looked after, this can result in reduced fitness and genetic variability. Having a database that holds the records of all the kiwi translocations would make it easier to analyse the factors that could influence kiwi populations.

So, what does the future hold for kiwi translocations? The main recovery goal, which was “restoring former distributions of all kiwi taxa”, has shown an increase in populations through translocations. Translocations have created new populations on islands, which can “fill in the gaps” in nature, which is a huge win! Guidelines suggest releasing 40 kiwi into a new population and that they are not related to the ‘founder population’ (this number can vary depending on specific factors to maintain high diversity).

As translocations start from newly established populations, it’s only through time that we will see if kiwi populations can further grow and maintain sufficient genetic diversity.

This article was prepared by Master of Science student Jessica Przychodzko as part of the ECOL608 Research Methods in Ecology course.

Jahn, P., Fernando Cagua E., Molles, L. E., Ross, J. G., & Germano, J .M. (2022). Kiwi translocation review: are we releasing enough birds and to the right places? New Zealand Journal of Ecology, 46(1): 3454. https://dx.doi.org/10.20417/nzjecol.46.1
September 4, 2025
Forests from grass: natural regeneration of woody vegetation on hill farms

If you’ve spent any amount of time travelling around Aotearoa New Zealand, you will have noticed the abysmal amount of forest trees in much of our country. Pre-human New Zealand was almost entirely covered in indigenous forest. You may have heard that statement before, but let’s just appreciate it for a second. 96% of the North Island and 72% of the South used to be lush with native podocarps, hardwoods, broadleaves, and beech trees.

Over the course of our relatively short history, we eventually destroyed a massive 14 million hectares of indigenous forest to make way for housing, industry, and farms. We were particularly keen on clearing drier and more arable regions like Canterbury and Central Otago, which have lost nearly 90% of their original vegetation.

By 2002, only a quarter of that indigenous vegetation remained. Don’t get me wrong, I like living here, that people can make money here, and I like eating fresh food. But, damn, I also like breathing oxygen…

Looking around Akaroa Harbour, the hills have mostly been cleared of indigenous vegetation at one point or another since human arrival to the area (own photos).

In all seriousness, native trees play much more important roles than that. Native forests can protect us from wildfires, help us avoid droughts, increase soil, water, and air quality, reduce erosion, and provide habitat for unique native species that do their part in making all of these ecosystem services available to us. As well as that, the land itself, the rugged forests, and activities like hiking through native trees forms part of our cultural identity, not to mention a reasonable chunk of our tourism industry.

What’s more, our native forests store an incredible amount of carbon – an estimated 1.7 billion tonnes.

In order for New Zealand to transition to a low-emissions economy and reach its climate change targets by 2050, we need to plant a lot more trees …up to 2.8 million hectares’ worth. The Productivity Commission suggested that most of this land could come from marginal farmland. As it turns out, there is an estimated 2.8 million hectares’ worth of suitable hill country that could be converted to forest. Hill country is essentially steep slopes at higher altitudes. It’s referred to as ‘marginal’ farmland because the economic gains are quite low compared to other landscapes. Steeper gradients are prone to erosion, and high-altitude climates don’t always lend themselves to agricultural productivity.

Steep slopes at high altitudes are key characteristics of New Zealand’s hill country (own photo).

So, how do we go about converting hill country farmland into a thriving native forest? Pedley, McWilliam, and Doscher discuss the factors that we must take into account.

Hill country revegetation projects are tough for the same reasons as hill country farming is tough, there are costs associated with buying nursery-raised seedlings and then planting on difficult terrain. As Pedley and colleagues suggest, the cheaper alternative is to simply let nature do its thing. Allowing forests to regenerate naturally is a form of passive or minimal interference management (MIM). Landowners, especially farmers, are among the most well-placed in the country to protect and expand our country’s native forest cover, and MIM is an attractive solution to the costs.

When it comes to revegetating farmland, Pedley and colleagues point out two major considerations.

One difficulty is that pasture grasses often suppress native seeds from establishing, so it’s important to help the seeds get a head start. The easiest way to do this is with nurse crops, which shade out the grass, shelter the natives, and protect them from browsers (particularly possums and ungulates, like deer and goats). Nurse crops can be exotic or indigenous shrubs and trees, and even existing weeds, like gorse, can be made useful. This is because NZ natives generally prefer to start out in the shade, eventually growing tall enough to overgrow the nurse crops.

Next is the issue of livestock that can be detrimental to natural regeneration. It does depend on which livestock species you have and which tree species are regenerating. Cattle can be extremely destructive to new plants, paddocks, and pre-existing vegetation. Sheep, on the other hand, don’t really seem to make a difference, though they tend to snack on broadleaved species that are a necessity for a healthy forest ecosystem.

Cattle should be reduced or excluded entirely from a revegetating area. Sheep can be reduced or excluded until there are a good amount of established seedlings, which usually aren’t as palatable to them. Just don’t forget to also keep out those pesky possums and unwelcome ungulates.

Cattle can be destructive to pastures and newly planted vegetation (“Cow Path to the Forest” by Tristan Schmurr, CC BY 2.0)

The most important part of natural regeneration is that the seeds have to come from somewhere. This means that the existing native vegetation on your property is one of your most important assets. This is the ‘passive’ part of the process and the money-saver, because you won’t need to buy seeds or establish nurse crops – the trees have got it covered. The native trees will shade out the grass in the space directly adjacent, enabling the seeds to gain a foothold and gradually expand the forest. Fencing off this area, or the paddock the trees are in, is enough to start the process.

A fair warning though: promoting natural regeneration with MIM can be slow, particularly through grazed pasture. Pedley and colleagues detected an annual regeneration rate of 0.2% from 2003 to 2019 at a southern Banks Peninsula station. At a time when New Zealand desperately needs to plant more trees, MIM is one of the ways landowners with limited resources can contribute, though more active management strategies will speed up the process. For example, consider pest management to exclude browsers (e.g. trapping, hunting, or fencing) and supplementary planting, especially if your remnant vegetation is limited to a few individual trees or species.

Policy and the barriers to getting involved

Finally, especially for those of us in the political and conservation sectors, I think it is our responsibility to encourage native tree planting among landowners, while understanding their barriers to doing so.

The most obvious barrier in converting farmland to forestry is the loss of income, however minor it is. Landowners meeting certain land and forest requirements may be eligible to participate in the New Zealand Emissions Trading Scheme (NZ ETS). With one hectare of ten-year-old forest, you might earn anything from 8-24 NZU per year, depending on the tree species. If sold at $58 per NZU, that’s an annual income of $464-$1392 per year – for essentially leaving the land alone. These figures grow as the forest matures, and with better policy, these figures could grow even more.

Our policies currently favour exotics over natives, and plantations over constantly-regenerating forest. Not all models consider the amount of carbon stored in the forest understory, which is much denser and richer in a native forest compared to a pine forest. New evidence shows that native ecosystems store much more carbon than previously thought, and over a much greater period of time than pine species.

Mature beech forest understory (own photo)

Mature pine forest understory (“Mount Thomas pines” by Jon Sullivan, CC BY-NC 2.0)

Another barrier to entry is our individualistic culture around climate change action. Many sheep and beef farmers report that pro-biodiversity action is not necessarily about a lack of resources, but the belief that their actions don’t benefit their own farms, or that they aren’t helpful in the bigger picture. It’s important that we change this mindset, because 89% of New Zealand’s emissions are created by our primary industries.

MIM cuts costs, but adding more trees to your property and protecting them not only benefits the landowner and the immediate environment, but also the rest of the country. It benefits the natural resources on which we all rely, stabilises the landscape, and protects us from fires and droughts. Natural regeneration of natives results in improved biodiversity outcomes, with higher richness and abundance of plants, birds and invertebrates, which not only make all of this possible, but also make the system sustainable. This means that landowners can cut costs in the long run by working with nature, using its natural characteristics and processes to their advantage.

In any case, growing a forest on a farm is not an overnight process

It requires a lot of patience, but those who are able to encourage native regrowth are safeguarding the country’s biodiversity and resources for all of us, and contributing to our sustainability. Native forests hold a much more strategic long-term position in the bid to plant more trees, and hill country farmers are the most well-placed to allow their regeneration.

Perhaps one day we will have the privilege of living and working alongside the lush and bustling forests that once supported us, as we learn to support them.

Mature beech forest (own photo).

This article was prepared by Master of Science student Sarah Gabites as part of the ECOL608 Research Methods in Ecology course.

Based on the article by Pedley, D., McWilliam, W. and Doscher, C. (2023). Forests from the grass: natural regeneration of woody vegetation in temperate marginal hill farmland under minimum interference management. Restoration Ecology 31:3. https://doi.org/10.1111/rec.13852

September 1, 2025
What went wrong with Himalayan tahrs in New Zealand?

How would you feel if an animal deeply respected and protected in your homeland was treated as a trophy animal and hunted in another country for being invasive? I was heartbroken to discover the fate of Himalayan tahrs when I first arrived here in New Zealand.

A proud Sherpa with Chhomolungma (Mt. Everest) in the background (Hey! He looks exactly like the author of this blog!!!) Photo: ©Author

Being from a native Sherpa community in the Khumbu region (popularly known to the world as The Everest region), I grew up roaming around the high alpine environment of the Himalayas. The region lies in the Sagarmatha National Park and Buffer Zone (SNPBZ) and is home to majestic mountains including the highest peak in the world, Khangri Chhomolungma (Mt. Everest in English), as well as stunning rugged terrains, glaciers, lakes and diverse flora and fauna.

A photo of male Himalayan Tahr taken on the way to Everest base camp trail Photo: ©Author

The Khumbu region is habitat to many endangered wild animals including snow leopards, musk deer and red pandas. Due to its rugged environment and mountain slopes, the region is also a suitable native habitat of the Himalayan tahr (Hamitragus jemlahicus). We call them “Ri Rau” in Sherpa language meaning “Wild Goat”.

A herd of Himalayan Tahr seen on the way to Everest Base Camp Trail Photo: ©Author

I was around 6-7 years old when I first saw a herd of the Himalayan tahrs grazing on the hills near my hometown Lukla while walking with my father. I remember watching and admiring them for hours hiding behind a rock. I was immediately mesmerized by their presence. The male stood out with their glossy thick brown coat of straight hair as if they came straight out of a salon, with strong dark horns surrounded by the females and their young ones. I was especially stunned by their ability to move confidently and swiftly across the rocky slopes. That moment still relives fresh in my memory. Since then, whenever I saw them, I always paused for a moment to admire their elegance and capturing the moments for memories.

The Himalayan tahr is currently listed as Near threatened on the IUCN Red list. In their native habitat they are mostly predated by common leopards and snow leopards. Due to anthropogenic activities such as habitat loss and illegal poaching, their population have been declining, and they are now protected in their native Himalayan environments.

When I first arrived in New Zealand, I discovered that the Himalayan tahrs are considered as invasive species, and they are hunted for recreational purpose in the country. I was really surprised by this as they are protected in the region that I come from. After doing some digging, I found out that the Himalayan tahrs were introduced in New Zealand in the early days of European settlements for sport, gifted by Duke of Bedford to help with recreational hunting option for emigrating Englishmen and released near the Hermitage at Mt Cook in 1909. As New Zealand doesn’t have any natural predators of Himalayan Tahrs, their population escalated rapidly reaching a population size of tens of thousands over the Southern Alps.

A Trophy Hunted Tahr
Photo: Image generated by ChatGPT (DALL-e) by OpenAI

The Department of Conservation of New Zealand (DOC) has been working on Himalayan Tahr population control since 1993 under the Himalayan Tahr Control Plan (DOC, 1993: HTCP) which allows limited population of around 10,000 tahrs within the seven defined management units. However, the tahr population has grown beyond the limitation of management plan in recent years, making it difficult to control them. The HTCP also includes a defined feral range to contain their population and permits farming or holding in game estates for commercial hunting only within the designated range.

A report from Lincoln University, conducted in 2020 by Geoff Kerr, Garry Ottmann and Fraser Cunningham studied the potential for containing tahrs in game estates outside their feral range to reduce demand on the wild tahr resource as recommended by the Game Animal Council (GAC, 2014). Three GPS tracked male tahrs were released in the High Peak Game Estate on 19th December 2018 to monitor their behavior and movement pattern inside the enclosure over a twelve-month period. While one tahr died of unknown causes, the remaining two were kept there until 24th December 2019. The study was done on the hypothesis that tahr containment within a game estate outside of their feral range would be successful.

The trial was successful showing that Himalayan thar can be effectively contained in game estates outside their feral range. GPS data showed minimal fence interaction, and the tahrs quickly adapted to their new territory. Most boundary activity occurred during the breeding season. The study also suggested potential for larger scale commercial operations due to their herding behaviour.

Despite extensive research and ongoing control efforts, Himalayan tahr continues to threaten New Zealand’s native biodiversity by heavily grazing on tussocks, alpine herbs, and shrubs, plants that have no evolutionary history of mammalian herbivory, thereby disrupting the natural ecological balance.

This problem also raises a serious question of human intervention with nature. More than wondering how to manage tahr populations, I find myself asking: What are they even doing here in the first place? Himalayan tahr has become invasive in New Zealand because people introduced them here without realizing its future consequences and it has backfired us, leaving us to manage the aftermath of our own decisions.

Witnessing the realities of a Himalayan tahr changing from a revered mountain dweller in my homeland to trophy hunted invasive species in New Zealand, has been an emotional and eye-opening experience for me. Looking at the conservation dilemma of tahrs between two different countries has challenged my perception and shown how the value of wildlife depends on the context. The Himalayan tahr’s journey, much like my own, has crossed oceans and adapted well into the new environment but the only difference is that the tahrs didn’t choose to come here. The Himalayan tahr’s story is a very powerful reminder of how human actions can disrupt the natural ecosystem. As someone who grew up admiring their beauty in the Himalayas, I hope their fate improves in the future.

The author, Ngima Chhiri Sherpa, is a postgraduate student in the Master of Applied Science (Environmental Management) at Te Whare Wānaka o Aoraki Lincoln University. This article was written as an assessment for ECOL 608 Research Methods in Ecology.

Paper Reference: Kerr, G. N. ., Ottmann, Garry., & Cunningham, Fraser. (2020). Himalayan tahr on game estates outside the tahr feral range. Centre for Land, Environment & People, Lincoln University. https://digitalnz.org/records/44715317

August 27, 2025
Kiwi Hedgehogs : A Journey of Curiosity and Connection

Curiosity often starts with a sense of wonder and a desire to understand the world around us. If you are a parent, I hope you have noticed and observed this in your children. Their endless questions and fascination with the world are a beautiful reminder of the joy and excitement that comes with learning and discovery.

I have four lovely daughters, among them four-year-old Arshifa Gul is a bundle of curiosity and always gives me a tough time replying to all her unexpected questions. She also loves watching animated movies, stories and travelling. Back in 2023, I took her to the Pakistan Museum of Natural History for the first time. She was shocked by seeing the animal models and skeleton structures, especially the huge dinosaurs and their roaring, Asiatic lions and their growling, and the realistic models of sharks and dolphins. At first, she was quiet, observing closely, making sure they couldn’t attack. Then, her surprising questions began. “Why is the dolphin here? Who made the dinosaur roar? How did they get so big? When did they live?”

As a wildlife biologist, I’ve worked with animals for years, but her questions confused me! It was the first time that I struggled to explain my own field. Her curiosity pushed me to think deeper and find ways to explain complex concepts in simple terms. Our trip ended but Arshifa Gul’s questions did not. Her curiosity shifted to linking the roars and growls to the human voice of the animals she heard in the animated movies

AI-generated image (Grok) of Arshifa Gul standing in awe before a towering dinosaur skeleton in a museum, her eyes wide with wonder, surrounded by animal models like lions and dolphins.

The next morning at breakfast, Arshifa Gul excitedly shared her thoughts about the characters from her favourite animated movie, “Allahyar and the Legend of Markhor”, set in Pakistan. She talked about the boy Allahyar and his animal friends, then asked where these animals lived, how big they were in real life, what their calls sounded like, and if we could visit them. I said yes we could, but explained that Khunjerab National Park, home to the markhor and snow leopard, was seven hours away.

Landscape of Khunjrab National Park, Pakistan © Nisar Ahmed

Her curiosity turned our breakfast into an adventure planning session. I gathered information on the park’s history, species like snow leopards, ibex, and Marco Polo sheep, and conservation efforts, including a trophy hunting program initiated by IUCN and WWF. 80% of the total benefits from this hunting initiative goes to the local communities while the remaining 20% is invested in habitat protection and improvement.

We visited the site, and she enjoyed the trip thoroughly and I answered most of her questions and her confusion cleared regarding voices and the original habitat of different species. Answering her is always tough, but it makes me see the world through her bright, wondering eyes, full of love for animals. She makes me realise how important it is to nurture this curiosity, not just in her, but in all children.

Curiosity is a powerful force that drives us to explore, learn, and grow. Arshifa Gul’s curiosity inspired me to write about the introduction of European hedgehogs into New Zealand. The European hedgehog, also known as the West European hedgehog, is a charming little creature native to Europe.

Hedgehogs can live in a variety of terrestrial habitats and are mostly active at night. They have a slow, hesitant way of walking and often stop to sniff the air. Unlike other hedgehog species that

Hedgehogs have fascinated people for centuries. Their spiky charm has made them popular in history, from ancient amulets to modern pop culture icons, like Sonic the Hedgehog. Did you know that New Zealand is the only country outside Europe where European hedgehogs have successfully been established in the wild? This fascinating story of how these spiky little creatures made their way to both the North and South Islands of New Zealand is filled with twists and turns.

Back in the 1869, acclimatisation societies in New Zealand introduced European hedgehogs to control pests. For a long time, it was believed that hedgehogs were first introduced to the South Island and later spread to the North Island. However, a molecular study in 2013 challenged this view and suggested that hedgehogs were independently introduced to both the islands directly from Europe. This means that the North Island had its own separate introduction of hedgehogs, rather than receiving them from the South Island.

To uncover the truth, researchers from various universities, including Lincoln University, turned to historical records, especially old newspaper articles. They discovered that there were at least four independent shipments of hedgehogs into the North Island before 1900 (which were not documented in the first publication back in 1975). These findings confirmed that the North Island’s hedgehog population did not originate from the South Island. This study highlights the importance of combining observational data, molecular studies, and historical records to understand the introduction pathways of species.

Hedgehog searching for food © Author

The European hedgehog population thrived well in NZ, too well, as it has now become problematic for native wildlife. For example, they prey on ground-nesting birds and compete with native species for food. Leading conservationists have classified them as a pest, and the Department of Conservation New Zealand has launched a campaign to protect native species from hedgehogs.

Arshifa Gul’s questions and the hedgehog share a common thread. Curiosity drives us to explore and learn. Whether it’s a child marvelling at a museum exhibit or scientists unravelling ecological puzzles, curiosity bridges wonder and action. It reminds us that conservation isn’t just about saving species—it’s about nurturing the spark that makes us care. As parents, educators, or stewards of the planet, or a teacher we can foster curiosity by encouraging, sharing stories, and exploring nature together by using interactive technologies.

The author, Muhammad Waseem, is a postgraduate student in the Master of Science at Te Whare Wānaka o Aoraki Lincoln University. This article was written as an assessment for ECOL 608 Research Methods in Ecology.

Reference: Pipek, P., Pysek, P., Bacher, S., Cerna Bolfikova, B., & Hulme, P. E. (2020). Independent introductions of hedgehogs to the North and South Island of New Zealand. New Zealand Journal of Ecology, 44(1), 3396. https://doi.org/10.20417/nzjecol.44.7

August 22, 2025
Never ask a lizard its age (Calculate it using science!)

Where were you during the 1969 moon landing? What about at the turn of the century when the world was bracing for the Y2K Apocalypse? Or during the 2020 Covid-19 pandemic?

What if I told you that there are world record-breaking geckos in Canterbury that were here through it all? That two geckos in particular, ‘Antoinette’ and ‘Brucie-Baby’, recently celebrated their 60th and 64th birthdays? That might seem unimpressive compared to a human lifespan, but most geckos are lucky to live 10-15 years elsewhere in the world.

So, what’s their secret? And how do we know this? It’s not like you can just ask a gecko its age (that would be rude! as well as difficult…). If you’ve worked with geckos or other lizards like I have, you’d also know that they’re elusive at the best of times and all look the same to an untrained eye. Well, like all great scientific breakthroughs, this story involves good record keeping, a bit of fancy maths, and, of course, Lincoln ecologists!

Antoinette and Brucie-Baby, the world’s oldest Waitaha geckos (Woodworthia brunnea). Image: Allanah Purdie | Department of Conservation 2025 (CC BY 4.0)

The Beginning

Let me take you back to the summer of ‘67. Staff from the Department of Scientific and Industrial Research (DSIR) are tramping across Motunau Island, which lies 64 km north of Ōtautahi Christchurch and 1 km off the Canterbury coast. Weeds, fire, and rabbits had drastically changed the island’s vegetation since the 1850s, but rabbits were eradicated in 1962 and Motunau had otherwise never seen an introduced mammal. That absence makes the island a decent refuge for native lizards and seabirds.

Under the leadership of ecologist, Tony Whitaker, a team of DSIR staff surveyed lizards there every summer until 1975. As part of this, they caught Waitaha Geckos (Woodworthia brunnea) along a 20 x 20 m grid using pitfall traps, which are essentially baited holes in the ground that lizards fall into trying to get a sweet treat (don’t worry , this doesn’t harm them!).

Motunau Island in Canterbury, New Zealand. Image: Wikimedia Maps n.d. (CC BY-SA 4.0)

Back then, Whitaker’s surveys had two main goals. The first was to test what kind of bait the lizards liked the most and the second was to figure out how to find nocturnal geckos in the dark. In case you were wondering, they found that lizards LOVE canned pear and that you can find geckos at night by spotlighting because their eyes reflect light like cats. For this story, though, the basic measurements taken from individual geckos over the years turned out to be far more interesting…

An Exciting Realisation

Fast forward several decades to the late 1990s and enter our Lincoln ecologists: Masters student Carol Bannock and Senior Lecturer Graham Hickling! Together with Tony Whitaker himself, they were going through Whitaker’s notes and realised that because geckos caught in the 1967-75 DSIR surveys were permanently marked by a unique combination of toes being clipped, they may be able to identify some of the same individuals 30 years later*. They also realised that because each individual had its snout-vent length (SVL) recorded, they could use growth rates to figure out how old each gecko was when first captured.

* Side note: I know toe clipping sounds brutal. We’ll unpack that later… For now, understand that although this method of identifying individuals is not used anymore, it was the best method for ecologists at the time because lizards shed their skin and therefore can’t be permanently marked by things like paint or dye.

Measuring the SVL of a Waitaha Gecko (Woodworthia brunnea) in Akaroa, Canterbury. Image: Alice McCormick 2024 (used with permission)

With no time to lose, the trio raced back to Motunau! With some searching, they found the original lizard grid from old survey pegs (who needs modern GPS?) and diligently caught and measured geckos between December 1996 and February 1997. Overall, they found 61 new geckos and recaptured 16 of the 133 toe-clipped between 1967-1975 (~12%).

To determine the growth rates of Motunau’s Waitaha Geckos, Bannock, Whitaker, and Hickling used the average SVL of one-year-old geckos caught in 1996-97 (identified by their small size) and the differences in SVL length for geckos caught 12 months apart in 1967-75 to create a growth curve. They then used that curve to estimate how old each gecko was when first caught in 1967-1975 (large geckos were categorised as 6+ years because Waitaha Geckos tend to stop growing after this). Next, they calculated the age of the 16 geckos recaptured in 1996-97 by adding their estimated ages to the number of years since first capture. The modelling for this is a little tricky, but it’s thoroughly explained in this paper by Ebert (1980), if you are interested. What you really need to know is that 10 of those 16 geckos turned out to be at least 36 years old!! The remaining 6 were between 29 and 34.

2025 and Beyond

In 1999 when Bannock, Whitaker, and Hickling published their paper, finding 30+ year-old geckos was huge news. It proved that Waitaha Geckos on predator-free Motunau could live equally as long in the wild as they do in captivity and added at least 15 years to the previously estimated maximum age for the species (or any gecko species in the world for that matter!).

The discovery was so exciting that it also prompted the Department of Conservation to immediately take charge of regular surveys on Motunau. In fact, it was in their most recent 2024-25 survey that ‘Antoinette’ and ‘Brucie-Baby’ were rediscovered (named in honour of Tony Whitaker and his co-worker, Bruce Thomas, in 1967 and 1969).

Iris pattern of a Waitaha Gecko (Woodworthia brunnea), annotated in I_³S Pattern. The three reference points (blue) and outlined identification area (green) were manually selected to allow I₃S to generate and compare key points (red) with other annotated photos. Image: © Samantha Dryden 2025.

That is not the end of Lincoln’s gecko searching though! Since 2021, our very own Dr Jennifer Gillette has been testing photography as a technique to identify individuals and to, hopefully, replace toe clipping in long-term studies. Together with her summer students, she has taken 1000s of photos of Waitaha Gecko iris and dorsal patterns around Akaroa Harbour and tested the ability of a pattern-recognition software called I³S to correctly match new photos with existing individuals in her database.

Dorsal pattern of a Waitaha Gecko (Woodworthia brunnea), annotated in I_³S Pattern. The three reference points (blue) and outlined identification area (green) were manually selected to allow I₃S to generate and compare key points (red) with other annotated photos. Image: © Samantha Dryden 2025.

According to Jennifer, the research on Motunau’s geckos has significantly impacted the way we understand and manage gecko populations in Aotearoa today. Because they live so long, Waitaha Geckos have evolved to be K-selected species, which means they mature slowly and have very few offspring. This strategy worked well before humans arrived, but today, most gecko populations in Aotearoa don’t have the luxury of living on predator-free islands like Motunau. This means that many geckos may be eaten before they are old enough to have babies, and their populations may take decades to recover from predation.

That is why being able to identify individuals like Antoinette and Brucie-Baby is so important! It’s also why no pest species can be overlooked in conservation and environmental management efforts!!

Lincoln University senior tutor, Jennifer Gillette (second from the right) and her students monitoring Waitaha Geckos (Woodworthia brunnea) around Akaroa Harbour, Canterbury. Image: © Samantha Dryden 2024.

The author, Sam Dryden, is a postgraduate student in the Master of Science at Te Whare Wānaka o Aoraki Lincoln University. This article was written as an assessment for ECOL 608 Research Methods in Ecology.

Article reference: Bannock, C. A., Whitaker, A. H., & Hickling, G. J. (1999). Extreme longevity of the common gecko (Hoplodactylus maculatus) on Motunau Island, Canterbury, New Zealand. New Zealand Journal of Ecology, 23(1), 101-103.

August 18, 2025
A Knobbly Future?

The Story of the Canterbury Knobbled Weevil

In 2011, scientists found a mere 26 individuals of Hadramphus tuberculatus, an endemic weevil species, nestled within a small reserve in the tawny high country of Canterbury, New Zealand. This was down from 49 individuals found in 2009. Why was the Canterbury knobbled weevil on the brink of extinction, and where does the population stand now – 14 years down the track?

Burkes Pass is like a portal – a steep hill that suddenly transforms from the Canterbury Plains of green pastures, forestry blocks and hedgerows into the vast glacial basins, dry riverbeds, tussocks and jewel-like lakes of the Mackenzie Country. The Mackenzie of South Canterbury is beautiful, but also brutal – the sweltering heat of summer paired with the freezing frosts of winter means few people live here.

On the saddle of Burkes Pass, it was discovered that a long-lost species of weevil did indeed live in this brutal landscape. Called the Canterbury knobbled weevil or Hadramphus tuberculatus, it was scientifically named in 1887, and was found in reasonable numbers, on the then-uncultivated Canterbury Plains. Since then, it has been seldom encountered, particularly after the clearing of its favourite host plant, the Aciphylla – commonly known as the Speargrass plant.

The weevil was considered extinct, until 2004, when a University of Canterbury student – Laura Young – stumbled across one of these knobbly weevils in a Burkes Pass reserve, rediscovering the species. However, a following study conducted in 2013 found that the species was in decline in Burkes Pass. So, how did they monitor it? How does this weevil survive and what is its future?

Illustration of Hadramphus tuberculatus, by Desmond W. Helmore (CC BY 4.0).

Like the birds of New Zealand, the insects here have evolved without most mammalian predators – with the New Zealand bats being an exception. Many species exhibit traits, such as flightlessness, gigantism, and an inability to self-defend from mammalian predators. The weevil genus Hadramphus is endemic to New Zealand and is a good example of these traits.

Hadramphus contains four species: H. spinipennis, H. stilbocarpae, H. pittospori and of course the Canterbury knobbled weevil, H. tuberculatus. A common feature amongst all Hadramphus species is their larger size relative to other New Zealand weevils, their flightlessness, and their unfortunate vulnerability to recently introduced mammalian predators.

The relatives of H. tuberculatus survive in far-flung parts of New Zealand, such as offshore islands and the remotest parts of Fiordland. H. tuberculatus lives in the tussock grasslands of Canterbury, where introduced mammalian predators are much more common. This probably explains the scarcity of the species. The Canterbury knobbled weevil also relies on speargrasses – which are terribly spiky plants but grows impressive flower bunches called inflorescences. Speargrasses were once more common on the lowlands of Canterbury, but have disappeared, due to changes in land use.

Interestingly, the Canterbury knobbled weevil is one of the few invertebrate species in New Zealand with a legally protected status – under the Wildlife Act. Most invertebrates in New Zealand are considered unprotected.

A Canterbury Knobbled Weevil adult in hand by Warren Chinn via iNaturalist (CC BY-NC 4.0).

Because of the apparent threats, entomologists (insect scientists) decided to conduct a survey-based study on the Canterbury knobbled weevil population at Burkes Pass. Through the summers of 2009-2011, pitfall traps were placed out in order to catch these weevils in a small section of a Department of Conservation reserve near Burkes Pass and in adjacent private farmland. This area has large amounts of the golden speargrass (Aciphylla aurea).

Empty pitfall traps are a type of non-deadly trap to catch insects. They are usually cups placed discreetly in the ground, that unsuspecting terrestrial critters fall into to. The researchers checked these pitfall traps weekly, and a little piece of speargrass was kept in the pitfall trap to feed trapped weevils. Weevils found in a pitfall trap were recorded, measured, and even marked with a unique identification number – in case it was recaptured.

Unfortunately, the study showed a worrying trend. In 2009, 49 weevils were captured in the pitfall traps, then 41 weevils in 2010 – and then in a drastic drop, 26 weevils were captured in 2011.

In the 2009 season, a small number of the weevils caught were in the farmland pitfall traps – meaning that they existed beyond the confines of the reserve. But, by 2011, this number of weevils caught in farmland became zero. This might have meant that the reserve was a better place for the weevils, but ultimately they were declining all the same. Many weevils in the reserve were recaptured again and could be re-identified with unique numbers written on their wings! Although the weevils can’t fly, some had been recaptured up to 190 metres away within the reserve – that’s a lot of walking for a flightless insect!

So, why were the weevils declining? The researchers make no specific discussion on this point, however introduced predators may be the main culprit – particularly rodents. A more recent 2024 study on large-bodied alpine invertebrates in southern New Zealand found that sites with mice had less wētā (a group of cricket-like insects) and these wētā were slightly larger on average when compared with sites without mice. Although wētā have a different ecology to weevils, there could be a similar story going on in the Canterbury high country.

Since this study, the outlook for the Canterbury knobbled weevil has been grim. Although a ton of work has gone into the Burkes Pass site – including pest-resistant fencing, weed control, and continued searching, there hasn’t been any recent re-discoveries of the weevil here, although bugs have a special talent of hiding in plain sight. Most people are not looking out for funny-looking weevils that live on one of the most hostile plants in New Zealand.

In a similar circumstance to the 2004 re-discovery, John Evans happened to come across a large weevil on a speargrass near Lake Heron – in the high country of Ashburton Lakes – in 2024. Uploading the observation to iNaturalist, it was quickly confirmed as a Canterbury knobbled weevil by entomologists – revealing a new population of the species. Later searches discovered even more weevils, creating new hope that the species could live on. Despite this amazing discovery, the same conservation issues remain – how can this species be effectively protected for long-term conservation? Perhaps new initiatives for pest control need to be developed – particularly for mice – but this has yet to be established.

Lake Heron, in the Ashburton high country basin. A new population of Hadramphus tuberculatus was recently discovered nearby. Photo by the author.

Unlike other species of Hadramphus, the Canterbury knobbled weevil cannot rely on remote offshore islands for survival – as the Canterbury speargrass ecosystems are important for its survival. Mammalian predator control and the protection of the weevil’s host plant should be the priorities.

Translocation of the species is another option that could be considered, especially given that the weevil did survive in captivity. The Canterbury knobbled weevil could be considered a flagship species for these unique dryland ecosystems in eastern New Zealand, which are often overlooked as important part of New Zealand biodiversity.

The critical status of this species is a reminder of the enormous loss of biodiversity that has occurred in the Canterbury region. Imagine if knobbled weevils were commonplace on speargrass plants again, living alongside various other native flora and fauna that is facing a similar fate? Losing this species to extinction would be a further loss of what makes this region unique.

This article was prepared by Master of Science student Noah Fenwick as part of the ECOL608 Research Methods in Ecology course in the Department of Pest-Management and Conservation.

Links/References

Bertoia A., Murray T. J., Robertson B. C., Monks J. M. (2024). Introduced mice influence the large-bodied alpine invertebrate community. Biological Invasions 26:3281-3297. https://doi.org/10.1007/s10530-024-03370-x

Fountain E. D., Wiseman B. H., Cruickshank R. H., & Paterson A. M. (2013). The ecology and conservation of Hadramphus tuberculatus (Pascoe 1877) (Coleoptera: Curculionidae: Molytinae). Journal of Insect Conservation 17:737-745. https://doi.org/10.1007/s10841-013-9557-9

Department of Conservation (New Zealand) Website (20 December 2024). “New population of critically endangered beetle found”. https://www.doc.govt.nz/news/media-releases/2024-media-releases/new-population-of-critically-endangered-beetle-found/

New Zealand Legislation. Wildlife Act 1953 (6 May 2022). “Schedule 7: Terrestrial and freshwater invertebrates declared to be animals.” https://www.legislation.govt.nz/act/public/1953/0031/latest/whole.html#DLM278595

Pawson S. M. (2005). Weevil Upheaval. New Zealand Geographic, Issue 72. https://www.nzgeo.com/stories/weevil-upheaval/

Young L. M., Marris J. W. M., & Pawson S. M. (2008). Back from extinction: rediscovery of the Canterbury knobbled weevil Hadramphus tuberculatus (Pascoe 1877) (Coleoptera: Curculionidae), with a review of its historical distribution. New Zealand Journal of Zoology 35:323-330.

August 12, 2025
Tips for wildlife paparazzi
How camera angles reveal the secret lives of elusive predators

On my first visit to New Zealand, I was amused to see fellow backpackers flipping through glossy magazines filled with paparazzi shots of A-listers. I remember thinking, what a strange profession, hiding in the bushes to snap a shot of someone and follow their day-to-day routes.

Fast forward a couple of decades and here I am, fascinated by research articles on the optimal camera angle to capture elusive creatures. Turns out, the world of conservation has its own paparazzi. Moreover, I feel everyone should know their tricks!

When it comes to elusive predators, capturing them in their tracks is more than a curiosity, it’s a conservation tool. Camera traps are effective in estimating animal densities, before and after control even in the most adverse habitats, like wetlands.

CC BY-NC-SA 2.0 Image by Gábor

The A-listers in this article are elusive foreign predators, feral cats and mustelids (stoats, ferrets and weasels), always on the move and few and far between, like true celebrities. The red carpet is the New Zealand bush – an exclusive venue lined with a crowd of endemic icons watching in fear as the foreign stars steal the spotlight. The photographers? Not screaming paparazzi, but silent, motion-triggered camera traps, stationed like field agents waiting for a predator in sight.

But here’s the million-dollar question: Does the camera angle make or break the shot?

Just like in Hollywood, where a low angle shot can flatter or fail, the positioning of a trail camera can dramatically influence what gets captured in the frame. Nichols et al. (2016) asked exactly that: Should camera traps aimed at cryptic predators, like feral cats and mustelids, be set up horizontally or vertically for the best results?

The red carpet

Conducted in the pastoral Toronui Station, Hawke’s Bay, the researchers placed 20 pairs of camera traps—each pair with one camera horizontally and the other vertically. A horizontal camera faces forward at animal eye level. A vertical camera looks downward, much like a security camera.

To increase the chances of a sighting, the cameras were positioned at the ecotones or edges of forest fragments where possible.

To lure the stars, they used bait: not truffles, caviar or fur coats but rabbit meat and ferret-scented bedding. The cameras were left running for two months, waiting for their moment to shine.

Setup of horizontal and vertical cameras, Toronui Station, New Zealand, in 2014. Photo Nichols et al. 2016

The Scoop: Horizontal lands the money shot

When the footage was reviewed, the results were clear:
- Horizontal cameras recorded about 1.5 times more images of the target predators than vertical ones.
- They also captured significantly more independent encounters—meaning more unique visits, not just a burst of shots from one animal loving the spotlight.
- Total photos (including non-target species) were also higher with horizontal setups.
- False triggers (empty shots) were similar between both orientations.
In short, if you’re trying to catch a predator in the act, horizontal cameras are your go-to paparazzi.

But vertical isn’t out of the picture

Interestingly, vertical cameras had an unexpected benefit: image clarity. Because they face straight down, they often captured finer detail—like coat patterns on cats. This could be important when trying to identify individual animals, for tracking their movements or population size estimates based on mark–recapture.

CC BY-NC 2.0 Image by Kari Nousiainen

However, there’s a catch. Cats are big. The narrow vertical field of view meant that 63% of cat photos taken from above only caught part of the animal.

Tips for conservation’s paparazzi

This study is more than a technological tweak. It is a lesson in field strategy. For conservationists using camera traps to monitor invasive species, the setup matters:
- Horizontal orientation is best for maximizing detection rates.
- Vertical orientation may still be helpful for species or individual identification, if the field of view can be adjusted.
And crucially, the orientation didn’t affect the rate of false triggers, so there’s no trade-off there.

Final frame

Whether you’re tailing Taylor Swift in LA or tracking a mustelid in the New Zealand bush, one thing is clear:

It’s all about the angle.

For conservation science, that angle could mean the difference between missing a species or getting the data needed to protect native wildlife. For our most wanted A-listers the red carpet might be made of forest floor, but the flash of a camera still tells a powerful story.

This article was prepared by Postgraduate Diploma in Applied Science student Ine Schils as part of the ECOL608 Research Methods in Ecology course in the Department of Pest-Management and Conservation.

Reference

Nichols, M., Glen, A. S., Garvey, P., & Ross, J. (2017). A comparison of horizontal versus vertical camera placement to detect feral cats and mustelids. New Zealand Journal of Ecology, 41(1), 145–150.
August 7, 2025
New Zealand’s most stubborn weed

Cirsium arvense is commonly known as the Canada thistle in USA and Californian thistle in Canada. No one wants to take responsibility for these prickly things. They actually come from Europe where they are called creeping thistles.

This thistle is a small weedy plant that can be a potential nightmare for New Zealand farmers. According to the NZ Ministry for Primary Industries, (2021), it cost the country $722 million in lost revenue in the year 2020 alone, up from $31 million in 2009.

^{Photo by Make It Old (Flickr User)}

Given the disruptive nature of this weed, Wendy Kentjens, a budding weed ecologist with the passion for gardening, along with her supervisors, Seona Casonato and Clive Kaiser, decided to learn more about controlling the Californian thistle population on New Zealand pastures.

To understand why Californian thistles are so weedy, Wendy decided to study the interesting microscopic world of the endophytes living inside, and how they may help or hinder the plant.

Sounds straight forward! Well, it was far from that.

Here is a summary of the challenges Wendy faced while carrying out research on Californian thistles.

‘Ah the prickly little devils…’ – Working with the thistles meant cuts and scratches all through the research.

‘Miss Unpopular, conducting pot trials at the nursery.’ – Turns out, planting weeds that no one likes is a fast way to make some frenemies.

‘The sheep ate my data!’ – Wendy found that the sheep initially didn’t eat thistles on pastures, but when they got infected with a rust fungus (Puccinia punctiformis), it made it very tasty for the sheep. She talks more about using rust fungas as a biocontrol agent in her paper “Californian thistle (Cirsium arvense):endophytes and Puccinia punctiformis” (Kentjens et al., 2024).

‘Hard to photograph the entire plant.’ – It can be really hard to see all the features of a plant from a single photo; Wendy’s mum made her a pencil drawing of the weed for her thesis.

^{Figure drawn by Marion van Cruchten}

How do you find the microscopic endophytes within the thistle?

To find all the endophytes present in these thistles, the bottom, the middle, and the top leaf of the plant were all cut into small 5 mm² pieces and placed in a petri dish over a growing medium. Then, spore by spore, each different looking fungus was isolated into new growing dishes and incubated.

Voila! Now Wendy had pure cultures of all the fungi she had found and was all ready for the next step.

DNA from these pure fungal cultures was collected and identified.

What did they find inside?

A total of 88 genera of fungi were cultured from the plant tissue, of which 65 were not previously associated with Californian Thistles.

The diversity found was a significant increase in our understanding of this infamous weed and what lives within its structure that makes it supposedly invincible.

Fungal biocontrol can be an effective tool against these weeds. However, Endophytes can alter outcomes of a host–pathogen interaction. A recent study published by Manaaki Whenua (Landcare Research), found that 60% of all rust fungus released as biocontrol had a medium effect on the weed host or a variable effect. Around 15% of all rusts released as biocontrols have failed to become established at all.

There could be a number of reasons for the variable or unsucessful results. In the case of the invasive Japanese knotweed (Fallopia japonica), two of the endophytes accociated with the weed (Alternaria sp. and Phoma sp.) hindered the establishment of fungal biocontrol by suppressing the production of rust pustules (raised masses of coloured spores that rupture epidermal leaf tissue). (Den Breeyen et al., 2022).

Understanding these organisms living within the thistle will help future studies on the effective use of fungal biocontrol in fighting these “lovely” weeds. Looking at the endophytes and how they are helping these weed propogate so sucessfully will help us get one step ahead of it and hopefully find biocontrol agents that can circumnavigate these endophyte-host relationships.

_{Note that the figure drawn by Marion van Cruchten is currently under review by the European Journal of Plant Pathology titled ENDOPHYTIC DIVERSITY AND COMMUNITY COMPOSITION OF CIRSIUM ARVENSE TISSUES OVER A GROWING SEASON. Authors Wendy Kentjens, Seona Casonato, and Clive Kaiser}

This article was prepared by Master of Science student Dee Patel as part of the ECOL608 Research Methods in Ecology course.

References:

Den Breeyen, A., Lange, C., & Fowler, S. V. (2022). Plant pathogens as introduced weed biological control agents: Could antagonistic fungi be important factors determining agent success or failure? In Frontiers in Fungal Biology (Vol. 3). Frontiers Media S.A. https://doi.org/10.3389/ffunb.2022.959753

Kentjens, W., Casonato, S., & Kaiser, C. (2024). Californian thistle (Cirsium arvense): endophytes and Puccinia punctiformis. In Pest Management Science (Vol. 80, Issue 1, pp. 115–121). John Wiley and Sons Ltd. https://doi.org/10.1002/ps.7387

Kentjens, W., Casonato, S., & Kaiser, C. (2024). Endophytic genera in californian thistle (Cirsium arvense (L.) Scop.). Australasian Plant Pathology, 53(2), 199–210. https://doi.org/10.1007/s13313-024-00972-w

Ministry for Primary Industries. (2021). Economic costs of pests to New Zealand (Nimmo-Bell & Associates, Ed.; Paper No: 2021/29). Ministry for Primary Industries. https://www.mpi.govt.nz/dmsdocument/48496-Economic-costs-of-pests-to-New-Zealand-Technical-report

_{– figure drawn by Marion van Cruchten is currently under review by the European Journal of Plant Pathology titled ENDOPHYTIC DIVERSITY AND COMMUNITY COMPOSITION OF CIRSIUM ARVENSE TISSUES OVER A GROWING SEASON. Authors Wendy Kentjens, Seona Casonato, and Clive Kaiser}

August 5, 2025