Category: wildlife ecology

Bellbird Babel: Dialect differences in NZ bellbirds

Bellbirds love to sing; they sing for everything that they do. Communicating, courtship, foraging, defending their homes, it’s almost like they’re living in a musical. I’ve always been captivated by the song of bellbirds. Whether I’m on a walk in the Port Hills, or at Willowbank Wildlife Reserve looking at the capybara and otters, I hear bellbirds singing in the background.

The New Zealand Bellbird, or Anthornis melanura, is a honeyeater species and a close relative of New Zealand’s Tūī (Prosthemadera novaeseelandiae). They have a variable diet, feeding primarily on nectar, but also fruits, insects, and scale insect honeydew. In Christchurch, bellbirds spend their summers in the Port Hills, feeding from the large nectar supplies that come from flowering native vegetation. Then, in the winter, some move to the city, where urbanisation creates a warmer environment, and sugar feeders and exotic plantings provide food.

In 2019, PhD student Jennifer Dent studied foraging and migratory patterns of bellbirds in Christchurch for her thesis, using their calls to determine where different groups were. Bellbirds in different areas make different calls, basically a different accent, language, or singing a song in a different key, and this is referred to as dialect.

New Zealand Bellbird. Photo CC0 Max G.W. Verheij. https://www.inaturalist.org/observations/162255122

For this, Jennifer placed DOC AR4 audio recorders at 59 locations. 29 locations were in the Port Hills, where recording took place in autumn. Sites were everywhere from Rapanui Bush in the east to Ahuriri Reserve in the west, totalling 15 km around the Port Hills. The other 30 recording locations were in Christchurch city during winter, from as far north as the Groynes, as far east as Sumner, and as far west and south as Lincoln. From this, Jennifer matched dialects in the Port Hills in autumn to those recorded in Christchurch city in winter.

Christchurch dialects

Jennifer found four different bellbird dialects in Christchurch.

Dialect A was the most common dialect. It was spread across the northern region of the Port Hills, as well as in more central areas, such as the Botanic Gardens.

Dialect B was the next most common. In the Port Hills, it was found in Kennedy’s Bush, and in the city, it was in south-western areas, such as Halswell and Hoon Hay.

Dialect C was the least common dialect that Jennifer observed. In the Port Hills, it was found in Omahu Bush, and in Christchurch, it was found outside of the city, but only as far as Tai Tapu and Lincoln.

Dialect D was the last dialect. This pattern is unusual because it was not found in the autumn Port Hills recordings, but was found in the winter Christchurch recordings around the eastern and northern parts of Christchurch, such as Sumner, the Groynes, and Riccarton Bush, but because it was not found in the autumn recordings, it is not known where they went after winter.

Map of Dialect Locations in Christchurch. Photo CC-BY Jennifer Dent https://researcharchive.lincoln.ac.nz/server/api/core/bitstreams/82c22265-dec3-419b-8880-4eb37f1aaee2/content

Why don’t the dialects overlap?

It’s surprising that four different dialects were found both so close together and with very little overlap, especially since there are no geographic barriers stopping members of one group from flying to another. Jenny suggested that there could be two main reasons for this: limited dispersal and vocal imitation.

Limited dispersal, or philopatry, is the theory that states that birds remain in the areas where they were born and raised perhaps because it is harder to survive outside their own groups. A second theory is that vocal imitation by bellbirds occurs when birds move between groups, but we don’t notice it because they are so quick to pick up on the new dialect. It is possible that both of these theories are occurring simultaneously.

Following bellbirds into the city

The presence of all Port Hills dialects in the Christchurch recordings suggests that seasonal dispersal from the Port Hills to Christchurch is a shared behaviour among all populations. Furthermore, as shown by the map, dispersing to the nearest suitable location rather than spreading across all of Christchurch also seems to be a shared behaviour.

Bellbirds in Christchurch likely remember foraging areas for different times of the year, but rather than remembering many locations across Christchurch, they remember only a few patches that are close together. This is referred to as patch-scale resource tracking, and it has been shown to be a low-work, high-reward technique for foraging by bellbirds.

Next time you hear a bellbird singing, you aren’t just hearing background noise, you’re hearing a local neighbour. That bellbird might be a Cashmere regular or a member of the Tai Tapu community. It makes Christchurch a more lively city, as it’s not only just a place for us, but for birds following their own routines, singing their songs as they go about their day.

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

Paper reference: Dent, J. M. (2019). Information use during foraging by New Zealand bellbirds (Anthornis melanura) : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University. Lincoln University. https://researcharchive.lincoln.ac.nz/server/api/core/bitstreams/82c22265-dec3-419b-8880-4eb37f1aaee2/content

September 2, 2026
If friend-shaped, why not friend?

It’s a fair question.

If an animal looks soft, furry, and, let’s be honest, kind of adorable… why wouldn’t we treat it like a friend? Picture a common brush-tailed possum, fluffy and wide-eyed, or a spiky little hedgehog snuffling through the undergrowth, both undeniably friend-shaped. They don’t exactly look like villains. In fact, they look like animals we might want to protect.

But here’s the uncomfortable truth: in Aotearoa/New Zealand, these “friend-shaped” animals are responsible for some of the most devastating environmental damage across the country.

A curious little hedgehog (Erinaceus europaeus). It doesn’t look dangerous, but they are surprisingly harmful predators.
Copyright CC BY-SA 3.0, by Tony Willis, from Wikimedia Commons

Early in my veterinary career, I realised just how complicated it can be to care about the environment. I’d signed up to help animals, not to think about how their populations should be controlled. But here in Aotearoa, even the cutest animals can be a big environmental problem.

The scale of the problem means pest management is essential. Conservationists must find a balance between the effectiveness of pest control techniques and animal welfare. This article explores how emerging technologies may help meet this challenge.

Cute… but catastrophic

Aotearoa’s wildlife is unique because it evolved for millions of years without land mammals. The only land mammals native to Aotearoa are, in fact, two species of bats. This isolation means many native birds nest on the ground, can’t fly well, and have limited natural defences against mammalian predators.

When humans arrived, they brought mammals, like hedgehogs, rats, stoats, and possums, with them. This is when everything changed. A stoat might seem sweet and harmless, but it will kill more than it needs. Possums, while wide-eyed and cuddly, can change the types of trees in native forests.

The stoat (Mustela erminea) is an adorable but efficient killer.
Copyright CC BY-SA, 2.0 by Soumyajit Nandy, from Wikimedia Commons

Introduced mammals have had a significant impact, contributing to widespread loss of biodiversity (variety of animals and plants) across Aotearoa. They have had a hand to play in the extinction of many native bird species and continue to threaten many more.

So, while these mammals might look adorable and harmless, their impact is anything but. It’s not that these animals are bad, they’re just in the wrong place.

Why we can’t just leave them alone

It’s tempting to think, “can’t we just let nature take its course?” The problem is, this isn’t how nature originally worked here. These species were suddenly introduced by humans, and native birds didn’t have time to adjust. So the decline in bird species isn’t natural, it’s our fault, and without intervention, many more native species will be lost.

The huia (Heteralocha acutirostris). A bird now extinct, lost in part to predation by introduced mammal predators.
Copyright public domain (CC0-style, no known copyright restrictions in place), by Johannes Keulemans, from Wikimedia Commons

This is why pest control is necessary. It’s not because we don’t like these animals, but rather we are trying to protect something even more vulnerable and important to Aotearoa’s history.

The challenges of traditional methods

Traditionally, pest control has relied on traps and toxins. While these methods are effective, they are not without their downsides. They can be costly, need regular checking and resetting, and pests often return quickly once control efforts stop.

These methods have been under scrutiny for several reasons. One concern is how humane these methods are. Animal welfare remains an important consideration even when trying to reduce or eliminate pest populations. There are also concerns about their environmental impact, including whether the toxins are retained in the soil and waterways. In addition, is the risk of harm to non-target animals, including native birds and other wildlife not intended to be affected.

Traditional DOC 200 trap. Using traditional traps requires substantial staff time, meaning that ongoing funding is needed to maintain them.
Copyright CC BY-SA 4.0, by Kimberley Collins, from Wikimedia Commons

Looking for better solutions

The good news is that things are changing in some really exciting ways! A 2014 study by Dr Helen Blackie and her team reviewed a range of emerging technologies and research for long-term mammalian pest management, several of which are discussed below. The team brought together scientists, university researchers, commercial pest management organisations and iwi (indigenous Māori tribal groups) who worked collaboratively to design new tools that are more humane, better targeted to specific pest species, and more effective over long timeframes.

Helen and her team develop new toxins to minimise animal distress. Some are even based on natural toxins derived from native plants, blending science with mātauranga Māori (traditional knowledge).

Highly poisonous Tutu plant (Coriaria arborea) has been investigated as a potential source of new toxins.
Copyright CC BY-SA 3.0 by Rudolph89, from Wikimedia Commons

Another innovation presented in the study is “set and forget” traps. While these devices have existed for some time. Newer versions use artificial intelligence (AI) to ensure only target pest species activate them. Once installed, these traps can remain in place for long periods without the need for frequent checks or bait replacement, a big advantage over traditional traps.

Smart trap that uses AI to target pest species while avoiding non-target species.
Photograph by Dr Helen Blackie, used with permission.

In the study, the group also helped develop traps that utilise new toxins in a clever way. When the specific pest interacts with the trap, a small dose of toxin is placed onto its coat. The animal then ingests it through grooming, reducing the risk of environmental contamination.

In addition, the group is learning more about pest behaviour, specifically how animals move, feed, and interact at different population numbers. This helps determine the best places for traps, increasing the likelihood that pests will interact with them.

People power in action

As this study has shown, pest control isn’t just about technology. It’s about how people work together to protect the environment. In Aotearoa, pest control programmes rely on collaboration between iwi, conservation groups, and scientists. Each group brings different expertise to the work, from scientific knowledge to local and cultural understanding.

When I discussed the new innovations with Dr Helen Blackie, she highlighted that some of the most successful pest control initiatives come from community-led groups. She emphasised that even though these groups may have fewer resources than larger programmes, they are still often highly effective. They work closely together with a strong commitment, enabling them to share ideas and adapt their approaches as needed. At the end of the day, pest control only works if people are willing to take part!

So…why not friend?

It’s okay to think these introduced mammals are cute, and the instinct to care about all animals is a good one. But, in Aotearoa, protecting native birds and plants requires managing introduced mammals. Not because they’re bad, not because they don’t deserve compassion, but because the balance has already been tipped, and without action, the consequences could be irreversible.

With better tools, smarter strategies, and more collaboration, we’re moving toward a future where pest control is more effective, more humane, and more sustainable.

And maybe that’s the real answer to the question, “if friend-shaped, why not friend?” Because sometimes, protecting one part of nature means making hard choices about another.

Tough decisions need to be made in order to protect tiny native birds like the titipounamu (Acanthisitta chloris).
Copyright CC BY-SA 4.0 by Melissa Boardman, from Wikimedia Commons

How can you help?

Looking after our environment is a shared effort, the more each of us does, the bigger the impact we can make. If you’re keen to take it further, organisations like Predator Free 2050, Department of Conservation, and Forest & Bird offer opportunities to get involved right across the country. Tools like Trap.NZ can also help you protect your own backyard and track your impact. Karawhiua!

Written by veterinarian and animal lover, Kim Telford, a student at Te Whare Wānaka o Aoraki/Lincoln University. Inspired by a curiosity for how humans and animals intersect, as part of the ECOL 608 Research Methods in Ecology course.

Explore the science: Blackie H, M., MacKay J.W., Allen W.J., Smith D.H., Barrett B., Whyte B.I., Murphy E.C., Ross J., Shapiro L., Ogilvie S., Sam S., MacMorran D., Inder S., Eason C.T. (2014) Innovative developments for long-term mammalian pest control. Pest Management Science, 70(3), 345-51. doi: 10.1002/ps.3627.

August 25, 2026
Fake terns for real conservation change

Not just for ducks

For myself, a plastic decoy is first, and foremost, synonymous with hunting. Perhaps to some this hobby seems counterintuitive coming from an ecologist, but rest assured, we pride ourselves on habitat protection and pest population management (with the added benefit of free-range tucker).

Over years of game-bird chasing, I have put out dozens of decoys. Never once did it cross my mind that a tool like them could be used for conservation.

But when you think about it critically, why would decoys not be useful? Decoys and callers are first and foremost attractants, playing on the target species’ keen senses and basic behavioural responses. As ecologists, we already familiar with attractants. The tried and true Pics peanut butter bait in tracking tunnels, enticing a wiry old possum to investigate, or the sprinkling of icing sugar in front of a wax tag, are very common in our conservation landscape.

Black-fronted terns (Chlidonias albostriatus)- credit Carey Knox (CC0 no rights reserved)

Social attraction – when decoys come into play

Species of birds that live within colonies use cues from peers to gauge habitat quality. To put it plainly, think of it like a review on a hotel. You’re probably more likely to go to one that your mate rated higher, right? So if your bird mates hang out in an area then this is probably a sign that it is a great place for a nest. These cues have the added benefit for colony birds of improved breeding success and survival.

Historically, conservation for colony-forming birds, such as the Kororā and Black-fronted tern in New Zealand, has underused this behaviour, relying heavily on predator control and habitat enhancement instead. These techniques are both particularly costly and need extensive upkeep for continued positive results. How about instead of focusing on getting the number of living birds up, we focus first on increasing the number of their plastic alternatives? … Have conservationists lost their minds? Quite the opposite.

Benefits of social attractants

Social attractants, such as decoys and audio players, can work effectively to encourage threatened species to inhabit more desirable areas. Decoys can mimick the cues that gauge habitat quality by colony-forming birds.

By actively encouraging individuals to inhabit these areas, this may reduce the number of birds attempting to nest in more dangerous locations. Those dangerous places could include a particularly low-lying section of coast where nests would be swept away during severe weather events, or an area without predator control.

Attractants could be used in combination with predator-proof fences, weeding and predator control, to create nesting sanctuaries. This is particularly useful for our more aeronautically inclined natives that are not confined by fencing, as opposed to their flightless counterparts. Nests and attractants would give them a reason to stay within these safe havens, which would improve survival and breeding success.

For our rarer species, social attractants may further aid breeding success by encouraging a higher number of individuals into a particular area. This would help boost reproduction rates due to more breeding-age adults being close together.

Illustration by Author (CC0 no rights reserved)

Trialing social attractants for black-fronted tern conservation

Social attractants were used in a Lincoln University study to identify their effects on black-fronted terns (Chlidonias albostriatus). This study was completed by Courtney Hamblin in 2019.

The types of social attractants that Courtney used included a sound anchor system, which played a variety of black-fronted tern calls, including fishing, begging, and kit calls, on a looped playback. Her study also used plastic decoys as visual attractants.

Courtney’s experiment used nine braided rivers within the Canterbury region, with ten locations each for both untreated (without attractants) and treated (with attractants) sites.

First up, Courtney needed to pick her sites on these braided rivers. She selected sites that best fit tern nesting, but without terns having nested there before. She also wanted the sites to be safe for terns to nest at if they chose to do so. It wouldn’t have been a good look if nests had started floating away!

Courtney then compared tern behaviour between sites with and without attractants. To do this, patience had to be a virtue. Over fortnightly 1-hour sessions for each site, she looked for interactions, particularly terns circling/hovering over these areas, landing within plots (land-in) and landing close by (land-out).

Diagram of the audio playback setup (Above) and example of a decoy used in the project (Below). Photo credits – Courtney Hamblin (CC BY – NC 4.0)

When the study had concluded, Courtney, and her supervisors Adrian Paterson (LU), James Ross (LU) and Richard Maloney (DoC), found that there was over nine times more activity recorded within plots with attractants than within plots that lacked any attractants.

Black-fronted tern nesting was also found to have occurred near eight out of ten treated sites. Of these, five sites had terns nesting within 300 m, which was significantly closer than distances from the untreated sites.

Unfortunately for me, as they were used together, there was no speculation on whether the decoys or the audio playback setup had the greater effect. So for now, I won’t be trading in my trusty wooden duck caller for a fancy electronic apparatus.

These results show that black-fronted terns do interact with social attractants. They could be useful for black-fronted tern conservation by helping to attract individuals into desirable areas to nest.

So social attractants could provide us with huge gains for black-fronted tern conservation, now that we understand all their neat uses!

Diagram of the treated plot – note there would be an equally sized area used for the untreated plots without decoys and speakers. Credit – Courtney Hamblin (CC BY – NC 4.0)

So what are the opportunities for social attractants? Endless!

Social attractants already have success stories. A notable win was their use in helping to restore the iconic Atlantic puffin to Eastern Egg Rock in Maine. But let’s ponder the future.

Think about the possibilities, such as their use in protecting species against climate change effects. Social attractants could readily be employed to move nesting locations away from at-risk coastal areas or encourage nesting within predator-proof sanctuaries to avoid exotic threats that are likely to arrive in New Zealand ecosystems.

Final thoughts

Even with all the prospective benefits, the study also made me think about issues that may arise with social attractants. Sure, they encourage some native colony birds to interact with them, but would this not be the same for native/exotic predators? They too key off cues from their target species, such as sounds and visuals.

This sparks memories of harriers circling over my decoys, ready to pounce on any shot birds, as if they were using my decoys as a marker for a prospective feast.

To me, this was a particularly poignant thought, which I would love to see investigated.

This article was prepared by Master’s of Bio protection student, Jonathan Morriss, as part of the ECOL608 Research Methods in Ecology course.

Hamblin, C., Paterson, A., Ross, J., Maloney, R. (2019). Social Attractants, a Conservation Tool for Black‐Fronted Terns. Wildlife Society Bulletin. 1-8. https://doi.org/10.1002/wsb.989

Additional Information:

Bonbaci, S., Pejchar, L., Innes, J. (2018). Fenced sanctuaries deliver conservation benefits for most common and threatened native island birds In New Zealand. Ecosphere. 9(11). https://doi.org/10.1002/ecs2.2497

Buxton, V., Enos, J., Sperry, J., Ward, M. (2020). A review of conspecific attraction for habitat selection across taxa. Ecology and Evolution. 10(23). 12690–12699. 10.1002/ece3.6922

Handley, S. (2022). Technical options for marine coastal habitat restoration in Te Tauihu. NIWA. https://www.envirolink.govt.nz/assets/Envirolink/2203-MLDC161-Technical-options-for-marine-coastal-habitat-restoration-in-Te-Tauihu.pdf

Herrera-Giraldo, J., Figuerola-Hernández, C., Wolf, C., Colón-Merced, R., Ventosa-Febles, E., Silander, S., Holmes, N. (2021). The use of social attraction techniques to restore seabird colonies on Desecheo Island, Puerto Rico. Ecological Solutions and Evidence. 2(2). https://doi.org/10.1002/2688-8319.12058

Lapin, K., Konrad, H., Leeb, C., Oettel, J. (2025). Species on the Move: Migration, Range Shifts, and Dispersal of Species. Ecological Connectivity of Forest Ecosystems. 23-38. https://link.springer.com/chapter/10.1007/978-3-031-82206-3_2

Taylor, G. (2000). Action Plan for Seabird Conservation in New Zealand. Department of Conservation. 16. https://www.doc.govt.nz/documents/science-and-technical/tsop16.pdf

August 21, 2026
Kiwi: now in 3D

‘Coming soon in 3D!’ Periodically throughout my life movie-makers have dabbled with making films that we can watch in three dimensions. You would get your special glasses before the movie session and then sit there wondering when to put them on until the action got going.

To be honest I don’t remember many of the movies that I saw like this. The Avatar movies have always had the option and I watched at least the second movie this way. Spears and monsters would lunge out of the screen at you.

Other than that I am drawing a blank. This is not to say that every 3D movie is bad but just that 3D on its own doesn’t make a film more memorable.

Avatar Adrian! Look out for the arrow!

I don’t even dislike the experience despite having to wear the 3D glasses over my own glasses. There is something immersive about dodging things ‘coming out of the screen’. However, I seldom choose this option if 2D is available. It all seems a bit too much like work perhaps?

Adding a third dimension can help with appreciating scale and movement though. It can also help with identifying who’s who in the screen – there’s just a bit more information that your brain can use.

Identifying individuals is a big deal in biology, especially conservation. When you have a small population you are interested in individuals. How are they doing? Are they breeding? Who do they hang out with?

Of course, for many species there are not a lot of features to differentiate between individuals. They are similar in height, uniform in coloration, and have similar behaviours.

To make them more distinctive we could always band our target with bright colours or paint an obvious mark on them but this involves capturing and interacting with the individual. This causes a great deal of stress and catching individuals is not always simple.

Ideally we could use cameras to take pictures that we could measure features in that are unique to an individual. Two dimensional pictures require an individual to be in an exact place with an exact orientation for this to work. So this is not a reliable method.

Bit wait! … Coming soon in 3D!

It turns out that if you take pictures with different devices from slightly different angles at the same moment then you can much more accurately calculate measurements on individuals. At least in theory.

Jane Tansell with her trusty kiwi dog. Picture from Jane Tansell.

Jane Tansell, a recently completed PhD student at Lincoln University, and her supervisors, Adrian Paterson and James Ross, set out to see if we could use this idea to identify kiwi. Kiwi populations and individuals are difficult to measure. They are nocturnal, usually found in scrubby terrain, are reasonably featureless, and spend a lot of time in burrows. We can use trained dogs to find them but this is quite stressful for kiwi. We can listen to their calls during the night but this is difficult to split into different individuals and certain parts of the population don’t call anyway.

Trail cameras have been used to successfully locate kiwi. Jane wondered if she could pair cameras 12-25 cm apart, taking images that could be used to essentially create a 3D image of features on each bird. Jane knew that kiwi bills vary between individuals and can be used as an ID.

Jane worked with the more technically literate Maurice Kasprowsky and Tom Gray to cobble together the cameras and get them to work together.

Jane, as reported in NZ Journal of Zoology, first tried the setup on a taxidermied kiwi in good light conditions. She found that the cameras could be used to measure the bills to within 1.5% of their actual length. This was a great achievement and would certainly be able to determine individuals.

In theory we should be able to photograph kiwi and recognise them by measuring their bills. Image from Adrian Paterson.

Jane then set up field trials with live kiwi. In the real world, with low light and moving birds the cameras were less efficient. At worst they were terrible but often they were within 3-4% of the actual bill length. This is not good enough to replace current field identification methods but it was still quite impressive given the relatively jury-rigged setup.

Improvements in cameras, especially 3D cameras, are happening quite quickly. With some more trial and error Jane should be able to start reducing the error enough for this to be a viable noninvasive method for following kiwi in the field.

While this is not as exciting as an arrow flying at you from an Avatar movie, this use of 3D does have real world uses that will help with understanding a national icon!

The author, Adrian Paterson, is a lecturer in the Department of Pest-management and Conservation at Te Whare Wānaka o Aoraki Lincoln University. Adrian is a kiwi but unfortunately has no bill to measure.

February 4, 2026
Tackling feral cats in Aotearoa New Zealand

Feral cats (Felis catus) are among the most proficient and effective hunters in the world. In Aotearoa New Zealand (NZ), their skills are lethal to native species that have evolved without mammalian predators. Feral cats have been linked to significant biodiversity declines across the country. Cats are opportunistic predators that hunt ground-breeding species, like birds, bats, reptiles and even some insects- many of which are endemic.

Fig 1: It looks like siblings fighting over a small bird, a moment that captures the competitive behavior of feral cats (Image by- Gilbert Mercier, Flicker User

The extinctions of six endemic birds are linked to feral cats. Well-known cases include a single cat, Tibble, that caused the extinction of NZ’s only flightless song bird: Lyall’s Wren on Stephens Island. A single cat killed 120 endangered native short-tailed bats in one week on Mt. Ruapehu. Dotterel populations on Stewart Island, Grand and Otago skink populations in southern ANZ are at risk due to feral cats. The list of species pushed to the verge of extinction by cats is long and growing.

Yet despite their impact, feral cats are not currently included in NZ’s Predator Free 2050 campaign. This raises a major question: how is NZ tackling the feral cat problem?

With growing concern for native wildlife, the government has implemented several methods to eradicate or control cats: lethal baiting, trapping, shooting, and fencing. While putting these methods into action is necessary, it’s equally important to ask their effectiveness: Are they actually working? And how can we tell?

Fig 2: Feral cat awareness at Arthur’s Pass Wildlife Trust (Photo credit: Muhammad Waseem (used with permission)).

These were the very questions a group of researchers from Lincoln University set out to explore. Using camera traps, they conducted a study on Hawke’s Bay farmland to test whether trapping and shooting could effectively control feral cat population, and whether the area will be re-invaded over time, to measure the effectiveness of the method.

Forty motion-sensitive cameras stood beside the traps like sentinels, monitoring everything. Cats walked into the view, lured by rabbit meat and ferret scent. The cameras recorded activities before, during, and six months after the control operation. Before the operation 20 cats were detected. 17 feral cats were then removed (shot). The result? An 84% drop in both cat numbers and camera detections.

Aware of the risk of reinvasion, the researchers monitored the site again six months later- and detected only three new cats. The outcome was encouraging and demonstrated how proper methods combined with well-monitored action can make real difference. With the help of camera traps, the research could measure the effectiveness of the control operation and can suggest similar methods in areas facing feral cat issues.

Today, thanks to advanced technology like camera traps, monitoring has become much more efficient and convenient. This allows conservationists to evaluate their methodologies, observe activities remotely, and respond effectively.

How did cats become a serious ecological problem in NZ?

In my home country of Nepal, cats are seen as beloved pet and, traditionally, the guardians of grain stores, not as an ecological threat. As someone new to NZ conservation practice, I initially found the conservation method used in this study confronting. But the more I learned, the more curious I became: how did a country with no native mammalian predators come to see cats as such a serious problem?

Fig 3: Stray cat basking sun on Fairmaid Street, Lincoln (Photo: Author 04/01/2025)

Cats didn’t arrive in NZ until the mid-1800s. Earlier cats had visited along with Captain James Cook. His ship, plagued by rodents, carried cats as a solution to control pests and protect food supplies.

European settlers brought cats as companions. Some escaped or were abandoned, eventually forming a wild population. Ironically, many animals (and even people) arriving by ships ended up becoming invasive. Over time, their arrival became strongly linked with biodiversity loss.

Today the feral cats are officially recognised as invasive predators. They not only kill native wildlife but also spread disease. It is no coincidence that many native birds began to disappear after cats were introduced. In the NZ conservation story, it’s not unusual to say: “To solve one problem often means creating another!”.

Although some early impacts were noticed, such as the extinction of the Stephen Island wren, surprising these events were simply viewed with the mindset as nature improving, where invasive species were seen as improvement rather than threats.

Cats, whether brought to control rodents or to ease the settler’s solitude, may have served a short-term purpose, but over time introducing them proved to be a double-edged sword, causing severe harm to NZ’s native wildlife.

Learning this made me realize that today’s conservation challenges are deeply connected to historical choices!

Moving ahead

While we cannot re-write history, we can certainly learn from it!

Fig 4: Who decided which story to tell? The Great Hall stained-glass window at University of Canterbury made from 4,000 pieces of glass, showing Captain James Cook at number 19 (Photo: author 02/05/2025).

The journey of cats in NZ is a classic reminder of how small actions can have a large ecological impact. The feral cat issue isn’t just about one species nor is it the only invasive challenge NZ faces, it’s about how we approach conservation in a complex and ever-changing environment.

Looking back, we don’t know how much damage to NZ’s biodiversity could have been prevented or reduced if the scale of damage was understood earlier. As the country continues its battle against introduced species to conserve biodiversity through Predator Free 2050 campaign, integrating reliable monitoring tools like camera traps will be crucial in making informed and effective conservation decisions.

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

Paper reference: Nichols, M., Glen, A. S., Ross, J., Gormley, A. M., & Garvey, P. M. (2023). Evaluating the effectiveness of a feral cat control operation using camera traps. New Zealand Journal of Ecology, 47(1), Article 3501. https://dx.doi.org/10.20417/nzjecol.47.3501

December 1, 2025
The three bird-iteers: all for monitoring and monitoring for all!

My time at Lincoln University has taught me that when it comes to bird monitoring, the most common practice is the 5 minute bird count (5MBC). This method is a simple and effective way of counting birds within a specific area by recording sightings and calls. Much of the time, using 5BMC, it is likely that you will not see the bird you are hearing, which is why being able to identify New Zealand birds just by sound is a very good skill.

Lincoln University legend Jon Sullivan did a study on different bird data collection methods that could also mahi together to build a more accurate picture of birds in an area. The study focused on wider Christchurch, beginning in 2003, and recorded patterns in bird species within the area.

One method that was used was the stationary method , which is pretty much the same as the 5MBC but is extended to 20 minutes. The other method used was the ‘mobile method’, also known as the ‘line-transect method’, where you collect data while moving at a fast pace, perhaps by bike, car, or running.

Now to the fun stuff – birds!!

In Jon’s study there was a focus on three bird species, which I call the three bird-iteers (with apologies to Alexandre Dumas). These are the grey warbler, fantail and the bellbird. These endemic birds are very adaptable to recent changes for forest bird species.

Grey Warbler

The grey warbler (Gerygone igata, riroriro) are found throughout New Zealand. They are small, grey/brown with a more pale shade of grey for the face to throat. They weigh approximately 6.5 g (lighter than a mouse) and their diet consists of insects and spiders.

Grey Warbler. Photo CC BY Mikullashbee, Flickr

Fantail/pīwakawaka

Fantails are one of my many favourite bird species, as they love to follow humans around when you are on bush walks. Fantails are able to adapt to environments that have been changed by humans, which is not very common for New Zealand native birds. Fantails (Rhipidura fuliginosa, piwakawaka) are often found in open native bush, exotic plantation forests, orchards and gardens. Their diet consists of insects, especially small species. Fantails are a small bird about the size of a house sparrow, but what makes them so distinctive? Well the answer is in their name…. Yes their tails, like their name suggests they have a long tail that fans out like a well a fan.

Fantail. Photo CC By Chris S, Flickr

Bellbird/ Korimako

Bellbirds(Anthornis melanura, koromiko)are commonly found in the South Island. These birds have a short, curved beak and are green with a slightly forked tail. Bellbirds, similar to Tūī’, have a distinctive song, it is like a high ringing that’s also kind of smooth, and the repeat the same tune. Bellbirds reside throughout native and exotic forest, scrubs and shelter belts of New Zealand. Their diet is nectar from native and exotic plants, although they do consume fruit in late summer and autumn. Also their diet consists of honeydew that’s found on beech trees.

Bellbird. Photo CC By Glenda Rees, Flickr

Back to the study

Jon Sullivan wanted to understand how nature responds to a forever changing world. He collected distribution and abundance information for many species with these three species being the focus. This is where the methods came into play as a standardised method and a repeatable one is needed to accurately tell us if a species is present or not. The methods talked about above were to work alongside each other.

Around 100,000 bird counts were collected. The approach used helped to summarise data that was from one location, a certain time each week, and one daily route. The results showed that this approach was effective and just as effective as the 5 minute bird count. Counting birds while riding your bike along a road was just as effective at estimating and following trends as more traditional methods.

Fantails, grey warblers, and bellbirds (but not to the same extent as the other 2) are majorly restricted to their forest biotopes and native plantings, particularly in spring.

Like any good study, more data are needed to get a better and clearer understanding. This could create a good opportunity at Lincoln University to teach students doing ecology to learn how to use different techniques besides just the 5MBC methods. Then we too can collect decades long information on our favourite birds.

This article was prepared by postgraduate student Caitlan Christmas, Masters of Science in Ecology and Conservation, for an assignment in ECOL608 Research Methods in Ecology.

Sullivan，JJ（2012). Recording birds in real time: a convenient method for frequent bird recording https://researcharchive.lincoln.ac.nz/server/api/core/bitstreams/04dc8df3-2e34-4fe9-96a6-ea8a505ad0cc/content

November 11, 2025
Silent hunters on the wetland edge: urban cats and nature conservation

The dark side of the cat

Cats doing what cats do.
Photo by Robert | Visual Diary | Berlin on Unsplash

In the autumn evening, a cat lies on the fence, with focused eyes and slightly wagging tail, this patient hunter is quietly locking onto a target and preparing to attack.

Cats are the standard feature in almost neighbourhoods in New Zealand. They are elegant, lazy, affectionate, and sometimes unpredictable. Some of them are pretty welcomed , moving freely around neighbourhoods everyday, accepting feeding and petting.

Behind these soft furs and friendlypurring, there is an ancient, untamed instinct hidden – hunting. Hunting is not just about hunger. Most cats were are well-fed—some are even fed multiple times a day. Yet, the urge to stalk, chase, and kill remains.

Travis Wetland: A natural island in the city

Wetlands, green spaces, and bushes are the last shelter for local plants and animals. These “ecological islands” are often located right next to the communities where we live.

Travis Wetland is a freshwater ecological oasis, located on the edge of Christchurch. Surrounded by residential areas, roads, and commercial development, it remains a vital refuge for more than 53 species of birds and many native invertebrates.

Living around this wetland, there are hundreds of free-moving domestic cats living. They can walk through the grass without permission, quietly enter the ecological core area, and become hunters of these small lives.

A Patient Hunter
Photo by Kristin O Karlsen on Unsplash

Silent pressure & hidden trail

It is easy for people to imagine a cat lazily lying in the sun by a windowsill, but what about the other side of their life when they step out the door?

Over the course of a year, 21 pet cats living near Travis Wetland were installed with GPS collars as part of a study by Lincoln University and the Christchurch City Council. The research, led in part by Shelley Morgan and Adrian Paterson, revealed some surprising results.

Researchers did not capture many cats with prey in their mouths (although more than a few did bring their prey back to their home). But there were other situations: cats were often visiting the edge of the ecological core of the wetland, where native birds, lizards and insects breed.

Fantail(Rhipidura fuliginosa)
Photo by Callum Hill on Unsplash

The cat threat does not necessarily come from killing, sometimes, just “attending” is enough. Birds may abandon their nests if they sense a nearby predator. Lizards may interrupt their mating if they feel targeted. In nature, energy is precious, and fear itself is also consumes energy.

More than half of the monitored cats entered Travis wetland at least once. Some of them went more than 200 metres into the wetland while their owners sleeping, crossing habitats and breeding areas for rare native lizards, insects and ground-nesting birds.

More than half of the monitored cats entered Travis Wetland at least once. Some of them went more than 200 metres into the wetland while their owners sleeping, crossing habitats and breeding areas for rare native lizards, insects and ground-nesting birds.

But not every cat causes the same amount of harm.The study found that younger cats—those under six years old—were more active and risky. They travelled further, spent longer inside the wetland, and brought home more prey. Some even swam across water to reach nesting islands. In contrast, older cats tended to stay near home and moved less.

A small number of energetic cats were doing most of the damage. Researchers called them “super-predators”. This suggests that cat behaviour and age both matter. While most cats seem harmless, a few individuals can quietly cause serious impacts to local wildlife.

This means the cat you see curled up by the fireplace in the afternoon may be walking the narrow line between urban life and ecological harm at night. It’s not the cat’s fault, and it’s not your fault, but it’s keep happening.

Cat by the Window
Photo by Aleksandar Popovski on Unsplash

Night walkers & tiny bells

Cats are typical “crepuscular” animals, that is, they are most active in the dawn and dusk. This explains why you see cats running around the living room at 10 pm or staring at the wall at 5 am. They don’t listen to a clock, they listen to the call of instinct.

Sunset and just after is also the time when many cats go out for their “night patrols”. According to the data from the study’s cat GPS tracking, cats move more frequently and walk farther at night. Some cats hardly go out during the day, only sneaking through the garden and visiting the fields after dark.

So, what can we do to reduce the impact of out furry friends? Some owners hang small bells on their cats’ collars, hoping that the sound will alert potential prey and give them time to escape. This method seems simple and effective, but the effect actually varies from species to species.

There is a study by University of Otago have shown that bells have a certain deterrent effect on birds and the study by Geiger shown that have little effect on lizards or insects because they are not sensitive to sound. Also some smart cats can even learn to “walk silently” – so that the bell doesn’t ring at all.

Nightwalker Cat
Photo by amir esfahanian on Unsplash

So, while bells may help a little, they are not a panacea. As with everything in this story, the answers are never simple.

Draw a ceasefire zone

Some solutions are simple, and others need some creativity.

In some parts of New Zealand, there is talk of creating a cat-isolation buffer zones — areas around nature reserves where cats are either required to be kept indoors full-time, or where cats are banned or a curfew(Wellington City Council. 2024) is imposed on cats near reserves (although curfews seem not work for protecting birds or lizards)

This idea is not to punish cat owners but to protect the most vulnerable parts of the ecosystem. Because may be the problem is that house cats may be found curled up in warm blankets, purring softly, eyes half-closed, and when just hours earlier, those paws may have landed a fatal blow on a small bird, or pinned a native skink to the ground.

Free-roaming cats in New Zealand are subject to different local management depending on their relationship with humans (such as companion cats, stray cats, and wild cats), but there is currently a lack of unified national laws(Sumner, C. L. 2022).

Threatened-Nationally Critical Skink: Alborn Skinks(Oligosoma albornense)
Photo by James Reardon

Some newly built areas even state in the purchase agreement that cats are not allowed to roam freely, and sometimes even completely prohibit cats(Preston, N. 2023).

To some people, such regulations may sounds really extreme. But to naturalists, it is a way of respecting boundaries, a quiet commitment to leave even a small area and keep distance for the creatures that have lived here long before we came here.

We would much rather have this scenario: ‘In the autumn evening, a cat looks out of a window at a fence, with focused eyes and slightly wagging tail, this patient hunter is quietly locking onto a target that it would love to attack. Frustrated, it curls up and goes back to sleep.’

This article was prepared by Master of Pest Management postgraduate student Linfeng Yu as part of the ECOL608 Research Methods in Ecology course.

Research paper: Morgan, S. A., Hansen, C. M., Ross, J. G., Hickling, G. J., Ogilvie, S. C., & Paterson, A. M. (2009). Urban cat (Felis catus) movement and predation activity associated with a wetland reserve in New Zealand. Wildlife Research, 36(7), 574–580. https://doi.org/10.1071/WR09023

References

Geiger, M., Kistler, C., Mattmann, P., Jenni, L., Hegglin, D., & Bontadina, F. (2022). Colorful Collar-Covers and Bells Reduce Wildlife Predation by Domestic Cats in a Continental European Setting. Frontiers in Ecology and Evolution, 10. https://doi.org/10.3389/fevo.2022.850442

Housing development near Auckland imposes cat ban to protect wildlife. (n.d.). 1News. Retrieved 5 May 2025, from https://www.1news.co.nz/2021/08/11/housing-development-near-auckland-imposes-cat-ban-to-protect-wildlife/

Preston, N. (2023, July 1). No cats allowed: Growing number of new neighbourhoods banning pets. Oneroof. https://www.oneroof.co.nz/news/no-cats-allowed-growing-number-of-new-neighbourhoods-banning-pets-43855

Responsible cat ownership. (2024, October 17). Wellington City Council. https://wellington.govt.nz/dogs-and-other-animals/cats/responsible-cat-ownership

Sumner, C. L., Walker, J. K., & Dale, A. R. (2022). The Implications of Policies on the Welfare of Free-Roaming Cats in New Zealand. Animals, 12(3), Article 3. https://doi.org/10.3390/ani12030237

October 22, 2025
Cat conundrum: Conservation, cameras, and capricious companions

You are probably well aware of the feral cat issues here in Aotearoa New Zealand and the detrimental impact that cats are causing in our unique whenua (land). However, if you are new here, let me get you up to speed. The popularity of these adorable companions –1,134,000 companion cats and 196,000 strays, to be accurate – has come with a tremendous cost to native wildlife in Aotearoa New Zealand.

With over a decade of experience in the veterinary industry, I’ve witnessed animal welfare concerns from both perspectives. I’ve seen the devastating impact cats can have on native wildlife, as well as the suffering of unwell, neglected feral cats. This dual perspective made becoming a cat owner myself all the more meaningful, thanks to a foster failure named Professor (pictured below), who quickly stole my heart. After adopting him, it was an easy decision to create a comfortable indoor life for him. Knowing the toll that cats can take on wildlife populations and thinking about his health and safety, it was an obvious decision for me to keep him as an indoor cat. But unfortunately, 196,000 cats in Aotearoa New Zealand do not have the cushy indoor lifestyle that Professor has become accustomed to.

Learn about what the experts have to say on cat management here: https://predatorfreenz.org/stories/animal-welfare-agencies-views-on-cat-management/

Professor the foster failure. Original image by Chloe Mc Menamin.

Now what does the science say about monitoring cats that don’t have a cushy indoor lifestyle? In 2019 a team of scientists at Lincoln University carried out a study to better understand just that. They deployed a camera detection system across two pastoral sites in the Hawke’s Bay region. One system was placed systematically (on a grid) and the other strategically (placement where the researchers believed cat activity would be the highest). Their goal was to compare which camera trap placements would be the most effective method for monitoring feral cat populations. While feral cats are notoriously difficult to detect due to their low densities and cryptic behaviours, these researchers did get some interesting results!

During a telephone interview, with primary author Dr. Margaret Nichols (Maggie), Maggie cheerfully shared how she began to question the use of her time after processing countless images of hedgehogs enjoying the smell and feel of the ferret pheromones used to lure in the cats. Then things took a surreal turn when she found herself pondering reality itself—prompted by turkeys performing what looked suspiciously like synchronised dances.

But, dear reader, that wasn’t the only captivating creature caught on camera. No! The top-featured animal was… you guessed it… a sheep! Yes, you read that correctly. A single sheep nearly drove Maggie to madness after it camped out in front of one of her cameras for four entire days, triggering over 500,000 images. Poor Maggie! I’d be pulling the wool from my jumper too if I had to process that many sheep shots. Surprisingly, cats turned out to be the least detected animals of all—truly showcasing their cryptic behaviour and highlighting just how important this research was to carry out.

Against all odds Maggie and her colleagues persevered – through the thousands of sheep, hedgehogs and dancing turkey’s images to reveal a striking discovery. Camera traps placed at the forest margins detected more cats compared to those in mixed scrub or open farmland. Specifically, at forest margin an average of 3 cats were detected per night at Site 1 (Toronui Station made up of a mixture of open farmland and native forest) and 1.7 cats at Site 2 (Cape to City ecological restoration area). This compelling pattern suggests that strategic placement of cameras in these areas is likely to maximise cat detection. Hats off to Maggie and the team, what a cool discovery.

Hedgehog self-anointing after contact with the pheromone. Image source Research Gate (Garvey., nd)

Well, there you have it reader – strategic camera placement at forest margins in the Hawke’s Bay area is the most effective way to monitor feral cats, but this is just the beginning of cat monitoring research in Aotearoa New Zealand. If you are like me and feeling inspired by Maggie and her colleagues’ findings, you might also be wondering where to even start tackling the feral cat population in your local area.

While science and data are fascinating, the telephone interview with Maggie wisely reminded me that the best part of her research experience were the organisations and the people involved along the way, particularly the Hawke’s Bay Regional Council , Predator Free South Westland, and Lincoln University. She reported that working with various stakeholders made the project not only successful but also deeply rewarding. She also noted that all research projects take more time than you think and to never underestimate the possibility of processing 500,000 sheep photos when doing camera monitoring!

Image of feral cat caught on camera during study. Orginal image provided by Dr. Margaret Nichols

What a great reminder that in life it’s not just about success or how long things take; it’s about the experiences and friendships you make along the way. Thank you, Maggie, for sharing that wisdom.

This article was prepared by Postgraduate Diploma in Applied Science student Chloe McMenamin as part of the ECOL608 Research Methods in Ecology course.

Now reader it is over to you, want to learn more about how you can help? Check out the The National Cat Management Strategy Group, or if you want to learn more about feral cats here in Aotearoa New Zealand check out what the Department of Conservation has to say.

Read full study here:
Nichols, M., Ross, J., Glen, A. S., & Paterson, A. M. (2019). An evaluation of systematic versus strategically-placed camera traps for monitoring feral cats in New Zealand. Animals, 9(9), 687. https://doi.org/10.3390/ani9090687

Image refernce:

Garvey, P,M. (nd). FigS3: Hedgehog self-anointing after contact with the pheromone/kairomone vial [Supplemental material]. ResearchGate. https://www.researchgate.net/publication/311713979_FigS3_Hedgehog_self-anointing_after_contact_with_the_pheromone_kairomone_vial

October 7, 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
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