Category: conservation

  • Wings of change: Protecting parrots where they belong

    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.

    Indian Rose-Ringed Parakeet
    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!

    Kea
    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

  • Keeping up with the Kiwis: Translocations and their forever holiday homes

    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

  • Forests from grass: natural regeneration of woody vegetation on hill farms

    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…

    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 SchmurrCC 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.

    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

  • Kiwi Hedgehogs : A Journey of Curiosity and Connection

    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

  • Never ask a lizard its age (Calculate it using science!)

    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 I3S 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 I3S 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.

  • A Knobbly Future?

    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 Des Helmore.
    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.

  • Under Cover of Darkness: Moon Brightness and Mammalian Predator Activity

    Under Cover of Darkness: Moon Brightness and Mammalian Predator Activity

    Written by Kate McDowell

    Last June, I found myself several hours into what would end up being a sixteen-hour run, in the middle of the night, on the coldest weekend of the year. As the ground visibly started to freeze in front of me, I realised that my head torch was struggling in the negative temperatures. Its battery couldn’t cope with the cold exposure. But you know what, I had a trick up my sleeve; it was a full moon.

    I was guided by the incredible illumination of the moon on a clear winter night, and by how few animals I saw apart from the sheep and cattle of Lake Taylor station. As I left the station and entered Lake Sumner Forest Park, my headtorch flickered in the biting sub-zero temps of mid-winter New Zealand near the Southern Alps. I had barely heard a sound since nightfall, apart from my own crunching footfalls on freshly frozen tussock.

    There were no pest animals dancing in the moonlight that chilly midwinter run, and I found myself wondering if our mammalian pests changed their activity based on how bright that big ball of cheese in the sky was. In 2016, Shannon Gilmore did a neat study on the effects of moon phase and illumination on activity of five introduced NZ mammals (cats, rats, mustelids, possums, hedgehogs) for her thesis at Lincoln University. 

    A trail runner foolishly runs 16 hours over an alpine pass, whilst being watched by introduced predators who may or may not be contemplating consuming the body of said runner. [Source: Chat GPT AI, Kate McDowell]

    I seemed to be one of the few introduced mammals blatantly puffing my way up the North Branch Hurunui riverbed. I have this strong memory of looking down and watching myself be followed by my own moon shadow. It made me question – how many eyes were following me in the dark canopy of the nearby beech forest?

    Gilmore found that increased vegetation cover and rain were contributing factors to pest detection. Sites with dense canopies had higher detection rates, potentially because they provide better shelter and reduced exposure from threats like light. While rainfall was not a statistically significant factor, pest activity generally decreased with rainfall. Gilmore suggested this may be because it is cold or the rain might be disrupting the animal’s sense of smell.

    So maybe my paranoia about forest animals staring me down wasn’t so crazy after all. It was certainly interesting to think back on the run and how many introduced predators there could have been in the nearby beech forests. The conservation implications for understanding where predators are and why they might change their activities also gave me some things to mull over the next day.

    Detecting these introduced predators is essential for informing control efforts; we need to know where predators are and how many of them are in a given area. Environmental conditions may be obscuring the predator’s true activity levels. Gilmore added to previous studies of moon phase effects on mammals by accounting for interaction effects of weather and vegetation. Whether these effects were caused by the lower light levels or by something else not explored in this study is yet to be answered.

    Many studies have looked at the role of moon phase and animal activity, but in 2016 few studies had investigated the additional factor of the moon’s brightness. Gilmore was the first to measure hourly light levels through the night and looked at how it affected the activity level of the nocturnal pest species. A highly sensitive light meter (Sky Quality Meter, or SQM) to measure illumination levels between moon phases in the Blue Mountains (Otago), Banks Peninsula (Canterbury) and Hawkes Bay.

    Gilmore found that while moon phase could not explain pest activity, moon illumination did. As the dark side of the moon grew larger, pests seemed to thrive under cover of darkness and became far more active. When the moon hits a mammal’s eyes, Gilmore theorised that they may be spurred to hide. Most introduced mammals in NZ are prey in their native countries and it is hard to say whether a single century of living without their native predators has changed their behaviour.

    SQM successfully managed to detect differences in illumination between moon phases and under different canopy cover levels. Canopy cover was found to have a larger impact on illumination than moon phase. SQM findings on Banks Peninsula suggested that on darker nights a pest is more likely to be active.

    Building on earlier research, Farnworth, Innes and Waas (2016) released a paper looking at the effect of light on mouse foraging behaviour. This study agreed with Gilmore’s results, finding that mice displayed strong preferences for foraging in unlit areas. Farnworth et al. further built on Gilmore’s conclusions by contemplating that artificial light could provide protection from predators in ecologically sensitive areas – for instance, in areas where predator proof fences have been breached by a tree limb dropping on it.

    Predator proof fence study by ZIP scientists showing a rat trying to escape. [Source: ZIP (Zero Invasive Predators Ltd), used with permission]

    The innovative organisation Zero Invasive Predators (ZIP) completed an interesting follow up study in 2018, focusing on whether or not light could deter rats from entering an area. They found that although light did not limit rats passing through, they were less likely to linger in lit zones. Their conclusion: illumination could be used in a layered deterrent system, where light is used to slow down pests.

    Conservation in NZ is generally hamstrung by lack of funding. Efficiency is key to making the most of the meagre dollars on offer, so studies like Gilmore’s can help optimise monitoring and control operations. So when that bad moon comes a-rising, you can bet that pest control and monitoring will be less effective, and it would be more useful to focus efforts during darker nights.

    I definitely felt exposed running through a riverbed under a full moon, so I can appreciate how light can serve as a useful predator deterrent. It’s another tool we should add to the belt as we work toward a predator-free country.

    We’ve reached the end of our illuminating lunar article, but the real question now is how many song references did you pick up on? 😉

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

    Paper: Gilmore, S. (2016). The influence of illumination and moon phase on activity levels of nocturnal mammalian pests in New Zealand (Master’s thesis, Lincoln University).

  • Detecting red panda, dancing with Kate Bush

    Detecting red panda, dancing with Kate Bush

    I’ve been a fan of Kate Bush since she released ‘Wuthering Heights’ when I was 10 years old. She famously does not tour or give shows and so I have never had the chance to see her live. A couple of weeks ago a tribute act ‘An evening without Kate Bush’ came through Christchurch. Great! I booked tickets and dragged Julie along.

    My wife is a long suffering SOKF (spouse of Kate fan), but she was happy to indulge me. Little did she know what was in store. It was a great show. Sarah-Louise Young danced and sang very well and was quite funny. Kate Bush always walks a fine line between quirky and bonkers. The Piano audience had a good time.

    The show was quite interactive. At one point Sarah-Louise asked what our favourite Kate song was. I stuck up my hand and she came over. In addition to the song (Get out of my house), she was interested in whether Julie was a fan (not particularly) and how long we had been married (30 years).

    As she turned to go, Julie added “Oh and Adrian proposed to me in a Kate Bush way.” Well that was that. Julie was then explaining The Dreaming album cover, the ring, the kiss and so on. Much hilarity ensued.

    The show continued on. We got to ‘Don’t give up‘, the song sung by Peter Gabriel with Kate. Sarah-Louise wanted a couple to come onstage and of course that was us. We had to slow dance for the song (much as happens in the video). That’s 6.5 minutes, or an eternity on the stage.

    So, there we were, literally, in the spot light, in front of 325 people. I didn’t find it too bad. I focused in the dancing and not tripping over. Julie was very uncomfortable and most definitely not herself. We reflected later that I am more used to ‘performing’ as a lecturer in front of crowds. Julie is a teacher but only has much smaller groups to perform to.

    I think that we did OK. It turned out that there were a couple of people in the audience who new us and messaged that we did some good dancing (probably they were just happy that they hadn’t been picked to do it).

    As we quietly swayed and turned on stage I did reflect on how the knowledge of being observed really does affect the behaviour of individuals. This links through to my research where I am often making observations of individual birds and mammals.

    A gaggle of red panda! Image from Sonam Tashi Lama

    Recently, we have been using trail cameras to get a better understanding of red panda, and other mammals, in their habitat of eastern Nepal. In these areas red panda are relatively cryptic and declining. Grids of cameras offer a way of observing red panda over long periods of time without humans needing to be nearby.

    Cameras can tell us about the distribution of species over daily and seasonal cycles (Collecting mammals: camera traps in eastern Nepal). We also observed that panda do notice the cameras and that this can lead to subtle changes in their behaviour (I see you: Sauron and the panda).

    In this work with Sonam Tashi Lama (Red Panda Network), and published in the Wildlife Society Bulletin, we set up 19 sites in the alpine forests of eastern Nepal. At each site we had two cameras, one set up in a typical manner at ground level and the other in the tree canopy 5 m above. The cameras collected data over several months.

    We found that red panda were active over the whole day (gotta eat a lot of bamboo and other vegetation!) but activity peaked around dawn and again at midday.

    Arboreal cameras took four times as many photos as ground cameras. These were mostly of leaves blowing in the wind but they were eight times more effective at capturing red panda images. These behaviours included action activities (e.g. tree climbing), clear images of faces, and motion‐lite activities, like sleeping and grooming.

    Image from Sonam Tashi Lama

    So, now we know that cameras can affect the behaviour of red panda being observed and that the placement of the cameras can affect how successful our observations are. Is this a problem? Perhaps, but it is better to know there is a problem when we conduct future research. Also, the information that we are gathering, even if there is some biases, is still way better than not knowing anything.

    We will take the net gain in what we now know about red panda and that can help us with managing them and their habitat.

    It was nice to be reminded about how it feels to be observed. Whether it is 300 Kate Bush fans or a trail camera, there is a physical reaction to knowing that something is out there and perhaps it is watching you. It’s something to keep in mind when designing these studies.

    Oh and don’t put your hand up when you are in the audience of these kinds of interactive shows!

    Adrian Paterson is in the Department of Pest-management and Conservation at Lincoln University. Now that he thinks about it, he has spent a lot of his research prying into the private lives of animals.

  • How to help lizards in your back yard/paddock

    How to help lizards in your back yard/paddock

    Has your cat ever brought in a nice present only for you to find it’s a lizard? Have you seen a lizard scutling away on a nice sunny summer’s day while walking around the garden? Well, you may have lizards residing in your back yard!

    In New Zealand we have over 125 different lizard species, 76 are skinks and 48 are geckos, all but one one skink species is native. Of these 126 species, 49 (~36%) are Threatened and a further 67 (~50%) are At Risk (Hitchmough et al., 2021). Therefore 86% of our lizard species are threatened by various factors, such as predation, urbanisation, habitat fragmentation, and agricultural intensification.

    We all need to play our part to ensure that lizards do not continue to decline.

    There are simple tools we can use that can help the lizards in our back yard. Skinks love to hide under rocks and in small gaps when startled. Geckos love to live in tight crevices, like spaces in wood, stone and even in various human-made structures (e.g. power boxes and garages).

    We can create structures called Artificial Retreats (ARs) that mimic these natural retreats that lizards love so much. Artificial Retreats are a tool that we can easily implement that can support vulnerable lizards.

    Currently, artificial retreats have been designed for scientific monitoring and are commonly constructed from roof-cladding Onduline sheets, which isn’t an easily accessible or cheap material. My thesis investigated two other alternative designs that are constructed in a manner that is easily accessible to landowners and public members keen to do their part in lizard conservation.

    One AR type was constructed from a stack of three bricks (Figure 1) that have a 10 mm wooden dowel stuck between each layer so that the lizards can easily move between them.

    The second was constructed from two plywood sheets (Figure 2), bolted together, with the 10mm dowel in between the sheets.

    The third was the common Onduline design (Figure 3). I tested these ARs across Canterbury farms located at Cleardale Station in the Rakaia Gorge, as well as Flea Bay and Goughs Bay on Banks Peninsula.

    I captured 26 lizards to test in the three AR designs and there was no preference among the three. However, the geckos at Cleardale Station preferred some designs more than the Flea Bay lizards. At Flea Bay, the lizards were more commonly found in the brick (46%  of all geckos) whereas at Cleardale they didn’t use the brick ARs. At Cleardale Station, a equal number (17%) were found in both Onduline and wooden ARs. At Flea Bay, 17% lizards were captured and only 4% of lizards were found in the Onduline design at Flea Bay.

    Depending on the location of the property and the species of lizards present, there will be differences in which AR they prefer. Having an option of several different AR designs is preferable. 

    During the field trials I found that the ARs did not withstand heavy stock (cattle)interactions and were frequently interfered with. However, I did not have any problems with ARs placed in sheep paddocks.

    Landholders can implement any or all three of the designs into their property and all have a chance of lizard occupation. A variety of designs means that landholders can choose which AR design to use based on what available materials they have.

    Having a choice of AR designs make it accessible to whomever wants to conserve lizard species on their properties without having to spend large amounts of money or spending valuable time having to source the materials to construct the AR.

    Key design components and considerations when planning and building lizard ARs.

    • The ARs need to have at least one gap that has a 10mm gap.
    • Placed in an area where lizards or their poo have been seen.
    • Recommended not to be placed in a paddock in cattle.

    Acknowledgements: A massive thank you to the financial support for this project from The Brian Mason Trust and the North Canterbury Forest and Bird Trust.

    Reference

    Hitchmough, R., Barr, B., Knox, C., Lettink, M., Monks, J., Patterson, G., Reardon, J., van Winkel, D., Rolfe, J., & Michel, P. (2021). Conservation status of New Zealand reptiles, 2021.  

    Written by Sam Fitzgerald, a MSc student in the Department of Pest-management and Conservation at Lincoln University.

  • Collecting mammals: camera traps in eastern Nepal

    Collecting mammals: camera traps in eastern Nepal

    Collecting things seems to have deep roots in the human brain. There are few things more satisfying than finding something unexpected that you really need for your collection. The shock (woah!), the excitement (at last!), the surprise (how did this get here?), the urgency (I better grab this before someone else does), even though anyone standing close to you probably won’t care about this!

    My youngest son had a few years of thrifting where he would scour second-hand stores for ‘cool clothes’ that he could buy and then sell on for a reasonable profit to people who wanted that retro look but didn’t want to spend time searching. Edgar trained me up to spot certain brands, labels, styles and so on. For about five or six years I spent a lot of time browsing ‘dead peoples’ clothes’ as my middle son Arthur called them. I still remember a great trip with Edgar as I took him to a university semester in Dunedin. We struck gold in Waimate (a little off the beaten track) and found 30+ items!

    A small selection of Tanith Lee.Active from the 1970s till the 2010s – prolific and great for collecting! The Winter Players and Companions on the Road are two of my favourite (short) books ever. Image from Adrian.

    What do I collect? I guess there is a distinction between hobbies and collecting? I have a lot of small plastic figures that I love painting but I am not searching for some elusive or rare halfling commando. I buy a lot of boardgames and there are some older games that I might keep an eye out for, but I would count these as hobbies not collecting.

    Books, I have a lot of books…. Some of that is hobby – reading the latest books by Tad Williams or Lindsey Davis, for example. But I definitely collect some authors (Tanith Lee, Robert Howard) and spend time in second hand book shops with a list…. I still remember the day that I found the original D&D colouring book in absolutely mint, uncoloured condition! So rare! So elusive! All mine! (Sadly it has somehow gone missing from my collection in recent years!).

    Collected on camera – a red panda. Image by Sonam Lama

    As a zoologist interested in natural history, you are also dealing with collecting. Typically you want to collect the types of species found in an area. This tells us a lot about species diversity and richness, conservation, ecological interactions, evolutionary adaptations and so much more! This collection could be physical (like the hundreds of thousands of insect specimens found in our LU Entomology Research Museum) or it could be observational, where spotting an individual from a species can be logged (like with iNaturalist). But it certainly scratches the collecting itch.

    Observations can be direct (e.g. I saw that animal) or indirect (e.g. I found a footprint of that animal). Either way these are data that tell us that a species is found in the area. We are increasingly relying on indirect methods to collect observations – in fact much of our wildlife research here in Pest-management and Conservation is around developing better ways to monitor our mammal pests.

    Sonam Lama was a Master of International Nature Conservation student at Lincoln University. He had spent a lot of time working for the Red Panda Network back in Nepal. As part of his research, with Adrian Paterson and James Ross, he was interested in being better able to monitor red panda in the wild (but that will be another story!). Sonam was also keen to find what other species share the red panda habitat in far eastern Nepal. Were there many predators? Were there many competitors?

    Sonam in the forest of eastern Nepal. Image by Sonam Lama

    Sonam worked within the high altitude (between 2-4000 m abs) forests of Ilam, Panchthar and Taplejung, which provide a corridor between the rest of Nepal and India. Over this large area Sonam identified sites where he could put his 60 cameras. Typically the cameras were attached to the base of a tree. Observations from these camera traps were made through winter and spring. Results have now been published in the European Journal of Wildlife Research.

    So what did Sonam collect? Over 3000 camera trap days about 90000 images were recorded. Two thirds were false triggers (vegetation moving in the wind, sudden changes in temperature with sunrise and sunset) – such is the bane of the camera approach. About 11000 were of local people moving through the forest. Amongst all of this were over 5000 images of mammals, including 23 different species, and 3600 images of birds, including 37 species.

    Seventeen of these mammals were medium to large and could be identified. Red panda were observed. The commonly seen species were a deer – northern red muntjac, wild boar and leopard cats. The rarest were other cats: marbled cat (first record in Nepal), Asiatic golden cat and common leopard. The spotted lingsang was also collected for the first time, as was the first melanic (black) leopard.

    Collecting images and video also allows us to look at behaviour. We can get a sense of when species are active. We can see which species move around in groups. Wild boar foraged for tubers in front of the camera, red panda marked their territory, two porcupines mated! Red panda and macaques were active during the day, red foxes and porcupines were nocturnal.

    Collected on camera, a melanic form of leopard. A first for the region. Image by Sonam Lama.

    All of these collected images and videos provide little snapshots of natural history for these species, many of which are difficult to find any other way. Our understanding of potential threats for red panda has also increased. They definitely share their habitat with several potential predator species (and we found a few that were not even known from Nepal). Perhaps more importantly we were able to show that people are common in these habitats and that they are often accompanied by dogs. Good to know from a conservation point of view!

    Collecting images of different species using trail cameras is an increasingly common tool around the globe. It is becoming an essential tool for monitoring species. It doesn’t hurt that there is that thrill of the collector when you find an image of something surprising in amongst all of those misfires.

    This article was written by Adrian Paterson (Pest-management and Conservation at Lincoln University). Yes he is a collector ( I guess you could argue that he collects EcoLincNZ articles!).