Tag: wildlife ecology

  • If friend-shaped, why not friend?

    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.

  • 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

  • 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.