EcoLincNZ

Category: conservation

  • Repelling New Zealand’s deer: keeping the target on predators

    Imagine walking through the lush forests of New Zealand, where native birds sing and the ecosystem thrives. For many, the thrill of hunting deer adds to the adventure, as these animals are both prized game and an integral part of the environment. However, lurking within this paradise are predators, like possums and rats, which threaten the very fabric of this delicate ecosystem.

    To combat these problem predators, New Zealand has employed a controversial yet effective method: aerial 1080 poison drops. These toxins are effective against pests but can inadvertently harm other wildlife, including the beloved white-tailed deer (Odocoileus virginianus).

    White Tailed Buck.
    Brad Smith. July 3rd 2006

    White-tailed deer are not native to New Zealand; they were introduced for hunting in the early 20th century. Despite being an introduced species, they have established a stable population and have become an important part of New Zealand’s hunting culture, especially the population on Stewart Island. Protecting them is crucial not only for maintaining biodiversity but also for supporting the recreational and economic benefits associated with deer hunting.

    Recent studies have shed light on how we can minimise this collateral damage by using deer repellents. Let’s dive into the findings and their implications for both wildlife management and conservation.

    New Zealand’s unique biodiversity is under constant threat from invasive species. Possums, rats, and stoats prey on native birds, insects, and plants, disrupting natural ecosystems. To protect these vulnerable species, aerial drops of sodium fluoroacetate, commonly known as 1080, are used. This toxin is highly effective at reducing predator populations, but it’s not without its drawbacks. One significant concern is the unintended by-kill of non-target species, such as the white-tailed deer.

    Intensive ground-based searches for white-tailed deer carcasses were conducted in the Dart Valley/Routeburn catchments following the aerial application of 1080 cereal pellets as part of the ‘Battle for the Birds’/Tiakina Ngā Manu predator control program in August 2014. Lincoln University PhD student Kaylyn Pinney, with her supervisors James Ross and Adrian Paterson, organised this search. Four areas, each 100 hectares in size, were searched over four days. The results were published in NZ Journal of Zoology.

    To estimate the effectiveness of their search, simulated deer carcasses were used. The success rate for finding these simulated carcasses was 78%. All actual white-tailed deer carcasses found contained traces of 1080 in their muscle tissue (ranging from 0.41 to 1.06 mg/kg). Based on these findings, researchers estimated that approximately 3.85 deer per 400 hectares died from 1080 poisoning. This translates to a potential mortality of about 146 white-tailed deer across the entire 15,215-hectare predator control area. These results suggest that recurrent predator control operations could impact the sustainability of white-tailed deer hunting. (For more on this see ‘Is it fair, for orcs and deer?’)

    Repellents are substances designed to deter animals from consuming certain items without causing them harm. In the context of predator control, deer repellents can be coated on 1080 baits to reduce the likelihood of deer ingesting the poison.

    Kaylyn Pinney then tested a deer repellent-coated 1080 bait to see if it could reduce the mortality of white-tailed deer during predator control operations. She tested two types of repellents: Epro Deer Repellent (EDR) and Pestex-DR. The study was divided into two parts: trials in a captive herd on the West Coast and monitoring of wild deer fitted with GPS collars in the Dart/Routeburn Valley in Otago, New Zealand.

    Routeburn Valley.
    yiwenjiang26, Routeburn vally closer up. March 10 2007.

    In the captive trials, five deer were presented with three types of cereal baits: non-repellent (NR), EDR-coated, and Pestex-DR-coated. The baits were placed in a controlled environment where deer could freely choose among them. The results were promising. The deer showed a clear aversion to the repellent-coated baits, with significantly less consumption compared to the non-repellent baits. The repellents appeared to be effective, though not infallible. One older buck did consume a single EDR-coated bait initially but avoided it afterward.

    The second part of the study involved monitoring ten wild deer equipped with GPS collars during a 1080 drop. To fit the deer with GPS collars, Kaylyn and crew captured the animals by tranquilising them and then attached the devices. Kaylyn could now track their movements and monitor their survival. The results were mixed. One deer, the youngest in the study, died from 1080 poisoning, suggesting that body size may play a role in susceptibility to the poison. Importantly, the study confirmed, however, that using EDR significantly reduced deer mortality compared to previous operations without repellents.

    While the study shows that repellents can reduce by-kill, there are challenges. Ensuring that every bait is adequately coated with repellent is crucial. Additionally, different deer may react differently to repellents, as observed with the older buck in the captive trial. Kaylyn suggests that using a lower concentration of 1080, such as 0.08%, could further reduce deer mortality, especially for smaller deer.

    The study also highlights the importance of understanding deer habitat use. The GPS collars allowed researchers to identify how much time the deer spent in different types of habitats. The varied exposure of the collared deer to the 1080 baits was influenced by their movement patterns and habitat preferences. Future studies should consider these factors to optimise bait distribution and minimize non-target impacts.

    1080 Warning Sign.
    Shaddon Waldie, 1080. July 30th 2009.

    These findings have significant implications for wildlife management and conservation in New Zealand. By using deer repellents like EDR and Pestex-DR, we can make predator control operations more targeted and reduce the unintended consequences for non-target species. This approach not only helps protect the native ecosystem but also addresses public concerns about the humane treatment of wildlife.

    The study underscores the need for continuous innovation and adaptation in conservation strategies. As we gain more insights into the behaviour and ecology of both target and non-target species, we can develop more effective and sustainable methods to preserve New Zealand’s unique biodiversity.

    The journey to protect New Zealand’s native species is complex and challenging. This study offers a glimmer of hope by demonstrating that deer repellents can significantly reduce the by-kill of white-tailed deer during aerial 1080 operations. While not perfect, these findings pave the way for more refined and humane conservation practices. As we continue to balance the needs of predator control with the protection of non-target wildlife, studies like this guide us toward a more sustainable and harmonious coexistence with nature.

    Imagine once again walking through those lush forests, now knowing that both the native birds and the majestic deer can thrive in a balanced ecosystem.

    This article was prepared by Master of Science postgraduate student Ella Gordon as part of the ECOL608 Research Methods in Ecology course.

    Link to the main article

    Pinney, K. A., Ross, J. G., & Paterson, A. M. (2022). Assessing EDR and a novel deer repellent for reducing by-kill of white-tailed deer (Odocoileus virginianus), during aerial 1080 operations. New Zealand Journal of Zoology, 49(3), 199–214. https://doi.org/10.1080/03014223.2021.1978510

    Additional Links and Further Reading

    New Zealand Department of Conservation

    The New Zealand Department of Conservation (DOC) website provides comprehensive information about New Zealand’s natural heritage, conservation efforts, and recreational opportunities. Key sections include:

    Parks & Recreation: Information on places to visit, activities, camping, and hiking.
    Nature: Details on native plants and animals, pest management, and habitats.
    Get Involved: Volunteering, funding opportunities, and educational resources.
    Our Work: Conservation projects, research, and monitoring programs.

    Manaaki Whenua – Landcare Research

    The Manaaki Whenua – Landcare Research website provides a wide range of information on New Zealand’s land environment and biodiversity. It covers research areas such as soil health, water management, biodiversity conservation, and climate change. Additionally, it offers resources for educators, data and mapping tools, and information on various conservation projects. The site also features sections for news, events, and opportunities for public involvement in environmental efforts.

    1080: An Overview

    The “1080: An Overview” page on the Predator Free NZ Trust website provides comprehensive information about the use of 1080 (sodium fluoroacetate) in New Zealand for predator control. It details what 1080 is, why it is used, its application methods, and its effectiveness. The page also covers the benefits and risks associated with 1080, including its impact on native species, non-target species, and the environment. Additionally, it includes examples of successful 1080 applications and addresses common concerns such as its impact on drinking water.

    Nugent, G., & Yockney, I. (2004). “Feral deer in New Zealand: current status and potential management.” New Zealand Journal of Zoology.
    This article discusses the status and management of feral deer populations in New Zealand.

    Morriss, G. (2007). “Epro Deer Repellent reduces by-kill of deer during aerial 1080 operations.” Landcare Research Report.
    This report provides detailed findings on the effectiveness of EDR in reducing non-target by-kill.

    Frampton, C. M., et al. (1999). “Efficacy of 1080 carrot baits in controlling possums.” New Zealand Journal of Ecology.
    This study examines the effectiveness of 1080 in controlling possum populations.

    Spalinger, D. E., et al. (1997). “Influence of learning and experience on foraging behavior of white-tailed deer.” Journal of Wildlife Management.
    This research explores how learning and experience affect deer foraging behavior.

    Bowen, L. H., et al. (1995). “Leaching rates of 1080 from RS5 cereal baits under simulated rainfall.” New Zealand Journal of Ecology.
    This paper discusses how environmental conditions affect the concentration of 1080 in baits.

    Pinney, M., et al. (2020). “Effectiveness of deer repellents in reducing non-target by-kill during predator control operations.” Journal of Wildlife Management.
    This study delves into the specific effects of deer repellents on non-target species during 1080 operations.

  • PredatorFreeNZ 2050: fantasy into reality

    High in the treetops of a lush forest, a group of native birds gathered together, their vibrant feathers glinting in the dappled sunlight. Excited chirps and melodic trills filled the air as they engaged in a lively conversation. Their voices carried the hopes and dreams of a restored ecosystem.

    Koru, a charismatic Tūī with iridescent feathers, fluttered his wings and cleared his throat. “Have you all heard the latest? The Humans are determined to make New Zealand predator-free by 2050!”

    The cheeky Kākāriki, a lively parakeet, interjected. “Can we truly reclaim our forests from the claws and jaws of those invaders?” A wise and observant Morepork owl, Ruru blinked his large, round eyes. “Is that so? Quite a lofty goal, but can they really do it?”

    Photo credit: CC BY-NC-ND 2.0 Simeon W Flickr
    Red-crowned Kakariki, Photo credit: CC BY-NC-ND 2.0 Simeon W, Flickr

    With its unique biodiversity, New Zealand is home to a huge array of species found nowhere else on Earth. However, many of these treasures face an existential threat from invasive predatory mammals, such as rats, stoats, and possums, introduced by human settlers centuries ago. These voracious predators ravage the native bird populations. Many species are now extinct, and more are now on the brink of extinction.

    Predator-Free New Zealand 2050 (PFNZ2050) was initiated in 2016 with an audacious aim of eradicating the most destructive trio of predators: possums, stoats, and rats; from New Zealand. This call for action echoed through the mountains and valleys, inspiring conservationists to make New Zealand, once again, a land of breathtaking beauty and thriving unique biodiversity. The ambitious aim of Predator Free 2050 is not without precedent. To date, New Zealand has successfully eradicated invasive mammals from 105 (admittedly much smaller) islands.

    In 2020, a journal article was published that assesses the feasibility and steps needed to achieve Predator Free 2050. it was written by James Ross, from the Centre for Wildlife Management and Conservation (CWMC) at Lincoln University, Grant Ryan from The Cacophony Project, Merel Jansen from the Department of Applied Biology, HAS University of Applied Sciences, Hertogenbosch, The Netherlands, and Tim Sjoberg, from the Taranaki Mounga Project. Together, these researchers have decades of experience controlling and monitoring pest mammals in New Zealand.

    The first step, removing predators with aerial 1080 poisoning and ground-based resetting traps, will help remove the majority of predators. A modified aerial 1080 approach, developed by Zero Invasive Predators (ZIP), can result in localised eradication. This was first tried in a 400-ha area at Mt. Taranaki in 2016, then at a 2,300-ha site in South Westland, using ground-based resetting traps. Regular servicing of resetting traps also gives better ground-based control results.

    Once pests have been eradicated from an area, the next big challenge is to defend the area from invasion. ZIP demonstrated how to defend predators from re-invasion in two sites using a “virtual barrier” of traps. A 2 km wide barrier of traps protected a 400-ha peninsula at Bottle Rock in the Marlborough Sounds. Using this virtual barrier of traps, ZIP prevented predators from re-invading at two sites, in the short term.

    Australian brushtail possums, initially introduced into New Zealand for the fur trade, and now one of the major pest mammals in New Zealand.
    Photo credit: CC BY-SA 2.0, Gnu Chris, Flickr

    Detecting the survivors is the next crucial phase for eradication, as any survivors can build a new population. The CWMC and Cacophony Project found that thermal cameras are 3.6 times more sensitive than trial cameras in detecting possums. Whilst trail cameras appear to improve detection rates, they do not always trigger when a small, fast-moving animal moves in front of them. These cameras also use infrared illumination at night, which may deter some animals.

    Thermal cameras are a new advanced technology that shows high sensitivity in detecting both small and large pest mammals. Because the motion detection is done using software, the sensitivity can easily be adjusted. Unlike trail cameras, thermal cameras do not require infrared illumination to operate at night.

    Videos collected by the thermal cameras are classified using AI technology (machine learning) trained on a library with more than 50,000 tagged videos. The AI can identify the animal species and only keep recordings for the target pests, which can be stored on-board the device or sent out using the cellular network.

    To achieve the PFNZ 2050 goal, detecting the last few individual pest mammals is complex and expensive. As a technical improvement in detection, ZIP has made an AI network of over 500 cameras across the Predator-free South Westland project area. The AI cameras use LoRa (low-powered radio technology) to send the information to solar-powered mini-satellites. The information is transferred to a web server that checks the information the next day. The AI cameras only need to be serviced twice a year to change the batteries. The AI cameras have reduced the time to detect one predator from around six weeks to just one day and have reduced the cost significantly.

    PFNZ2050 will require more innovative strategies, control tools, and wider public support to be successful in its ambitious challenge. Future control work will increasingly take place in and around urban areas. As such, the next most important advancement needs to be construct control tools that community groups can use. There should be a bottom-up-driven approach to community engagement in conservation so that as new technologies become available, the number and size of invasive mammal-free publicly and privately managed reserves can increase. In a recent study, people showed high support for species-specific toxins, but there is a shortage of funding for registration of these toxins.

    NZ has a 60-year history of eradicating pest mammals, from tiny 1-ha Maria Island to more than 11,000 ha Campbell Island, with suitable techniques and public support. This is an example of how the impossible becomes possible when passion, science, and community unite.

    With a final chorus of their harmonious calls, the native birds took flight, their wings carrying their hopes and aspirations to the corners of the land. From forests to cities, their songs echoed, touching the hearts of all who listened.


    This article was prepared by postgraduate student Mohamed Safeer as part of the ECOL 608 Research Methods in Ecology course for his Master of Pest Management degree.

  • Detecting eDNA: everything, everywhere all at once

    Let’s say you want to know what animal species are present in a forest. You could walk along line transects and record the species visually observed. You could set up trail cameras to take pictures of passing animals for as long as there is enough space in the memory card and battery life in the cameras. You can use the acoustic survey method to study bats, birds, frogs, and even some monkey species, as they can be distinguished based on their sounds and calls.

    Depending on the size of your study area, making a list of the animal species present might take a several hours to several months because you will need to carry out various methods to identify them, which may also require species experts.

    These are well-established conventional methods for biodiversity monitoring, but is there no single method to find all the species in a given area at once? A one-size-fits-all t-shirt?

    There is a rapidly developing method that can identify a good portion of species in a given study area, including those living on the ground, in the ground, in the water, and even those flying in the air.

    Every organism contains genetic material called deoxyribonucleic acid (DNA), passed down from parents to children. All organisms from the same species have very similar DNA.

    An illustration of the double-helix of the DNA molecule. Original public domain image from Wikimedia Commons

    This technology takes advantage of the traces that organisms leave of their DNA in their environment, whether feathers, skin, scales, urine, or faeces. These traces, known as environmental DNA (eDNA), can be found in soil, water, and air.

    This shiny new method is called DNA metabarcoding. Simply put, it identifies organisms by matching their DNA with reference DNA from the gene database or library. It is like matching the barcode of products when you check out at the supermarket.

    The process begins with collecting water or soil, or even air, samples from the study area. These samples typically contain genetic material from diverse organisms, including bacteria, plants, and animals.

    Once samples are collected from the field, they are brought to the laboratory. DNA is separated from the samples, amplified, and sequenced to generate vast amounts of genetic data that can be compared with existing DNA databases and reference libraries such as GenBank for species identification.

    Environmental DNA – An emerging tool in conservation for monitoring past and present biodiversity – Scientific Figure on ResearchGate. Available from: https://www.researchgate.net/figure/The-overall-workflow-for-environmental-DNA-eDNA-studies-with-examples-of-organisms-that_fig1_269724781 License: CC BY-NC-ND 4.0

    DNA metabarcoding can detect a broad range of organisms at once, providing a snapshot of the species diversity within the study area. That way, you can avoid performing various sampling methods. How convenient is that!

    Of course, no method is perfect, even DNA metabarcoding. Since it is still developing, there are limitations. The public gene library has the DNA references of many species but this is still a small fraction of all the species on earth, so far. There can be contamination in the samples, which could disrupt the results. Errors can occur not only during sample collection in the field but also in the laboratory.

    Compared to DNA metabarcoding, conventional methods have stronger standardised techniques for sampling and for interpreting the datasets. Besides, in the context of biodiversity monitoring, conventional methods can provide detailed information, such as abundance, age, sex ratios, and individual animals’ special characteristics, such as colours and conditions, which DNA metabarcoding cannot tell us.

    Conventional methods are like pictures with tiny pixels portraying good resolution, but their taxonomic scope is limited, whereas those of DNA metabarcoding cover a broad range of species, but the resolution is coarse.

    Is there the best of both worlds?

    Yes! Robert Holdaway and colleagues, including Ian Dickie working at Lincoln University, suggested that combining DNA metabarcoding with conventional monitoring methods will benefit scientists in many ways.

    Using them together will enable scientists to test and improve the reliability and accuracy of our still-developing DNA metabarcoding method. Moreover, combining them will result in a higher chance of detecting species from the same lineage.

    Robert and colleagues provided three case studies in New Zealand that can benefit from the dynamic duo.

    First, the duo can be of advantage to the nationwide measurements of New Zealand’s biodiversity. They can provide greater taxonomic coverage and more thorough information on the relations among biodiversity, ecosystem functions, and services.

    Second, integrating DNA metabarcoding with Māori biodiversity monitoring approaches will bring more understanding to the Māori worldview of interconnections among living and non-living beings. Metabarcoding can enhance biodiversity inventories, identifying species important and relevant to Māori which are rare or hard to find using conventional methods.

    Third, combining DNA metabarcoding with traditional surveillance in detecting pest species at the early stage will secure native species and landscapes from harmful biosecurity threats, such as harmful pests and diseases.

    In addition, DNA results shared from various surveys using the dynamic duo will be added to the reference libraries making them more resourceful and convenient for future research. Having more reference DNA sequences of species in the reference libraries, like GenBank, will make biodiversity monitoring much easier by identifying species with just a few clicks.

    DNA metabarcoding is a rapidly developing and powerful tool for monitoring biodiversity. Integrating it into conventional methods will lead to a stronger method to get plausible results. Overall, as Robert and colleagues indicated, not only will they add value to New Zealand’s biodiversity and Māori culture, but they will also protect the native natural environment and species through early detection of pests.

    This article was prepared by Master of Science postgraduate student Zin Mar Hein as part of the ECOL608 Research Methods in Ecology course.

    Together, they will indeed make the best of both worlds for conservation.

  • Buried treasure: the hidden gems of alpine peatland

    Growing up, I had a fascination with pirates.

    I’m not sure if it was the fact that they stole buried treasure, sailed the seven seas, and broke all the rules or if I liked that they used the term “swashbuckling” to describe themselves. All I know is that I wanted to be exactly like Captain Jack Sparrow. Granted, Johnny Depp does quite well at making Jack Sparrow seem like the best and worst pirate at the same time, which definitely influences the likeability and comedy factor of the character.

    Peat Area in Perigi village, Pangkalan Lampam District, Ogan Komering Ilir Regency.
    Photo by Rifky/CIFOR cifor.org, CC BY-NC-ND 2.0 (Flickr)

    For the majority of the first Pirates of the Caribbean: The Curse of the Black Pearl, Sparrow, with the help of his slightly awkward, bumbling, and unlikely traveling companion, Will Turner (played by Orlando Bloom), attempts to chase down his precious pirate ship and crew of the Black Pearl.

    To steal back his ship and find treasure along the way, Sparrow and Turner must make their way through various tunnels and streams until they finally reach the be-all-and-end-all of all treasure rooms, full of the loot that the pirates have collected over the years.

    Oftentimes, to get to these places of “great treasure”, the pirates would use maps to find the hidden jewels they so desired, and if they were underground, well, they would dig for them!

    But what if hidden gems are not always jewels?

    Even Sparrow, the death-defying pirate who escapes prison, steals ships, drinks copious amounts of rum and loves treasure, says:

    “Not all treasure is silver and gold, mate.”

    Treasure is “wealth stored up or hoarded, something of great worth or value” and “a collection of precious things,” according to Merriam-Webster Dictionary. In terms of natural resources, water is a treasure.

    Water is crucial for humans. Water is also a critical worldwide currency and supports life as we know it. Beyond using water for cooking, cleaning, or washing, water is critical for supporting agricultural crops, farms and, therefore, our food sources. In many communities, water also has a spiritual value, more than a monetary or physical value. In New Zealand, the Whanganui River even has personhood status, highlighting just how important water is.

    Considered a natural treasure, water is extremely precious in dry, arid regions with little rainfall or annual precipitation, meaning plants and animals must adapt to limited water sources. The same applies to agriculture; farmers must adapt in dry regions, using water sparingly and wisely. In these regions, it is essential to understand where water comes from and goes to and how it is potentially stored underground upstream from agricultural land.

    Buried treasure, some might say.

    In the arid Chilean Andes, this treasure is buried in mountain peatland.

    Peatlands are wetlands with layers of compact and partially decomposed plants and organic material (i.e., dead and decaying plants) in water-logged soil. If you’ve heard of the “Tollund Man” (a well-preserved body from the Iron Age), then you’ve heard of peatland. Peatland may have standing water or vast swaths of very soggy ground, as pictured below. This makes it difficult to immediately understand their capacities to hold water.

    Great Kemeri Bog, Latvia. Photo by: Runa S. Lindebjerg, CC BY 2.0 (Flickr)

    Shelly MacDonell (Lincoln University) and a team led by Remi Valois and Nicole Schaffer investigated the ability of Chilean peatland in the Elqui Valley to store water and estimated its role in delivering water to agricultural areas via streams.

    The researchers chose a peatland (bofedal) in Spanish, called “Piuquenes” for their study because of its central location compared to surrounding peatlands and its elevation (approximately 3000 meters above sea level), making it a great representation of other Chilean alpine peatlands. This peatland was also chosen based on a proposal to place a dam at the edge of Piuquenes for agricultural water control downstream.

    To study the inner workings of Piuquenes, the researchers had to look below the surface. Picture someone on the beach using a metal detector to find potentially valuable items under the surface (like a modern-day pirate), and that is a very simplified view of the tools used to visualize the geology and structure of the peatland below the surface. However, using Ground Penetrating Radar (GPR) and Electrical Resistivity Tomography (ERT), the researchers were able to create a 3D image of what might be under the surface. Through this 3D image, they could calculate the potential storage capacity (volume) of the studied peatland and estimate the role of high-alpine peatland in the area’s water cycle.

    According to estimates by researchers, the peatland itself could hold between 164,000 and 243,000m3 of water. That’s between 66 and 97 Olympic-sized swimming pools worth of water!

    The study found that the Piuquenes peatland can actually contribute water to lower agricultural regions downstream. However, the peatland is also vulnerable to water loss through evapotranspiration, which is a fancy word for water that evaporates and is lost from the vegetation and soil.

    Despite this water loss, researchers determined that Piuquenes was still important for supporting the surrounding ecosystems and could still act as a significant reservoir (i.e., source of water) for downstream agriculture and livestock grazing. They also discovered that the peatland could shield the area from drought impacts because of its water capacity. This means Piuquenes peatland could deliver water to grazing and low land agricultural areas via streams and limit the most severe effects of drought even in low-rain seasons.

    In addition to storing water, the Piuquenes peatland can also help produce soil from the slow build-up of decaying plants, store carbon, help plants grow and provide watered grazing areas for livestock.

    Understanding the inner workings of Piuquenes advances our knowledge of high-alpine peatland and its natural benefits to lowland agriculture. This study also adds valuable information to the discussion of if and how a dam should be built at the edge of this high-alpine peatland.

    Piuquenes, although located in the Chilean Andes, is an excellent example of how critical preserving and conserving peatlands worldwide.

    Studies have further investigated the secrets and treasures of peatlands, such as the carbon storage capacity, internal chemistry and nutrient cycling effects on methane emissions, proving that peatland continues to be a valuable ecosystem and that there is indeed treasure hidden beneath the surface.

    Peatland in Torronsuo National Park, Tammela, Finland. Photo by: Tero Laakso, CC BY 2.0 (Flickr)

    Current efforts have also focused on how to conserve these valuable landscapes and how local management initiatives could be applied worldwide. For example, Global Peatlands Initiative is a group dedicated to informing people about the importance of peatlands and keeping you updated on peatlands around the world.

    I’m pretty sure Jack Sparrow wasn’t referring to peatland as the treasure in his quote about silver and gold, but he was on the right track. If only he had known about the inconspicuous treasure hidden in the high reaches of the Andes!

    So, next time you’re on a swashbuckling adventure, keep your eyes open for what might be lurking under the surface and could be even more precious than silver or gold.

    This article was prepared by Master of International Nature Conservation student Alaina Eckert as part of the ECOL608 Research Methods in Ecology course.

    P.S. Here is a really cool (and short) video about Peatland Protection from the UN!

  • Toxins help rare birds

    As a birder, there is a unique and somewhat pure excitement to seeing a bird you’ve never seen before – at least that’s my experience. Spotting a “lifer” (a.k.a. a species ‘new to you’ in birding lingo) comes with a feeling of accomplishment, especially if the bird turns out to be rare. For example, I could still tell you when and where I saw my first California condor, Great bustard, or Rock wren/tuke. Some birders, or “twitchers” to separate them from more casual birdwatchers, even make somewhat of a sport out of seeing as many rare species as possible. I recommend watching “The Big Year” if you want to learn more about this and have a good laugh while you’re at it.

    As a conservation biologist, spotting a rare bird often brings about feelings other than excitement. After the initial high, it leaves a little bit of a bitter taste behind because, more often than not, there is a not-so-great reason why a bird is rare.

    I feel this particularly strongly when birdwatching in New Zealand, where introduced predators have wreaked havoc on the unique and vulnerable bird life and caused many species to disappear from large parts of their natural ranges. Many native birds now survive in wildlife sanctuaries and are difficult to spot in the wild.

    “Since the arrival of humans, [59 species of bird] have been recorded as lost to extinction as a result of changes to the landscape and the introduction of predatory mammals.”

    Te Mana o Te Taiao – Aotearoa New Zealand Biodiversity Strategy 2020

    While New Zealand’s charismatic rarities certainly are a great addition to any twitcher’s life list, I find it hard to forget that some of these species are on the brink of extinction. The birdwatcher and conservation biologist in me are at odds when I go birdwatching here, and I never know how to feel when spotting a rare bird. When I saw my first yellowheads/mohua near the Blue Pools by Haast Pass, I felt ecstatic and sombre at the same time – it’s quite the dilemma.

    Rock wren in Fiordland. © Antonia Ulle

    The upside is that New Zealanders know the value of their native wildlife and are committed to conserving it. Native birds, along with other indigenous species, are considered taonga and, as such, an important part of the country’s national identity – why else would a kiwi shooting laser beams have been such a popular design for New Zealand’s alternative flag back in 2015?

    Naturally, making rare species not as rare is one of the cornerstones of New Zealand’s Biodiversity Strategy, and protecting native birds is a national priority. This goal goes hand in hand with eliminating the mammals that threaten their existence.

    On a landscape scale, predator control often requires dropping 1080 (a biodegradable poison) from helicopters and planes in the rugged backcountry to target mammals in areas that are otherwise hard to reach. Experts say that for birds with a remote and inaccessible range, such as rock wrens, kiwi, blue ducks/whio, yellow-crowned parakeets or mohua, that this is currently the only practical management tool. Despite research showing that the aerial application of 1080 helps the recovery of native bird populations, this strategy is often criticised by members of the public for being indiscriminate and endangering the very species it is supposed to protect.

    So, how does DOC make sure native birds aren’t dropping dead left, right and centre when they use 1080 for predator control? The answer is research, research and … more research! Preliminary research, follow-up research, and intensive monitoring of bird populations during pest control operations, all help the people in charge understand how 1080 affects native birds with the aim of reducing their poisoning risk is as low as possible during any 1080 drop.

    Some of this important research was done here at Lincoln University when Jakob Katzenberger and James Ross investigated how mohua were affected by a pest control operation using aerial 1080 in the Catlins State Forest Park back in 1999. Intensive monitoring before and after the 1080 drop showed that the control operation didn’t have unwanted non-target effects for mohua. More specifically, the researchers concluded that mohua numbers didn’t differ significantly before and immediately after the control operation.

    While this might not seem like the most exciting result, it tells an important story – that 1080 worked and only killed what it needed to kill. Now, in case you’re wondering if these results still hold true since the research for this study was carried out over 20 years ago – rest assured, they do. Studies conducted in the Landsborough, Dart and Routeburn valleys since then have shown that both mohua numbers and nesting success increased following predator control using 1080. In 2006 and 2009, nesting success of mohua was on average twice as high after 1080 than without it in the Dart and Routeburn valleys, and in the summer of 2015 89% of mohua nests in the area were successful.

    Another key takeaway from the study by Katzenberger and Ross is that the timing of 1080 control operations is critical to maximise the benefits for native species. While the 1080 drop in 1999 did not affect mohua in the Catlins negatively, it could have provided more benefits had it been timed better. Monitoring showed that a predator boom caused by beech masting in the summer after the 1080 drop caused drastic declines in the resident mohua population. Applying 1080 after this masting event could have reduced predator numbers and, therefore, protected mohua more effectively by providing a “predator free” window for them to breed.

    Benefits of aerial 1080 for mohua from the 2014 “Battle for Our Birds” pest control operations in the Dart valley.
    © Department of Conservation 2016

    In 2014, DOC managed to protect mohua and other natives in a year of heavy beech masting with the “Battle for Our Birds” campaign by applying aerial 1080 just before predator numbers skyrocketed. Without predator control, that beech mast and the resulting high predator numbers would have been detrimental for the populations of native animals. This is an excellent example of how protecting native species is a learning process, and how research helps us learn, and improve conservation practices.

    What we can take from this is that 1080 works and that native birds do better where it is used. Researchers don’t just leave it at that though. A lot is still being done to make aerial 1080 baiting as “bird proof” as possible and ensure that birds gain the maximum benefit from it. Baits are improved continuously, sowing rates are reduced, and bird populations are carefully monitored. Overall, 1080 baiting has come a long way since it was first done, and now is an effective tool to protect native species. Some people may always oppose the use of 1080 no matter how loud the science talks, but, to use the words of Dr Nick Smith, New Zealand’s 6th Minister of Conservation, “reason must trump prejudice about poisons when the very species that define our country are at stake”.

    I consider myself lucky to have seen many of New Zealand’s birds, rare or not. Some of the encounters I’ve had here have been quite magical and, to be honest, almost cheesy. Like the time I was hiking Gertrude saddle in Fiordland, wondering if I would get to see a rock wren – only to have one poke its head around a rock to check me out while I was having lunch. Or when a family of mohua landed in the trees right next to me in Hawdon valley and I got to watch them for a good half an hour.

    Mohua in Hawdon Valley. © Antonia Ulle

    With research continuously improving how introduced predators are controlled, I hope that, in the future, encounters like this will once again become the rule rather than the exception.

    This article was prepared by Master of International Nature Conservation student Antonia Ulle as part of the ECOL608 Research Methods in Ecology course.

    Katzenberger, J.K. & Ross, J.G. (2017). Mohoua ochrocephala abundance in the Catlins following aerial 1080 control. New Zealand Natural Science, 42, 1-8.

  • Small animals show us the value of old natural forests

    Hambach. You are in Germany right now, halfway between Cologne and the Belgian border. I’d like to warmly welcome you to the Hambach forest – an ancient forest that is dominated by oak and hornbeam, representing a rare forest type in modern Germany. The Hambach forest is the last remnant of a forest that ranged over wide flat plains since the end of the last ice age around 12,000 years ago. Regrettably, it has become famous for being gradually absorbed by a vast hole!

    Tree house in the Hambach forest.
    CC BY-NC 2.0 by Tim Wagner, Flickr

    The Hambach forest used to range over an area of around 5 500 ha. During the past four decades, around 90 percent has already vanished. What remains today is not a normal forest anymore – idyllic, undisturbed, and peaceful. The forest is not only threatened by further sliding into the hole. In 2018, the Hambach forest also became the stage for one of the largest major police operations, owing to another curiosity about the Hambach forest: it is inhabited by people, living in tree houses. Occupying the forest, they want to protect what is left of it and demonstrate against the further expansion of the hole. However, since the forest is privately owned by the company that sacrifices it for the hole, activists were forced out of the forest with the help of police power – before occupying it again.

    So what is the gigantic hole? It is the result of four decades of open-cast coal mining in the Hambach region. However, its further growth will eventually take an end. For the year 2038, Germany has committed itself to complete the coal phase-out, a critical step for Germany’s energy transition. Until then, coal power stations in Germany can be fuelled by coal – extracted from German coal mines (“holes”), with a spectacularly bad impact on the climate. Still, based on the coal-phase out, the remaining part of the Hambach forest can be saved.

    Hambach open-cast coal mining hole.
    CC BY-SA 2.0 by Traveling Tourist, Flickr

    Growing up close to the Hambach forest, that received international attention in the environmental and climate movement, I’ve been concerned about one question for a very long time: How can we replace an ancient forest that is destroyed for mining purposes?

    “If we are moving several villages, people, and a motorway for the open-cast coal mining, why don’t we also move the forest?” That is how people in my region would have addressed this question in the past. Believe me or not, that’s exactly what has been done. At one end of the gigantic hole, the largest artifical hill worldwide was created and recultivated with trees. It serves the region now as a recreation area, comprising an about 70km network of hiking trails. “Forest is forest. There is no difference”, people say in my region. So why be concerned?

    But is it really that easy? Are humans really able to shape a new forest within a few years as a replacement for a destroyed ancient forest, that has the same value for biodiversity and people? And will the planted trees provide an appropriate habitat for all mammals, birds, insects, spiders, herbs, lichens and other important life forms that used to inhabit the lost forest?

    In many countries around the world, there are nowadays regulations regarding compensation and restoration measures that mining and other companies have to fulfil when their activities destroy land. However, in reality, is it always possible to restore an ecosystem that has undergone complete degradation from a natural forest to a mining site, back to its original state and biodiversity value? Otherwise, it is possible to shape a new ecosystem with the same values at another site – like it was aimed with the planted artifical hill as a compensation for the destruction of the Hambach forest? Fortunately, there are ecologists who have learned the answers to these questions. Closely monitoring the process of ecosystem restoration they can tell how successful undertaken restoration efforts are for biodiversity.

    So, now that we’ve already practiced thinking in great dimensions, let’s undertake a great jump to another mined forest – we’re jumping off Germany, over Italy and the Mediterranean Sea, crossing the Arabian Peninsula and the Indian Ocean, passing Australia and are finally landing in… Auckland! Well done! We’re standing here at the Hunua Quarry site, near Papakura in South Auckland. It is part of the Hunua ranges that consist of over 20 000 ha of native forest, comprising tawa, podocarp, kauri–hard beech, and taraire forest as main vegetation types.

    The Hunua Ranges.
    CC BY-NC 2.0 by Neil Hunt, Flickr

    The Hunua Quarry is managed by Winston Aggregates, New Zealand’s largest aggregates provider. As a restoration measure, in six years over 140 000 plants have been planted in this highly modified habitat after quarrying. The aim is to provide a new forest as a replacement of the forest area destroyed. Next to the restoration area, you can still recognize unrestored areas of exotic grassland that have established after quarrying, as well as undisturbed mature native forest.

    Researchers from Lincoln University (Mike Bowie and colleagues) studied the invertebrate communities at Hunua Quarry, including wetas, beetles, cockroaches, crickets, spiders, centipedes, earthworms, ants, flies, mites, moths, slugs and snails, amongst many others. Although rather small animals, invertebrates are essential for the functioning and health of ecosystems, thereby making an important contribution to biodiversity. The objective of their study was to develop a better technique for the assessment of restoration success after mining, using invertebrates as bioindicators. Bioindicators are species that react sensitively to changes in their environment so that they can be used to assess the quality of an ecosystem.

    The researchers collected invertebrates in the undisturbed mature forest, in restored areas, as well as in the unrestored exotic grassland. They compared how many and which invertebrates were living in the respective areas. Interestingly, the undisturbed mature forest, the restored areas, and the unrestored exotic grassland were characterized by very different invertebrate communities. The invertebrates found in the six-year-old restored areas were mostly still very unlike those found in the undisturbed mature forest. For instance, the researchers were able to collect eight times more cave weta in their pitfall traps in the undisturbed mature forest than in the restored areas. In addition to cave wetas, the mature forest also harboured many spiders and beetles. Hence, if the forest restoration process is successful, it is expected that more cave weta, spiders and beetles typical for mature forest will inhabit the restored sites in the next years. At the same time, fewer exotic snails, slugs and earthworms that were found to be characteristic for the unrestored exotic grasslands are expected.

    This beetle,
    Holcaspis mucronata,
    was found most abundant in the mature forest.
    CC BY 4.0 by Birgit E. Rhode, Wikimedia Commons

    The study identified several invertebrate species as bioindicators. These can be used in future studies to assess the success of forest restoration at mine or quarrying sites. The study findings have been recognized in several other invertebrate studies of different parts of the world, for example, in a global synthesis on how good forestry plantations are at providing habitats to native beetles in comparison to natural forests. In that study, restoration sites were considered as forestry plantations, being planted by humans for conservation purposes and therefore different from natural forests. Another study dealt with the effect of removing an invasive plant as a restoration measure on an Mediterranean island. It referred to the study at Hunua Quarry for the use of beetles as bioindicators to observe the effects of restoration.

    All in all, the study showed that invertebrates might tell us more about the quality of a forest than you would easily see yourself. Hence, studying invertebrates as bioindicators has great potential for making better decisions in ecosystem management and for restoration projects. I hope that research about restoration will also raise public awareness for the complexity of biodiversity and the needs for appropriate habitats. Perhaps, I will hear many people around the Hambach forest region in Germany say: “Forest is not like forest. We need to consider old natural forests as valuable habitats and save them from vanishing, not only for the sake of spiders and beetles.”

    This article was prepared by Master of International Nature Conservation student Vivien Michel as part of the ECOL608 Research Methods in Ecology course.

    Link to the research article:

    Bowie M, Stokvis E, Barber K, Marris J, Hodge S. 2018. Identification of potential invertebrate bioindicators of restoration trajectory at a quarry site in Hunua, Auckland, New Zealand. New Zealand Journal of Ecology 43.

    Read more:

    Donahue, Michelle Z. 2018. Is Germany’s Hambach Forest Doomed by Coal? National Geographic, April 13. https://web.archive.org/web/20190914181247/https:/www.nationalgeographic.com/news/2018/04/hambach-forest-germany-logging-coal-conservation-science/

    Coal exit will save Hambach Forest: activists. Deutsche Welle, January 27, 2019. https://www.dw.com/en/german-coal-exit-plan-will-save-hambach-forest-activists-say/a-47251256

  • Testing new bait coatings for conservation

    Mickey Mouse and Scabbers the Rat, are causing biodiversity loss in Aotearoa, New Zealand. They are committing crimes against some of our most endangered wildlife and arriving uninvited to the party. Protecting our taonga falls into the hands of conservationists and wildlife managers. New research plays a vital role in protecting our precious taonga.

    Menacing mouse – a little creature creating a big problem. Photo by Nils Fleischeuer (CC BY-NC)

    Would you be surprised to read that mice (Mus musculus) have been recorded eating live albatross (300 times their size)? I sure was! How could a little mouse possibly kill a bird known for having the largest wingspan in the world? Sadly, lots of albatross die from mouse predation every year. When mice aren’t eating albatross, they dine on many species of insects, chicks, eggs and lizards.

    If mice are so terrible, what about rats? There are three species of rat in Aotearoa, the Norway rat Rattus norvegicus, Black rat Rattus rattus and the Polynesian rat Rattus exulans. They are all bad news – they kill adult birds, chicks, snails and insects. They also compete for food that should be there for our native fauna.

    Due to the negative impacts of these rodents, and other introduced predators, many of New Zealand’s most critically endangered fauna are whisked away to predator-free off-shore islands. Some are protected behind expensive predator-resistant fences. PHEW, job completed, right? Not so fast!

    Despite eviction notices, Micky and Scabbers can wriggle their way back into our protected areas. Maybe it’s a quick hop along a fallen tree that bridges the now not so “predator-resistant” fence or a long swim to an off-shore island. When they do appear, we need to have proven tools in the toolbox to deal with them. One of the tools to control them is cereal poison bait.

    These baits are like your breakfast cereal in that they are made from similar ingredients – apart from the poison! Picture this: you reach for your new box of breakfast cereal in the morning and notice an open, very much neglected, box of cereal sitting at the back of your pantry. It’s been there for so long you can’t remember opening it (or you’ve just been ignoring it for many months). It smells stale and has gone slightly soggy, so you bin it, knowing full well that it will taste nasty.

    A good rat is a dead rat! Photo by Jacqui Geux, iNaturalist NZ, (CC-BY)

    Bait stations are used to protect the bait from the rain. However, just like you with your open box of stale cereal, mice and rats also have preferences when it comes to eating their cereal. The longer that bait is stored inside bait stations, the less palatable it is to rodents, the less they eat and the longer it continues to sit and weather.

    To make things worse, the bait stations are often irregularly serviced, so wildlife managers need a bait that stays palatable to mice and rats for as long as possible. This is an issue on remote predator-free islands and fenced predator-resistant sanctuaries that have difficult access and limited funds. Stale or mouldy bait in particular will not control rodents if they aren’t even going to eat it.

    If only there was a way to prevent baits from absorbing moisture and going mouldy – keeping the bait fresh for longer so that mice and rats were more likely to eat it when they come across it …

    This is where researchers at Lincoln University (NZ), James Ross and colleagues, had an idea to coat the baits in a material that will do just these things. Also the material will not reduce the palatability of the baits to mice and rats. To test this idea, they created an experiment using two coatings, Polyvinyl butyral (PVB) and Shellac. Shellac is already used as a food glaze and as a coating to mask the bitter taste of Paracetamol/Acetaminophen. Shellac is also fully biodegradable, which makes it environmentally friendly.

    The coatings were tested using four combinations of the aforementioned substances. First, they had to ensure the new coatings didn’t reduce the palatability compared to uncoated baits. If mice and rats do not eat the new bait coatings, it would be a waste of time to test them further. If Whitakers coated your favourite chocolate bar in something strange, you might take one bite and decide that the new “sardines & whipped cream” coated chocolate bar was not your vibe.

    This image has an empty alt attribute; its file name is 518244606_bcc3409a3a_c.jpg
    An easy pill to swallow – A Panadol tablet, commonly coated in Shellac. (CC BY-NC-SA 2.0) Photo by venana, Flickr. 

    The researchers also had to measure whether coated pellets remained palatable after extended environmental exposure because this is highly likely how mice and rats will find the baits in the real world. In the experiment the coatings were placed on the food the captive rats and mice were fed on. Mice, and more so rats, are neophobic (afraid of new things). So placing new food in their cages might affect the results in such a way that the researchers are measuring the wrong thing. Putting the coatings on their food means their wary responses will be minimised, since they eat rodent pellets every day. After the mice and rats had munched their way through their favourite snacks, the bowls were weighed, and the results were in – Shellac for the win.

    There were differences between the bait coating combinations; Shellac was the most palatable, it performed the best for both mice and rats. Shellac out preformed the PVB coating and the mix of PVB/Shellac. This experiment demonstrated that mice and rats are picky eaters and highlights the importance of testing the different coating types. Coatings, although no thicker than 500 micrometers (really thin), will affect how much mice and rats will eat. Ironic given that mice and rats will eat out of a trash can – now we know they are fussily searching for the “best rubbish”.

    This research is a step in the right direction for conservation in Aotearoa. I call it a small win for the native fauna. With Shellac showing promising signs, researchers and wildlife managers can test the new bait coatings in the field. Wild Mickey and Scabbers can try out some of the mould free, ‘fresh as can be’ Shellac bait. So next time Mickey and Scabbers arrive uninvited to the party, it may be the last thing they do.

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

  • A giant pest problem: elephants in the backyard

    New Zealand has a huge agricultural industry. It also has a pest problem. I myself have been out to a friends’ farm and was told to “squash a mouse if you see one”! Which I think we can all empathise with to an extent. When the little b*stards are eating your food, they might as well be infesting your wallet.

    Image CC-BY-SA Diego Delso on Wikimedia Commons: Elephants and humans live in close contact in Africa

    Now, think about scaling that up a couple of levels. You no longer have nuisance, albeit damaging, mice scurrying around your farm shed. Instead you have elephants, in herds of 11+, munching through entire fields and even ripping doors off your grain sheds. Stomping won’t quite suffice here (and may go the other way).

    This is an issue that Abel Mamboleo and his PhD supervisors, Chile Doscher and Adrian Paterson, at Lincoln University investigated in their JOJ wildlife and Biology paper in 2020. Instead of the standard numbers, quantities and figures you may expect in a science paper, here they take a slightly alternative approach to the topic. What do people think is happening in their backyards? After all, fear and perceptions are powerful things.

    To start with a bit of context – who are we talking about when referring to people? This study interacted with people in the region of Bunda, a very densely populated region in Tanzania. Much of its land is a part of the idyllic Serengeti ecosystem, and boasts an internationally renowned tourism hotspot.

    Bunda location within Tanzania – right next to the Serengeti: Image CC-BY-SA Macabe 5387 on Wikimedia commons

    These people rely heavily on farming. In fact, 80% of annual income in Bunda comes from this industry. You can imagine how devastating it is to have these creatures, as amazing and majestic as elephants may be, decimate their fields of crops.

    Elephants eating crops is not a new story. In fact, there are even somewhat humorous accounts of elephants eating rotten fruit in orchards and getting themselves rather drunk in the process. Thieving behaviour may even be tolerated – these giants are big money for tourism. However, in this particular context, such interactions are becoming more and more problematic. In this area, as the human population grows, human-elephant interactions also increase.

    Mamboleo went to this area to ask local people their thoughts about these interactions. Using interviews and questionnaires in local languages to ensure clear messages, they found that 88% of those asked thought these human-elephant interactions were on the increase. Furthermore, 79% of respondents reported these events were most common on farms.

    This in and of itself is not necessarily an issue. Local people had described the elephants as generally ‘docile’ and can even be safely approached to within 50 m. In the past, farmers have sometimes been able to simply scare elephants away themselves using traditional techniques, such as patrolling and fencing. Elephant ‘friendliness’ has even been suggested in other parts of Africa, with some suggesting elephants are going as far as to domesticate themselves. However, now, elephants are beginning to ignore these scaring techniques, some becoming bolder and potentially more dangerous.

    How is this affecting people?

    You can begin to see how conflicts between elephants and humans are likely to grow, with 32% of people thinking that elephants will react to seeing a person by killing them, and guarding crops being a main way for these people to protect their livelihoods. And for another large minority, 42% of those asked, they experienced elephants simply continuing to eat their crops in the presence of humans. Evidently, these people don’t have effective tools to deter elephants and protect their farms.

    Extreme measures: what to do next?

    We can see how people would be having a hard time with their elephant neighbours here. But what about the elephants?

    Elephants are protected in Tanzania. The people of Bunda know this. However, desperate times sometimes call for desperate measures. Therefore, occasionally, when an elephant is raiding crops, people may turn to lethal measures. Whilst few people who were interviewed list this as a response to seeing elephants raiding crops, Mamboleo raises the valid point that this number could be higher. Local people know that there could be consequences of authorities finding that illegal elephant kills had taken place in the Bunda region.

    Elephants & mice – really that different? Image by GlobalP from iStock

    This may seem like a drastic response. However, killing pests such as rats, rabbits and mice that eat crops in NZ doesn’t seem so drastic, does it? Of course, this is a very different situation – elephants are native to this area, and are endangered and protected. But this comparison does make you realise that wanting to kill the problem can be a fairly universal response.

    Mamboleo notes that cheap responses can be turned to in the absence of timely support from conservation authorities…so what can be done about that?

    Well, there are some cool things being done across Africa to help with these conflicts. For example, do you know that elephants are scared of bees? Who’d have thought. Some projects actually exist to build bee hives around fences to keep elephants away, and this seems to work pretty well. It also turns out that elephants don’t like spicy food – so chilli can be used in a similar way.

    Image by Kengee8 on Wikimedia Commons: Example of elephant-bee fence

    More ideas, such as this would, be very useful to help in these situations. Answering questions such as when are elephants most likely to visit the farms may also be helpful for targeted responses, Mamboleo says.

    Knowing how people feel, how they’re responding to the situation, and what they need to do to help them resolve the situation for the best outcomes for people and wildlife is a great first step here. That’s the valuable context needed to now take the next steps and make solutions that will work. Especially when we can’t just stomp on the problem!

    This article was prepared by Master of International Nature Conservation student Sally Sinclair as part of the ECOL608 Research Methods in Ecology course.

  • Kea pine for a new home?

    Kea, our smart alpine parrots, are sometimes a little too clever for their own good. They are a species struggling to maintain large and healthy populations. Part of their problem is that they are very curious and seem to be fascinated by what humans do, and more importantly, often live in human-influenced habitat. This is not such a good trait when it leads them to interact with hazards like lead or toxins, nor is it useful if they find human ‘junk’ food.

    This curiosity is also not helpful when we want to study kea. Many of the approaches that work with other bird species just fail for kea. Instead of going about their business they come and see what you are doing, and that’s not great for understanding key aspects of their life histories.

    Spot the kea at the top of the tree! Image by Adrian Paterson.

    I has some first-hand experience with researching kea about twenty five years ago, when I was a newly minted Lincoln University lecturer. I was helping Kerry-Jayne Wilson to supervise a masters student, Mark Jarratt. Mark was interested in how much lead, and other nasty waste, the kea were finding in the local Arthur’s Pass area, and consuming, in their habitat. For example, lead was present in paints, shotgun pellets and rubbish in the tips and kea were often observed eating it.

    Mark had to catch kea to take blood samples to check for lead contamination. Catching kea can be fairly challenging. They are not easily fooled and they can learn by observing others. Adding to the difficulty was that we had to keep the birds in captivity for an hour or so as part of the procedure. And this was a problem.

    We initially used a cage. We would capture a kea, put it in a holding cage, and then go and try and capture the next one. However, each kea would often figure out how to escape the cage. We would return to find a cage open and our patient free (and not likely to be so easily caught again). So then we took the cage with a kea into a small hut nearby, thinking that if the bird got out of the cage then they would at least be in the hut. Unfortunately, some of the kea managed to figure out how to open the windows in the hut. Moral: don’t work with animals smarter than you are!

    So, when PhD student Jodanne Aitken came to James Ross and me and wanted to do a project on kea, I was a little hesitant. However, Jodanne is nothing if not persistent, passionate and persuasive, and a project on kea was begun.

    Early morning in the plantation. The native forest in the distance was often commuted to and from by kea. Image by Adrian Paterson.

    Jodanne was interested in how kea move about and utilise the landscape. Much of her PhD work is in the Southern Alps around Arthur’s Pass, where she is using transmitters to figure out just how mobile kea can be. Is that kea you see gnawing your car wiper blades from the local valley or could it be from several mountain ranges away? More on that in future EcoLincNZ articles!

    Jodanne’s initial work was in looking at how kea might be using plantations of introduced pine and Douglas fir in the Nelson region. Forestry has become a dominant part of many regional landscapes, often hilly and where native forests once grew (and kea once flew). This is especially the case in the Nelson region. The question that Jodanne wanted to answer was whether these forestry plantations, typically monocultures with a lot of human activity, provide a net gain or loss for kea.

    Jodanne filming kea foraging behaviour. Image by Adrian Paterson.

    Are plantations the equivalent of barren wastes for kea, where there is little food and high densities of mammalian predators (not to mention hazards that humans introduce into an area)? Alternatively, do plantations offer new food resources and places to roost and nest? Of course there could be a range of outcomes from positive to negative.

    Jodanne was able to work in forestry blocks run by Nelson Forestry Limited. Local workers were key to providing Jodanne with almost real-time information on kea presence within blocks that were being actively harvested. One advantage of working in plantations were the forestry roads that gave rapid, if a little hair-raising, access to most of these areas.

    Jodanne was able to capture three kea and mount GPS trackers in fancy backpacks to collect movement data. She also observed kea during the morning and late afternoon-early evening periods for several months, mostly to record their feeding. Jodanne used direct and video observations to observe their foraging. Kea poo was also collected when available to get some physical information about diet.

    The kea with transmitters spread their time between the plantation areas and neighbouring native forest. The majority of time was spent in the pines where they foraged, roosted and nested. Kea were observed eating pine seed, as well as tissue stripped off newly harvested Douglas fir logs. The faecal samples, well the bits that could be identified, contained lots of invertebrates.

    Kea have discovered that they can strip the bark of newly harvested logs, scrape off the cambion tissue, chew this and get something nice out of it. (Maybe a bit like eating sweets?) This may be one of the attractions of being in plantations. Image by Adrian Paterson.

    In short, as summarised in a NZ Journal of Zoology paper, kea seemed to be using the pine plantations in similar ways to more natural areas. Good news! However, one of three kea that carried a GPS recorder was killed by a cat. So, there may be some significant risks for kea spending a lot of their time in these areas. ‘Swings and roundabouts’ as they say.

    Despite this being a relatively small scale study, it does indicate that we could learn a lot more about kea in these highly modified landscapes. Jodanne has taken this training and shifted her sights to a much larger scale project on kea movement in the Southern Alps and southern Westland.

    Kea are one of the smartest bird species on the planet but they still need our help to let them survive the arrival of the smartest mammal species and the changes that we have made. Understanding this clever species is fundamental to helping them. This tricky challenge has been accepted by Jodanne and her research colleagues.

    Article by Adrian Paterson, an Associate Professor in the Department of Pest-management and Conservation at Lincoln University.

  • Kiwi calling: when listening is not enough

    I don’t know about your’s, but my mum gets worried when I don’t respond to her phone calls for a few hours. Once, I can’t remember what I was doing, but I didn’t hear the phone ringing. When I finally checked my phone I saw about 17483 missed calls, oops. I can only wonder what went through her mind when I wasn’t responding: she was probably picturing me skydiving, in an ambulance, or lost in the woods during a hike.

    But what if she’d had a more statistical mindset and thought about why I hadn’t responded? Or even better: what if she’d thought about reasons why she could not detect me?

    Ecologists and conservationists consider something similar when analysing data obtained from searching an area for a certain animal species. An animal could be present at a certain site, but still go undetected. First, they have to consider what ecological reasons might have determined where the species was present or absent (for instance, where is there suitable habitat within the considered area). Second, they have to take into account what factors might have influenced the likelihood of actually observing the species (such as the distance from the observer, or the fact that the surveyor may not be skilled enough to recognise the species). These are defined, respectively, as occupancy (which is the same as saying “presence”) and detection probabilities, and can be estimated by using statistical models.

    Occupancy probability and detection probability are described by two different models and both of them will influence what will be observed during a survey. Taking into account that not all the animals will be observed is very important when attempting to accurately assess a species’ presence, which could otherwise be underestimated.

    A young roroa being released as part of the Operation Nest Egg programme. Image by Jon Sullivan on Flickr.

    Peter Jahn, James Ross, Darryl MacKenzie and Laura Molles, in a study published in 2022, wanted to know how accurate acoustic surveys of roroa-great spotted kiwi (Apteryx maxima) were between 2011-2015. During this time, 18 birds were translocated from the Hawdon Valley, in Arthur’s Pass National Park, to the Nina Valley, in Lake Sumner Forest Park, representing one of the initial efforts of the Operation Nest Egg programme. The researchers also wanted to compare kiwi presence before and after 2015, and between the two areas.

    They gathered data from a survey conducted in 2012-2013 by DOC in both the valleys and then repeated the methodology in 2017-2018. The technique they used was passive acoustic monitoring (PAM). PAM is effective when studying elusive species such as kiwi. Automatic recorders were deployed in the two study areas and left there for up to three weeks, activating just before sunset and switching off shortly after sunrise.

    The team analysed the kiwi calls recorded in each of the valleys. The goal was to find a model that would best describe the obtained data, and use it as a base to estimate occupancy and detection probability. Peter Jahn and colleagues wanted to know which factors were important in detecting the kiwi and looked at the study area (Nina and Hawdon Valleys), year, length of the survey night, breeding/non-breeding season, precipitation, wind speed, night length, varying recorder battery capacity.

    Similarly, my mum could have considered the fact that my phone may have been in silent mode, or had no service, or estimated the actual likelihood of me being in an ambulance. All of these factors could have influenced her imperfect detection of me.

    In both the study areas, the detection probability was found to be higher during the breeding season, to increase with longer survey nights and to be influenced by wind speed, rain accumulation and recorder sensitivity. Also, as expected, kiwi presence in the Nina Valley increased after the translocation, as it did in the Hawdon Valley. Moreover, it was found that the number of sites where kiwi calls were recorded increased in 2017-2018 in both the areas and that, in total, many more calls were detected in the Hawdon Valley than in the Nina Valley.

    The Hawdon Valley in Arthur’s Pass National Park. Image CC-BY-NC by Jon Sullivan on Flickr.

    Wait, the number of sites where calls were recorded and the presence of kiwi increased in the Hawdon Valley after kiwi were removed from there? How is that possible? Yeah, that was one surprising finding of the study. In fact, the researchers were expecting that occupancy would decrease after the birds’ removal, but what they found actually suggests that new pairs re-occupied the territories left inhabited by the translocated individuals.

    This is a promising result, because it means that such conservation strategy doesn’t necessarily negatively influence the population from which the individuals are taken. Also, the ongoing pest mammal control in the Hawdon Valley could have balanced the negative effect of the translocation. I guess the only thing left to do now is find out what makes kiwi desire those territories so much that they can’t stay away: maybe they have the most delicious earthworms of New Zealand?

    To conclude, these findings demonstrate that the species is reacting well to this reintroduction programme, considered that kiwi presence increased in the Nina Valley too. Furthermore, this study showed that combining occupancy estimates through statistical models with acoustic monitoring is very useful when studying the outcomes of kiwi’s translocations. However, if you, reader, can’t wait to know more about what happens to our dear kiwi when we move them around, sit back and read Peter Jahn’s PhD thesis: never stop learning.

    Finally, going back to my mum trying to “detect” me: I suggest the probability would increase a lot if she learned to call outside of my usual napping times!

    This article was prepared by Master of International Nature Conservation student Francisco Bini as part of the ECOL608 Research Methods in Ecology course.

    Jahn, P., Ross, J. G., MacKenzie, D. I., & Molles, L. E. (2022). Acoustic monitoring and occupancy analysis: Cost-effective tools in reintroduction programmes for roroa-great spotted kiwi. New Zealand Journal of Ecology, 46(1), 3466.