EcoLincNZ

Category: biological control

  • Kiwi Hedgehogs : A Journey of Curiosity and Connection

    Kiwi Hedgehogs : A Journey of Curiosity and Connection

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

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

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

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

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

    Landscape of Khunjrab National Park, Pakistan © Nisar Ahmed

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

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

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

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

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

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

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

    Hedgehog searching for food © Author

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

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

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

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

  • Echoes of misunderstanding: Invasive species or welcome guests?

    In a new age of ‘fake news’, the exponentially growing ChatGPT, and being talked at by your climate change-denier uncle at the dinner table, how do we know who to trust? Well, the scientists obviously. But what happens when the scientists get it wrong?

    An article released in January of 2024 “Systematic and persistent bias against introduced species” by Patricio Pereyra and colleagues, ruthlessly called out conservation biologists for demonstrating a bias against introduced species. Researchers were accused of shedding a negative light on introduced species no matter their taxonomy, habitat, time of introduction, and regardless of their attributed harm.

    Photo: Amelia Geary / Design: Archi Banal

    Pereyra speculated that the invasion of zebra mussels in North America had a strong impact on the establishment of the bias. Most cases of negative framing in publications were from North America.

    A month later, a counterargument article, led by Dan Simberloff and including Phil Hulme from Lincoln University, was submitted to the same journal. This response tore Pereyra’s article to shreds. For example, there is so much more published material labelling invasive species as harmful simply because most research is driven by funding to deal with harmful species.

    The “guilty until proven innocent” was seen by Pereyra as a bias, whereas Simberloff argued that it was the safest approach. Better to prevent outbreaks first rather than assume innocence and scramble to clean up the mess later.

    The validity of Pereyra’s research methods was also called into question. In their assessment of 300 publications, Pereyra and colleagues based their assessments on only the introduction of each paper, the section where no current research is reported. Pereyra stated that no non-native species have caused any type of extinction, by citing a study that only assessed their impact on native plants. This would be news to those in New Zealand dealing with the impacts of introduced mammalian predators. In addition, all of the assessments made in this article were made by two authors, with a third brought in when those two disagreed.

    Photo: Author

    Pereyra and colleagues continued to selectively use evidence that matched their hypothesis by making continual reference to the ‘tens rule’. This states that only 1% of non-native species will become pests. As more research on more diverse taxa was undertaken, this rule became a misleadingly low estimate. In fact, it is estimated that 50% of invasive vertebrates lead to harm. So while modern conservationists are able to recognise that the tens rule is outdated, the average person reading at home will not.

    This is just a tiny example of a much larger problem science is facing right now; the power of a harmful narrative in science and its implications for the general public. The science world has been struggling for a while now with issues like P-hacking (selecting data analyses that produce results aligning with their hypothesis), fraudulent scientific papers making it to publication (fabricating research that has not taken place to boost career accolades and experience in industry), and like the mentioned article, lack of rigorous scientific procedure.

    False science can turn certain areas of science into a debate to be had by those who are not fully equipped enough to have it. By now I believe just about everyone in the Western World knows about the reports that vaccines cause autism, an idea that originated from two academic physicians in the 1950s.

    Image: outtacontext

    Over 70 years later there is a massive group of people who still believe this to be true, despite countless modern scientists disproving this idea. Not only do scientists have to conduct research to further the field, they now have to spend countless years using countless resources trying to prove to the public that the beliefs they are so desperately holding on to are, in fact, not accurate.

    While the article accusing scientists of holding a bias against non-native species may not have such a wide reach as the vaccine debacle, it does have the ability to change the minds of people. It can change the environmental beliefs they hold, the way they look at conservation, and the future research they conduct, as well as aligning with their personal beliefs outside the world of science. It creates issues that would otherwise not have arisen; spreading misinformation, fostering unwarranted skepticism, and contributing to the polarisation of environmental issues.

    For example, the Pereyra paper could cause shifts in perception, such as questioning established ecological principles, potentially undermining conservation efforts aimed at preserving native biodiversity. This can have a ripple effect, influencing policy decisions, funding allocations, and public support for important conservation initiatives. While openness and debate in the scientific community is important and should be encouraged, you simply have to get your facts right.

    So again I ask, what happens when even the scientists get it wrong? Actually, it happens all the time. Trial and error are the engine of science! Scientific theories are tested to be disproven to ensure we actually have a full understanding of whatever it is we are studying.

    People at home can also look to disprove scientific theories. Pay attention to the transparency of the method and study size, credibility of sources, and citations from reputable journals and research institutions. It may not save your life, but it will save you from a lifetime of ill-informed conversation around the dinner table. You don’t want to be that relative.

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

  • Creeks spread invasive herbs in New Zealand

    Invasive plants can have a devastating impact on our natural environment.

    What are invasive plants? Put simply, they are non-native plants that spread rapidly within New Zealand and pose a significant threat to ecosystems, agricultural production, or human health. It sounds awful.It is even worse than it sounds.

    Lodgepole pine (Pinus contorta) CC BY by Chris Schnepf, University of Idaho, Bugwood.org

    Invasive plants pose a threat to natural ecosystems as they are often highly competitive compared to native plants. Invasive species also spread rapidly to take over the living space of native plants, alter ecosystem structures, and reduce biodiversity.

    Many exotic plants are invasive, such as lodgepole pine (Pinus contorta) and Scotch thistle (Cirsium vulgare). Invasive plants change the composition of plant communities and affect food webs and ecosystem balance. For example, the introduction of eucalyptus alters soil chemistry and moisture content, affecting the survival of other plants and animals (Mengistu, 2022).

    Invasive plants also impact agriculture and grazing and can cause massive economic damage. Scotch thistle (Cirsium vulgare) can quickly spread and take over farmland, reducing crop yields. Unpalatable invasive plants can compete with pasture grasses, reducing the area of grassland available for grazing and affecting livestock husbandry (Massey Universy).

    Scotch thistle (Cirsium vulgare) CC BY by John Barkla,  

    Some exotic plants are harmful to human healthy, like Giant Hogweed (Heracleum mantegazzianum),  which can cause third-degree burns and even blindness by simply touching it!

    Knowing how invasive plants spread can help us to control them effectively. A study conducted at Lincoln University in 2013 focused on whether creek habitats are a source of spread for these invasive plants.

    Researchers from Lincoln University (Alice Miller and colleagues) studied Hieracium lepidulum (Asteraceae), an invasive herbaceous plant that has proliferated in the South Island in recent decades. It now occurs in a wide range of upland habitats, from improved short tussock grasslands, to intact beech forests, to alpine herbaceous fields. Hieracium is a more shade-tolerant relative of the widespread pasture hawkeed.

    Historical data suggests that Hieracium is common in naturally disturbed habitats, such as stream edges and forest canopy gaps. Alice selected creek catchments in the area with the longest known history of  H. lepidulum invasion in New Zealand:  Craigieburn Forest Park on the eastern side of the Southern Alps, Canterbury, New Zealand. She surveyed 1,144 spots along 17 creek catchments.

    Giant Hogweed (Heracleum mantegazzianum). CBS News

    Alice and colleagues found that creek habitats (e.g., stream edges and disturbed areas) play an important source role in the dispersal of H. lepidulum. These areas tend to be subject to more natural and human-caused disturbances, which provide a suitable growing environment for  H. lepidulum, and contribute to its rapid reproduction and accumulation in these areas.

    The high resource availability and frequency of disturbance at stream edges allow H. lepidulum to colonise and spread rapidly. Disturbed areas, such as forest clearings and trail edges, provide similarly favourable conditions. Stream habitats provide connected linear dispersal paths that allow H. lepidulum to spread rapidly along streams and from there into neighbouring areas.

    The dispersal patterns of H. lepidulum in forests and subalpine areas were found to differ. In forests, the dense canopy and ground vegetation form a natural barrier to the spread of this plant. As a result, the density of H. lepidulum in forests decreases rapidly with increasing distance from creeks, except in areas with higher light availability, such as tree-fall gaps.

    Forested areas near creek edges remain vulnerable to invasion. In contrast, in subalpine habitats, H. lepidulum density declined more gently with increasing distance from creeks. This suggests that these areas are less restricted to seed dispersal corridors and more susceptible to invasion.

    Location of study area with the 17 surveyed creeks in bold and indicated by an asterisk. From Google Map

    The study also found that multiple environmental variables had an effect on H. lepidulum abundance, with dense canopy cover reducing light and inhibiting its growth. Areas closer to stream mouths were usually more frequently disturbed and H. lepidulum abundance was relatively higher. Higher elevation areas pose a challenge to H. lepidulum growth due to harsher climatic conditions, but the invasion is still significant in subalpine areas. Disturbances, such as human activities, increase the chances of reproduction and dispersal of H. lepidulum.

    Alice provided several recommendations for managing and conserving areas affected by H. lepidulum. First, she suggested prioritising efforts to limit the spread of this invasive plant by reducing disturbances in the environment and using biological control methods. Second, she recommended setting up monitoring systems in vulnerable subalpine habitats to detect and control H. lepidulum early and prevent it from forming large populations. Finally, while disturbances are natural in these ecosystems, it is important for managers to consider the additional impact of human activities, such as building roads and trails, which can exacerbate the invasion, especially in subalpine areas where the barriers to invasion are lower.

    Hieracium lepidulum Stenstr. (Asteraceae).CC BY by John Barkla

    Through this study, we have gained valuable insights into the dispersal patterns and environmental impacts of the invasive plant H. lepidulum. This hardy invader tends to thrive along creek margins and in disturbed areas, making these locations hotspots for its spread. It is our responsibility to protect these pristine landscapes from invasive species.

    If you’re hiking in New Zealand’s stunning mountains, keep an eye out for those little H. lepidulum spreading on the sly. Let’s be the guardians of nature and protect this pristine land from these “little invaders” that are taking over our ecosystem.We can help preserve the natural beauty and biodiversity of New Zealand’s ecosystems, ensuring that these “little invaders” do not take over and disrupt the delicate balance of our environment.

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

    References:

    Mengistu, B., Amayu, F., Bekele, W., & Dibaba, Z. (2022). Effects of Eucalyptus species plantations and crop land on selected soil properties. Geology, Ecology, and Landscapes, 6(4), 277-285. https://www.tandfonline.com/doi/full/10.1080/24749508.2020.1833627

    Miller, A. L., Wiser, S. K., Sullivan, J. J., & Duncan, R. P. (2015). Creek habitats as sources for the spread of an invasive herb in a New Zealand mountain landscape. New Zealand Journal of Ecology, 39(1), 71-78. https://www.jstor.org/stable/26198696

    massey.ac.nz/about/colleges-schools-and-institutes/college-of-sciences/our-research/themes-and-research-strengths/plant-science-research/new-zealand-weeds-database/scotch-thistle/

    https://www.cbsnews.com/news/giant-hogweed-plant-causes-blindness-third-degree-burns-discovered-in-virginia-other-states/

  • Dirty little secrets or tiny heroes of the soil world?

    Dirt was one of my first friends. My earliest days were spent collecting worms from the backyard and trying to convince my parents I hadn’t done any dirt taste testing that day (I probably had, but for purely scientific reasons). I was fascinated by what seemed like an entirely different world in the soil of my parent’s garden. I could find all kinds of goodies from insects to plant roots.

    At university I was introduced to the truly magical world in soil: microbes. Although not visible to the naked eye, the tiny worlds inhabited by fungi, bacteria, viruses, and other unbelievably small things, should not be overlooked. These tiny worlds are called the microbial community and they have important roles in New Zealand forests.

    Photo of soil microbes under a microscope. Photo by Pacific Northwest National Laboratory (CC-BY-NC-SA 2.0)

    A good place to start thinking about microbial communities is our own bodies. Most people have heard of their gut microbiome. The microbes in our digestive system are important for our health from immune function to digestion (especially for dirt tasters). However, some microbes, such as the COVID-19 virus, can make us sick. Soil microbes in forests are not so different.

    Forests are dependent on microbes that cycle nutrients, decompose waster, and aid plants in nutrient uptake. Like humans and the common cold, some soil microbes hurt their associated plants. An example of this is kauri dieback disease, a disease spread by a spore in the soil that attacks tree roots and trunks. This disease hinders the tree’s ability to uptake and transport nutrients, essentially starving and killing the tree. Kauri dieback is incurable and fatal for kauri.

    Tāne Mahuta, the largest surviving kauri. Photo by Jodie Wiltse (Author)

    Kauri dieback is named after the tree it infects, New Zealand’s mighty kauri tree. The Department of Conservation explains that kauri can grow up to 16 m in circumference and live over 2000 years. The legendary status of kauri is clear in the language used to describe them. The largest surviving kauri is called Tāne Mahuta, which means ‘lord of the forest’. If you were to visit Tāne Mahuta today, you would find boot cleaning stations, warning signs, and only be able to view the great tree from a platform. Moreso, entire trails have been shutdown to stop people from spreading soil around kauri. Why?

    A soil microbe, Phytophthora agathidicida, travels under the name of kauri dieback. This microbe cannot be seen with the naked eye but has the power to kill tremendously large kauri trees. In humans, the heroic microbes of our immune system save us when nasty microbes make us sick. Are there unseen heroes hiding in the soil that can help kauri?

    During a PhD project at Lincoln University, Dr. Alexa Byers studied soil microbial communities under kauri to find out. The goal was to identify microbes that suppress kauri dieback and can aid in kauri conservation.

    The first step was to understand how microbial communities under kauri react to kauri dieback disease. Alexa infected kauri seedlings with kauri dieback and looked for changes in the soil microbial community. When humans are attacked by illness causing microbes, our immune system amps up to protect us. When soils were infected, Alexa found bacteria that were involved in disease suppression. This was a promising result suggesting that heroic soil microbes could build up their numbers to fight off kauri dieback.

    Kauri tree bleeding resin, a common symptom of kauri dieback disease. Photo by Onco p53 (CC BY-SA 4.0).

    Next, Alexa looked into how specific strains of bacteria from kauri soil impacted the development of kauri dieback. She identified Paraburkholderia and Penicillium microbes that inhibited the growth of kauri dieback in soils. Paraburkholderia are known to enhance plant growth and fix nitrogen. Penicillium are fungi that can kill or stop growth of other bacteria. We officially have some heroic contenders!

    The battles between heroic microbes and kauri dieback in the soil could determine the fate of the kauri above them. Hopefully, researchers can find a way to rig microbial battles in favour of these unseen heroes. More research is needed to determine their true potential, but these soil microbes could be called to action in the near future.

    The world under kauri is just one example of fascinating soil microbes. Soil microbes have been found to be key for carbon storage, impact the taste of tea, and reduce nitrogen runoff from agriculture, among many other amazing things. This is your reminder to appreciate the little things, even the things so little you cannot see them. Next time you play in a garden or walk through a forest, I hope you take a moment to think about all the tiny microbes working away in the soil to help (or hinder) plants and make the natural world work.

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

    Research Paper: Byers, A.K. (2021). The soil microbiota associated with New Zealand’s kauri (Agathis australis) forests under threat from dieback disease: A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University. Lincoln University. https://hdl.handle.net/10182/13887

  • Thistle do me: a fussy biocontrol beetle

    My mother makes a great liver and bacon. Like many cooks who have spent decades on a sheep farm she is also a dab hand with a great mutton roast, scones, and sponge cakes. She can also preserve fruit at a moments notice. The highest compliment I every received for my own infrequent cooking attempts was from my son when I made some excellent gravy – “Well, he is Nanny’s son” he explained. Family feasts around birthdays and Christmas are common at my mother’s house.

    Edith’s fish pie

    One curious dish that makes an appearance amongst the roast veggies and mint sauce is a dish of fish pie. It’s not a typical part of most peoples’ ‘event dining’ but it is a regular for us in amongst the more high flying hams and legs of lamb. Mum’s humble fish pie is tasty, with lots of eggs and white sauce, and the right amount of rice and corn. More impressively, my sons, my nieces and nephews also love it.

    When someone needs a perk up, they’ve been unwell, or they are passing through on their way to a cold, old student flat, a bowl of Nanny’s fish pie will arrive. When there are lots of different options on a laden table, there is always room on your plate for the fish pie.

    Family gathering, three brothers, empty fish pie dish in centre!

    I can understand how I like it, I’ve been eating it all of my life. I guess it is the same for the grandchildren. It’s a constant and comforting food. I’m sure that every family probably has a similar dish.

    How ingrained are food preferences? Do we build them up over a lifetime of experience or do we arrive with inherited preferences? Perhaps a bit of both? It can make a difference.

    Thistles, from the Cardueae tribe, have been introduced into New Zealand, mostly by mistake as passengers with more useful seeds. Like many other species, thistles have done well here and have established in large numbers and with wide distributions. One of the worst is the Californian thistle (Cirsium arvense), close relative of a nearly as successful invader, and a little more photogenic, Scotch thistle (Cirsium vulgare).

    There have been many attempts to control the spread of these thistles with varying, but generally unsuccessful, outcomes. Ideally, it is great to have a solution that can work without too much effort on our part. A successful biocontrol agent can fit that prescription.

    The green thistle beetle (Cassida rubiginosa) forages and lays eggs for their larvae to grow on species from the Cardueae tribe. This creates problems for health and survival of these plants. Excellent, a solution to our prickly problem!

    Cirsium

    Not so fast. Cardueae is a large group (over 2400 species with many natives in New Zealand). The last thing that we need is a beetle that chomps up lots of the species that we are trying to protect. We also don’t want a beetle that gets distracted by eating other species when it should be eating the target. We’ve been there and done that (see the mustelids brought into NZ to eat the rabbits! Oops). We need to know that this beetle is a little more fussy in its likes.

    A Lincoln-based group, including Jon Sullivan from Pest-management and Conservation, have tested the preferences of the green thistle beetle. They have published in Pest Management Science. They selected 16 different plant species from the Cardueae tribe. Beetles were given the chance to eat each species either with no choice (plonk the beetles on a plant and see what they do) or choice (allow them to select between any pair that is presented to them).

    Crucially, the evolutionary relationships were known between the different plant species. Ideally we want the beetles to only eat thistle species of interest and not just anything vaguely similar (just those that are closely related).

    Green thistle beetle samples in Lincoln University Entomology Research Museum.

    When given no choice the beetles tended to make the best of what was offered. When you are really hungry then that marmalade is edible even if you don’t like it! Give the beetle a choice, however, and they go for the species that is most closely related to the Cirsium species. In fact this was such a strong preference that the researchers were able to conclude that the green thistle beetle is very unlikely to become a problem for anything other than the thistles that we want to control.

    The green thistle beetles are born with preferences for the type of plant that they want to eat and to lay their larvae in. These preferences allow them to adapt and specialise more fully to these plant species. New Zealand does not have any native Cirsium, or other closely related species. So the beetle can go forth and munch to their hearts’ content.

    So, was I born with a hankering for mum’s fish pie? Well it is an old family recipe, so the preference for it probably has passed down through our lineage, probably as something that we re-learn every generation. Now if I get some grandchildren, I will have to make sure that they are exposed to fish pie at an early age!

    Adrian Paterson is a lecturer in Pest-Management and Conservation at Lincoln University. He has a lot of preferences that he would like to explain!

  • 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.