The Tom Yum project timeline: Facilitating human-elephant coexistence in Asia through planting unpalatable crops

Lemongrass, galangal, kaffir lime, and chili – these ingredients of the Tom Yum soup, a classic Thai dish, don’t simply remain in the bowl. They also play a role in facilitating human-elephant co-existence. Our partner in Thailand, Bring The Elephant Home (BTEH), began the Tom Yum project in 2020 to help support the local community by designing and implementing experiments using alternative crops that are unpalatable to roaming elephants. In 2022, we also welcomed Ph.D. researcher Tyler Nuckols of The University of Colorado, Boulder in Ruam Thai for a first 4-month pilot study on the potential of alternative cropping as a method to promote human-elephant coexistence, which will contribute to the completion of their Ph.D. dissertation. Three years after its conception, this project has grown from helping farmers alleviate economic losses to a profitable and eco-friendly venture. What’s going on in Ruam Thai nowadays?

Experimental alternative crop trials

In 2020, BTEH kickstarted the Tom Yum project with preliminary experimental plots containing crops that are believed to be unpalatable to elephants.  Preliminary results of BTEH’s Country Director Ave Owen’s research showed that among the crops planted, lemongrass and citronella experienced the least damage from elephants. These two crops were also resistant to insect-transmitted diseases, drought, and other environmental factors that impacted the yield of other experimental crop species. Furthermore, no damage was recorded when elephants walked through the experimental plots; spending little time there, only to make their way to neighboring pineapple plantations. We believe that as the alternative crop project grows, elephants will have less incentive to enter human-dominated areas, and if they do, farmers won’t experience such devastating financial losses as they did before.

Left: Chidapha “Bee” Oiumao (BTEH’s Activity Coordinator) follows elephant tracks to monitor their movement
Right: The first major harvest of lemongrass and citronella from the Tom Yum project experimental plot

The community’s pulse

Between Aug and Sept 2021, Ave Owen conducted a household survey among 239 community farmers to gauge their interest in and experience in planting alternative crops. The majority (90%) of participants reported negative experiences living near wild Asian elephants and expressed willingness to switch crop species to reduce crop damage from wildlife.

A year later, in Nov-Dec 2022, 51 interviews were conducted among pineapple farmers to gain insight into: the economics of current farming practices, and the economic barriers that could discourage farmers to transition to alternative crops. In line with the interviews, BTEH also evaluated the minimum and maximum market value for pineapple, lemongrass, and citronella to gain perspective on the potential economic impact of transitioning to alternative crops. By doing so, they were able to plan community interventions that not only mitigate human-elephant conflict (HEC) but also caters to the people’s economic needs, by finding a reliable and fair market. While full analysis is an ongoing task, data gathered in these questionnaires and interviews are used to optimize the potential impact of the project to conservation and the community.

“Elephants have already pushed over all the trees in my land and the land of neighboring farmers. If we can plant these [alternative] crops like how the farmers are doing here, we can all keep farming without worrying about elephants.” – Khun Noot

“Our land is different and our weather is different, but I want to try planting these crops and if there is a guaranteed market I think other farmers in our village will want to try too.” – Khun Sak

Human Elephant Coexistence Through Alternative Agriculture Research ​(HECTAAR)

Together with a research affiliate of BTEH, Tyler Nuckols began working in Ruam Thai in May 2022, first for a 4-month pilot study. And eventually moving to the village full-time by Dec 2022 to complete their study on human-elephant interactions through a social-ecological approach and the subsequent impacts on the Tom Yum Project at large. Tyler first sought to test and improve their research methods, gain firsthand experience with the focal study location, network with community members, listen to local experiences with elephants, and complete a preliminary social-ecological inventory. During this pilot field season, Tyler accomplished the following:

Visited Kuiburi National Park regularly to document and understand the community-based safari and tourism program as well as observe the wild Asian elephants

  • Worked with Ave Owen to learn previous methods, and understand current study designs and data collection processes, such as crop damage enumeration
  • Guarded crops with farmers at night, conducting semi-structured interviews and observing Asian elephant activity in crops employing new night vision technology
  • Met with the Chief of Kuiburi National Park for introductions and preliminary discussions
  • Joined educational coexistence walks to learn firsthand about the human-elephant conflict present in the Ruam Thai community and farmers’ perception toward elephants
  • Learned the process of creating elephant-friendly value-added products and participated in the harvest of experimental lemongrass and citronella plots together with the community
  • Joined national park rangers, WWF staff and farmers in a community weeding of the national park border observing the park boundary and paths elephants use to crop raid
  • Together with Brooke Friswold, a Ph.D. candidate of King Mongkut’s University of Technology Thonburi, developed trail camera data collection methods
  • Met with the Village Chief of Ruam Thai to gain research permissions, make introductions, and conduct a semi-structured interview
  • Conducted five semi-structured key informant interviews in Ruam Thai
  • Co-hosted two focus group sessions to gain feedback on our social science tools and conduct informal interviews with participants
  • Conducted 30 surveys with randomly selected households in Ruam Thai to gather baseline data and test the instrument.

Following the pilot study and preliminary data analysis, Tyler has adjusted and reframed their study to address the following questions:

  1. What are the areas of highest elephant presence, activity, and crop damage in our focal study location of crop fields surrounding Kuiburi National Park?
  2. What social and ecological conditions result in vulnerability to human-elephant conflict for smallholder farmers, and how does this vary across the landscape?
  3. How does the practice of growing mono-crop pineapple compare to a regime of crop species unpalatable to elephants in terms of changes in measurable farmer vulnerability and adaptive capacity?
  4. Is there a significant difference in elephant presence, activity, damage, and repeated individual visits between farms growing mono-crop pineapple and those pursuing nonpalatable crops and varying levels of measured household vulnerability?

Their study aims to create a model that combines social, spatial, and ecological data to identify hotspot areas of high HEC, human vulnerability, and elephant activity to target management and mitigation solutions. The community in Ruam Thai and management team of Kuiburi National Park, will have full access to this model and map. After the study’s conclusion, the smart AI camera trap network can serve as an early warning system in crop fields surrounding the national park.

The importance of Fair Trade

In September 2022, BTEH connected with Fairtrade Original in the Netherlands. Fairtrade Original closely collaborates with farmers in Thailand, assisting with training and capacity building to aid farmers in getting Fairtrade certified, a visual guarantee that farmers and producers are fairly compensated for their labor. Once certified, farmers can begin collaborating with a factory in Bangkok to export the products to the Netherlands.

Farmers from Ruam Thai visiting the Sisaket Fairtrade Farmer Group in December 2022

As a first introduction to Fairtrade Thailand, representatives of Ruam Thai’s pineapple growers visited the Sisaket Fairtrade Farmer Group (FFG), part of Fairtrade Original, and learned valuable lessons. The farmers in Ruam Thai have experience in growing alternative crops for personal use, but not so much as a cash crop. They were eager to hear more about how the Sisaket FFG grows these crops commercially, and more importantly, the value of fair trade, and how this model can contribute to the well-being of individual farmers, as well as the community. Counting 12 years of experience with Fairtrade, the Sisaket FFG shared their knowledge with great enthusiasm.

Ruam Thai farmers learned about what it takes to become Fairtrade certified; they visited certified farms and left with invaluable insights and inspiration. The second step to certification involves a site visit of Fairtrade Thailand to the village. During this visit, environmental conditions such as availability of water and use of chemicals in the farms will be inspected along with the farmers’ knowledge and experience in planting the alternative crops.

This could be a game-changer for Ruam Thai farmers, the Tom Yum project, and in realizing human-elephant coexistence. We are grateful for the hospitality and guidance of the farmers in Sisaket and the guidance from Fairtrade Original.

Capacity building and product marketing

Whenever there is an opportunity, the Tom Yum Project community group sells elephant-friendly products and shares stories about how alternative crop initiatives help realize human-elephant coexistence. The Tom Yum Project team attended a SEED replicator program and learned about previous successful Eco-Inclusive enterprises. Our team also had a chance to present the history, challenge, and vision of the Tom Yum Project.

The Tom Yum products are for sale at their webshop , and now available in six eco-friendly stores in Thailand. 

Where The Elephants Roamed

By S. de Silva

This slider shows areas containing habitat for elephants (yellow) in the year 1700 vs. 2000.

Where Did The Elephant Habitats Go?

The bulk of conservation efforts center around protected areas as the primary means of safeguarding wildlife and wild places. This is in response to recognizing that human activities are altering the face of the earth at an alarming pace, leading to the loss and fragmentation of habitat for numerous species. Often, our attention is on proximate threats and especially on particular biomes, such as forests. But over what sort of timescale and what sorts of ecosystems have these changes actually been taking place? In order to protect the biodiversity we have today, we have to really understand the processes that maintain them and how we got to where we are.

Asian elephants provide a good perspective on the problem. I’d heard some conservation organizations state that elephants had lost as much as 90% of their historic range, but I couldn’t find a single scientific reference that showed this. Was it true? When I first saw their distribution on a map, I got curious – though classified as a single species, Asian elephant populations occupy many different types of landscapes ranging from grasslands to rainforests that are now cut-off from another. At one time, these disparate populations must have been joined together and if we could reconstruct what happened to these habitats over time, we would have part of the answer. So, I enlisted a team of collaborators to find out exactly when and where elephant habitats started disappearing. In a way, you can think of elephants as being ambassadors for these ecosystems (a reason they’re referred to as “flagship” species). But we couldn’t know exactly where elephants or their habitats had been simply by looking at maps or records directly, so we needed a different trick.

Asian elephants live in 13 different countries. The supposed post-glacial range of elephants, shown in orange, covers a lot of mountain and desert where they probably never lived. The red dots are locations we used to train the model based on where we know elephants are found today, with purple areas showing this known range. Image from Figure 1 of de Silva et al. 2023.

Modelling The Past

We used an approach called “ecological niche modelling” (aka “species distribution modelling”). Basically, we take locations where we know there are wild elephant populations today and relate them to ecological characteristics of those locations. The important thing is that the locations should represent places where elephants could conceivably thrive, not those where they’re likely to conflict with people (such as agricultural plantations). As the first step, we therefore compiled locations that represented as many of the different ecosystem types from as many countries as we could verify that wild elephants actually occurred, from locations that still contained good habitat.

The second step was to find a dataset that provided the ecological features of these locations. We could think of a lot of features that might matter, but since I was interested in the history of the landscapes, the tricky part was that these same variables had to be available going back in time. Lucky for me, a group from the University of Maryland had just released a new version of something they called the Landuse Harmonization Dataset (LUH2) which did just that. It modelled different land-use and land-cover categories (including not only forests and pastures but also primary non-forested lands, various types of agriculture, and wood harvesting rates) all the way back to the year 850 CE!

With these two types of data, we could construct our model. First we used a machine-learning algorithm called MAXENT (which stands for Maximum Entropy) to relate the locations of elephants to 20 of the LUH2 variables for the year 2000, which we used as our base year. We then took this trained model and re-used it again and again to generate maps for prior years back to 850. We also made maps up to the year 2015, where the LUH2 historical dataset ends. The resulting maps give us a sort of index of “suitability” with 0 being areas that elephants might be less likely to occur and 1 being areas they’d love. In order to calculate how much habitat was available for elephants and how it fragmented over time, we had to convert this continuous scale into a simpler binary classification of unsuitable vs. suitable, which we did based on a statistical cut-off threshold.

Mapping Changes Over the Centuries

Since our dataset didn’t go all the way back to the end of the Pleistocene, I can’t really tell you if that map up there is justifiable. But we did see that there was plenty of habitat for Asian elephants all throughout the continent way back in 850, and it pretty much stayed that way until the 17th or 18th centuries. But then the amount of available habitat took a nosedive, and by 2015 there was a loss of 64%. The video above, from our paper, shows this progression with yellow being “suitable” habitat.

Back in the 1700s, if you were an elephant, you could have more or less wandered around over 40% of the continental habitat without interruption – this doesn’t mean it was all a single type of habitat, because remember, elephants are generalists; these may have been forests, grasslands, or lots of things in-between, but they had plenty of good vegetation. This included landscapes within 100 kilometers of where elephants live today. But by 2015 the largest patch of habitat constituted barely 7% of the total available and less than half of their current range was classified as being suitable.

Just think about that for a minute.

This means that perhaps half of the elephant populations are living in suboptimal habitat – areas that aren’t really so good for them. As we discussed in an earlier post about another study, elephant populations can hang on for quite a while even when things are not so great, because they are long-lived (unless hunted) and breed slowly, so it might be difficult to notice when there is a slow decline. But poor habitat means they will breed even more poorly and calves may not survive, eventually causing the population to go extinct – unless they move to better habitat. This can create its own challenges, as elephants might pass through places that are unused to having elephants, with people who don’t know how to react.

Going country by country, the largest losses happened in India (which lost >80%) and China (>90%). These two countries had the largest land areas and hence the largest amounts of absolute habitat to begin with. Today, India still has the largest share of the elephant population, but China has a very small share. In these and other countries, the loss of habitat not just in the short term but these very long timescales may underlie so-called “human-elephant conflict” as elephants and people adjust to the new normal: lots of elephants trying to make a living on inadequate habitat, and lots of agrarian communities trying to make a living next to elephants.

Why did this happen and what should we do? Read on to find out.

A paddy field by day contains lots of human activity but by night the elephants are out and about.

Two Revolutions

The changes in Asia reflect events that swept the globe during that time across all continents. Colonialism, which was already happening, had already made inroads into the natural resources of many countries. But the industrial revolution really allowed these resources to get exploited at a pace and scale that was unprecedented. These two together dramatically changed the way lands were managed – taking them out of the hands of local communities and placing them in the hands of governing bodies or enterprises that were pre-cursors to modern-day multi-nationals. The conversion of these elephant ecosystems, as I call them, reflects this massive geopolitical and economic shift, which was most pronounced in South Asia as well as the far East.

But looking carefully at the timing, another observation really stands out. Something else is going on in Southeast Asia. Notably, the biggest and brightest patch of habitat, which was located in what is now central Thailand, was around much longer. It doesn’t disappear until the middle of the last century, right around the time of a different kind of revolution – the so-called Green Revolution that brought about industrial agriculture. Large-scale plantations such as tea, rubber, coffee, timber and the like had already been put in place during colonial times, but now there were fresh land conversions for crops such as rice, fruit and vegetables. Of course, there are many other human activities that have ramped up too – mining, road building, urbanization. But all of this really represents this pair of revolutions that continue to play out today as our globalized economy gobbles up resources at an alarming pace.

What Next?

So what can we do? Should we redouble our efforts to increase the amount of land that is strictly protected from human activity?

Well, not exactly.

As we discussed in a post about our last study, elephants can’t be contained in protected areas because usually these areas are just too small. There’s no way any park or sanctuary in Asia can be large enough to be fully sufficient without also displacing a lot of people, which has been the way many protected areas were created in the first place.

But a more profound observation, based on mounting evidence from other studies, is that people might have been an important component of these very ecosystems. The vast majority of ecosystems – be they grasslands, forests, or something in-between – have been managed by people for hundreds if not thousands of years. Humans (yes humans!) may be vital to maintaining the kinds of habitats that species like elephants and other wildlife actually thrive in. Practices such as setting managed fires, seasonal and shifting cultivation, creation of water sources, and lots of other things that people historically did in these landscapes long before they were colonized and claimed for other purposes.

This was a difficult thing for me to wrap my head around, because as a biologist in many ways I had been trained to think about how “wild” nature operates independently of us. Non-interference with what is happening is fundamental to the study of animal behavior, for instance. It wasn’t just my scientific training, I later recognized, but it’s the separation of humans from nature that arises from a very particular social-cultural worldview that now predominates our society. This view has largely buried our actual history – one in which we were respectful stewards of the land.

As a species, we most certainly do not practice non-interference: when we see an elephant (or any other animal) in trouble, some of us go out of our way to help it. This is something I love about our species, and it gives me hope.

The world today is a very different place. As we head towards a planet of 8 billion people with climate change looming, is it even possible to share space with wildlife like we did before? Elephants force us to reckon with our place in nature if we are to continue to live together.

Read the paper: 

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Dry Rations Donations in Udawalawe

By Salik Ansar

At the beginning of 2022, no one would have anticipated Sri Lanka’s year to be so dire (and that’s saying something after the anguish from the global pandemic we all shared in!). The country suffered from one of its most severe economic crises – there was no fuel, extended power cuts, no fertilizer, no food crops, no tourism, and the list goes on… With no political and economical stability, Sri Lanka was looking over the precipice of a terrible crisis. Given Sri Lanka’s demographics, the majority of the people in rural areas are farmers and they were severely affected by these difficult times.

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A tribute to our beloved Jasmine

Remembering a gentle spirit.

Jasmine, and Asian elephant.
Jasmine (center left with pink ears), in 2012 with her calf Josh.

From Shermin:

When I first started the project in 2005, I was touched to see the relationship between an inseparable pair of elephants. The elder, who I named Janet, was toothless and slender, clearly a grandmother who was peacefully nearing the end of her long life. The other, who looked almost exactly like a younger version of her, was in the peak of her life. I thought this must be her daughter, somewhere in her twenties perhaps. I named her Jasmine, after my favorite flower, because I thought her so pretty with her perfectly triangular and symmetric pink-edged ears. She was perfectly proportioned, a textbook example of elephant-ness. They went everywhere together, drifting in and out of a larger social group that I thought might be a single family.

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How elephants in Sri Lanka use protected areas

By Annie Madsen

Elephant behavior has long endeared the public. From complex social structures to tool use, hearing stories about behavior not only teaches about fantastic ecological adaptations, it shows a window into elephant’s lives that we can understand and relate to on a personal level. Showcasing behaviors has often been used to help elephant conservation. However, behaviors are sometimes disconnected from how managers actually conserve elephant populations. In a new study, we examine elephant space use behavior in the hope that it can directly inform management practices.

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Are Trenches Really the Solution to Human-Elephant conflict in Sri Lanka?

By Salik Ansar     


Day by day, elephants are losing their habitat. Hour by hour, they are losing their sources of food and water. Now, they are faced with yet another threat – falling into man-made trenches. These falls, and getting stuck in trenches, could be life-threatening. In 2021, the State Ministry of Wildlife Conservation decided to dig trenches to try to prevent elephants from crossing into human-occupied lands. However, experts fear the decision will cause more harm to the animals than good.

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Sri Lankan Economic Crisis: Why it Matters

UWERP’s field technician, Janaka, delivering a month’s supply of dry rations to a rural Sri Lankan family

The story so far

Over the last few months, Sri Lanka’s economy crashed and the island nation is now facing its worst economic crisis in history. For Sri Lankans, the crisis has turned their daily lives into an endless cycle of waiting in lines for basic goods – many of which are being rationed. Why is this happening?

The main reasons are loss of foreign currency due to COVID’s impact on tourism, and mismanagement of the country’s predominantly agricultural economy. Foreign reserves have been reduced by roughly 85%, grinding daily life to a halt. There are huge lines for fuel (for transport) and gas (for cooking). The lack of fuel also affects the country’s power supply, with people facing up to 16 hrs of power cuts daily. The lack of fuel has created a shortage of vegetables in the market and thus the prices have shot up by 30-80%. Additionally, as the country cannot afford imports, products like butter and milk powder are now unavailable. The Sri Lankan Medical Association has also stated that medical supplies are running low and by the end of April, Sri Lanka ran out of key medicines and medical supplies. 

Why are we helping farming communities? 

Trunks & Leaves has been involved in the Udalawawe area for more than a decade. We have worked with communities around the national park helped them for many years, because we know that people are key to conservation success. Although farmers are sometimes painted as villains owing to their part in so-called “human-elephant conflict,” nothing could be further from the truth. Farmers recognize and appreciate the value of elephants and other wildlife, they simply need to earn a livelihood as well. Last year in 2021, farmers in Southerns Sri Lanka actually went on a hunger strike, demanding the creation of a promised reserve, which they hoped would help the elephants and reduce the pressure on their croplands.

This year, we were to launch our trials of (elephant-resistant) alternative crops on a larger scale, but have had to put everything on pause given the current crisis. And yet we realized, NOW is when help is needed the most. Although we are a wildlife conservation organization and not dedicated to providing humanitarian aid, we couldn’t stand by and do nothing.

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New pan-Indian study of elephant genetics reveals surprises

Herd of elephants in Terai Arc Landscape

Asian elephants were once widely distributed in India, but are now restricted to four widely separated regions: the north-western (NW), north-eastern (NE), east-central (ECI), and the southern India (SI). When you undertake the population genetics study of a wildlife species, the quality of the result is related to the design of the field sampling protocol. This is to ensure that the sampling is extensive covering different areas to avoid over-sampling of more accessible populations. When we started our population genetics study of the Asian elephant (Elephas maximus L.), we planned to collect fresh elephant dung samples from across the beats and various ranges of protected forests in India. This of course often involved traversing through inhospitable and difficult terrain with a forest staff in attendance. The first problem were the elephants themselves. To get fresh dung, one had to go close to elephants for collecting samples. This often did not go down too well with some individuals who responded to the invasion by a determined charge. We were fortunate not to have suffered any mishaps and ultimately it worked out well and we were able to collate an impressive database of elephant dung samples.

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Camera Trapping Elephants in Agricultural Areas

In partnership with Bring The Elephant Home in Thailand, we’re excited to share this picture diary from the field, by Brooke Friswold, who is a PhD student at King Mongkut University of Technology Thonburi!

Written by Brooke Friswold

It has been another busy month in Ruam Thai Village! We have erected ten camera traps on pineapple farms with the consent of local farmers in areas with reported high frequency of visitation and five on lemongrass farmland rented by Bring the Elephant Home.

In speaking with the farmers they were very excited and enthusiastic to share their experience: some of the farmers say that the elephants are coming most nights to their land, while others say it can be weekly or also come in waves, with times of high visitation followed by lapses in appearance. The farmers were very eager and interested to share and discuss where the best placement would be for the camera traps, the trails the elephants use to enter, and the recent visitations they had.

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Trialing Camera Traps 

We’re partnering with Bring The Elephant Home in Thailand to trial the potential of alternative crops to support farmers living with elephants. We’re excited to bring the first news from the field, by Brooke Friswold, who is a PhD student at King Mongkut University of Technology Thonburi!

by Brooke Friswold

The team in Thailand has been busy over the last two months – especially while director and founder of Bring the Elephant Home (BTEH) Antoinette van de Water has been in country! With the start of data collection for a subset of five BTEH rented lemongrass plots and ten community-owned pineapple plots on the horizon, equipment and methodology trialing has begun. Data collection via camera trapping is set to begin in mid-May to record baseline elephant behavior in control and experimental plots for the HECTAARE project and for Brooke Friswold’s PhD research with King Mongkut’s University of Technology Thonburi (KMUTT) in partnership with BTEH and HECTAARE. 

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