How mint leaves and lemon trees are helping elephant conservation in Nepal

Who doesn’t love the lively scent of mint? Or the bright, citrusy perfume of a lemon plucked fresh from the tree? Asian elephants, actually — and that’s a good thing. 

In Nepal’s Terai Arc Landscape — a region known for its rich ecological diversity as well as for being home to endangered species like tigers, rhinos, snow leopards and elephants — there’s an ongoing conversation about how to balance the need for human livelihoods with the urgency of protecting habitat for at-risk species.  

An elephant roaming the Khata biological corridor at night, Nepal. © Emmanuel Rondeau / WWF-US

For the Asian elephant, the continent’s largest land mammal which boasts an appetite as big as its range, one solution is to find out what they don’t like to eat, and to strategically plant more of it. 

Close encounters

It’s estimated that fewer than 250 wild Asian elephants roam Nepal today.  

Since the 1960s, elephants in Nepal have lost 80 per cent of their natural habitat to human development, which means that they often find themselves wandering into farmland while looking for something to eat.  

Getting too close to settlements is dangerous for elephants and humans alike: with huge appetites and huge bodies, elephants can easily destroy a hectare of cropland overnight, devastating a farmer’s livelihood. They can also attack humans who get too close, and deaths — both of humans by elephants, and of elephants by humans in retaliation — have created an uneasy situation in many rural communities in the region.

A wild elephant, Bardia National Park, within the Terai Arc region of Nepal. © Gary Van Wyk / The Ginkgo Agency / Whiskas / WWF-UK

“There is a strong correlation between elephant habitat fragmentation and crop loss,” says Rinjan Shrestha, WWF-Canada’s leading expert on Asian species. Today, human-elephant conflict remains the number one threat to the already-small Asian elephant population in Nepal. “The answer,” says Shrestha, “is to connect and restore historical habitats for growing numbers of elephants.”

Habitat restoration is the best way to keep both elephants and humans safe. Protecting elephants’ pathways, also called corridors, is key to ensuring they can use their vast and varied habitat without as many dangerous encounters with humans. And it means elephants can continue their important work of being “ecosystem engineers for the areas they travel through.

Traditional fences are an obvious answer and used widely in Nepal where elephants are known to raid crops. But they can come with challenges. High-voltage electrified fencing is known to seriously harm and even kill elephants, other livestock and humans. They are also laborious to build and maintain, often requiring hard-to-come-by resources for repairs and upgrades.

Plus, elephants are smart. They can quickly suss out a fence’s vulnerabilities, like unelectrified wooden support posts, which they often kick down.  

It’s a problem that raises a tough conservation question: How do you keep communities and their economies safe while preserving as much of elephants’ natural habitat as possible? In other words, how do you fence out elephants without fencing them in? 

Fences for the senses

For some communities working on their conservation strategies, it’s not about getting rid of fences altogether. It’s about growing them literally from the ground up. 

Krishna Tharu taking his cows to grazing pasture close to the electrice fence protecting farms from elephants. © Emmanuel Rondeau / WWF-US

Biological fencing, or “biofencing” — the practice of making barriers out of natural, living things — is one way to help guide Asian elephants through their natural habitat without tempting them to wander into cropland. 

Often, this type of fencing involves planting quick-growing crops that are natural elephant deterrents because they are non-palatable to them — that is, unpleasant to eat, but not harmful.  

Crops like lemon trees are especially effective because they grow densely, are easy to maintain and distinctively aromatic because of their high concentration of essential oils.

And because smell is a language in which elephants are fluent, the sharp and often overpowering citrusy scent is a cue to move along without the fence piquing their curiosity about what might lie beyond. Other plants like mentha (mint), chilis and chamomile have also been proven to be effective elephant deterrents. The result is an elephant rerouted by part of its habitat rather than by an artificial, and sometimes hostile, object within it.  

But there’s another benefit to biofences: they are an alternative agricultural solution for farmers and landowners, who can sell their crops for a profit during the off-season. 

In the Khata Corridor, which serves as a transborder “wildlife highway” between Nepal and India, and as a result sees a concentration of human-wildlife conflict, WWF works directly with local farmers to cultivate mentha (a plant from which essential oil is extracted). Planted strategically, mentha effectively deters elephants without a need for electrified fencing. Since work began in 2002, more than 12 mentha distillation plants have been installed and over 300 households are engaged in mentha farming in the region. Farmers can also reap the benefits of their conservation solution by selectively harvesting and selling their crop to supplement their income and support the local economy, thereby fostering community resilience and conservation. 

Mentha farming has helped reduce the human wildlife conflict in Khata. © Simon de Trey White / WWF-UK

But the solution is not without its own challenges. For one, the market price fluctuations of these alternative crops can sometimes dissuade farmers from planting them in quantities large enough to deter elephants. Other factors, like the damaging effects of early monsoon seasons and intensive irrigation needs for some deterrent crops, can also be a disincentive. 

Still, biofencing holds promise in Nepal: communities believe the strategy to be effective long-term deterrent, and the potential economic benefits to farmers are encouraging. Its success has also helped reframe farmers as collaborators rather than antagonists in the story of elephant conservation, and to encourage a view of elephants as neighbours rather than nuisances.  

The important part is ensuring that biofencing is planted in the right places so that elephant habitat is not further fragmented and their walking routes are unimpeded. Because that range is so vast — extending over thousands of square kilometres — biofencing can look different depending on an area’s climate and soil. And because elephants often return to the same areas, it can also be customized to address the behaviour of individual animals; knowing elephants’ particular likes and dislikes helps inform spatial planning of crops and break the pattern of conflict. 

Keeping pace

© Wim van Passel / WWF

The strategy is just one part of a much larger elephant conservation initiative currently underway in Nepal’s Terai Arc Landscape, in partnership with WWF, where communities are working in tandem with government and researchers to monitor elephants’ numbers and behaviour using remote satellite technology, protecting existing habitat from being disturbed, compensating communities who have been affected by human-elephant conflict and empowering local people for their stewardship in conservation initiatives. 

“We are beginning to see a ray of hope in our attempts to save wild elephants in Nepal, thanks to the holistic conservation approach that is being adopted by the country,” says Shrestha. “Now more than ever, we need to make concerted efforts to keep this momentum going. One promising way of doing this is to tackle one of the fundamental issues — the human-elephant conflict — head-on by ensuring the well-being of both local communities and wild elephants.”  

There are only 250 Asian elephants left in Nepal, but your support can help restore the habitats that will see their numbers grow. 

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