B Sivappan’s banana plantation in Thengumarahada, a scenic village on the eastern slopes of the Nilgiri plateau in Tamil Nadu, was raided by elephants in December. “Earlier they used to run away when we made a noise, lit small fires,” the 61-year-old said. “Now, they don’t seem to care; they just eat as much as they can and then amble away.”

The plateau, which is part of the 5,500-square-kilometre Nilgiris Biosphere Reserve in the Western Ghats mountain range, has seen a rapid increase in incidents of human-wildlife conflict. One reason for this is the proliferation of invasive plant species – plants that are introduced in regions far away from their homeland and thrive at the cost of the native biodiversity – such as the Prosopis juliflora (seemai karuvelam) and Lantana Camara, which seem to endure extreme weather better than their indigenous counterparts. The unprecedented drought in southern India has only exacerbated the situation.

“While not the only factor behind human-wildlife conflict, plants such as prosopis are definitely an important reason why this happens,” said R Venkatachalam, a research associate with the Ashoka Trust for Research on Ecology and the Environment, whose work focuses on the Moyar-Bhavani region inside the Sathyamangalam Tiger Reserve, also part of the Nilgiris Biosphere Reserve. “In the last six months, I have heard of incidents of crop raiding by elephants not only in Thengumarahada but also in the nearby villages of Sirumugai, Kandiyur and Thasamapalayam. Prosopis can be toxic and causes severe indigestion and tooth decay to wildlife, hence they stray into the fields more often because of the lack of better fodder in the wild.”

Traces of prosopis were found in elephants that reportedly died of starvation at the state’s Mudumalai Tiger Reserve last week, as well as in another dead elephant found near Thengumarahada.

The skeletal remains of elephants at the Sathyamangalam Tiger Reserve in the Nilgiris. Photo credit: Sibi Arasu
The skeletal remains of elephants at the Sathyamangalam Tiger Reserve in the Nilgiris. Photo credit: Sibi Arasu

Alien species

Of the world’s 100 worst invasive species, 11 are found in India, and several of these inside the country’s protected areas, according to a paper published in 2013.

Invasive species, be they plant, fish or fauna, have been introduced across various regions of the world and in India for a multitude of reasons. The Lantana camara, native to South America, was brought to India in the early 19th century as an ornamental plant to occupy prime real estate in botanical gardens. The plant, with its pretty flowers, also became popular as a hedge to protect gardens and mark boundaries. Today, it is estimated to occupy 1.3 lakh square kilometres of land across India – a spread that is the size of the country of Nicaragua.

Birds perch on Lantana camara near Kotagiri, Nilgiris. The plants, with their pretty blooms, were earlier used to adorn gardens.  Photo credit: Anita Buragohain
Birds perch on Lantana camara near Kotagiri, Nilgiris. The plants, with their pretty blooms, were earlier used to adorn gardens. Photo credit: Anita Buragohain

Prosopis, on the other hand, was literally dropped from the sky in the 1960s. The plant was considered a great source of firewood and large areas of Tamil Nadu, which was going through a drought at the time, were sprayed with prosopis seeds. Rural communities were encouraged to grow the plant. But as the need for firewood diminished, the plant took root and its sturdy nature allowed it to spread in a far more robust manner, especially in the prevailing drought conditions, than indigenous plant varieties.

“The dung of many animals that consume prosopis acts as a distributor as well as a seed bank, enabling the plant to spread far and wide,” said Venkatachalam of the Ashoka Trust. “In STR [Sathyamangalam Tiger Reserve], which is 1,440 square kilometres, I’d say the plant has taken over at least 40% of the area.”

On Monday, the Madras High Court ordered the removal of prosopis from the entire state as a drought mitigation measure, because the plant with its deep roots is known to deplete groundwater. The court also asked the state government to enact a law for the same.

The verdict was a follow-up to previous court rulings on invasive species. The first of these came in April 2014, when the Madurai bench of the High Court directed the removal of wattle, an Australian plant introduced as timber in the Western Ghats in Tamil Nadu.

But the actual process of ridding the state of every single prosopis plant is an arduous task to say the least.

Prosopis juliflora plants inside the Sathyamangalam Tiger Reserve. They are toxic and cause indigestion and tooth decay in animals. Photo credit: Sibi Arasu
Prosopis juliflora plants inside the Sathyamangalam Tiger Reserve. They are toxic and cause indigestion and tooth decay in animals. Photo credit: Sibi Arasu

On the frontlines

S Kalanidhi, district forest officer in the Nilgiris North Division, admitted as much when he said that getting rid of the invasive plant “would take some time”. But he agreed that it was responsible, to a certain extent, for rising human-wildlife conflicts. “Even if not direct, surely the effect is there, especially in relation to crop raiding and so on,” he said.

Kalanidhi and his colleagues in the department oversee a 550-square-kilometre area and are responsible not only for the conservation of wildlife there but also for preventing them from coming into contact with humans. “In our zone, I think at least 30% of the area is covered by invasive plants,” he said. “We’re now focusing on removing the plants before it flowers, so its spread reduces.”

The underfunded forest department started work on getting rid of the invasive plant only on the court’s directive. Despite a number of such judgements in the last few years, proactive removal of these species has not been on the department’s agenda, despite the widespread presence of these plants.

C Badrasamy, a retired divisional forest officer, said, “We shouldn’t forget that during the British era and also post-Independence, it was us who planted the trees for livelihood and commercial purposes.” He added that while these trees were then a requirement, they have now become an environmental hazard.

Pointing out that getting rid of them after all these years would not be an easy task, he said, “These trees have been here for decades if not centuries. We can’t just remove them overnight.” Listing out the difficulties, he added, “Over the last decade, there’s been an emphasis to protect the sholas [patches of evergreen forests], to not let the invasive plants spread further than they already have. Extraction is bound to proceed at a slow pace because of many impediments. Financial constraints, working constraints and lack of adequate technical training to name a few.”

Black bucks stand amid prosopis plants in the Sathyamangalam Tiger Reserve. Photo credit: Sibi Arasu
Black bucks stand amid prosopis plants in the Sathyamangalam Tiger Reserve. Photo credit: Sibi Arasu

Compensation for losses

In the upper reaches of the Nilgiris, the invasive plants have caused losses for residents while also bringing them in conflict with the wildlife. “In this period without rain, invasives such as the scotch broom, yellow cassia, wattle and so on have eaten up most of the shola forest patches in the land of the Toda communities [native to the Nilgiris],” said Siddhartha Krishnan of the Ashoka Trust. “The thickets that they form have become suitable for predators to prey upon their buffaloes. So they find it difficult to locate good grazing land.”

Ajay Desai, advisor to the World Wide Fund for Nature, said, “What we see today is a combination of factors and invasive plants are an important part of that combination.”

Speaking of compensation for the losses suffered by humans because of the presence of these plants, he said, “The main agency to deal with these issues is of course the forest department. Their compensation scheme is poor in terms of losses actually compensated and has several problems in its implementation. However, that remains the only widely available mechanism for overcoming losses. There are a few scattered schemes from animal husbandry, crop insurance [recent], which help locally at some sites but are not widely available at present.”

To receive the compensation offered by the forest department for crop loss due to raiding animals means going through a lengthy bureaucratic procedure. For farmers to be eligible for this payment, which can range from Rs 5,000 to Rs 10,000, they need a certificate from an agricultural officer as well as the village administrative officer. Only then will their claims be processed.

Compensation for death or permanent disability as a result of an attack by a wild animal is more straightforward, though. And it ranges between Rs 20,000 and Rs 1 lakh in the case of disability and Rs 3 lakhs and Rs 5 lakhs in case of death.

The department and a few non-governmental organisations also offer communities in the area assistance and financial aid for bio-fencing (natural fencing using shrubs and thorns) as well as electric fencing and digging of trenches to keep animals away.

The Nilgiris near Manjur village with tea estates in the foreground, invasive plants such as the Australian eucalyptus and wattle to the left, and shola forests at the far end. Photo credit: Sibi Arasu
The Nilgiris near Manjur village with tea estates in the foreground, invasive plants such as the Australian eucalyptus and wattle to the left, and shola forests at the far end. Photo credit: Sibi Arasu

India’s problem

“Human-wildlife interactions and biological invasion may appear as distinct problems but in many occasions, reduction in native food plants due to increase in cover of invasive plant species have been stated as one of the reasons of straying out of wild herbivore in search of food,” said Monica Kaushik of the Wildlife Institute of India in Dehradun.

Kaushik and her colleagues have been following the linkages between these issues closely over the last few years. “The biggest hurdle in mitigating the conflict is the lack of scientific research related to behavioural aspects,” she said. “Therefore, making country-wide population estimates and gaining an understanding of the behaviour of the species is advocated as the first step towards mitigation of the conflict in the long term. It’s important to restore the wild habitat to prevent the wandering of wild animals out of the natural habitat for food resources.”

As Siddhartha Krishnan of the Ashoka Trust put it, “The local communities are not able to do anything about the invasives. There needs to be a concerted effort, the economic costs have to be worked out. Overall, India needs to care about this more before things get worse.”

Sibi Arasu is an independent journalist based in Kotagiri, Nilgiris. He tweets @sibi123.