Wildlife & Biodiversity

No food in forests: Invasive species and altered habitats in Karnataka’s Western Ghats are creating a food crisis

The crisis may be fueling conflicts between humans and wildlife, prompting animals to venture into human settlements

By M Raghuram
Published: Tuesday 16 January 2024
A lantana plant. Representative photo: iStock

This is the first part of a series exploring the food crisis for wildlife.

In Western Ghats, the pervasive invasion of non-native plant species is swiftly displacing indigenous vegetation, triggering a profound ecological imbalance. This insidious takeover is instigating a pressing food crisis as the invasive plants disrupt the natural habitat of crucial prey species. The ensuing scarcity compels wildlife to venture into human settlements, intensifying conflicts between communities and animals. 

The scenic patches of the Western Ghats, particularly those adjacent to major roads like national highways, state highways and major district roads, are witnessing a transformation. The natural vegetation is being replaced by exotic species like Simarouba glauca, as well as economically valuable ones like coffee, areca, red sanders, teak, mahogany and rubber.

Invasive species such as Lantana, Eupatorium and Parthenium are causing additional ecological disruption. These aggressive invaders are decimating traditional forest fruit-bearing trees such as wild mango, wild jack, wild plantains, forest jack, and various berries, which are critical sources of food for animals, rodents and simians.

As invasive species establish themselves and spread, the Western Ghats’ flora and fauna are changing dramatically. Large mammals, particularly leopards, are venturing into human habitats in search of food. The loss of habitat and the transformation of vegetation, combined with an increase in the population of large carnivores, contribute to escalating conflicts.

Lantana has invaded 87,224 hectares (863.62 square kilometres) of Bandipur National Park (BNP), accounting for approximately 75 per cent of the park’s total area. The dense growth of the invader ranges from 20 per cent to 80 per cent in different pockets, restricting the movement of animals. In some areas, the weed has grown so lushly that even a herd of elephants behind it would remain hidden, according to conservationist Giridhar Kulkarni.

In the 1990s, the BNP was a grazing ground for many herbivores like gaur, chitals and four-horned antelopes, said Jenu Kuruba community leader Narasimha, who also works as a forest watcher. “The grazing areas would often turn into hunting grounds for tigers, dholes (wild dogs) and leopards. The Parthenium started appearing in smaller numbers in mid-2000s and the forest officials and the village forest committees (VFC) jointly tried to weed it out,” he said.

But the efforts were in vain — after a monsoon season, Lantana had also invaded the park, said Narasimha. “Over 1,200 tribal villagers from 60 villages were in the weeding campaign along with the forest department, but it still failed. There was not a part of BNP without Lantana by 2017,” he said. 

After the takeover of the grasslands by the invasive plants, the resident herbivores either migrated or perished, the community leader said. “The prey animals no longer wander the region freely. The villagers are still trying to weed out Lantana,” Narasimha said.

Over 40 per cent of the land area in Biligiri Rangaswamy Temple Tiger Reserve, Karnataka is also overtaken by Lantana, said Deputy Conservator of Forest Santhosh Kumar.

Lack of food and restricted movement has resulted in wild animals entering human settlements. In the last three years, Nagarahole National Park in Karnataka has witnessed an increasing number of wildlife incursions into human habitation — about 100-120 per year, said Nagarholay Bheemappa, VFC member from the park’s K Gudi division. Meanwhile, VFC networks reported 41 cases from 2006 to 2011.

“Leopards enter villages and pick up dogs and cattle, whereas larger carnivores, such as tigers, attack humans and cattle,” he said. 

Habitat destruction caused by linear projects, mining, encroachment and irregular tourism are the primary causes of increased human-wildlife conflict, according to Kulkarni. “The connectivity between wildlife corridors used by large mammals — especially elephants, tigers — has also been lost in many areas,” he pointed out. 

Elephant migration routes in Hassan, Kodagu, and Mysuru districts have also changed as agricultural and commercial plantations have expanded. The Alur-Brahmagiri migration route, one of Karnataka’s longest, passes through densely populated areas as well as newly developed agricultural pastures. 

Bamboo and wild plantains are the traditional food of the elephants; these are now in short supply on this migration route for various environmental reasons due to human-made infrastructure corridors, including pipelines, power transmission lines, roads, and irrigation projects. The jumbos stick to their migration route, consuming whatever comes their ways —  banana plantations, arecanut trees, pineapple gardens, pepper vines and even paddy crops. 

Ganesh Naika of Sullia taluk says, “Ours is the last village in Karnataka before the elephants enter Kerala; the corridor has undergone changes all the way till Wayanad. Recently, elephants were also seen devouring paddy on this route. It has also enhanced the chances of human-elephant conflicts and during the last three years, 12 people have been killed in different places in Sullia,” Naika claimed.

In the face of this ecological upheaval, several rainforest complexes, including Nagarahole, Anshi National Park, Kudremukh National Park and Bhimgad Wildlife Sanctuary, are proactively addressing the invasion of invasive species. Initiatives such as yearly seed dispersion and grassland development programmes are underway to mitigate the impact and restore a semblance of balance.

The forest department is encouraging planting local fruit and berry-yielding trees to retain wildlife inside the national parks, said AV Satish, assistant conservator of forests. The forest department has also created nurseries of forest trees in more than 45 locations. “In fringe areas, we plant wild mangoes, Nerale (black plum), jackfruit and wild jack varieties to prevent animals from foraging in human habitation,” he said.

Lantana infestations date back 200 years and are a problem in all four states of Western Ghats, said senior wildlife official and former executive director of Chamarajendra Zoological Garden, Mysuru, BP Ravi. “The only way to make way for the growth of natural grasslands is by manually removing them with human hands. Once the grasslands come back to their natural expanse and growth pattern, the herbivores will remain inside the forests, and even the predatory animals will stay put in their habitats.”

Former Principal Chief Conservator of Forests Vinay Luthra, however, disputed the notion that a lack of food is the sole cause of wildlife incursion. He emphasised, “The wildlife incursion into human habitations is not a new phenomenon, it has been happening forever. When extra high-calorific food is available just around the corner, wildlife, particularly elephants, will invade it irrespective of the food inside the forests,” he said. 

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