Pushed to The Edge: Lion-tailed Macaques and the Case of Disappearing Forests

Destruction of forests is pushing a growing population of the shy lion-tailed macaques to look for food in human settlements

By Bhanu Sridharan

When forests are broken up by human activities, the impact on wildlife is manifold. Many species lose their habitat, sources of food and are forced to navigate increasingly risky landscapes like busy roads, agricultural fields and human habitation. Lion-tailed macaques in the Valparai plateau in the Anamalai Hills in the Western Ghats face all these issues. But their attempts to adapt to their changing landscape is forcing these once shy, elusive animals into increasing contact with human beings. The result, according to researchers, is a new conflict situation in the plateau.

Several species of primates interact with humans across the planet. With shrinking forests, primates like bonnet macaques often learn to beg for food or raid human settlements. Rhesus macaques occupy public spaces like temples, old monuments and gardens. These monkeys learn to survive on human food supplies by raiding kitchens, rummage through garbage or subsist on food handed out by people around their original habitats. But where bonnet and rhesus macaques are widely distributed — and highly adaptable — lion-tailed macaques (LTMs) are a little different.

LTMs are an endemic species that are found only in small pockets of the rainforests of the Western Ghats. Studies report that there are currently between 3000 to 4000 individuals left in the wild, including small populations in the Kudremukh and Sharavathi Wildlife Sanctuary in Karnataka, the Anamalai Tiger Reserve and Megamalai Wildlife Sanctuary in Tamil Nadu and the Parambikulam Wildlife Sanctuary and Silent Valley National Park in Kerala.

Map shows how LTM populations are restricted to fragments of rainforests across the Western Ghats. Image from the paper Ram et al (2015) published in the journal Plos One. Stuck in a rainforest
LTMs move through the forest searching for fruiting trees. Seen here feeding on Cullenia exarillata. Cover Photo: P Jeganathan/CC BY-SA 3.0

One reason for LTMs to be restricted to rainforests is their diet, explained Ajith Kumar, the director of the Wildlife Biology and Conservation Programme run by the Centre for Wildlife Studies and National Centre for Biological Sciences. Kumar, who started studying LTMs in the 1970s, was one of the first researchers to study the ecology of the species in the Top Slip region in the Anamalai mountains, as part of his doctoral work.

He explained that LTMs are primarily fruit-eaters, which presents them with two problems. “One is that you need to have fruits available throughout the year,” he said. This is only likely in evergreen rainforests where there is a greater diversity of trees compared with dry forests. Trees in rainforests also fruit at different times of the year, ensuring that LTMs and other fruit-eaters have some food supply year-round. “If you go to a dry deciduous forests, there are times, several months of the year, [when] there are no fruits,” Kumar added.

There are lean periods in rainforests, especially during the dry season from November to March, when not too many species of trees bear fruits. LTMs are forced to then move across the forest looking for fruiting trees. But fruits, don’t provide all the nutritional requirements that the macaques need. So, they supplement their fruit diet with insects for proteins. Insects, Kumar pointed out, are most likely to be attracted to green leaves. “Again, green leaves are there only in tropical rain forest throughout the year. So, that’s another reason why they’re sort of trapped in evergreen forests,” he added.

LTMs typically move through the canopy of trees while tracking fruits. During Kumar’s early research and indeed for several years after that, ecologists and naturalists noted how rare it was LTMs to descend to the ground. In fairly large continuous stretches of forests like Silent Valley National Park, LTMs were always observed through the dense green veil of the forest canopy.

Read more: Do we need flexible spaces for humans and animals?

The descent of macaques

But the fragmentation of rainforests in the Ghats is breaking up this network, restricting movement. As a result, the monkeys started coming to the ground, forced to walk across roads and plantations to reach the next fragment of forests in search of food. Nowhere has this been more apparent than in Valparai plateau in the Anamalai hills. In the 1800s, British colonisers began to clear vast tracts of the Valparai rainforests to plant coffee and tea and exotic trees like Eucalyptus. The result is a patchwork of about 40 rainforest fragments surrounded by plantations and human settlements.

Researchers estimate that a population of around 1108 macaques live in the Anamalai hills. Like several other primates, LTMs live and move in troops. While most of this population seems to be restricted to the contiguous rainforests of the Anamalai Tiger Reserve, about nine troops of around 200 LTMs have been reported to live in fragmented rainforests interspersed with tea and coffee plantations in the Valparai plateau.

In a study published in 2001, researchers from the Bio-psychology lab at the University of Mysore noted that LTMs in the Pudhuthotam estate in Valparai were spending far more time on the ground than before. The researchers had observed LTM behaviour between 1990 and 1991 and then again between 1999 and 2000 in the rainforest fragment. Pudhuthotam is a private estate that until 1990 had a mix of coffee and cardamom plantations interspersed with rainforests. By 1999, when the researchers came back to study the LTM troops, about 197 hectares of coffee plantation that had a canopy of shade trees, had been cleared for open tea plantations with no trees. The approach to Valparai town is also through the Pudhuthotam estate.

With this loss of the rainforest, LTMs started changing their behaviour considerably. By 2000, the researchers noted a 22-fold increase in the amount of time LTMs spent on the ground resting and a nine-fold increase in the amount of time they spent feeding on ground. Instead of exclusively foraging for fruits in the trees, the macaques were on ground looking for fallen fruits to eat, a behaviour the researchers noted was rarely observed in undisturbed rainforests. This period was when the researchers also observed LTMs crossing roads and entering people’s homes.

By 2001, researchers started noticing that the arboreal LTMs were now spending more time feeding on the ground and crossing roads, resulting in road kills and electrocution. Photo: P. Jeganathan / Wikimedia Commons

These results assume even more significance today, because even as the rainforest fragment shrinks in Pudhuthotam, the LTM population is steadily increasing. In 1978, researchers recorded 25 LTMs in the estate. By 1991, Mewa Singh and his colleagues recorded 51 LTMs that had split into two troops. By 2011, this number had gone up to 122 monkeys in three troops.

Currently, Ashni Dhawale, a PhD scholar from National Institute of Advanced Studies, Bangalore, who is studying LTM troops in Pudhuthotam, believes there are about 156 monkeys in five troops. In work that has not yet been published, Dhawale has also been recording increasing interactions between LTMs and people, where the macaques were seen eating more human food (from garbage and raids on homes) and spending more time on the ground.

What do these increasing interactions mean to the people living in Valparai?

The conflict with humans

In 2018, researchers from the Nature Conservation Foundation turned their gaze to this new set of behaviours. They realised that in areas where LTMs were forced to share spaces with people, a new conflict situation was brewing. Using a questionnaire survey, P. Jeganathan and his colleagues tried to understand how people of Valparai perceived LTMs based on their interactions with the monkeys.

Jeganathan interviewed residents, most of them tea estate workers, living near three different forest fragments in the plateau: the Pudhuthotam fragment, Korangumudi fragment and Old Valparai.

“We actually realised from the community that the monkeys are entering houses. We thought we’ll do something about it, but before that, we thought we’ll understand where this is happening and what people think about LTMs in that fragmented landscape,” explained Jeganathan. To do this, the researchers asked people questions to understand if they were aware of the LTMs, whether they had seen them around their homes, if they understood their conservation status and most importantly, how they felt about the macaques. People were asked to explain if they viewed the macaques positively, negatively or were neutral.

With an increasingly degraded forest, LTMs are now looking for food in people’s homes in Pudhuthotam estate. Photo: P. Jeganathan/Wikimedia Commons

To Jeganathan’s surprise in Korangumudi 23 of the 35 residents he interviewed were not even aware of the presence of LTMs. “Some people are aware of it, and some people never knew about them because they don’t come close to the human habitations,” he said. In Old Valparai, most residents knew about the existence of LTMs, but they had only seen them in forests away from their houses. Most of the residents in Korangumudi and Old Valparai were neutral about LTMs, meaning they had no positive or negative view.

But in Pudhuthotam, with its burgeoning macaque population, LTMs were viewed with much more animosity. At least 90 of the 136 people (66 percent) interviewed in Pudhuthotam had negative views of the LTMs. This negative perception appears to be related directly to the macaques’ behaviour. About 90 percent (122 of the 136 residents) from Pudhuthotam reported that monkeys entered their houses every few days, raiding kitchens and feeding on the residents’ food supply.

Apart from tree felling, Pudhuthotam’s rainforest is also broken up by a major road and a power line running through the estate. The fragmented forests have forced monkeys to look for alternative sources of food, explained Jegan. “Even the forest that is left is very degraded,” he said.

Residents interviewed also blamed tourists feeding monkeys making them adapt to human food. Poor garbage management within the estate and the adjoining Valparai town was also a problem. Indeed, Dhawale noted in an email, that garbage patches in the town were attractive enough that some LTMs were moving beyond Pudhuthotam to adjoining areas in the Valparai town.

What’s notable is that even though residents were irked with the LTMs, the researchers saw glimpses of tolerance for the animals. While 67 percent of the Pudhuthotam residents expressed negative views about the LTMs, of the remaining people, more expressed a positive sentiment than a neutral or indifferent one. These were not people who had been unaffected. “We were also surprised,” said Jeganathan, recalling interviews with residents who expressed sympathy for the LTMs.

“They would say they [LTMs] are really problematic. But they’re also like us, and you know, they are also paavam [innocent].” Even those residents who expressed negative sentiments would rarely retaliate from Jeganathan’s observations. “One or two people would put some crackers, so that they go away. And one person used to actually guard the houses when the people were away, but that person was not there all the time. Sometimes, people pour hot water to deter them,” he recalled. “But I didn’t find people keep chasing them all time. It’s not like elephants.”

While all this may be causing problems for Pudhuthotam’s residents, Ajith Kumar who is not associated with the NCF study, pointed out that it was the very presence of humans that was sustaining such a large population of LTMs in this tiny estate. “So, if there is only fragmentation of habitat and nothing else, no people around them, the monkeys may not be able to survive,” he said. “What happened in Pudhuthotam is that people came in and they planted things. They planted jackfruit, and avocado, and passion fruit and guava and mangoes. Everything is edible to the monkeys.

Residents with tiled and asbestos roofs were most vulnerable to LTM raids. Photo: P. Jeganathan/Wikimedia Commons

But the problem according to Kumar was that if these trees don’t fruit, they have no source of food. “Whereas in the rain forest, they eat some 200 species and they’re not really dependent on one of the species. In Pudhuthotam if the jackfruit doesn’t fruit one year they are in serious trouble,” he added. “So, that is what has prompted them to do two things: one is to go into peoples’ houses and the second thing is to go out into the local town. Somebody [a monkey] discovered a town here and a market there and all of them have rushed in,” he added laughing. “They have learnt this. Because this behaviour was not there to 20 years ago.”

But what can people learn to mitigate this behaviour?

Repairing human homes and restoring monkey forests

There are two immediate solutions that the researchers suggested. One was proper garbage management in the estate as well as the larger Valparai town. Second, changing the roofing materials the residents were using. The residents of Pudhuthotam largely used – tiled roofs or asbestos. The study showed that LTMs seemed to most adept at removing tiles and entering the houses. They were also able to exploit gaps in asbestos sheets. Unsurprisingly these were the residents that were most negative about LTMs.

Jeganathan explained that NCF was working on identifying hotspots where the LTMs were most likely to raid houses and help change the roofing structures in these areas. Other mitigation measures that NCF has been attempting are the introduction of canopy bridges so LTMs don’t have to walk across roads and restoration of the degraded rainforests in the landscape. “But we are a small NGO with limited resources. We have to get estate owners, local residents and the government involved to make any big changes,” he said.

Residents with tiled and asbestos roofs were most vulnerable to LTM raids. Photo: P. Jeganathan/Wikimedia Commons.

This article was first published in Mongabay India


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