In the 1970-80s, the Kerala State Electricity Board proposed a hydroelectric dam across the Kunthipuzha river in Silent Valley. The project threatened to submerge the pristine rainforests of Silent Valley, one of the last continuous habitats of the lion-tailed macaque. Scientists, students and local communities united to stop the project in one of India’s earliest major environmental movements, and made the primate a symbol of the fragile interconnectedness of life in the Western Ghats.
In 1983, the then Prime Minister Indira Gandhi cancelled the project and declared the area a national park. The movement became a landmark in India’s environmental history and the macaque, once a symbol of vulnerability, became a beacon of hope. But now this “lion of the rainforest”, as the macaque is called owing to its dark fur, silver-white mane and tufted tail, has once again become one of India’s rarest and most endangered primates. Older assessments by the International Union for Conservation of Nature estimated 3,000-3,500 individuals in the wild. Recent research, however, suggests fewer than 2,500 remain across the Western Ghats. Expanding plantations, roads, tourism and scattered land-use changes have created a mosaic of forest fragments that isolates macaque populations and restricts gene flow.
Over the last decade, joint surveys by the forest departments of Kerala and Tamil Nadu have begun systematically verifying populations, mapping genetic diversity and locating dwelling forests. The surveys confirm that Silent Valley still supports the largest known cluster. Smaller but viable groups persist in the Anamalai, Nelliampathy and Agasthyamalai ranges. Karnataka’s central Western Ghats retain small populations around Kudremukh and the Sharavathi valley, while Tamil Nadu’s Kalakkad-Mundanthurai Tiger Reserve holds isolated troops. Researchers say that although presence is confirmed across three states, there is no recent peer-reviewed estimate of mature breeding individuals, underlining how difficult field monitoring remains in evergreen rainforest habitat.
Habitat fragmentation is a major threat to the macaque, as it is perfectly adapted to its lofty home in tropical evergreen forests. Being arboreal, it spends nearly its entire life in the trees, moving silently through the canopy and feeding on fruits, leaves, insects, small reptiles and bird eggs. As a vital seed disperser, it regenerates forests as it feeds, maintaining ecological balance.
Forest communities call it kattu kurangu (the forest monkey) and believe that the primate embodies ancestral spirits that protect the woods. Its haunting calls at dawn and dusk are seen as omens of balance and change. Even in plantation belts like the Valparai tea estate, workers greet the macaques with a quiet “Hey raja”, because they believe it brings luck before a day of hard work. The presence of a troop on a plantation path is seen as a sign that the monsoon will not fail.
This cultural connect has led to community-led mitigation efforts. Community groups, researchers and plantation managers in Valparai and parts of the Anamalai hills have installed canopy bridges across forest gaps to help macaques move safely above roads and power lines. Forest departments are also identifying priority locations where bridges could reconnect fragmented habitat and reduce mortality. People have learned to slow their vehicles near forest roads to avoid hitting any primates crossing the road.
Kerala and Tamil Nadu are now mapping genetic diversity to identify isolated groups for targeted conservation while conservationists call for habitat restoration, canopy bridges across forest gaps and stricter protection. Community-based eco-tourism around Silent Valley and Valparai has also helped reduce conflicts and renew attention toward this forgotten species.
The lion-tailed macaque once sparked a movement that saved a forest. Its survival now depends on whether India can rekindle that spirit, to see, once again, in the gleam of the macaque’s silver mane, the reflection of a rainforest worth saving.
This article was originally published as part of the December 16-31, 2025 print edition of Down To Earth