By Rishika Pardikar
Lion-tailed macaques are primates that are endemic to the southern and central Western Ghats. According to latest estimates, their population is under 4,000 individuals, of which approximately 500 live in the Anaimalai Hills. Like all arboreal animals, lion-tailed macaques spend most of their lives in the upper branches of trees, and need canopy connectivity for easy passage through the forest. In cases where forests lack density and are fragmented by roads, the possibility of human-wildlife interaction increases. And in case of heavy vehicular traffic (like that in the tourist destination of Valparai) highways turn into danger zones for wildlife.
Wildlife casualties along Tamil Nadu’s SH78 often go unreported. Speeding vehicles claim the lives of lion-tailed macaques and myriad other wild animals — unfortunate victims of the increasing number of roads and railway lines cutting through India’s diminishing forests. Photo: P Jeganathan - CC BY-SA 4.0.
“Puthuthottam is a fragmented rainforest surrounded by tea plantations, and the lion-tailed macaques of the region cannot move around easily,” says P Jeganathan, a scientist from Nature Conservation Foundation’s (NCF) research team, focusing on the Anaimalai Hills.
“Roads also cut through the (Puthuthottam) landscape” Jeganathan explains, “and in places where there is no canopy cover, they (lion-tailed macaques) have to climb down the trees and cross the road and this leads to many deaths.” In such a situation, one of the mitigation measures is a canopy bridge that connects tree tops across roads. And this is what Jeganathan and team worked on as part of their rainforest restoration programme in the Anaimalai Hills.
A lion-tailed macaque surveys its fragmented habitat from a canopy bridge in the Anaimalai Hills. Canopy bridges across roads help arboreal animals avoid risking their lives crossing highways. Photo: Dhritiman Mukherjee
Between 2011-2012, NCF, through a grant provided by the Critical Ecosystem Partnership Fund (CEPF), constructed five canopy bridges. Four were built in Puthuthottam and one in Varattuparai — locations where lion-tailed macaques and other arboreal animals like the Nilgiri langur, and Indian giant squirrel were frequently observed crossing the road and where tree connectivity was weak or absent. Before the start of this project, NCF had installed two other canopy bridges in Puthuthottam as a trial. Since then, they have documented lion-tailed macaques and even giant squirrels using such bridges to cross-over to the other side of the road.
In addition to canopy bridges, the other move that was implemented to mitigate mortality was the construction of speed bumps in targeted locations, with the help of the Tamil Nadu Forest Department and the Tamil Nadu Highways Department.
The lion-tailed macaque population in Puthuthottam requires such concerted efforts owing to its geographical proximity to human-dominated landscapes like towns and tourist destinations.
“Sensitising tourists in such locations is also important,” Jeganathan said, elaborating on responsible tourism and other modes of conservation. “We have employed watchers to ensure that vehicles don’t speed on these routes and also to educate tourists and prevent them from feeding lion-tailed macaques.”
Encouraging local populations to plant trees in such critical habitats is another aim. “We need to preserve canopy cover, especially for arboreal animals,” he said noting that canopy bridges and speed bumps are merely “engineered structures” and can only offer a “short-term solution”. “What we need to do in the long-term is not cut trees, especially those around highways,” Jeganathan says.
