Month: February 2011

Bridging the canopy gaps

Bridging the canopy gaps

On a fateful morning in June 2008, four lion-tailed macaques (LTM) including a pregnant female were found dead on the road.

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A lion-tailed macaque killed on the road (Photo: Kalyan Varma).
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Post-mortem of the pregnant LTM revealed this fetus (Photo: Kalyan Varma).

Within a month, yet another individual was a casualty on the same stretch of the road.

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And another death on the highway (Photo: NCF).

There may have been multiple reasons for this sudden and unprecedented tragedy hitting a population of a 100-odd endangered macaques found in Puthuthottam, a rainforest fragment adjoining Valparai town in the Anamalai hills. With a push to attract tourists, the Highways Department has been widening the road and consequently the canopy gap has become wider. This is an obstacle for arboreal mammals and they now have to come down to the ground to cross the road. There has been a sharp increase in the number of tourists and the noiseless cars speeding down the 3 km road through the fragment. And, of course, because of the seemingly well-intentioned feeding of the macaques by people, the monkeys have become bolder and frequently hang out by the roadside.

The LTM are now forced to cross on the ground at risk from fast-moving vehicles on the widened road that lacks any speed breakers (Photo: NCF).
The LTM are now forced to cross on the ground at risk from fast-moving vehicles on the widened road that lacks any speed breakers (Photo: NCF).

Since it seemed that all these reasons were beyond our control, we decided to make some efforts to prevent future deaths. As a first step to tackle this problem, we employed an LTM watcher, Joseph, to keep an eye on the monkeys and the tourists. Soon, we had to employ one more watcher, Dharmaraj, as the 3 km long road passing through this fragment was too much to be patrolled by a single person. Together, their job was to ensure that the monkeys crossed the road as quickly as possible, that tourists were made aware of the monkeys when they were on the road and requested to drive slowly as well as not feed them. Jegan and Dina also conducted ‘LTM – watch’ programmes to build awareness and garner support of school children to protect these endangered monkeys.

LTM watch: Valparai students hold an awareness placard exhorting vehicles to go slow (Photo: NCF).
LTM watch: Valparai students hold an awareness placard exhorting vehicles to go slow (Photo: NCF).

The deaths of the monkeys had occurred despite the efforts of the Forest Department to put up half a dozen bamboo bridges from tree to tree across the road. This was acting on the advice of Dr Mewa Singh of the University of Mysore, and choosing locations identified by Anand and his team, based on their knowledge of the frequent crossing points over the road. These bamboo bridges, although useful, need to be renewed at least annually.

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One LTM crosses on the bamboo bridge even as another looks for a crossing over tree branches in the background (Photo: NCF).

Even now, the roads are being widened and the canopy gap is widening, even as more and faster vehicles ply on the road. Speed breakers would really help reduce the risk of accidents both for people as well as monkeys and other mammals on these hill roads. Meanwhile, we needed a good solution to facilitate the crossing over the road by monkeys. In May 2010, during a visit to Borneo, we saw tarpaulin/canvas strips being used to build canopy bridges for the apes and other monkeys to cross the River Kinabatangan. We thought it would be a good idea to use such canopy bridges here, too. Although we believe that engineering solutions will not provide long-term redressal to ecological problems such as fragmentation and roadkills, it seemed the best option at the moment. At least these would last longer than the bamboo bridges.

With the help of our friends Kalyan Varma and Ganesh Ragunathan, we procured lengths of used fire hoses from Bangalore, as these seemed more durable, with rubber-lining inside and a canvas outside layer. We wove them into a bridge and replaced the decaying and breaking poles of bamboo that otherwise formed the bridges in two locations. They were installed on the trees across the road with the help of two of our field assistants, who are the best tree climbers and honey collectors—Ganesan from Erumaparai and Dinesh from Nedunkundru. We have had a long association with Ganesan since 1993 and Dinesh has been with us since 2000.

Installing the canopy bridge: Ganesan on the tree, with Dinesh (left) and Joseph (right) helping below.
Installing the canopy bridge: Ganesan on the tree, with Dinesh (left) and Joseph (right) helping below (Photo: Nisarg Prakash).

Within a day, we were gratified to see the monkeys comfortably negotiating these bridges to safely cross the road overhead.

A lion-tailed macaque crosses the road on the new canopy bridge.
A lion-tailed macaque crosses the road on the new canopy bridge (Photo: Kalyan Varma).

Although engineering solutions are not what we hope to have for all conservation problems, we will have to live with these for now. Hopefully, not too far into the future, the Highways and Forest Departments and the people visiting these areas will find it aesthetically pleasing to have large, native trees lining these roads, with branches overlapping over the road that double-up as natural canopy walkways for the monkeys and other arboreal mammals like giant squirrels and brown palm civets.

This post is a means to thank all those who have helped and are helping (particularly Ramki Sreenivasan, Cornelia Bertsch, Kalyan Varma, Ganesh Raghunathan, other friends, and the Forest Department) to keep these monkeys safe and as akin to their truly wild kin.