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Restoring The Western Ghats’ Ariyankavu Corridor

Restoring The Western Ghats’ Ariyankavu Corridor

Srinivas Vaidyanathan and Dr. A.J.T. Johnsingh urge for the protection of a critical link between the Periyar and Agastyamalai landscapes in the southern region of the Western Ghats.

The proposed location for a wildlife overpass within the Kottavasal corridor on the interstate boundary between Kerala and Tamil Nadu. Photo: Srinivas Vaidyanathan.

Wild elephants in Asia and Africa are fighting a losing battle for survival. In India, which harbours over 50 per cent of the wild Asian elephant population, the combined effects of habitat loss, fragmentation, degradation, poaching for ivory and increasing human-elephant conflict threaten their survival. Over the decades, elephant populations have become isolated and now occur in populations smaller than what is needed for their long-term survival. Many Protected Areas where elephants occur are surrounded by intensive human-use areas.

It is scientifically recognised and established that small populations with very few males are vulnerable to extinction. This is a major cause of concern, particularly since males are targeted for their ivory and are more likely to die in conflict. Recent reports from south India suggest that poaching in the past few years has led to the killing of around 100 tuskers. Often, only bull elephants move between fragmented and degraded habitats, and this is what maintains the genetic connectivity between isolated populations. Clearly, small and isolated elephant populations with few bulls, inherently vulnerable to the threats mentioned above, or no bulls are at a greater risk of local extinction.

Presence of elephant families can be observed close to the linear barriers. Photo Courtesy: FERAL. 

One such isolated elephant population of about 150 to 200 individuals exists in the Agastyamalai landscape in the southern tip of the Western Ghats. In the southern region of Western Ghats, there is a pass between the Periyar and Agastyamalai landscapes known as the Ariyankavu pass or Shencottah gap. Since time immemorial, elephants and other large animals have used this pass to move between Periyar and the Agastyamalai hills.

However, over time, this natural pass has witnessed unplanned development and rapid transformation. This is largely the result of a railway line and a National Highway (NH-208) both from Madurai to Kollam. Additionally, vast swathes of primeval forests were cut down to raise plantations of rubber, teak and tea. Inexorably, the traffic along the road and rail increased, as did the number of human settlements. Consequently, the movement of elephants between the Periyar and Agastyamalai landscapes stopped a few decades ago. And it wasn’t just elephants that suffered. Other large mammals including tigers, lion-tailed macaques and gaur were also impacted.

Elephants in the Agastyamalai landscape survive largely within Protected Areas such as Shendurny, Peppara, Neyyar and Kalakad-Mundanthurai Tiger Reserve. We have no accurate information on the number of bulls in this population. Our research over five years has revealed that around 25 bulls use an area of approximately 350 km. on either side of the pass. Our findings also suggest that as a result of human disturbance (settlements and traffic), movement of bulls across the gap is non-existent. In locations where settlements are negligible, the terrain is too rugged for the animals to negotiate.

Our studies reveal two potential elephant passages – one on the western end of the pass (known as Mean Sea Level or the MSL corridor in Kerala) and the other on the eastern end of the pass (the Kottavasal corridor on the interstate boundary of Kerala and Tamil Nadu with a major part of the corridor in the latter). These wildlife corridors desperately need legal protection. We have documented bulls and family groups near these corridors, close to both sides of the pass. But human disturbances and the tough terrain deter even bulls from crossing.

An artist’s impression of the proposed wildlife overpass at Kottavasal to facilitate the movement of large carnivores and herbivores across the Ariyankavu pass. Photo Courtesy: FERAL.

The separation between the Periyar and Agastyamalai elephant population in the MSL corridor is just about 200 m. Even minimal management interventions such as an appropriate underpass large enough for elephants to use could help manage the probem. Protection of the Nagamalai corridor area, which belongs to Harrisons Malayalam Ltd. from development inimical to large mammal movement is also a must to strengthen the MSL corridor. Sambar, gaur and perhaps, elephants could use the passage along the Kottavasal corridor, provided we remove the encroachments along the road, build a flyover for vehicles over the existing S-bend and restrict land use on either side of the corridor so that it is compatible to large mammal use. Presently, paddy fields and mango orchards have taken over either side of the S-bend. Another viable option is to build an overpass across the highway for species such as sambar, tigers and leopards in the location where the Karuppaswamy temple is currently located.

Restoration of this connectivity between Periyar and Agastyamalai will benefit elephant conservation in many ways. First, the Agastyamalai population will be buffered from local extinction as it will be linked to a larger population of around 1,000 elephants north of the pass. It would also ensure the future of about 5,000 sq. km. of viable wilderness – the Periyar-Agastyamalai landscape where a host of wildlife would have a secure future.

Such conservation imperatives are triggering massive investments in the creation of wild corridors across the globe. This includes species-recovery plans for endangered wildlife populations, often involving precisely the kind of linking of corridors that enable isolated populations to be reconnected. Such initiatives may be likened to ‘bandages’ for wounded landscapes. And where they have been implemented, they have proven to be cornerstones for the conservation of endangered species.

These two young bulls were captured on camera traps close to NH-208, which has impacted wildlife movement across the Ariyankavu gap.
Photo Courtesy: FERAL.

In India, however, we are yet to see an iota of understanding of such imperatives within powerful sections of decision makers, who believe that creating human-made infrastructure justifies the annihilation of natural infrastructure such as forests, wetlands, grasslands and riverine tracts.

A map highlighting areas that need to be restored to facilitate large mammal movement across the Ariyankavu pass. Map Courtesy: FERAL.

In conclusion, it is our considered opinion that maintaining and restoring corridors identified by robust field studies should become a major priority for India. There is no dearth of financial resources to restore such connectivity. For example, only a small fraction of the all-India budget of Rs. 36,000 crores available under the Compensatory Afforestation Fund Management and Planning Authority (CAMPA) could be used to restore and secure Ariyankavu’s corridors. This idea is not new. In 2009, the Ministry of Environment and Forest announced a scheme to restore connectivity for tigers across the Ariyankavu pass, but it never materialised. While the CAMPA funds could be made available to secure the corridors, the actual mitigation structures can also be easily funded by the National Highway Authority of India and the Public Works Department. Our success in linking the Periyar and Agastyamalai elephant populations will be a test case for India that demonstrates whether or not the country has the political will to accomplish tasks that would benefit wildlife conservation.

Author: Srinivas Vaidyanathan and Dr. A.J.T. Johnsingh., First appeared in: Sanctuary Asia, Vol. XXXVII No. 2, February 2017.

 
 
 

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