A Vital Corridor For Large Mammals In The Southern Western Ghats
February 2008: Most of our Protected Areas are being islanded, with their connecting corridors to other forested areas literally torn asunder. In the forests extending from the Palghat Gap, south to the Agasthyamalai Hills (called the southern Western Ghats landscape), over 4,000 elephants, a viable tiger population and a number of other endangered species continue, to survive, tenuously.
This 10,000 to 12,000 sq. km. landscape consists of three distinct units – the Anamalai-Palani Hills, the Periyar-Srivilliputtur Hills and the Agasthyamalai Hills. Connecting forest corridors between these areas are either broken or under threat.
The Ariankavu Pass (c. 80 sq. km.) is vital to establish the connectivity between the Periyar-Srivilliputtur Hills (c. 3,000 sq. km.) and the Agasthyamalai Hills (2,000 sq. km.). The key wildlife areas north of the Ariankavu Pass are Gudalur, Chinnamanur, Meghamalai and Varushanad; the Periyar Tiger Reserve and Srivilliputhur Grizzled Giant Squirrel Wildlife Sanctuary of Theni Forest Division (FD); Goodrickal Range of Ranni FD; Mannarapara and Naduvathamozhi Ranges of Konni FD; Kanayar, Kallar and Achankoil Ranges of Achankoil FD and Sivagiri, Sankarankoil and Kadayanallur Ranges of Tirunelveli FD. To the south of the Pass, the forests continue into Courtalam Range of Tirunelveli FD; Shendurny Wildlife Sanctuary, Kulathupuzha and Palode Ranges of Trivandrum FD; Neyyar Wildlife Sanctuary; Peppara Wildlife Sanctuary; Kalakad Mundanthurai Tiger Reserve (KMTR) and Kanyakumari FD.
The low-elevation valley of the Ariankavu Pass is a major conduit for trade and commerce between southern Tamil Nadu and Kerala. The heavily-used Madurai-Quilon National Highway (NH-208) and the century-old Shencottah-Punalur metre-gauge heritage railway also run through the pass. Apart from human settlements along the railway line and highway, teak (owned by the forest department), rubber, pineapple and tea plantations (company-owned) cover much of the landscape. Much of the native vegetation along the Pass has been lost. The only forest cover that remains lies at the top and on the eastern slopes, along the main ridgeline of the Western Ghats, bordering Kerala and Tamil Nadu.
Though wildlife may move across the rubber and teak plantations, the human settlements at Ariankavu, Murugapanchal, Edapalayam and Kaluthuritty and several other areas have affected the suitability of even this habitat for wildlife. Steep embankments on the sides of NH-208, particularly in the area of the 13-arch rail bridge, also make it difficult for any large wild mammals to cross the road. Though rail traffic is limited on the metre-gauge line, illegal encroachments make it unsuitable for wildlife crossing.
The Nature Conservation Foundation (NCF), Mysore, which undertook three short surveys of the Ariankavu Pass over the last one and a half years, has, however, identified three potential corridors for large mammals to move across the Pass. These are: 1. Achankoil – Harrison Malayalam Rubber Estates (e.g., Nagamala) – 13-arch rail bridge – Shendurny Wildlife Sanctuary, referred to as ‘13-arch Corridor’. 2. Achankoil – Priya Estate – Ambanad Tea Estate – Suvarnagiri Estate – Senagiri Estate – Murugapanchal – Bedford Estate – Shendurny Wildlife Sanctuary, referred to as ‘Murugapanchal Corridor’ and 3. Kottavasal (Achankoil) – Puliyarai Beat of Kadayanallur Range – Kottavasal (Ariankavu) – Karkudi Beat of Courtalam Range – Shendurny Wildlife Sanctuary, referred to as the ‘Kottavasal Corridor’.
Of the three, the ‘13-arch Corridor’ was found to be the least suitable. In the case of the Murugapanchal Corridor, plantations and human settlements plus the infrequent use of the corridor by large mammals still remain limiting factors. The Kottavasal Corridor is used more frequently by elephants and tigers, as the forest cover is relatively more extensive and wildlife habitats, north and south of the corridor, are closer. Fewer settlements in the corridor also add to its advantage. Voluntary relocation of locals must be encouraged and better alternatives provided to them.
Sanctuary readers are encouraged to write to the Ministry of Environment and Forests highlighting the importance of a large-mammal friendly corridor in the Ariankavu Pass, and making the following points:
1. Tigers in Periyar and KMTR can only be protected if the entire 5,000 sq. km. landscape connecting the two and their associated forests are kept free from human interference. The Ariankavu Pass could provide up to 2,000 sq. km. of prime tiger habitat.
2. A forested corridor in the Ariankavu Pass will secure the future of large mammals in the southern Western Ghats.
Ministry of Environment and Forests (MoEF),
Government of India,
New Delhi – 110021.