The National Highways Authority of India (NHAI) has proposed an elephant pass in the Sanamavu reserve forest near Hosur along NH 844 to enable the elephants to migrate from the Cauvery Wildlife Sanctuary in Tamil Nadu to Andhra Pradesh and back. But the existing highway NH 44, connecting Chennai and Bengaluru and running parallel, continues to carry heavy traffic and the proposals for three eco-bridges, made in the not-so-distant past, have been nearly forgotten.
In the application before the Supreme Court for removal of 901 trees in the Sanamavu reserve forest of Krishnagiri, the NHAI has said NH 844 is part of Bharatmala connecting Bangalore Urban District (Karnataka) to Dharmapuri in Tamil Nadu. As NH 44 could not be made an eight-lane road because the Hosur region became an industrial hub, it was decided to improve the existing State Highway 17 (now upgraded as NH 844) to avoid congestion in Hosur. After completion, it is expected that around 40% of the traffic on NH 44 will be diverted to NH 844. The alignment plan, submitted along with the application, has a provision for an elephant underpass.
“Yes, definitely there is an elephant crossing in the Sanamavu reserve forest along NH 844. Therefore, we designed an underpass,” says an NHAI official. The NHAI document states that human-elephant encounters are regular at the location. The herd usually comes out of the reserve forest, damages crops and challenges human life, often in the villages of Beerjapalli, Aagaram, Azhiyalam and Podur Pallam adjoining the forest.
Though the highway passes 1 km along the forest, the proposed elevated corridor will have eight 30-metre spans to a total length of 240 metres with a 4.5-metre vertical clearance, costing ₹47.03 crore. Asked if there were plans to have a similar underpass on NH44, NHAI officials said it was discussed some years ago, but there was no proposal at present.
On the need for eco-bridges
There were, indeed, discussions on the need to restore the migratory elephant corridor in 2016. After a major accident in June that year, the Krishnagiri Collector held a meeting of line departments and discussed ways of avoiding frequent fatal accidents. Senior officials inspected the area and discussed the construction of eco-bridges at five points. The Collector directed the project director of the NHAI’s Krishnagiri unit to submit a proposal for construction of eco-bridges at three important crossing points — Sanamavu, Kamandoddi and Melumalai — where elephants were frequently crossing the national highways.
“It is not a traditional elephant corridor. It is the seasonal movement of crop-raiding elephants which go back and forth between Karnataka, Tamil Nadu and Andhra Pradesh from the 1990s. About 50% of the elephants that cross NH 844 arrive at NH 44,” says K. Karthikeyani, Wildlife Warden, Hosur. “We try to prevent them from crossing NH 44 as the fragmented forests beyond are not a viable habitat for elephant herds. As of now, the focus is on containing the elephants within the Cauvery North Wildlife Sanctuary,” she says.
The Cauvery North Wildlife Sanctuary, which starts from the Bannerghatta National Park, is a contiguous stretch of forests in the south and fragmented forests in the north and the east. The fragmented patches render the straying elephants vulnerable to a negative interaction with humans. This negative interaction results in 6 to 8 elephant casualties; 8 to 10 human casualties; over 250 hectares of crop damage a year, affecting 1,000 farmers, according to Forest Department accounts.
Lantana camara, an exotic weed, has invaded the foraging landscape of the forests pushing the elephants out of the sanctuary and into human settlements. This invasive species has taken over 40% of the forests here, accentuating a crisis of habitat loss also brought on by a range of factors, according to the Forest Department.
Now, the Forest Department is constructing a steel wire rope fence, first seen in Addo Elephant National Park in South Africa, which was later tried out in the Mudumalai Theppakadu Sanctuary for six months. It was piloted in the Jawalagiri forests. Vertical pillars with horizontal wires are an obstacle to the elephants straying out of the sanctuary.
It is proposed to barricade nearly 120 km of vulnerable stretches with a steel wire fence. Of the total, 30 km-35 km of the northern part of the sanctuary has already been barricaded. It has so far been seen as foolproof; but, it is pushing elephants into the eastern fragmented patches of Dharmapuri, says Dharmapuri District Forest Officer K.V.A. Naidu.
This was borne out by the elephant casualties last month when four elephants were electrocuted after straying into human areas. The deaths prompted calls for erecting steel wire fences in the eastern end of the sanctuary, which comes under the newly created Cauvery South Wildlife Sanctuary.
Meanwhile, about 200 non-resident, migratory elephants start their journey from the Bannerghatta National Park around October, a journey that continues until April, when they return to the national park. It is this migration along the Cauvery Wildlife Sanctuary — which is a contiguous forest stretch running a significant number of square kilometres and fragmented in parts — that is fraught with human-animal negative interactions. This migration of non-resident elephants also pushes the resident elephants to the forest fringes and outside.
Some herds go into Andhra Pradesh crossing NH 44. Earlier, they used to cross during Deepavali and return during Pongal. Now, there is no particular season or routine, says A. Prakash, forest veterinarian, Hosur. The elephants are fond of paddy fields and orchards of ragi, mango, tamarind and tomato.
History of conflict
There are no scientific data explaining the purpose of the herds crossing into Andhra Pradesh. In a 2009 paper on human-elephant conflict in the Koundinya Wildlife Sanctuary, the renowned elephant expert, Ajay Desai, and his team noted that in the early 1980s, a herd of elephants moved into the Kuppam and Palamaner forests (now the sanctuary) from Hosur in Tamil Nadu and more herds migrated in 1986. Twenty-four deaths were reported between 1987 and 2003, half of them due to electrocution during crop raids, and 45 people were killed in the same period. Over the years, the human-elephant conflict declined as the elephant population dipped from about 80 to 12 individuals, with 56 problematic elephants translocated out of the isolated areas, the study revealed.
Even now, three herds, comprising seven, 13 and eight elephants respectively, have crossed over and are locked in the Andhra Pradesh side. With the linear structure of the Koundinya sanctuary, the elephants get down into the Vaniyambadi and Gudiyatham forests, leading to conflicts with humans, officials say. The human-elephant conflict has been happening on both sides of the border. Tamil Nadu Forest Department teams chase the herds towards Andhra Pradesh, only to see them chased back in a week, they point out.
The movement of the migratory herds along the fragmented forest landscape is also fraught with dangers from abandoned mines, industries, electrocution, roads and railways and open wells.
Not all herds from Bannerghatta move towards Andhra Pradesh. However, the map of crop damage shows an increasing pattern of herds moving away from the sanctuary. “Earlier, crop damage was closer to the sanctuary. But that is now extending farther away from the sanctuary’s boundaries every year,” says Ms. Karthikeyani.
Several reasons are cited for this change in the behaviour of the herds. All herds move with young ones that need nourishment. The forest degradation inside the sanctuary, the availability of nutritious crops outside, land use patterns and disturbances to the habitat and encroachments have all destroyed the equilibrium.
Meanwhile, about 200 non-resident, migratory elephants start their journey from Bannerghatta National Park in Karnataka around October every year, a journey that continues until April, when they return to the park. It is this migration along the Cauvery Wildlife Sanctuary that is a contiguous forest stretch for a significant number of sq.km and fragmented in parts, that is fraught with human-animal negative interactions. This migration of non-resident elephants also pushes resident elephants to the forest fringes and outside.
Some herds continue to go into Andhra Pradesh, crossing NH 44. Earlier, they used to cross during Deepavali and return during Pongal. Now there is no particular season or routine, says A. Prakash, forest veterinarian, Hosur. The elephants are fond of fields and orchards of ragi, mangoes, tamarind, tomatoes, and paddy.
“This landscape is a unique elephant habitat, comprising Nilgiris-Eastern Ghats. These inter-State corridors will ensure a viable population in this landscape,” says M. Santhanaraman, advocate, Madras High Court. The three State governments should coordinate to re-establish the elephant corridors in this landscape, especially by providing elephant pass bridges in the national highways that cut through the elephant migratory routes, and restore the fragmented habitats, he says.
(With inputs from P.V. Srividya)