Tiger-friendly corridor across river Ganga: the need of the hour

HOME

Tiger-friendly corridor across river Ganga: the need of the hour

Dr A J T Johnsingh

The most important tiger-elephant corridor in north India is the one across the river Ganga, known in scientific literature as the Chilla-Motichur corridor (Johnsingh et al. 1990). This corridor provides a tenuous connectivity between the eastern and western parts of Rajaji National Park (NP) across the Ganga (Fig.1), and is still used by elephant bulls (Elephas maximus), sambar (Cervus unicolor) and chital (Axis axis). This corridor is important as it has the potential to link the productive forests west of the Ganga in the states of Uttarakhand, Uttar Pradesh, Haryana and Himachal Pradesh (totaling ca. 2000 km2) with the forests east of the river, which are contiguous up to Gola river near Haldwani (totaling ca. 4000 km2, with ca. 400 km2 contributed by the Bijnor Forest Division of Uttar Pradesh). The large mammals commonly seen in the forests west of the Ganga include elephants (a maximum of 120 animals), leopard (Panthera pardus), sambar, chital, barking deer (Muntiacus muntjak), nilgai (Boselaphus tragocamelus) and goral (Nemorhaedus goral). The status of the tiger (P. tigris) in these forests is extremely precarious, with recent surveys of the Wildlife Institute of India (WII), Dehra Dun, reporting only one or two animals, and likely to become extinct at any time.

The major reason for this drastic decline is the stealing of tiger kills by bhabar (Eulaliopsis binata) grass cutters who throng this area in hundreds in the winter. Tigers are less successful in breeding and raising cubs if their kills are regularly stolen. Kill stealing can also affect the less abundant but most preferred prey of tiger, sambar. Some tiger experts may argue that we can periodically restock tigers west of the Ganga from Chilla Range or from Corbett Tiger Reserve (TR). But the long-lasting laudable goal in Uttarakhand should be to have a continuous tiger range between Yamuna and Sharada rivers.

During my 20-year (1985-2005) association with Rajaji NP, it was only in November 2005 that I saw for the first time a total ban on bhabar grass cutting, and the credit for accomplishing this extremely difficult and sensitive task goes to Mr. G.S. Pande of the Indian Forest Service, who was the Director of the Park. WII faculty and trainees, during their field exercises that year, reported tiger pug marks in all the four river beds (Harnol, Chidak, Rawali and Ranipur) of the Ranipur Range where I had never seen pug marks in the recent past. I wish that the ban continues forever, as it would enable the predators to fully consume the kills they make after investing enormous effort and energy. This would also help the tiger to stage a come-back in the forests west of the Ganga. If tigers become extinct west of the Ganga, then the best way to bring them back is to have a functional corridor across the river, as only the emigrating tigers from Chilla-Koluchaur-Corbett TR can repopulate this area. The major problems identified in this corridor are:
• Biotic disturbances on the east (left) bank of the Ganga,
• Increased vehicular traffic along the Chilla-Kunaun road even at night, to the ashrams on the left bank
• Disturbances such as wood cutting and grazing on the islands of the Ganga
• Army ammunition dump
• Khand Gaon III (a village of 30 or so households relocated from the Tehri dam site)
• Increasing traffic along the Haridwar-Raiwala road, which the Government wants to make four-lane as part of the proposed Delhi-Dehra Dun Highway.

The recommendations given by Johnsingh et al. (2004) to address the above problems are the following:
• Relocation of Gangabhogpur villages and Kunaun goth from the left bank to Barkote Range (Dehra Dun Forest Division), which has lost most of its large mammal values. Demolition of the narrow bridge across the power channel in front of Kunaun goth, so as to give improved protection to Bidasani block of ca. 20 km2, an area of hilly terrain and dense vegetation, with an immense potential to support a high density of sambar and serve as a tiger breeding site
• Building a bridge across the Ganga near Lakshman jhula at Rishikesh, to divert the traffic that goes along Chilla-Kunaun road to the ashrams on the left bank of the Ganga
• Total protection to the islands from human and livestock use
• Shifting of the Army ammunition dump, a problem identified in 1984
• Relocation of Khand Gaon III village
• Building of a two-lane 800-1000 m long flyover between Haridwar and Raiwala for vehicular traffic, and preventing people from using the underpasses. The road below the flyover should be dismantled as soon as the flyover is built. Pre-fabricated structural elements should be used to build this flyover within a short span of time, so as to minimize the impact on the surrounding forests by the labour force that will camp in the vicinity during the construction phase (Rajvanshi et al. 2001).

Now it is anticipated that the Indian Railways may add one more track to the existing railway track between Haridwar and Dehra Dun. Trains use the existing track nearly 25 times a day. The Uttarakhand Government is debating what should be done in such a situation. The most important habitat link in this corridor is the 60-80 m wide Motichur rau, along which even now large mammals move between Motichur forests and the Ganga, as the road and rail bridge over this rau is high enough to permit even elephant bulls to pass under. Johnsingh et al. (2004) recommend the planting of tree species such as Polyalthia longifolia along the right bank of Motichur rau, as a bio-screen, so that the rau remains dark at night. It is also advised that developments be banned for 50 m along the right bank, to avoid electric lights in the area.

The best option to solve the problem of double railway track is to have two sufficiently large, ca. 50 m long, underground tunnels for the animals below the railway tracks, 100 and 200 m from the existing Motichur railway crossing towards Raiwala. The aqueduct below the power channel at Dogudda, Gauri Range, which is used by tiger, elephant bulls and all other large mammal species of the area, can be a good model. More importantly, the forests in this corridor area need to be much more assiduously protected, particularly from the people of Haridwar town and Raiwala township, who are presently hacking away the forest bit by bit.

If the flyover idea is overruled, and the idea of an overpass for animals is implemented instead, it has to be made at least 200 m long and 100 m wide (assuming that the Khand Gaon village and the ammunition dump are relocated). If the ammunition dump is not relocated, then the overpass has to be at least 1.5 km long and 100 m wide. In the Haridwar-Raiwala zone, which is bustling with human activity, a shy species like tiger and even elephants, may never use the overpass that has been suggested to be built across the proposed four-lane Highway and the two-lane railway track. The proposed four-lane Highway will be a disaster for the narrow belt of forests between Haridwar and Raiwala. Overpasses for large mammals have been successful in many places in North America, but the crucial facts to remember are that these overpasses are usually short (ca. 50 m), built in places where the forests on both sides are well protected and free of human disturbances, and often animals are directed towards the overpass by chain link fences on both sides of the road. Dean (2006) describes one such overpass which is 50 yards wide: “Approached from the woods, the crossover resembles any other sloping hill, covered with brushy grass, shrubs, saplings and even a clump or two of pussy willow. Earthen beams on either side hide the road and mute the noise of the tens of thousands of cars that pass by daily, winter and summer. Animals have worn a trail along one edge and, at the top, leave prints on a cleared stretch of dirt, a so-called track pad, monitored by motion-sensitive cameras with night-vision lenses”.

Acknowledgements: Dr.Nima Manjrekar, Dr. K. Ramesh and Mr. Abishek Harihar are thanked for their help in writing this article

References:
Dean, C. 2006. Home on the Range: A corridor for Wildlife. The New York Times. Environment, Page. 1.

Johnsingh, A.J.T., Prasad, S.N. and Goyal, S.P. 1990. Conservation status of the Chilla-Motichur corridor for elephant movement in Rajaji-Corbett National parks area, India. Biol. Conserv. 51:125-138.

Johnsingh, A.J.T., Ramesh, K., Qureshi, Q., David, A., Goyal, S.P., Rawat, G.S., Rajapandian, K. and Prasad, S. 2004. Conservation status of tiger and associated species in the Terai Arc Landscape, India. Wildlife Institute of India, Dehra Dun, Pp. viii +110.

Rajvanshi, A., Mathur, V.B., Teleki, G and Mukherjee, S.K. 2001. Roads, Sensitive Habitats and Wildlife Environmental Guidelines for India and South Asia. Wildlife Institute of India and Canadian Environmental Collaborative Limited Publication.

Dr. A.J.T. Johnsingh, Eminent Wildlife Biologist, Nature Conservation Foundation, Mysore; and Honorary Wildlife Advisor, WWF-India.