Highways Cut Through India's Last Wildlife Lifelines
Roads, railways and canals are fragmenting the forest corridors tigers and elephants depend on, even as engineered overpasses offer a rare model for coexistence
Synopsis
India's wildlife corridors - the forested corridors with protected areas which enable the movement, breeding and the maintenance of genetic diversity of the tigers, elephants and other species are under significant threat from the growing transect of highways, railways, canals and power lines. There is no one genetically independent sub-population of tigers in Central India without any corridor connectivity, although it has more than one third of the country's tigers. The current article focuses on the extent of fragmentation and some new mitigation measures, such as the latest Indian wildlife overpass.
Why Corridors Matter
Wildlife corridors are small fragments of remaining natural habitat linking large forest patches, enabling wild animals to spread out, to find mates, and to reach food supplies in areas that have become fragmented.
Wildlife Conservation Trust research has revealed that tiger numbers within a number of Indian tiger corridors are as high as or higher than in Tiger Reserves, casting doubt upon the view that corridors are just transit corridors and not habitat.
The stakes are especially high in central India where the Trust has found almost 35 per cent of the country's tiger population, with none of the sub-populations being viable without movement of tigers between areas.
The Cost of straight Line Infrastructure
The overall threat to corridor connectivity nation-wide has shifted to roads, railway lines, canals and power infrastructure. According to a citizen-science initiative led by the Wildlife Conservation Trust, at least 150 elephants were shot in railway lines from 2011 to 2019, while the Wildlife Protection Society of India reported seven tiger deaths due to linear infrastructure in 2023.
The two great roads, the National Highways 6 and 7, have been mentioned in textbook terms as examples of roads running right through the central part of the Bor-Melghat, Navegaon-Nagzira and Kanha-Pench corridors of India.
In Assam, environmentalists have been raising concerns about ongoing new development projects in corridors that connect the Kaziranga National Park with Karbi Anglong Hills, which are considered as safety zones for elephants, rhinos and swamp deer to flee during the monsoons, despite a Supreme Court ban on new construction in the area across nine identified corridors in 2019. The Supreme Court's Central Empowered Committee is hearing the case.
Living in the midst of 'middle ground'
Not all new infrastructure has been at the cost of wildlife. The Delhi-Mumbai Expressway now passes through the buffer zone of Ranthambore Tiger Reserve with five elevated overpasses and one underpass, which is the longest continuous wildlife passage (1.2 km) built in consultation with Wildlife Institute of India and reported no wildlife deaths in their construction.
Also, other mitigation measures, such as the canopy bridge in Assam for hoolock gibbons, and the 750-metre underpass along the Kanha-Pench corridor, indicate that coexistence can be engineered if taken early.
The National Wildlife Action Plan's third edition proposes more coordination between the road transport and railways, mining and petroleum ministries at the planning phase — something conservationists say is not done consistently and protection of corridors is often an afterthought.