A highway to wildlife protection

Development versus ecology. Human-animal conflict. These two have been recurring topics of debate for years.

But when it comes to the construction of a national highway through ecologically sensitive areas, India's Ministry of Road Transport and Highways is betting on its project between Delhi and Dehradun, which passes through a forested region inhabited by endangered species like tigers, elephants, greater hornbills and king cobras.

The highway was inaugurated by Prime Minister Narendra Modi today (14 April).

The state-owned National Highway Authority of India (NHAI), in collaboration with the Wildlife Institute of India, released a study documenting the first evidence of wildlife using animal underpasses on the Delhi–Dehradun Economic Corridor, including Asia's one of the largest wildlife elevated corridors standing at an average height of 6 to 7 meters to accommodate even the largest mammal.

The corridor demonstrates that national highway development can coexist with the preservation of ecologically sensitive areas and the study provides an empirical finding on Wildlife Mitigation measures.

Conducted along an 18km stretch of Delhi–Dehradun Economic Corridor between Ganeshpur and Asharodi, the study was undertaken with the objective of assessing patterns of underpass use by wildlife, factors affecting usage of underpasses by different wild species and effectiveness of the underpasses.

The 20-km-long stretch between Ganeshpur and Asharodi features a total of 10.97km of animal underpass designed specifically to facilitate unobstructed animal movement.

The area of the study covered flat riverbed, hilly terrain and mixed stretches of Sal Forest in the Shivalik Himalayan range, through a 40-day monitoring programme using 150 high-tech camera traps and 29 AudioMoth acoustic recorders.

The study documented a total of 111,234 images of humans, domestic animals, and wildlife. Among these, 40,444 were attributed to 18 unique wild species utilising the underpass, including various carnivores, herbivores, ungulates, pheasants and primates. The golden jackal was the most frequently captured, followed closely by nilgai, sambar and spotted deer.

Smaller mammals, including the Indian hare, also showed consistent movement through the structures.

The study also recorded 60 instances of the elephants safely utilising the corridors, establishing that even the largest wild animals can navigate the new infrastructure to maintain their natural migration patterns.

The research identified the management of the soundscape as a primary factor in facilitating natural wildlife behaviour beneath the corridor.

The data indicate that while generalist species like golden jackals and wild boar have habituated to significant traffic sound, sensitive species like elephants and spotted deer selectively utilise underpass segments with lower sound levels.

Deployment of advanced noise reduction strategies, including targeted sound barriers, in high-frequency crossing areas will further enhance passage for noise-sensitive species.

The development of the Delhi–Dehradun Economic Corridor has not only significantly reduced the probability of human-wildlife conflict but also mitigated the risk of population isolation in the Shivalik landscape.