NH-44 Kanha–Pench Wildlife Underpasses — Camera-Trap Verified Tiger Corridor (Madhya Pradesh, India)

The Kanha and Pench tiger reserves in Madhya Pradesh anchor one of central India's most important tiger populations, but a 2012 GIS least-cost-path study found the roughly 145–200 km corridor between them constrained by "weak links" as narrow as 4 km, with National Highway 44 (formerly NH-7) cutting directly through Pench Tiger Reserve (Rathore et al., PLoS ONE, 2012).
In response, India's road authorities built nine dedicated wildlife underpasses along the NH-44 stretch through Pench, including two structures 750 m long – among the longest wildlife underpasses built for a highway anywhere. The underpasses were built to Wildlife Institute of India (WII) specifications, with natural soil substrate to encourage use.
A WII camera-trap monitoring programme recorded 468 animal images across 15 species over a 90-day survey window, documenting tigers, leopards, wild dogs, gaur, sambar and other large mammals using the passages; more than ten individually identifiable tigers were recorded using the underpasses within months of monitoring beginning.
The Kanha–Pench underpasses became a reference design for India's wider highway-mitigation effort: in 2016 the roads ministry sanctioned 25 further "leafy" underpasses across 10 additional national highways, and the Wildlife Conservation Trust's broader corridor-mapping work has since identified some 150 tiger corridors nationally, only 26 of which had previously been formally recognised by government.

Read the full analysis: https://ntca.gov.in/assets/uploads/Reports/WII/NH%207%20Underpass%20Monitoring%20Report%202020.pdf