Golden langur (Trachypithecus geei) Canopy bridge over National highway in Assam, India by Ashoke Kumar Das
Assam has introduced innovative hanging canopy bridges to protect wildlife, particularly endangered primates, from electrocution and road mishaps. This initiative is a response to increasing habitat fragmentation and wildlife casualties due to expanding infrastructure such as highways and railway lines.
Key Features of the Canopy Bridge Initiative
Purpose and Target Species
- The primary goal is to ensure the safe movement of arboreal species, especially the endangered golden langur and Hoolock gibbon, across man-made barriers like highways and railway tracks.
- Golden langurs, found mainly in western Assam, have suffered significant habitat loss and face threats from road accidents and electrocution due to power lines.
Implementation and Design
- Four hanging canopy bridges have been installed over NH-117 in Bongaigaon, Assam, as a joint effort by the district administration, forest department, NHIDCL, and local communities.
- The bridges are constructed using sturdy, plastic-coated materials and wires for durability and safety.
- In the Hoollongapar Gibbon Sanctuary, three canopy rope bridges were built using high-quality mountain climbing ropes to reconnect fragmented gibbon populations separated by a railway line.
- The design of these bridges was inspired by successful models in China and tailored for local conditions, with input from the Wildlife Institute of India and Northeast Frontier Railway.
Effectiveness and Adaptation
- The first bridge on NH-117 was used by langurs within five days of installation, demonstrating rapid adaptation.
- Monitoring through camera traps is planned to assess the usage and effectiveness of these bridges, especially for gibbons who may be initially deterred by train noise.
Broader Conservation Impact
- These bridges restore landscape connectivity, reduce wildlife mortality, and enhance genetic diversity by enabling safe movement and breeding across fragmented habitats.
- Similar initiatives are being expanded to other regions and species, with canopy bridges also planned for the Gibbon Wildlife Sanctuary in Jorhat and elsewhere in India.
Summary Table: Assam’s Canopy Bridge Initiative
| Feature | Details |
|---|---|
| Species Benefited | Golden langur, Hoolock gibbon, other arboreal mammals |
| Locations | NH-117 (Bongaigaon), Hoollongapar Gibbon Sanctuary (Jorhat) |
| Materials Used | Plastic-coated wires, high-quality mountain climbing ropes |
| Key Partners | Assam Forest Dept., NHIDCL, Wildlife Institute of India, local communities |
| Conservation Goals | Reduce road/electrocution deaths, restore connectivity, genetic diversity |
| Monitoring | Camera traps, ongoing adaptation studies |
This initiative is a notable example of how infrastructure development and wildlife conservation can coexist through innovative, science-based solutions.
