Context: Recently, the first 90-foot eco-bridge for reptiles and smaller mammals has been built in Ramnagar Forest Division, Nainital district, Uttarakhand.
What is an Eco-bridge?

• Eco-ducts or eco-bridges are areas of a habitat that aim to enhance wildlife connectivity that can be disrupted because of human activities or structures including highways or logging.

These include-

• Canopy bridges (usually for monkeys, squirrels and other arboreal species).
• Concrete underpasses or overpass tunnels or viaducts (usually for larger animals).
• Amphibian tunnels or fish ladders (for aquatic animals).
• Green roofs (for butterflies and birds).
• Culverts (for small mammals such as otters, hedgehogs and badgers).
• It is a way to preserve the ecosystem.
• Usually, these bridges are overlaid with planting from the area to give it a contiguous look with the landscape.

Criteria to build an Eco-bridge

• There are two important aspects of building eco-bridges – size and location.
• It also depends on the animal habitats in the area, topography, disturbance types, road length and its curvature.
• The span and distribution of eco-bridges should depend on animal movement patterns.
• Example, barking deer prefer closed habitats need smaller bridges.

Why Eco-bridges are needed?

• Human activity and intervention in natural environment leave fragmented patches of land intact, putting the ecosystem at risk.
• Resulting in a breakdown of various ecological processes such as species migration, recycling of nutrients, pollination of plants and other natural functions required for ecosystem health.

As a result, the habitat will suffer:-

• Severe biodiversity decline.
• Local extinction of sensitive species.
• Lack of access to the particular habitats to animals.
• An increased mortality rate of animals.

In such circumstances, eco-bridges can help halt biodiversity loss and redress some of the impacts of the degradation and isolation of the ecosystem.
Road Ahead

• Aim to ensure that ecological processes and corridor function are maximised.
• Maintain and increase vegetation cover and habitat quality to maximise the connection between larger remnants of vegetation.
• Help dispersal of wildlife populations between larger remnants.
• Ensure genetic interchange and seasonal wildlife movement.
• Provide specific habitat resources and ecological needs particularly for threatened species.
• Maximise corridor width and function by re-vegetation and control of weeds and feral animals.
• Maximise the protection/linkage of landforms (i.e. valley floors, floodplains, gullies, mid-slopes and ridges etc.).