In India when a new road or bridge project is planned, there is only perfunctory reference to impact on wildlife. An EIA (Environmental impact analysis), might be done in some cases to meet the needs of the statute books, but there is absolutely no proviso for making the roads and bridges wildlife friendly in its true sense. In several European countries, US, and Canada, in house transportation biologists are an integral part of the whole process of roads and bridges building. They see to it that roads and bridges projects avoid or circumvent sensitive wildlife habitat and help minimize and mitigate environmental impacts to streams, wetlands, and other prime wildlife habitats. Sometime exclusive wildlife bridges (ecoduct) are also built. These wildlife bridges guarantee safe crossing for wildlife in the maze of heavy traffic and cacophony of highways.
In the Netherlands, which has taken a leading role in the field of wildlife friendly roads, there are 600 tunnels to direct wildlife away from highways. Fencing is also resorted to in concert with tunnels, as good option in guiding wildlife to safe crossing structures and prevent crossing in vulnerable areas. In wildlifers’ parlance this practice is called funnelling. Animals’ use of these passages can be optimised by providing plant cover near the entrances. Reducing the plant cover along road curves and increasing it along level stretches has been found to be very effective in bringing down road kills.
I was thrilled to read recently about what Sarah Piecuch,a transportation biologist working with New York State Department of Transportation (NYSDOT) did for otters. While involved in a road a project at Melvin Brook in Clyde, New York, early in the project’s development, Sarah noticed an otter (Lontra canadensis) kill, at a project site. Her inquisitiveness led her to a large culvert in the area which was constantly filled with water. This culvert was interrupting the scent trail of the otters. Scent trail is very important in the biology of otter. The lack of an upland area forced the otters to come out of the water and travel over the road embankment to leave a scent trail. This upland travel made them vulnerable to road traffic and many were inadvertently getting killed. Sarah explained the need and ideal parameters for an upland bench to the engineers. The project engineers were delighted to take up the challenge and came up with an ingenious upland bench below the culvert. It was fruition of great team work of biologists and engineers. Sarah identified the need and the engineers found a perfect solution. This kind of teamwork is what is needed for our roads and bridges projects and not hastily sewn up EIA.
The transportation biologists have to be involved right from the planning stages. It is easy to find solutions at the early stages. Providing enough culverts for wildlife, to use as underpasses, could come in very handy, as topography has the greatest impact on road kills. Studies by University of Calgary researchers have found that, small animals were far less likely to get killed on sections of roads that were raised than on sections that were level with the surrounding terrain. Engineers and biologists working as a close knit team could come up with perfect solutions.
Even existing structures can be made wildlife friendly with innovative planning. Species like barn owls and cormorants very effectively use the bridges in urban scenarios. Many other birds use the bridges for perching, nesting and roosting. A transportation biologist can advise the engineer, how to take in to account the needs of the birds while repairing or painting the structures. Bridges can provide suitable day and night roosting habitat for bats.
The avenues of transportation biologists and engineers working hand in hand are multifarious. Road ecology has become an important new branch of science and has made great strides abroad. It is high time we did something along these lines in India also. The time to act is ripe, as India is on a fast track of infrastructure developments. India should not lag behind is this sphere. Mitigating interactions between roads and wildlife is going to be very important in the years to come.
For people wanting to know more about wildlife friendly roads here is a very useful book. Safe Passages: Highways, Wildlife, and Habitat Connectivity , Edited by Jon P. Beckmann, Anthony P. Clevenger, Marcel P. Huijser and Jodi A. Hilty, published by Island Press.