Healing touch for fractured habitats

The government’s move to demarcate eco-sensitive zones around protected reserves is a timely move. But, wildlife corridors too need equal attention. Every animal, from a hare to an elephant, and a snow leopard to a butterfly, needs the forest in its entirety and cannot survive in fractured fragments. Development has to be woven around wildlife, observes Atula Gupta

In 2011, a young wild tiger was captured from the Shikaripur area of Karnataka. Officers thought it might have strayed out of the Bhadra tiger reserve and released it back into the forests. But later, camera trapping results revealed that the tiger had actually come from far south, the Bandipur tiger reserve. In 15 months or even a lesser period, this big cat had essentially travelled a distance of more than 280 km.

While this is one of the longest ever movements recorded of wild tigers, the insightful finding stresses that conservation of protected reserves is just not enough. Protecting wildlife corridors is equally mandatory.

As rapid economic expansion continues to shape the Asian landscape on which many species depend, time is running out for conservationists aiming to save wildlife such as tigers and leopards. Scientists at the Smithsonian Conservation Biology Institute have used genetic analysis to find that the natural forest corridors in India are essential to ensuring a future for these species.

According to two studies recently published in two papers, these corridors are nothing less than the blood vessels of the natural world, successfully connecting populations of tigers and leopards to ensure genetic diversity and gene flow.

“This research provides crucial information about the need to maintain these vital veins to support tiger and leopard populations,” said Sandeep Sharma, lead author. “These habitats and corridors in India are threatened by infrastructural developments and need to be conserved if we want to save these species for future generations.”

Pathway to diversity

Mega species like tigers and leopards can never have a healthy existence if they are cooped up inside a forest. The isolation can lead to inbreeding and a genetic bottleneck that affects the long-term viability of the population. Thankfully, researchers found that tiger and leopard populations in four reserves in central India: Satpura, Melghat, Pench and Kanha had genetic diversity, showing that they were passing from one protected reserve to the other and breeding in a wide range.

However, what was also noted is that the proliferation of roads, rail lines, mining, urbanisation and other forms of development through the corridors was jeopardising the ability of these species to move. Several coal mines have been proposed in the forest corridor between the Satpura and Pench tiger reserves, as has the widening of a national highway (NH-7) and a broad-gauge railway line that cut across the corridor between the Kanha and Pench tiger reserves.

“By looking at two species, we were really able to illustrate the functionality of these corridors,” said Trishna Dutta, lead author of the Diversity and Distributions paper. “Conserving a whole landscape, rather than piecemeal protected areas, would ensure a better chance for the long-term persistence of these and other species.”

The situation is not very different in other parts of the country. In the Western Ghats, reserved forests are packed together with plantations such as coffee that have shade, cover and some food availability and act as corridors for wildlife movement. But other than these, there are also the eternal demands for wider roads, railway lines, power projects and mines. When the landscapes get packed with concrete jungles, the larger vertebrates will have no path to traverse.

Corridor protection

For wandering wildlife, the movement is never from point A to point B, more so in the case of leopards, which are more agile than tigers and naturally more adventurous. A leopard fitted with a radio collar in 2009 in Maharashtra stunned its observers when, in 78 days, it covered the terrains of the Sahyadri range and reached Borivilli National Park in Mumbai from Maleshej Ghat 120 km away.

Ironically, it had been earlier rescued by the Forest Department when it came looking for prey such as dogs or pigs in a small village near the forests and had fallen into a well — another glimpse of increasing human invasion.

The four to five per cent of land in India that is termed ‘protected’ for wildlife might seem sufficient but this area is not exactly a caged dwelling where all the wildlife can be contained. The government’s declaration of strictly demarcating the eco-sensitive zones around these protected reserves is a timely move; however the corridors too need equal attention.

And it is not just for the sake of tigers and leopards. Every animal from a hare to an elephant, a snow leopard to a butterfly, needs the forest in its entirety and cannot survive in fractured fragments. Development is imperative, but it has to be woven around the biology of wildlife.

In Assam, the endangered Golden langurs were frequently being mauled over by passing vehicles because their vital corridors were wiped out by a highway near the Chakrasila wildlife sanctuary. Knowing that the langurs are essentially arboreal and not very agile on the ground, Wildlife Trust of India (WTI) made a ropeway bridge for the monkeys.

The monkeys, hesitant at first, now frequent the bridge safely away from human traffic. Though all solutions may not be as simple in a nation of billion plus humans, it would still be vital to consider clearing the roadblock for wildlife diversity.