Corridors of uncertainty

Saving corridors connecting big cat habitats is a must

 
By Richa Malhotra
Published: Saturday 04 July 2015

Corridors help big cats migrate which is essential to maintain genetic diversity

SCHEMES and projects on tiger and leopard conservation in India are primarily focused on protected areas. Much less attention has been paid to the protection and restoration of corridors that connect fragmented habitats where the remaining tiger and leopard populations survive. Researchers are now finding mounting evidence to suggest that protecting the corridors might be the best way to ensure the survival of big cats. Naturally existing corridors help in their migration, thereby maintaining genetic diversity crucial for survival.

In two large sample analyses, researchers from the US collected about 1,400 faecal samples, representing 273 tigers and 217 leopards, from central India. The samples belonged to four tiger and leopard populations from five tiger reserves–Kanha, Melghat, Satpura, Pench (Maharashtra) and Pench (Madhya Pradesh)–spanning an area of about 45,000 sqÔÇêkm. The researchers calculated the gene flow between these reserves in the past 20–25 years and simulated historical data for about 2,500 years. They found that the gene flow between populations had reduced in areas that had lost forest cover and connectivity, but had a high rate in areas where corridors were conserved.

Trishna Dutta, a researcher at Smithsonian Conservation Biology Institute in the US, told Down To Earth, “We should definitely protect corridors if we want tigers [and leopards] to persist for a longer duration of time.”

The study on tigers was published in Proceedings of the Royal Society B: Biological SciencesÔÇêand the one on leopards in Evolutionary Applications this September. The studies come at a time when the Ministry of Environment and Forests has given clearance to coal mining projects in a functional corridor under study (Pench-Satpura) and is considering the expansion of National Highway-7 that passes via the Kanha-Pench corridor.

“This is going to be detrimental to tiger and leopard movement between the reserves,” says Sandeep Sharma, author of both the studies. According to Uma Ramakrishnan, researcher at the National Centre for Biological Sciences, Bengaluru, “A lot of the discussion on tigers is about numbers... and such studies are important because they draw attention to the issue of connectivity.”

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