Grass not green enough? Nameri tigers face threat of shrinking grasslands

Guwahati: Shrinking grasslands have become a cause of concern for the 344-sq km Nameri Tiger Reserve (NTR) in Sonitpur district. The latest assessment report on NTR's predator and prey status has revealed that it has lost nearly 50% of its grasslands between 1973 and 2011.

The assessment, carried out between 2012 and 2014, said NTR has around five to eight tigers, with a big cat density of 1.3 to 1.5 tigers per 100 sq km.

The grasslands are crucial for the survival of tigers as they sustain different species of herbivores, who, in turn, form the prey base for the big cats. Expansion of woodlands and erosion of river banks are said to have contributed to the rapid decline of grasslands in NTR.

The tiger reserve is bound by the Jia-Bhoreli river on its west and the Bor-Dikorai river on its east. The Naduar and Balipara reserved forests in Sonitpur, which forms NTR's buffer zone, have also borne the brunt of encroachment over the years, leading to a further decline of grasslands.

In the assessment report, National Tiger Conservation Authority's assistant inspector general of forest Rajendra G Garawad said NTR's riverine grasslands help conserve herbivores like hog deer. Garawad, who was the divisional forest officer of western Assam wildlife division during the assessment period, said the focus now should be on preserving remaining grasslands to prevent the hog deer from becoming locally extinct.

"To increase tiger density, the protection of predators and prey base needs to be enhanced by better habitat management," the report said.

Located on the northern part of Sonitpur, NTR adjoins Arunachal Pradesh's Pakke Tiger Reserve. Despite its small size, it is known for its rich flora and fauna.